Re: [PEDA] OT - Complex boards and time to Layout?
Ian & Brad, Ya got my vote on this one 100%. Both well said. Bob Wolfe - Original Message - From: "Ian Wilson" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Wednesday, October 09, 2002 12:33 AM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > On 08:26 PM 8/10/2002 -0700, JaMi Smith said: > > > > > > I refer you to their capability page: > > > http://www.lintek.com.au/boa.htm > > > > > > Note the text "(Tolerance on track widths is +- 0.008mm or better > > > depending > > > on the design and uniformity of copper distribution.)" > > > > > > >Please note that they state "uniformity of copper distribution", which in > >most instances means the uniformity of copper thickness across the surface > >of the board, which is at least as big a problem as the one that we are > >discussing. > > Rubbish - it means they can ensure better fine line quality and control > when there is an even density of copper over the board. Nothing to do with > thickness. I know these people well. They do not make idle and confusing > statements. In the PCB manufacturing industry everyone knows what is meant > by density and distribution. You seem to be having some issues here with > this, as well as having a tendency to wish be Last-Word-JaMi. > > Over an out on this from me. We should all have taken it to the OT list > ages ago. Getting silly now. > > Ian > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
I see you're with SBC...Well there's another company having huge problems. (another several thousand planned layoffs coming soon I think.) I can't belive I'm saying this, but I have been pretty darn happy with my AT&T cable modem service. I usually can't stand AT&T. > -Original Message- > From: JaMi Smith [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, October 08, 2002 9:05 PM > To: Protel EDA Forum > Cc: JaMi Smith > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > Just now this minute finally received Ians post supposedly > sent at 2:44 PM > - only 6 hours and 15 minutes - and for this I pay 50 bucks a > month! JaMi > - Original Message - > From: "Ian Wilson" <[EMAIL PROTECTED]> > To: "Protel EDA Forum" <[EMAIL PROTECTED]> > Sent: Tuesday, October 08, 2002 2:44 PM > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
On 08:26 PM 8/10/2002 -0700, JaMi Smith said: > > > > I refer you to their capability page: > > http://www.lintek.com.au/boa.htm > > > > Note the text "(Tolerance on track widths is +- 0.008mm or better > > depending > > on the design and uniformity of copper distribution.)" > > > >Please note that they state "uniformity of copper distribution", which in >most instances means the uniformity of copper thickness across the surface >of the board, which is at least as big a problem as the one that we are >discussing. Rubbish - it means they can ensure better fine line quality and control when there is an even density of copper over the board. Nothing to do with thickness. I know these people well. They do not make idle and confusing statements. In the PCB manufacturing industry everyone knows what is meant by density and distribution. You seem to be having some issues here with this, as well as having a tendency to wish be Last-Word-JaMi. Over an out on this from me. We should all have taken it to the OT list ages ago. Getting silly now. Ian * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Just now this minute finally received Ians post supposedly sent at 2:44 PM - only 6 hours and 15 minutes - and for this I pay 50 bucks a month! JaMi - Original Message - From: "Ian Wilson" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 2:44 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Jami, what the original post implies is that the fabricator had some issue with being able to etch the board in a manner that met the specified requirements. Those requirements have not been spelled out for us, nor do we know the limitations or concerns of the fab shop. Therefore we are discussing this topic theoretically which can tend to exagerate the discussion. In short my comments would thank the fabricator for being honest and showing integrity for whatever reason they felt that they couldn't fabricate the board as is. There are all manner of fabricators out there, I know I have run into all the types over the years. Some have tight controls, some have virtually no controls. Some have plastic tubs of etchant, some have no aggitation, some have bubbling to aggitate etchant, some move the boards through the etchant and some use spray etchers of all descriptions, some have completely automated lines. Some do your boards alone in the tank, some do 5 companies boards at a time in the tank. Maybe that is where the problem lies but we don't know for sure. We can just be thankful that this fabricator shows minimal integrity in admitting that they felt they could not fab the board as it was laid out. That is not a problem with the fabricators etching methodology, it is a limitation that they acknowledge. A major asset in a board shop in my opinion. Sincerely, Brad Velander. -Original Message- From: JaMi Smith To: Protel EDA Forum Cc: JaMi Smith Sent: 08/10/2002 7:53 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? What I am saying, and what I have always said, is that the statement in the original post implies no agitation / circulation / replenishment, and that IS a MAJOR problem. Do any of you guys actually dissagree with that? JaMi * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Ian, please see below > --- In [EMAIL PROTECTED], "Ian Wilson" > <[EMAIL PROTECTED]> wrote: > On 02:05 PM 8/10/2002 -0700, JaMi Smith said: > snip > Chemistry is not one dimensional. Agreed > . . . It takes longer to etch a few > microns > off a large area of copper than it does a small area. Granted, but not monumentially as everyone would imply. > . . . Balanced > copper as > being discussed is a general even density across the design. It has > been a > standard desire by almost all board houses I have spoken to over the > last > 20 years that I have been doing boards. > While I will agree that almost all board houses request a balanced copper design, they almost unanomously do so for other reasons, and not this reason. In over 35 years of doing boards I cannot remember ever having had one board house bring up this issue in the context now being argued. > We have a company in this country that does very high end work. The > do > their etch on 2 micron copper plated boards (plasma plating is one of > their > first steps). This very fine layer means very tight edge control and > under > etch etc (they will do 2 mil tracks as a special and padsless-vias I > think). When issues such as line width, edge control, undercut, etc., are important in a design, they must be specifically specified, and then your board house will get into working out the details with you, but in the absence of specific stated requirements, nothing that we have discussed would go beyond standard tolerancing issues, and create a problem of the magnatude that everyone is implying. > > I refer you to their capability page: > http://www.lintek.com.au/boa.htm > > Note the text "(Tolerance on track widths is +- 0.008mm or better > depending > on the design and uniformity of copper distribution.)" > Please note that they state "uniformity of copper distribution", which in most instances means the uniformity of copper thickness across the surface of the board, which is at least as big a problem as the one that we are discussing. JaMi * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Thomas, your comments are too familiar. The problem is that your average PCB designer/buyer has no manner to accurately check trace tolerance or undercut. At best most may have access to something like a tooling microscope which will only give you a top down approximation of track tolerance. The shops know it and generally they will judge how realistic your requirements are and second guess what they can get away with rather than discussing it with the designer/buyer. I quite often will have new shops quote the board, start fab and then call me to question the nature of my requirements even though they were clearly spelled out form the start. In a few rare cases shops have actually backed out of doing the job once they found out I was serious about my tolerances. We still have some problems from order to order with some long term shops. Sincerely, Brad Velander -Original Message- From: Thomas To: 'Protel EDA Forum' Sent: 08/10/2002 5:29 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? Ian, both your and Max's comments sound reasonable, I'll endeavour to help out my board house next time. I had thought about this problem before (particularly with regards to 'undercut' over etching on one side), but as I'd never heard any complaints I assumed all was ok. Tom. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Terry please see below, - Original Message - From: "Terry Harris" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 6:43 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > On Tue, 8 Oct 2002 14:54:55 -0700, JaMi wrote: > > >> Nothing you can do will eliminate the problem, just hope to reduce the > >> effects. A lot of copper in one area of the PCB will take longer to etch > >> resulting in over etching (undercutting) in areas with less copper. The > >> board house can't afford to over etch because some tracks will undercut > >> unacceptably (or even completely and fall off the board), under etching > >> risks leaving shorts in the dense areas. You are giving them process > >> control and yield problems seems reasonable they want you to pay extra. > > >I can accept this as applies to a board with different weights of copper on > >each side, but not for the same thickness of copper . . . * * * * * * * * * * > > > > > (specifically not to the -- -- * * * * * * * * * * > > > > > extent that you appear -- -- * * * * * * * * * * > > > > > to be stating here), -- -- > > . . . where the only issue is "area", > >and there is proper replensihment and removal of etchant. > > The trouble is your idea of 'proper' isn't possible. If each molecule of > etchant came into contact with its own molecule sized area of the board and > was magically whisked away then copper density would make no difference but > that doesn't happen. > I am not saying there is no difference, I am saying that it is not a "major problem". > It hits the board surface then moves around a bit. It reacts with the first > copper atom it meets and for the rest of its journey across the board > surface it is just getting in the way of the remaining active etchant > molecules. > granted, granted, granted, granted, but this is nowhere near the the monumental problem that you guys are making it out to be. > The more copper area on the board surface the higher the proportion of > spent etchant in contact with the board. You can not avoid this effect just > try to reduce it by reducing the time each etchant molecule stays on the > board surface (by spraying or agitation or bubbling or whatever). > granted, but this is NOT THE SAME as saying that the acid on this side of the board is going to get weak, in the sense that we are talking about. The specific statement I am replying to implies (unquestionably to me) that there is NOT adaquate circulation / agitation / replenishment of the etchant, period. I am not talking about molecular levels, I am talking about the difference between dropping the board in a tank and letting it sit, which is directly implied in the original post, and giving the board the proper agitation / circulation of the etchant, and removal of copper in solution from the area that it needs to etch properly. I cannot see how proper circulation could possibly ever let the "acid on one side get weak", and I cannot accept that your description above qualifies as letting "the acid on one side get weak". How many times do I have to say it, the problem you are discribing is minor by comparison, to the problem as it appears to be described in the original description in the post that I responded to. Are you guys trying to say that the original post does not imply that there is improper agitation / circulation / solution removal? None of you seem to be saying that, but you are all telling me I am out to lunch because I am saying that. What you are talking about is a minor problem compared to what I am talking about, and if the quote of what the board house said is anywhere near accurate, I still say look for another board house. Please remember that I agree that there are far more important reasons to balance the copper (and the layer stackup) in a board than this, but I still maintain that this is a minor problem in comparison to those issues, and the issue of simply dropping a board in a tank of etchant and letting it sit so that the "acid on one side gets weak". - I have just logged onto Yahoo! Groups and I find that for some reason I have not received all of the posts for this thread. I have received all of Brads, and all of yours Terry, but I am missing number 12425 from Ian (which I just forwarded and will now go read), although I got a later one from Ian, and the same is true with Thomas (missed his earlier post but got his la
Re: [PEDA] OT - Complex boards and time to Layout?
On Tue, 8 Oct 2002 14:54:55 -0700, JaMi wrote: >> Nothing you can do will eliminate the problem, just hope to reduce the >> effects. A lot of copper in one area of the PCB will take longer to etch >> resulting in over etching (undercutting) in areas with less copper. The >> board house can't afford to over etch because some tracks will undercut >> unacceptably (or even completely and fall off the board), under etching >> risks leaving shorts in the dense areas. You are giving them process >> control and yield problems seems reasonable they want you to pay extra. >I can accept this as applies to a board with different weights of copper on >each side, but not for the same thickness of copper (specifically not to the >extent that you appear to be stating here), where the only issue is "area", >and there is proper replensihment and removal of etchant. The trouble is your idea of 'proper' isn't possible. If each molecule of etchant came into contact with its own molecule sized area of the board and was magically whisked away then copper density would make no difference but that doesn't happen. It hits the board surface then moves around a bit. It reacts with the first copper atom it meets and for the rest of its journey across the board surface it is just getting in the way of the remaining active etchant molecules. The more copper area on the board surface the higher the proportion of spent etchant in contact with the board. You can not avoid this effect just try to reduce it by reducing the time each etchant molecule stays on the board surface (by spraying or agitation or bubbling or whatever). Cheers, Terry. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Ian, both your and Max's comments sound reasonable, I'll endeavour to help out my board house next time. I had thought about this problem before (particularly with regards to 'undercut' over etching on one side), but as I'd never heard any complaints I assumed all was ok. Tom. > -Original Message- > From: Ian Wilson [mailto:i.wilson@;considered.com.au] > Sent: Wednesday, 9 October 2002 10:56 > To: Protel EDA Forum > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > On 10:19 AM 9/10/2002 +1100, Thomas said: > >Sometimes that's just not possible though. > >I've recently finished a double sided PCB with allot of > controlled impedance > >tracks on one side widely spaced to prevent xtalk and to > prevent arcing (its > >a surge protection device) with a solid ground plane on the > other side. > > > >My board house has not complained (yet). > > > >Tom. > > Even on such a board there are often things that can be done > to help even > copper distribution. In areas widely spaced from the active > tracks you can > place copper balancing squares or even a hatched polygon. > > When I fully specify a production panel (break offs, tooling > strips etc) I > will usually say the that the production tooling is > uncontrolled space and > the board house is free to add copper balancing features. > Some will, some > won't. Those that do usually add squares along the tooling strip. > > I have not had a board house complain for years about > unbalanced copper > density, but I have had some thank me for making an effort to > balance the > copper. > > Ian Wilson > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:proteledaforum@;techservinc.com * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:ForumAdministrator@;TechServInc.com * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@;techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Brad, You've kind of lost me here, because while I know that this thread was originally started back on 9/24, and has meandered around "topicwise" for a while, the specific post that I responded to, is copied here for clarification. >Interesting, I thought that the copper "balancing act" was only for >containing possible warpage. Makes sense, though. Thanks for tip. > >aj > >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] >>... >> I did this type of pour and had the board house >> slap my wrists ...The explanation was that if >> you have a big pour with lots of copper on one >> side you need about the same copper on the other >> side to balance it. Otherwise the acid on one side >> gets weak while the other side remains strong, >> resulting in overetching on one side or >> under-etching on the other This is when I entered the conversation, earlier today, and this last paragraph is what I am commenting on. Specifically, the sentance that begins "Otherwise the acid . . . " is what I am having trouble with. I do admit in my initial reply that there are in fact reasons to "balance copper", but my problem is that I do not believe that this is one of them, or certainly not a major one. Please note that the we are simply talking copper removal given the above parameters, and not talking about different weights (thicknessess) of copper on different sides of the board, nor are we talking about warpage, but simply about the last sentance of the above statement (beginning "Otherwise . . .). This is why I asked you what you ment by "unbalanced copper", because there is absolutely nothing in the above statement to indicate different weights or thicknesses. Do all of your comments apply when you have different weights or thicknesses? Of course. Is designing a board with uneven distributions of copper or uneven distributions of layers prone to warpage? Of course. Once again, what do either of these issues have to do with what is discussed in the above statement that I replied to? Since I made my comment on the above statement, there have been three replies that I am aware of, your original reply, a reply by Terry Harris, and your followup reply which I am responding to here. Maybe I am not getting all of the emails on this subject, but Terry hardly constitutes "three others". I still say that if you limit your term of "unbalanced copper" stricly to "area", as indicated in the above statement, then I still say that the last statement beginning "Otherwise . . ." indicates that there is a problem with the board house, because with proper "agitation" and "circulation" there will not be a problem that in anyway lives up tp the enormity that you guys (you and Terry) are making of it. That does not mean there is no difference at all, but that just as I said, there is not a "problem", and certainly not a "major problem". Do board houses want you to have the minimum amount of copper removal on all of your boards so that they can extend the life of their etchant? Sure, but that does not mean that it they have to etch a lot away that it is a bad design, does it? Of course not. I would suggest that the only way that this would become a major problem, would be if there were not enough replenishment of the etchant coupled with removal of the etchant containing copper in solution. To me, this problem speaks of there not being enough "replenishment" and "removal" of the etchant as described above, and if your board house seems to consider it a major problem, then maybe you should be asking the same question of "why" as it relates to them. Are they simply dropping your boards in a tank with out any agitation or circulation too? Anyway, how does a spray system with a common collector and pump that supplies the same etchant to all of the spray nozzels, end up with "weak acid" on "one side" any how? And please do feel free to pick on me when I need it, which I know I do from time to time. JaMi - Original Message - From: "Brad Velander" <[EMAIL PROTECTED]> To: "'Protel EDA Forum'" <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 3:38 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > Jami, > > Unbalanced copper is exactly what the conversation started on, > uneven distribution of Cu and spaces or gaps across the surface or area of > the PCB. I am not talking different Cu thicknesses. > > I am not trying to pick on you Jami, but I deal with numerous > fabricators on this very issue day in and day out. To achieve even and equal > etching one must have an even distribution of Cu and similar gaps or spaces > across a prescribed area. At least three other
Re: [PEDA] OT - Complex boards and time to Layout?
On 10:19 AM 9/10/2002 +1100, Thomas said: >Sometimes that's just not possible though. >I've recently finished a double sided PCB with allot of controlled impedance >tracks on one side widely spaced to prevent xtalk and to prevent arcing (its >a surge protection device) with a solid ground plane on the other side. > >My board house has not complained (yet). > >Tom. Even on such a board there are often things that can be done to help even copper distribution. In areas widely spaced from the active tracks you can place copper balancing squares or even a hatched polygon. When I fully specify a production panel (break offs, tooling strips etc) I will usually say the that the production tooling is uncontrolled space and the board house is free to add copper balancing features. Some will, some won't. Those that do usually add squares along the tooling strip. I have not had a board house complain for years about unbalanced copper density, but I have had some thank me for making an effort to balance the copper. Ian Wilson * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Hi Thomas, I agree with all of those who have indicated that it is desirable to balance the copper density on both sides of the board. In cases such as you mention, the board manufacturer still has some options available. Remember that the board manufacturer will take your data and step and repeat it onto a panel. In addition to your data, this panel also includes venting or thieving patterns surrounding your data. The density of these patterns can be modified to compensate for an unbalanced condition in your "raw" data. In a case such as you mention, the manufacturer could put a very dense venting pattern on the side of the board having the widely spaced traces and a very sparse venting pattern on the side containing the ground plane. Additionally, if the board is small enough (so that there are a lot of boards on the panel), then some of them can be turned "ground plane up" and some can be turned "ground plane down", again helping to balance the copper. Best regards, Max P. Henzi CEO, PentaLogix LLC Tel. (925) 952-3890 Fax. (925) 934-6978 Email [EMAIL PROTECTED] Web. www.pentalogix.com -Original Message- From: Thomas [mailto:[EMAIL PROTECTED]] Sent: Tuesday, October 08, 2002 4:20 PM To: 'Protel EDA Forum' Subject: Re: [PEDA] OT - Complex boards and time to Layout? Sometimes that's just not possible though. I've recently finished a double sided PCB with allot of controlled impedance tracks on one side widely spaced to prevent xtalk and to prevent arcing (its a surge protection device) with a solid ground plane on the other side. My board house has not complained (yet). Tom. > -Original Message- > From: Brad Velander [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, 9 October 2002 04:18 > To: 'Protel EDA Forum' > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > Aj or others, > same issue with plating. Differences in copper density > (over area) > effect the plating rate of Cu to the circuit pattern. > Balanced copper side > to side, area to area, is the fabricators best friend (yours > also in the > end). > > Sincerely, > Brad Velander. > > Lead PCB Designer > Norsat International Inc. > Microwave Products > Tel (604) 292-9089 (direct line) > Fax (604) 292-9010 > email: [EMAIL PROTECTED] > http://www.norsat.com > Norsat's Microwave Products Division has now achieved ISO 9001:2000 > certification > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > Sent: Tuesday, October 08, 2002 9:51 AM > > To: Protel EDA Forum > > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > > > > Interesting, I thought that the copper "balancing act" was only for > > containing possible warpage. Makes sense, though. Thanks for tip. > > > > aj > > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > >... > > > I did this type of pour and had the board house > > > slap my wrists ...The explanation was that if > > > you have a big pour with lots of copper on one > > > side you need about the same copper on the other > > > side to balance it. Otherwise the acid on one side > > > gets weak while the other side remains strong, > > > resulting in overetching on one side or > > > under-etching on the other > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Sometimes that's just not possible though. I've recently finished a double sided PCB with allot of controlled impedance tracks on one side widely spaced to prevent xtalk and to prevent arcing (its a surge protection device) with a solid ground plane on the other side. My board house has not complained (yet). Tom. > -Original Message- > From: Brad Velander [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, 9 October 2002 04:18 > To: 'Protel EDA Forum' > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > Aj or others, > same issue with plating. Differences in copper density > (over area) > effect the plating rate of Cu to the circuit pattern. > Balanced copper side > to side, area to area, is the fabricators best friend (yours > also in the > end). > > Sincerely, > Brad Velander. > > Lead PCB Designer > Norsat International Inc. > Microwave Products > Tel (604) 292-9089 (direct line) > Fax (604) 292-9010 > email: [EMAIL PROTECTED] > http://www.norsat.com > Norsat's Microwave Products Division has now achieved ISO 9001:2000 > certification > > > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > Sent: Tuesday, October 08, 2002 9:51 AM > > To: Protel EDA Forum > > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > > > > Interesting, I thought that the copper "balancing act" was only for > > containing possible warpage. Makes sense, though. Thanks for tip. > > > > aj > > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > > >... > > > I did this type of pour and had the board house > > > slap my wrists ...The explanation was that if > > > you have a big pour with lots of copper on one > > > side you need about the same copper on the other > > > side to balance it. Otherwise the acid on one side > > > gets weak while the other side remains strong, > > > resulting in overetching on one side or > > > under-etching on the other > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Jami, Unbalanced copper is exactly what the conversation started on, uneven distribution of Cu and spaces or gaps across the surface or area of the PCB. I am not talking different Cu thicknesses. I am not trying to pick on you Jami, but I deal with numerous fabricators on this very issue day in and day out. To achieve even and equal etching one must have an even distribution of Cu and similar gaps or spaces across a prescribed area. At least three others have answered your comments with similar and like comments, nobody has stood up to defend your comments. Seems like there is a consensus building. I might add that you may think that your boards are being controlled and monitored for undercut but unless you are testing or specifically ordering tests (cross-sections) to be performed , then you are probably not getting what you think you are getting. Sincerely, Brad Velander. Lead PCB Designer Norsat International Inc. Microwave Products Tel (604) 292-9089 (direct line) Fax (604) 292-9010 email: [EMAIL PROTECTED] http://www.norsat.com Norsat's Microwave Products Division has now achieved ISO 9001:2000 certification > -Original Message- > From: JaMi Smith [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, October 08, 2002 2:06 PM > To: Protel EDA Forum > Cc: JaMi Smith > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > Brad see below . . . > > - Original Message - > From: "Brad Velander" <[EMAIL PROTECTED]> > To: "'Protel EDA Forum'" <[EMAIL PROTECTED]> > Sent: Tuesday, October 08, 2002 12:25 PM > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > > Jami, > > that's just blatantly not true! There is nothing questionable about > > a board house that directs you to issues of uneven etching > or plating > > because of varying Cu distribution. Not even with spray etchers. > > > > Spray etchers are generally better than tanks but they are not > > perfect either when it comes to unbalanced copper. Some of > the best fab > > houses using spray etchers will still point out unbalanced > etching because > > of unbalanced copper, even though they 'can' adjust the > spray rates and > > pressures to compensate at least side/side or one general > area to another. > > what are you saying and meaning when you speak of "unbalanced copper". > > first - to my knowledge we are not talking about 1/2 oz on > one side and 1 oz > on the other side, which is does in fact cause uneven etching > problems, but > that was not stated in the original post that I responded to, > nd as far as I > know this is not the topic of this discussion. > > secondly - we are not talking about the "warpage" issue which > I specifically > excluded. > > all that taken into consideration, given the proper circulation of the > etchant (which includes removal of the etched copper now in solution), > copper is copper, and etchant is etchant, and a specific > etchant will remove > a specific thickness of copper in a given period of time, > irrespective of > whether we are talking about a 1/4 sqiare inch area or a 10 > square inch > area. > > ? ? ? > > > However, they cannot compensate for variances in a > different areas over > the > > same side. It is all a time issue, how long is the area of > copper in the > > etchant, spray or otherwise, verses how much copper there > is to etch off. > > all other things considered, this is usually a "thickness" > issue, and not an > "area" issue, unless you are talking about larve "variances" > in thichness", > which I would call a process control or material problem. > > > The more copper to remove, the more time required. Less > copper to remove, > > less time. > > again "thickness', not "area". > > > Thus with unbalanced copper the shop has to define some median > > time to adequately remove all the copper to be etched > without removing or > > undercutting other areas too badly. > > as far as I know this only applies to boards or panels or > layer pairs where > the copper weights are "unbalanced" from one side to another, > and NOT to a > board or a panel or a layer pair where the weights are > "balanced", but there > is more copper to remove on one side or the other. > > > Remember that these spray etchers are > > conveyorized, they can't sense areas of a board and speed > up or slow down > > the conveyor. Let alone sense what is on the other side of > the panel, what > > is o
Re: [PEDA] OT - Complex boards and time to Layout?
Terry please see below - Original Message - From: "Terry Harris" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 12:36 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > On Tue, 8 Oct 2002 11:18:07 -0700, you wrote: > > >Some boardhouses may still "dip" or submerge the board into an "etchant > >tank", where the board simply sits in the etchant, however, there should be > >enough "agitation" or "circulation" of the etchant to prevent what they are > >describing from happening. > > Nothing you can do will eliminate the problem, just hope to reduce the > effects. A lot of copper in one area of the PCB will take longer to etch > resulting in over etching (undercutting) in areas with less copper. The > board house can't afford to over etch because some tracks will undercut > unacceptably (or even completely and fall off the board), under etching > risks leaving shorts in the dense areas. You are giving them process > control and yield problems seems reasonable they want you to pay extra. > I can accept this as applies to a board with different weights of copper on each side, but not for the same thickness of copper (specifically not to the extent that you appear to be stating here), where the only issue is "area", and there is proper replensihment and removal of etchant. (Please see my reply to Brad) > Before the etching problem there is a similar problem with plating. Need > 100A for the copper on one side of the board and 5A for the other - how do > you arrange that? I think the only thing they can do is fiddle around with > anode spacing on each side of the board to try to balance it a bit. They > can't plate at 100A anyway because it puts too much current through the > sparse areas and leaves the tracks with an uneven 'frazzled' appearance. > Plating is an issue that IS related to surface area, and NOT what we are talking about here, although it would be an somewhat applicable comparison if in fact there was no "agitation" or "circulation" of the etchant, which is what I was saying was a problem in the first place. > Again you are giving them process control and yield problems and slowing > them down. > Again, I will state that I believe that the original statement by the board house, as stated in the post that I responded to, indicates a problem with how the board house is dealing with the board (unless there are addional factors that were not stated, such as uneven weights of copper on the different sides of the board). JaMi * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
On 02:05 PM 8/10/2002 -0700, JaMi Smith said: >what are you saying and meaning when you speak of "unbalanced copper". > >first - to my knowledge we are not talking about 1/2 oz on one side and 1 oz >on the other side, which is does in fact cause uneven etching problems, but >that was not stated in the original post that I responded to, nd as far as I >know this is not the topic of this discussion. > >secondly - we are not talking about the "warpage" issue which I specifically >excluded. > >all that taken into consideration, given the proper circulation of the >etchant (which includes removal of the etched copper now in solution), >copper is copper, and etchant is etchant, and a specific etchant will remove >a specific thickness of copper in a given period of time, irrespective of >whether we are talking about a 1/4 sqiare inch area or a 10 square inch >area. Jami, Chemistry is not one dimensional. It takes longer to etch a few microns off a large area of copper than it does a small area. Balanced copper as being discussed is a general even density across the design. It has been a standard desire by almost all board houses I have spoken to over the last 20 years that I have been doing boards. We have a company in this country that does very high end work. The do their etch on 2 micron copper plated boards (plasma plating is one of their first steps). This very fine layer means very tight edge control and under etch etc (they will do 2 mil tracks as a special and padsless-vias I think). I refer you to their capability page: http://www.lintek.com.au/boa.htm Note the text "(Tolerance on track widths is +- 0.008mm or better depending on the design and uniformity of copper distribution.)" If you want to continue the discussion I suggest you make contact with a number of PCB makers and speak to their process engineers first. Ian Wilson * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Brad see below . . . - Original Message - From: "Brad Velander" <[EMAIL PROTECTED]> To: "'Protel EDA Forum'" <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 12:25 PM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > Jami, > that's just blatantly not true! There is nothing questionable about > a board house that directs you to issues of uneven etching or plating > because of varying Cu distribution. Not even with spray etchers. > > Spray etchers are generally better than tanks but they are not > perfect either when it comes to unbalanced copper. Some of the best fab > houses using spray etchers will still point out unbalanced etching because > of unbalanced copper, even though they 'can' adjust the spray rates and > pressures to compensate at least side/side or one general area to another. what are you saying and meaning when you speak of "unbalanced copper". first - to my knowledge we are not talking about 1/2 oz on one side and 1 oz on the other side, which is does in fact cause uneven etching problems, but that was not stated in the original post that I responded to, nd as far as I know this is not the topic of this discussion. secondly - we are not talking about the "warpage" issue which I specifically excluded. all that taken into consideration, given the proper circulation of the etchant (which includes removal of the etched copper now in solution), copper is copper, and etchant is etchant, and a specific etchant will remove a specific thickness of copper in a given period of time, irrespective of whether we are talking about a 1/4 sqiare inch area or a 10 square inch area. ? ? ? > However, they cannot compensate for variances in a different areas over the > same side. It is all a time issue, how long is the area of copper in the > etchant, spray or otherwise, verses how much copper there is to etch off. all other things considered, this is usually a "thickness" issue, and not an "area" issue, unless you are talking about larve "variances" in thichness", which I would call a process control or material problem. > The more copper to remove, the more time required. Less copper to remove, > less time. again "thickness', not "area". > Thus with unbalanced copper the shop has to define some median > time to adequately remove all the copper to be etched without removing or > undercutting other areas too badly. as far as I know this only applies to boards or panels or layer pairs where the copper weights are "unbalanced" from one side to another, and NOT to a board or a panel or a layer pair where the weights are "balanced", but there is more copper to remove on one side or the other. > Remember that these spray etchers are > conveyorized, they can't sense areas of a board and speed up or slow down > the conveyor. Let alone sense what is on the other side of the panel, what > is on the other board within the panel but 16 inches away under the other > etchant nozzles. Or how about the etch nozzles that swivel/sway back and > forth, how would you vary them for differing areas of the board when they > are sweeping large areas of a panel that is also moving. It is all a game of > averages, you average your Cu distribution, they average their etching, you > receive a good well-etched board. > again, I / we are NOT talking about different weights of copper on the different sides, which leaves us with a simple "area" problem, and I don't think that what you are saying is really applicable, given a proper rate of etchant replenishment and removal. > We tightly control our etching tolerances and undercut on almost all > of our boards. So we go through this all the time with big high tech > fabricators and smaller low tech fabricators as well. Some of the biggest > etching F-ups and the whining afterward, have come from big high tech shops > with very good reputations and the best etching equipment around. I have had > fabricators hedge their bets against being able to control their etching to > our requirements, until they can see our boards/panels. They are looking for > the even distribution of the Cu in order to meet the tight etching > tolerances. > All of what you say above is true for any board in a general sense, except I can not accept your trying to to apply it to different size areas of copper where the thickness is the same, because it simply does not apply in anything more than the most minor sense. All of what you say does apply where you are etching a board / panel / layer pair with different weights of copper on each side, but that is not what the discussion was about. JaMi * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTEC
Re: [PEDA] OT - Complex boards and time to Layout?
On Tue, 8 Oct 2002 11:18:07 -0700, you wrote: >Some boardhouses may still "dip" or submerge the board into an "etchant >tank", where the board simply sits in the etchant, however, there should be >enough "agitation" or "circulation" of the etchant to prevent what they are >describing from happening. Nothing you can do will eliminate the problem, just hope to reduce the effects. A lot of copper in one area of the PCB will take longer to etch resulting in over etching (undercutting) in areas with less copper. The board house can't afford to over etch because some tracks will undercut unacceptably (or even completely and fall off the board), under etching risks leaving shorts in the dense areas. You are giving them process control and yield problems seems reasonable they want you to pay extra. Before the etching problem there is a similar problem with plating. Need 100A for the copper on one side of the board and 5A for the other - how do you arrange that? I think the only thing they can do is fiddle around with anode spacing on each side of the board to try to balance it a bit. They can't plate at 100A anyway because it puts too much current through the sparse areas and leaves the tracks with an uneven 'frazzled' appearance. Again you are giving them process control and yield problems and slowing them down. Cheers, Terry. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Jami, that's just blatantly not true! There is nothing questionable about a board house that directs you to issues of uneven etching or plating because of varying Cu distribution. Not even with spray etchers. Spray etchers are generally better than tanks but they are not perfect either when it comes to unbalanced copper. Some of the best fab houses using spray etchers will still point out unbalanced etching because of unbalanced copper, even though they 'can' adjust the spray rates and pressures to compensate at least side/side or one general area to another. However, they cannot compensate for variances in a different areas over the same side. It is all a time issue, how long is the area of copper in the etchant, spray or otherwise, verses how much copper there is to etch off. The more copper to remove, the more time required. Less copper to remove, less time. Thus with unbalanced copper the shop has to define some median time to adequately remove all the copper to be etched without removing or undercutting other areas too badly. Remember that these spray etchers are conveyorized, they can't sense areas of a board and speed up or slow down the conveyor. Let alone sense what is on the other side of the panel, what is on the other board within the panel but 16 inches away under the other etchant nozzles. Or how about the etch nozzles that swivel/sway back and forth, how would you vary them for differing areas of the board when they are sweeping large areas of a panel that is also moving. It is all a game of averages, you average your Cu distribution, they average their etching, you receive a good well-etched board. We tightly control our etching tolerances and undercut on almost all of our boards. So we go through this all the time with big high tech fabricators and smaller low tech fabricators as well. Some of the biggest etching F-ups and the whining afterward, have come from big high tech shops with very good reputations and the best etching equipment around. I have had fabricators hedge their bets against being able to control their etching to our requirements, until they can see our boards/panels. They are looking for the even distribution of the Cu in order to meet the tight etching tolerances. Sincerely, Brad Velander. Lead PCB Designer Norsat International Inc. Microwave Products Tel (604) 292-9089 (direct line) Fax (604) 292-9010 email: [EMAIL PROTECTED] http://www.norsat.com Norsat's Microwave Products Division has now achieved ISO 9001:2000 certification > -Original Message- > From: JaMi Smith [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, October 08, 2002 11:18 AM > To: Protel EDA Forum > Cc: JaMi Smith > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > Rob, > > As AJ points out, part of what they say is correct, and you do need to > "balance" the layers, and the primary reason is to prevent > "warpage" and > related problems. > > However, the remaining issue, is raising a "flag" about your > boardhouse. > > Most boardhouses today use equipment that continually > "sprays" the etchant > on the surface of the board, and hence also washes away the > "etched copper". > > Some boardhouses may still "dip" or submerge the board into > an "etchant > tank", where the board simply sits in the etchant, however, > there should be > enough "agitation" or "circulation" of the etchant to prevent > what they are > describing from happening. > > What they are telling you is that they simply "dip" your board into an > etchant tank and leave it there, with no "agitation" or "circulation", > which, yes, will cause the symptoms they describe. > > But they are also telling you that they are not making your > boards properly > and that you should be looking for another boardhouse. > > JaMi > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Rob, As AJ points out, part of what they say is correct, and you do need to "balance" the layers, and the primary reason is to prevent "warpage" and related problems. However, the remaining issue, is raising a "flag" about your boardhouse. Most boardhouses today use equipment that continually "sprays" the etchant on the surface of the board, and hence also washes away the "etched copper". Some boardhouses may still "dip" or submerge the board into an "etchant tank", where the board simply sits in the etchant, however, there should be enough "agitation" or "circulation" of the etchant to prevent what they are describing from happening. What they are telling you is that they simply "dip" your board into an etchant tank and leave it there, with no "agitation" or "circulation", which, yes, will cause the symptoms they describe. But they are also telling you that they are not making your boards properly and that you should be looking for another boardhouse. JaMi - Original Message - From: <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 9:50 AM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > Interesting, I thought that the copper "balancing act" was only for > containing possible warpage. Makes sense, though. Thanks for tip. > > aj > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > >... > > I did this type of pour and had the board house > > slap my wrists ...The explanation was that if > > you have a big pour with lots of copper on one > > side you need about the same copper on the other > > side to balance it. Otherwise the acid on one side > > gets weak while the other side remains strong, > > resulting in overetching on one side or > > under-etching on the other * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Aj or others, same issue with plating. Differences in copper density (over area) effect the plating rate of Cu to the circuit pattern. Balanced copper side to side, area to area, is the fabricators best friend (yours also in the end). Sincerely, Brad Velander. Lead PCB Designer Norsat International Inc. Microwave Products Tel (604) 292-9089 (direct line) Fax (604) 292-9010 email: [EMAIL PROTECTED] http://www.norsat.com Norsat's Microwave Products Division has now achieved ISO 9001:2000 certification > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, October 08, 2002 9:51 AM > To: Protel EDA Forum > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > Interesting, I thought that the copper "balancing act" was only for > containing possible warpage. Makes sense, though. Thanks for tip. > > aj > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > >... > > I did this type of pour and had the board house > > slap my wrists ...The explanation was that if > > you have a big pour with lots of copper on one > > side you need about the same copper on the other > > side to balance it. Otherwise the acid on one side > > gets weak while the other side remains strong, > > resulting in overetching on one side or > > under-etching on the other * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Interesting, I thought that the copper "balancing act" was only for containing possible warpage. Makes sense, though. Thanks for tip. aj > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] >... > I did this type of pour and had the board house > slap my wrists ...The explanation was that if > you have a big pour with lots of copper on one > side you need about the same copper on the other > side to balance it. Otherwise the acid on one side > gets weak while the other side remains strong, > resulting in overetching on one side or > under-etching on the other * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
> they were meatball 10/10 mostly 12/12 bds > there was a giant pour on the entire top > the clearance on the pour was 20 mils all the way around the pads (to > make it easy and not get shorts!) > > they said with a big plane it is harder to etch > > there must be at least a bit of truth to that because i have had this > trouble with this type of board from 3 different shops - albeit not the > highest tech shops kicking around I did this type of pour and had the board house slap my wrists and tell me because of it they would have to electrically test the boards even though they were very simple. The explainattion was that if you have a big pour with lots of copper on one side you need about the same copper on the other side to balance it. Otherwise the acid on one side gets weak while the other side remains strong, resulting in overetching on one side or underetching on the other. Better circulation in the acid bath helps, but yield still goes down and thus cost goes up. If you do a big pour on only one side you should do it with a crosshatch pattern so that the copper is balanced and etching is even. After that wrist slapping I've have learned my lesson and I try hard to keep the copper even. Robert D. LaMoreaux MTS Systems Corp. Powertrain Technology Division 4622 Runway Blvd. Ann Arbor, MI 48108 734-822-9696 Fax 734-973-1103 Main Desk 734-973- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout? - Shorted Planes
[EMAIL PROTECTED] wrote: > Run a couple of amps (from a current limited power supply) through the short and > use a 5 1/2 digit voltmeter on the millivolt range and you can get the short > circuit location fairly easily. Yes, that's the procedure. But, with perhaps 500 holes tied to the ground plane, covering the whole board, the voltage drop across the planes can be REAL small. I ran 6.5 A between the power plane and ground, and was able to apply about 15-20 mV between the planes. The actual location of the short was found at a through hole with about 2 mV difference than the neighbors. But, there was probably 5 mV of voltage drop across the planes. So, it had to be compared to local pads that weren't shorted to spot the bad one. Then, I had to burrow into the board, through 2 layers, to dig out the short right next to a grounded pad. Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout? - Shorted Planes
There is also an inexpensive instrument ( about $180US ) called "Leak Seeker" from Electronic Design Specialists ( www.eds-inc.com ) that does a very respectable job of finding the location of internal board shorts. It takes a little practice to get the most out of it, but it does work. Polar Instruments ( www.polarinstruments.com ) also makes a similar instrument called "ToneOhm", but it is on the 'pricey' side. At 10:45 AM 9/27/02 +1000, you wrote: >Run a couple of amps (from a current limited power supply) through the >short and >use a 5 1/2 digit voltmeter on the millivolt range and you can get the short >circuit location fairly easily. > > > > >"Jon Elson" <[EMAIL PROTECTED]> on 27/09/2002 07:43:21 AM > >Please respond to "Protel EDA Forum" <[EMAIL PROTECTED]> > >To: "Protel EDA Forum" <[EMAIL PROTECTED]> >cc:(bcc: Clive Broome/sdc) > >Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > >Danny Bishop wrote: > > > funnily enough it never happened to me, I have never found a fault on my > > boards, and hence don't concern myself too much with the tests on basic > > double sided. > >I've hardly ever had a problem on 2-sided, and they are easy to spot >visually >and fix in a moment. But, major trouble deep inside a 6-layer board will >drive you nuts! Locating the exact point where two split planes or two >power planes are shorted is a real bear! > >Jon snip * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout? - Shorted Planes
Run a couple of amps (from a current limited power supply) through the short and use a 5 1/2 digit voltmeter on the millivolt range and you can get the short circuit location fairly easily. "Jon Elson" <[EMAIL PROTECTED]> on 27/09/2002 07:43:21 AM Please respond to "Protel EDA Forum" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> cc: (bcc: Clive Broome/sdc) Subject: Re: [PEDA] OT - Complex boards and time to Layout? Danny Bishop wrote: > funnily enough it never happened to me, I have never found a fault on my > boards, and hence don't concern myself too much with the tests on basic > double sided. I've hardly ever had a problem on 2-sided, and they are easy to spot visually and fix in a moment. But, major trouble deep inside a 6-layer board will drive you nuts! Locating the exact point where two split planes or two power planes are shorted is a real bear! Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Dennis Saputelli wrote: > they said with a big plane it is harder to etch > > there must be at least a bit of truth to that because i have had this > trouble with this type of board from 3 different shops - albeit not the > highest tech shops kicking around > > the board was pretty long, about 15 inches, that may or may not be a > factor Boards with large density variations can cause a problem. A single gap in a large plane of copper is usally etched first, and large areas of non-copper will locally deplete the etchant, preventing full etching in that area. Conversely, for plating, where most of the trace definition is done in the SMOBC process, the large areas of copper may deplete the copper bath, and leave the plating thinner there. Anyway, modern process gear is a lot more tolerant of this sort of variation, as the boards we design drive the industry to develop equipment that can handle it without stressing the process to where it becomes unreliable. Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Danny Bishop wrote: > funnily enough it never happened to me, I have never found a fault on my > boards, and hence don't concern myself too much with the tests on basic > double sided. I've hardly ever had a problem on 2-sided, and they are easy to spot visually and fix in a moment. But, major trouble deep inside a 6-layer board will drive you nuts! Locating the exact point where two split planes or two power planes are shorted is a real bear! Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Not my homepage, they are a company I have been using for years (since 1988) to layout our more complex PCB's. Ian Middleton > -Original Message- > From: Terry Harris [mailto:[EMAIL PROTECTED]] > Sent: 25 September 2002 17:38 > To: [EMAIL PROTECTED] > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > On Wed, 25 Sep 2002 16:05:26 +0100, you wrote: > > >Try http://www.dunneroberts.co.uk/allsites/gallery/big.htm for a monster > >Protel board. > > >Or http://www.dunneroberts.co.uk for home page. > > Well I hope your PCBs are better than your web site. > > Your homepage consists of > > "Adjusting to your system settings of 1920X1440" > > I don't know why anyone imagines my screen resolution dictates the size of > my browser windows. > > Then when I navigate into the site by viewing and cutting and pasting from > the raw HTML I get ugly repeating background images, a stupid spotlight > animation and the thing plays a 1.7MB wav file at me. > > The images for the monster board are missing anyway. > > Cheers, Terry. > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Thanks, Dennis. W/o naming names of the 'bad' guys, whose the good guy? Sincerely, Tim Hutcheson "There are 10 kinds of people in the world; those that can read binary and those that can't." -- Anonymous -Original Message- From: Dennis Saputelli [mailto:[EMAIL PROTECTED]] Sent: Wednesday, September 25, 2002 7:42 PM To: Protel EDA Forum Subject: Re: [PEDA] OT - Complex boards and time to Layout? no, it was worse than that (easier bds) they were meatball 10/10 mostly 12/12 bds there was a giant pour on the entire top the clearance on the pour was 20 mils all the way around the pads (to make it easy and not get shorts!) they said with a big plane it is harder to etch there must be at least a bit of truth to that because i have had this trouble with this type of board from 3 different shops - albeit not the highest tech shops kicking around the board was pretty long, about 15 inches, that may or may not be a factor once i got the right shop and ACTUAL testing, all the problems vanished now we just turn em on and ship em what a difference between that and chasing microscopic slivers to ground at random points! i don't want to name names because as they say 'sh*t happens' - i just don't go there anymore Dennis Saputelli Tim Hutcheson wrote: > > What were the track and gap specs on these boards? Are they consistently > having trouble only on the 7/8 boards, or what? > > Sincerely, > > Tim Hutcheson > > "There are 10 kinds of people in the world; > those that can read binary and those that can't." > -- Anonymous > > -Original Message- > From: Dennis Saputelli [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, September 25, 2002 6:54 PM > To: Protel EDA Forum > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > it has happened to me twice > 2 different shops > they charged for test setup, testing, but there were short all over some > of them and they were only double sided > > Dennis Saputelli > > Jon Elson wrote: > > > > Bagotronix Tech Support wrote: > > > > > With a board that complex, your board vendor had better actually be > doing > > > electrical test, instead of just charging for it and not doing it... > > > > What? This is endemic in the industry? I've had to can several vendors > > for pulling this stunt. But, when they get caught by me, with my (in > > comparison) quite modest boards, there's no doubt what is going on, > because > > the boards come back with 50% failure rate. IE. 50% of the boards have at > > least > > one internal short or open. I usually get the test report from Advanced > > Circuits, > > so I know what their yield is on multilayer boards. And, it is somewhere > > between > > 50 and 75% on most runs. The 2-sided usually come back at 90% or better > > passing. > > > > So, it is real hard for me to believe that many fabricators pull these > > stunts of > > pretending to do electrical test as a routine matter. I think they'd get > > caught > > WAY too often. > > > > Jon > > -- -- ___ www.integratedcontrolsinc.comIntegrated Controls, Inc. tel: 415-647-04802851 21st Street fax: 415-647-3003San Francisco, CA 94110 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
no, it was worse than that (easier bds) they were meatball 10/10 mostly 12/12 bds there was a giant pour on the entire top the clearance on the pour was 20 mils all the way around the pads (to make it easy and not get shorts!) they said with a big plane it is harder to etch there must be at least a bit of truth to that because i have had this trouble with this type of board from 3 different shops - albeit not the highest tech shops kicking around the board was pretty long, about 15 inches, that may or may not be a factor once i got the right shop and ACTUAL testing, all the problems vanished now we just turn em on and ship em what a difference between that and chasing microscopic slivers to ground at random points! i don't want to name names because as they say 'sh*t happens' - i just don't go there anymore Dennis Saputelli Tim Hutcheson wrote: > > What were the track and gap specs on these boards? Are they consistently > having trouble only on the 7/8 boards, or what? > > Sincerely, > > Tim Hutcheson > > "There are 10 kinds of people in the world; > those that can read binary and those that can't." > -- Anonymous > > -Original Message- > From: Dennis Saputelli [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, September 25, 2002 6:54 PM > To: Protel EDA Forum > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > it has happened to me twice > 2 different shops > they charged for test setup, testing, but there were short all over some > of them and they were only double sided > > Dennis Saputelli > > Jon Elson wrote: > > > > Bagotronix Tech Support wrote: > > > > > With a board that complex, your board vendor had better actually be > doing > > > electrical test, instead of just charging for it and not doing it... > > > > What? This is endemic in the industry? I've had to can several vendors > > for pulling this stunt. But, when they get caught by me, with my (in > > comparison) quite modest boards, there's no doubt what is going on, > because > > the boards come back with 50% failure rate. IE. 50% of the boards have at > > least > > one internal short or open. I usually get the test report from Advanced > > Circuits, > > so I know what their yield is on multilayer boards. And, it is somewhere > > between > > 50 and 75% on most runs. The 2-sided usually come back at 90% or better > > passing. > > > > So, it is real hard for me to believe that many fabricators pull these > > stunts of > > pretending to do electrical test as a routine matter. I think they'd get > > caught > > WAY too often. > > > > Jon > > -- -- ___ www.integratedcontrolsinc.comIntegrated Controls, Inc. tel: 415-647-04802851 21st Street fax: 415-647-3003San Francisco, CA 94110 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
funnily enough it never happened to me, I have never found a fault on my boards, and hence don't concern myself too much with the tests on basic double sided. > -Original Message- > From: Dennis Saputelli [mailto:[EMAIL PROTECTED]] > Sent: Thursday, 26 September 2002 9:54 AM > To: Protel EDA Forum > Subject: Re: [PEDA] OT - Complex boards and time to Layout? > > > it has happened to me twice > 2 different shops > they charged for test setup, testing, but there were short > all over some > of them and they were only double sided > > Dennis Saputelli > > Jon Elson wrote: > > > > Bagotronix Tech Support wrote: > > > > > With a board that complex, your board vendor had better > actually be doing > > > electrical test, instead of just charging for it and not > doing it... > > > > What? This is endemic in the industry? I've had to can > several vendors > > for pulling this stunt. But, when they get caught by me, > with my (in > > comparison) quite modest boards, there's no doubt what is > going on, because > > the boards come back with 50% failure rate. IE. 50% of the > boards have at > > least > > one internal short or open. I usually get the test report > from Advanced > > Circuits, > > so I know what their yield is on multilayer boards. And, > it is somewhere > > between > > 50 and 75% on most runs. The 2-sided usually come back at > 90% or better > > passing. > > > > So, it is real hard for me to believe that many fabricators > pull these > > stunts of > > pretending to do electrical test as a routine matter. I > think they'd get > > caught > > WAY too often. > > > > Jon > > -- > __ > _ > www.integratedcontrolsinc.comIntegrated Controls, Inc. >tel: 415-647-04802851 21st Street > fax: 415-647-3003San Francisco, CA 94110 > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
What were the track and gap specs on these boards? Are they consistently having trouble only on the 7/8 boards, or what? Sincerely, Tim Hutcheson "There are 10 kinds of people in the world; those that can read binary and those that can't." -- Anonymous -Original Message- From: Dennis Saputelli [mailto:[EMAIL PROTECTED]] Sent: Wednesday, September 25, 2002 6:54 PM To: Protel EDA Forum Subject: Re: [PEDA] OT - Complex boards and time to Layout? it has happened to me twice 2 different shops they charged for test setup, testing, but there were short all over some of them and they were only double sided Dennis Saputelli Jon Elson wrote: > > Bagotronix Tech Support wrote: > > > With a board that complex, your board vendor had better actually be doing > > electrical test, instead of just charging for it and not doing it... > > What? This is endemic in the industry? I've had to can several vendors > for pulling this stunt. But, when they get caught by me, with my (in > comparison) quite modest boards, there's no doubt what is going on, because > the boards come back with 50% failure rate. IE. 50% of the boards have at > least > one internal short or open. I usually get the test report from Advanced > Circuits, > so I know what their yield is on multilayer boards. And, it is somewhere > between > 50 and 75% on most runs. The 2-sided usually come back at 90% or better > passing. > > So, it is real hard for me to believe that many fabricators pull these > stunts of > pretending to do electrical test as a routine matter. I think they'd get > caught > WAY too often. > > Jon -- ___ www.integratedcontrolsinc.comIntegrated Controls, Inc. tel: 415-647-04802851 21st Street fax: 415-647-3003San Francisco, CA 94110 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
it has happened to me twice 2 different shops they charged for test setup, testing, but there were short all over some of them and they were only double sided Dennis Saputelli Jon Elson wrote: > > Bagotronix Tech Support wrote: > > > With a board that complex, your board vendor had better actually be doing > > electrical test, instead of just charging for it and not doing it... > > What? This is endemic in the industry? I've had to can several vendors > for pulling this stunt. But, when they get caught by me, with my (in > comparison) quite modest boards, there's no doubt what is going on, because > the boards come back with 50% failure rate. IE. 50% of the boards have at > least > one internal short or open. I usually get the test report from Advanced > Circuits, > so I know what their yield is on multilayer boards. And, it is somewhere > between > 50 and 75% on most runs. The 2-sided usually come back at 90% or better > passing. > > So, it is real hard for me to believe that many fabricators pull these > stunts of > pretending to do electrical test as a routine matter. I think they'd get > caught > WAY too often. > > Jon -- ___ www.integratedcontrolsinc.comIntegrated Controls, Inc. tel: 415-647-04802851 21st Street fax: 415-647-3003San Francisco, CA 94110 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Bagotronix Tech Support wrote: > With a board that complex, your board vendor had better actually be doing > electrical test, instead of just charging for it and not doing it... What? This is endemic in the industry? I've had to can several vendors for pulling this stunt. But, when they get caught by me, with my (in comparison) quite modest boards, there's no doubt what is going on, because the boards come back with 50% failure rate. IE. 50% of the boards have at least one internal short or open. I usually get the test report from Advanced Circuits, so I know what their yield is on multilayer boards. And, it is somewhere between 50 and 75% on most runs. The 2-sided usually come back at 90% or better passing. So, it is real hard for me to believe that many fabricators pull these stunts of pretending to do electrical test as a routine matter. I think they'd get caught WAY too often. Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Tim Exley wrote: > Try http://www.dunneroberts.co.uk/allsites/gallery/images/big-top.jpg > and http://www.dunneroberts.co.uk/allsites/gallery/images/big-bot.jpg WOW! I'm glad I didn't have to design (or pay for) that one! Vast numbers of big quad flat packs on BOTH sides! Jon * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Wow! I'm amazed that boards like that can be produced with any yield greater than zero. And that's just for the PCB. How about the part population process? There's gotta be at least one or two pin shorts or opens coming off the assembly line on a board that complex! With a board that complex, your board vendor had better actually be doing electrical test, instead of just charging for it and not doing it... Best regards, Ivan Baggett Bagotronix Inc. website: www.bagotronix.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Try http://www.dunneroberts.co.uk/allsites/gallery/images/big-top.jpg and http://www.dunneroberts.co.uk/allsites/gallery/images/big-bot.jpg Tim Exley -Original Message- From: Ian Middleton [mailto:[EMAIL PROTECTED]] Sent: Thursday, 26 September 2002 3:05 a.m. To: Protel EDA Forum Subject: Re: [PEDA] OT - Complex boards and time to Layout? Try http://www.dunneroberts.co.uk/allsites/gallery/big.htm for a monster Protel board. Or http://www.dunneroberts.co.uk for home page. > -Original Message- > From: Phillip Stevens [mailto:[EMAIL PROTECTED]] > Sent: 25 September 2002 02:58 > To: Protel EDA Forum > Subject: [PEDA] OT - Complex boards and time to Layout? > > > > Someone asked me the other day how long it would take to layout a > reasonably large and somewhat complex design. I gave them what I > thought was my best guess (a month). > > So, now I'm curious. What's the biggest, baddest PCB you've ever > created, and how long did (just) the layout take for it? > > Assume you had been handed: > - The schematic and a netlist. > - The footprints for all the parts. > - An already dimensioned PCB outline template to use. > > Also curious if there are any URL's that might have viewable > examples of complex boards with completion statistics. > > This maybe a bit OT for this list, feel free to e-mail me directly, > unless anyone else seems to be curious. > > ---Phil > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Hmm... no images on that page -Original Message- From: Ian Middleton [mailto:[EMAIL PROTECTED]] Sent: Wednesday, September 25, 2002 11:05 AM To: Protel EDA Forum Subject: Re: [PEDA] OT - Complex boards and time to Layout? Try http://www.dunneroberts.co.uk/allsites/gallery/big.htm for a monster Protel board. Or http://www.dunneroberts.co.uk for home page. > -Original Message- > From: Phillip Stevens [mailto:[EMAIL PROTECTED]] > Sent: 25 September 2002 02:58 > To: Protel EDA Forum > Subject: [PEDA] OT - Complex boards and time to Layout? > > > > Someone asked me the other day how long it would take to layout a > reasonably large and somewhat complex design. I gave them what I > thought was my best guess (a month). > > So, now I'm curious. What's the biggest, baddest PCB you've ever > created, and how long did (just) the layout take for it? > > Assume you had been handed: > - The schematic and a netlist. > - The footprints for all the parts. > - An already dimensioned PCB outline template to use. > > Also curious if there are any URL's that might have viewable > examples of complex boards with completion statistics. > > This maybe a bit OT for this list, feel free to e-mail me directly, > unless anyone else seems to be curious. > > ---Phil > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
I get the "broken graphic" placeholder for those images. Best regards, Ivan Baggett Bagotronix Inc. website: www.bagotronix.com - Original Message - From: "Ian Middleton" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Wednesday, September 25, 2002 11:05 AM Subject: Re: [PEDA] OT - Complex boards and time to Layout? > Try http://www.dunneroberts.co.uk/allsites/gallery/big.htm for a monster > Protel board. > > Or http://www.dunneroberts.co.uk for home page. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Phil, A month is most likely about right for most of these type of complex boards, but only if there are not constant changes made or the fact that key info needed to do the layout has properly been available. Not just libraries and an outline need to be there. But I have seen that month grow by a couple weeks easily because of this kind of stuff. Unless your bidding an absolute drop dead complete date a month later, than you just have to work 30 hours each day. Bob Wolfe - Original Message - From: "Phillip Stevens" <[EMAIL PROTECTED]> To: "Protel EDA Forum" <[EMAIL PROTECTED]> Sent: Tuesday, September 24, 2002 9:57 PM Subject: [PEDA] OT - Complex boards and time to Layout? > > Someone asked me the other day how long it would take to layout a > reasonably large and somewhat complex design. I gave them what I > thought was my best guess (a month). > > So, now I'm curious. What's the biggest, baddest PCB you've ever > created, and how long did (just) the layout take for it? > > Assume you had been handed: > - The schematic and a netlist. > - The footprints for all the parts. > - An already dimensioned PCB outline template to use. > > Also curious if there are any URL's that might have viewable > examples of complex boards with completion statistics. > > This maybe a bit OT for this list, feel free to e-mail me directly, > unless anyone else seems to be curious. > > ---Phil > > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Re: [PEDA] OT - Complex boards and time to Layout?
Try http://www.dunneroberts.co.uk/allsites/gallery/big.htm for a monster Protel board. Or http://www.dunneroberts.co.uk for home page. > -Original Message- > From: Phillip Stevens [mailto:[EMAIL PROTECTED]] > Sent: 25 September 2002 02:58 > To: Protel EDA Forum > Subject: [PEDA] OT - Complex boards and time to Layout? > > > > Someone asked me the other day how long it would take to layout a > reasonably large and somewhat complex design. I gave them what I > thought was my best guess (a month). > > So, now I'm curious. What's the biggest, baddest PCB you've ever > created, and how long did (just) the layout take for it? > > Assume you had been handed: > - The schematic and a netlist. > - The footprints for all the parts. > - An already dimensioned PCB outline template to use. > > Also curious if there are any URL's that might have viewable > examples of complex boards with completion statistics. > > This maybe a bit OT for this list, feel free to e-mail me directly, > unless anyone else seems to be curious. > > ---Phil > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/proteledaforum@techservinc.com * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
