Re: [PEDA] Shortened Designator on Silkscreen

2002-04-24 Thread Abd ulRahman Lomax

At 11:30 AM 4/23/2002 -0700, JaMi Smith wrote:
Most of these boards are built in house, but the error rate on stuffing
components (the wrong ones in the wrong locations) is very high and the
trouble-shooting time to find these assembly errors is exhorbinate, so I
really do need the silkscreen every place I can get it.

No, you don't. You need good process for assembly. Good assemblers don't 
even look at the silkscreen. It's too time-consuming. Instead, efficient 
hand assemblers would, in my experience, prefer to have a golden board, 
i.e., a board which has been correctly assembled.

It's not essential, but if they have a flicker viewer, so much the better 
(i.e., a viewer which switches quickly from a view of one pcb to the other, 
with the images positioned identically. Very efficient for detecting 
differences, first used, I think, in the search for what was later named 
Pluto. I think I have heard of such a device being used for assembly, but 
I'm not sure.

Similar would be a device which superimposed an image of an assembly 
drawing over a view of the physical PCB.

Presumably, however, if assembly has been making lots of errors, they don't 
have tools like this. One reason, by the way, to send difficult assembly 
out. You really can't compete with them, when all is said and done.

Herein lies the problem. I have 4 duplicate channels, with ref
designators currently numbered as R1_1, R1_2, R1_3, R1_4, R2_1, etc. in
the 4 parallel and identical channels.

That's a problem in itself, perhaps, though it is one possible 
configuration. Other posts have often described ways to do duplicate 
channels in PCB. The default naming that Protel uses when you simply copy a 
block of components is *not* intended for serious use in duplicating 
blocks. You could consider these names as placeholders. Their meaning is 
obvious.

But if you like those names, it is obviously easy to obtain them.

The solution starts with a good renumbering in the schematic. The use of 
channel postfixes (like A, B, C etc), assigned number sequences (like 
channel A contains all refdes numbers between 100-199, B contains 200-299, 
etc) should be done at the schematic level.

It is possible to use match on selection status to rename parts block by 
block, or if each section has its own page on the schematic, Protel's 
annotation tool can handle some kinds of channel numbering.

Global edits with appropriate match criteria can be used to add distinctive 
characteristics to each block. As I recall, there are some irritating 
limitations in replacement criteria which has led me in the past to use the 
spreadsheet to add channel designators; one should realize that complex 
manipulations of refdes and comment text can be done in the spreadsheet, 
and one would have all the tools available in, say, Excel. I've not had 
good luck with the Protel spreadsheet editor, but perhaps I did not 
correctly intone the incantations. I use the Protel spreadsheet tool just 
for exporting the data and taking it back into the Schematic or PCB. If one 
wants to use the spreadsheet, I advise looking back into the archives for 
posts about how to Update from Spreadsheet. It can be quite persnickity, if 
you look cross-eyed at it, it can fail.

  My ref designators are already as
small as our fab house will go for which is .025 high and .005 thick
lines, and I am also tenting all of my vias so that they will not
interfere with the silkscreen.

Good. Though, as was implied in what I wrote before, I would not let 
silkscreen requirements override fab and assembly quality requirements. If 
you want tented vias, perhaps to reduce solder bridging, or you can at 
least tolerate them -- some assemblers, as I recall, don't like them, 
perhaps because of outgassing during soldering -- fine. Otherwise I would 
not go very far to make a complete silkscreen.

But if you want a complete silkscreen for 0402 parts, there is lots of room 
between the parts if you cut out some of the outline, especially if you can 
handle 5 mil text. I've never gone that small. I'd make some custom 
footprints with the outline designed for this use. You could, of course, 
unlock primitives for a footprint and edit the outlines, but I would only 
do this if there were just a few places where it were necessary.

  I could however get a lot more
designators placed in the limited room that I have if I could eliminate
the channel designator part of the ref designator, i.e.: reduce the R1_1
to simply R1, which is much shorter, and which due to the layout is
acceptable since the channels are physically very clear and already
labeled as CH_1, CH2, etc.

Sure. And this is not at all difficult to do. See below.

However, if I shorten the actual designator, it makes for
synchronization problems with the schematic, as well as hell to pay in
the DRC department.

Right. Don't do that. Instead use the Comment field, which is otherwise a 
bicycle for a fish. To make the comment fields correspond to the 

Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Mira

Solution 1. Use different numbering R1, R101, R201...
for the different channels.

Solution 2. Provide a separate drawing of the silk
screen (in PDF format for example) to your assembly
house. You can place the text inside the part
outlines. There won't be mistakes.


Mira

--- JaMi Smith [EMAIL PROTECTED] wrote:
 I have a small problem with small parts in a small
 area on a small board
 (so what else is new?).
 
 I have 4 parallel channels of a Quad Transimpedance
 Amplifier circuit,
 which is very high gain and requires good isolation.
 The circuit is all
 descrete analog components, mostly 0402, except for
 the S0-8 op-amps,
 and is packaged quite densely with only .020
 between components in the
 tight spots, and no room for package outlines. The
 circuit is layed out
 very nicely, and is electrically excellent, but
 unfortunately, there is
 no room for designators.
 
 Most of these boards are built in house, but the
 error rate on stuffing
 components (the wrong ones in the wrong locations)
 is very high and the
 trouble-shooting time to find these assembly errors
 is exhorbinate, so I
 really do need the silkscreen every place I can get
 it.
 
 Herein lies the problem. I have 4 duplicate
 channels, with ref
 designators currently numbered as R1_1, R1_2, R1_3,
 R1_4, R2_1, etc. in
 the 4 parallel and identical channels. My ref
 designators are already as
 small as our fab house will go for which is .025
 high and .005 thick
 lines, and I am also tenting all of my vias so that
 they will not
 interfere with the silkscreen. I could however get a
 lot more
 designators placed in the limited room that I have
 if I could eliminate
 the channel designator part of the ref designator,
 i.e.: reduce the R1_1
 to simply R1, which is much shorter, and which due
 to the layout is
 acceptable since the channels are physically very
 clear and already
 labeled as CH_1, CH2, etc.
 
 However, if I shorten the actual designator, it
 makes for
 synchronization problems with the schematic, as well
 as hell to pay in
 the DRC department.
 
 I want to keep the ref designators the same for the
 same component in
 the different channels for the sake of circuit /
 schematic /
 troubleshooting clarity, etc. Renumbering them to
 100 series for channel
 1, 200 series for channel 2, etc, is not only very
 time consuming but
 doesn't really get me much shorter designators
 anyway.
 
 Hiding the original designators, and replacing them
 with loose text is
 not only very time consuming, but prone to error,
 not only now, bur
 especially in the future if someone else has to
 modify the board and
 move components, since the loose text is not
 related to the component.
 
 I have thought of copying off the final database and
 modifying all of
 the designators and then generating a new gerbers
 from the modified file
 and substituting those overlay gerbers in the final
 set for fab, but
 that is a massive amount of work that will have to
 be done all over
 again if there is any substantial change to the
 board.
 
 I do in fact own an Official Mickey Mouse Club Tee
 Shirt and Hat, which
 I am about to pull out and put on, but there has got
 to be a better way
 of handling duplicate circuits in Protel, or should
 I just throw up my
 hands and look for another product all together
 (PADs, Mentor, Verybest,
 etc.). It appears that Protel truly has no provision
 to handle any kind
 of duplicate circuits, especially of the Step and
 Repeat variety,
 whatsoever.
 
 Anyone out there got any useful ideas?
 
 JaMi Smith
 
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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread David W. Gulley

What I have done is to unhide the Comment field and use it to label 
small components so the Ref Des is not changed and therefore corresponds 
with the schematic/netlist. Obviously everybody involved needs to 
understand and approve such a shortcut. I then show the Ref Des on the 
Assembly drawing where the IC is to be placed.

On one design that had multiple identical channels, a box (Top Overlay 
and Bottom Overlay) was drawn around the identical sections and a Text 
Field added to the Box saying Channel N and then the individual 
components were just labeled (using the Comment) as you indicated using 
 the shortened designator. Since all Rn in the channels were 
identical and there were no other Rns (i.e. make sure that if you have 
R1-1, R1-2, etc. there is no R1 in the non repeated section of the 
board) the assembly personnel had no difficulty stuffing the boards.

On another design, I was asked to use Alpha characters for the 
indicators (again using comments) so I had sections that looked like 
alphabet soup!


JaMi Smith wrote:

 I have a small problem with small parts in a small area on a small board
 (so what else is new?).



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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Rene Tschaggelar

Those components are supposed to be placed by machine aren't they ?
If not, you should get better trained people, or instruct them 
differently.
Or have a placement plan in 10 to 1 size on paper.

And do the prototypes yourself.

Rene
-- 
Ing.Buero R.Tschaggelar - http://www.ibrtses.com

JaMi Smith wrote:
 
 [ high error rate in manual SMD placement ]

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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Dennis Saputelli

here come the 0201's !!
try putting some text and boxes around those

saw a recent article about hand reworking them
pretty scary
apparently it takes something known as 'operator skill'

re this thread
i think the best idea is what dgulley said
use the comment field and hide the desig
this way the database is still good and you don't have to use 'loose'
text

another idea (depending on how many values) is to use a simple code
like:
'A' or '1' = 1.00K res
'B' or '2' = 0.01m cap

it doesn't tell you which of several is which but it's pretty small and
easy to build this way

JAMI, re: your component to component spacing
can this be pick and placed?

Dennis Saputelli


Dwight wrote:
 
  -Original Message-
  From: JaMi Smith [mailto:[EMAIL PROTECTED]]
  Sent: Tuesday, April 23, 2002 11:30 AM
 snip
  I have thought of copying off the final database and modifying all of
  the designators and then generating a new gerbers from the modified file
  and substituting those overlay gerbers in the final set for fab, but
  that is a massive amount of work that will have to be done all over
  again if there is any substantial change to the board.
 
 
 Position the refs as if they didn't have the _1, _2...; then it's only 4
 global edits -- use the brace notation like this:
  {_1=}
 That will remove all the _1's; do the same for 2,3, and 4.  You can backup
 just the .pcb within your current ddb, do the 4 edits, generate the full
 gerbers, then copy back the real pcb.
 
 So far we've used notation like R1A, R1B, etc.  This saves one character
 width.  But we're only down to 0603, not 0402 like you!  We also supply the
 assembly house a printout of the board that's about 2x normal so they can
 double-check anything unclear.
 

-- 
___
www.integratedcontrolsinc.comIntegrated Controls, Inc.
   tel: 415-647-04802851 21st Street  
  fax: 415-647-3003San Francisco, CA 94110

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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Dennis Saputelli

WARNING
after i sent this it occurred to me that the comment field may get
trashed by a netlist load
david can you confirm that this works?
do you use the sync or netlist load?

Dennis Saputelli


Dennis Saputelli wrote:
 
 here come the 0201's !!
 try putting some text and boxes around those
 
 saw a recent article about hand reworking them
 pretty scary
 apparently it takes something known as 'operator skill'
 
 re this thread
 i think the best idea is what dgulley said
 use the comment field and hide the desig
 this way the database is still good and you don't have to use 'loose'
 text
 
 another idea (depending on how many values) is to use a simple code
 like:
 'A' or '1' = 1.00K res
 'B' or '2' = 0.01m cap
 
 it doesn't tell you which of several is which but it's pretty small and
 easy to build this way
 
 JAMI, re: your component to component spacing
 can this be pick and placed?
 
 Dennis Saputelli
 
 Dwight wrote:
 
   -Original Message-
   From: JaMi Smith [mailto:[EMAIL PROTECTED]]
   Sent: Tuesday, April 23, 2002 11:30 AM
  snip
   I have thought of copying off the final database and modifying all of
   the designators and then generating a new gerbers from the modified file
   and substituting those overlay gerbers in the final set for fab, but
   that is a massive amount of work that will have to be done all over
   again if there is any substantial change to the board.
  
 
  Position the refs as if they didn't have the _1, _2...; then it's only 4
  global edits -- use the brace notation like this:
   {_1=}
  That will remove all the _1's; do the same for 2,3, and 4.  You can backup
  just the .pcb within your current ddb, do the 4 edits, generate the full
  gerbers, then copy back the real pcb.
 
  So far we've used notation like R1A, R1B, etc.  This saves one character
  width.  But we're only down to 0603, not 0402 like you!  We also supply the
  assembly house a printout of the board that's about 2x normal so they can
  double-check anything unclear.
 
 
 --
 ___
 www.integratedcontrolsinc.comIntegrated Controls, Inc.
tel: 415-647-04802851 21st Street
   fax: 415-647-3003San Francisco, CA 94110

-- 
___
www.integratedcontrolsinc.comIntegrated Controls, Inc.
   tel: 415-647-04802851 21st Street  
  fax: 415-647-3003San Francisco, CA 94110

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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Clive . Broome



Sounds like you are using cut and pasted sections and getting Protel to
automatically renumber the new pasted sections. Protels renumbering system is
very poor - actually unusable, and the best way I found to renumber whilst
keeping sch and pcb numbers synced is to download and install a renumbering
server from the RSI website. This will allow you to shorten the designators.
Another way to ease assembly on tightly packed board is to have a slightly
different style of footprint between caps and resistors. Maybe resistors have
squared off  silkscreen outlines whilst caps have circular  outlines so when you
look at the board the outlines aid in identifying the part type.




___

Clive Broome
IDT Sydney Design CentrePh: +61 2 9763 3513
8 Baywater Dr, Homebush Fax:+61 2 9763 3409
Sydney,  NSW, 2127  Email:[EMAIL PROTECTED]
Australia

___







JaMi Smith [EMAIL PROTECTED] on 04/24/2002 04:30:27 AM

Please respond to Protel EDA Forum [EMAIL PROTECTED]

To:   Protel EDA Forum [EMAIL PROTECTED]
cc:   JaMi Smith [EMAIL PROTECTED] (bcc: Clive Broome/sdc)

Subject:  [PEDA] Shortened Designator on Silkscreen



I have a small problem with small parts in a small area on a small board
(so what else is new?).

I have 4 parallel channels of a Quad Transimpedance Amplifier circuit,
which is very high gain and requires good isolation. The circuit is all
descrete analog components, mostly 0402, except for the S0-8 op-amps,
and is packaged quite densely with only .020 between components in the
tight spots, and no room for package outlines. The circuit is layed out
very nicely, and is electrically excellent, but unfortunately, there is
no room for designators.

Most of these boards are built in house, but the error rate on stuffing
components (the wrong ones in the wrong locations) is very high and the
trouble-shooting time to find these assembly errors is exhorbinate, so I
really do need the silkscreen every place I can get it.

Herein lies the problem. I have 4 duplicate channels, with ref
designators currently numbered as R1_1, R1_2, R1_3, R1_4, R2_1, etc. in
the 4 parallel and identical channels. My ref designators are already as
small as our fab house will go for which is .025 high and .005 thick
lines, and I am also tenting all of my vias so that they will not
interfere with the silkscreen. I could however get a lot more
designators placed in the limited room that I have if I could eliminate
the channel designator part of the ref designator, i.e.: reduce the R1_1
to simply R1, which is much shorter, and which due to the layout is
acceptable since the channels are physically very clear and already
labeled as CH_1, CH2, etc.

However, if I shorten the actual designator, it makes for
synchronization problems with the schematic, as well as hell to pay in
the DRC department.

I want to keep the ref designators the same for the same component in
the different channels for the sake of circuit / schematic /
troubleshooting clarity, etc. Renumbering them to 100 series for channel
1, 200 series for channel 2, etc, is not only very time consuming but
doesn't really get me much shorter designators anyway.

Hiding the original designators, and replacing them with loose text is
not only very time consuming, but prone to error, not only now, bur
especially in the future if someone else has to modify the board and
move components, since the loose text is not related to the component.

I have thought of copying off the final database and modifying all of
the designators and then generating a new gerbers from the modified file
and substituting those overlay gerbers in the final set for fab, but
that is a massive amount of work that will have to be done all over
again if there is any substantial change to the board.

I do in fact own an Official Mickey Mouse Club Tee Shirt and Hat, which
I am about to pull out and put on, but there has got to be a better way
of handling duplicate circuits in Protel, or should I just throw up my
hands and look for another product all together (PADs, Mentor, Verybest,
etc.). It appears that Protel truly has no provision to handle any kind
of duplicate circuits, especially of the Step and Repeat variety,
whatsoever.

Anyone out there got any useful ideas?

JaMi Smith







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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread David W. Gulley

Actually, this is a VERY good point, the Comment IS updated on a netlist 
load. I have used two methods:
  a) Set the Comment field in the schematic (assuming I have control)
  b) edit the macros generated by the netlist load to delete any
  changes to the comments (these are usually the last macros
  generated so they are easy to find)

It really depends on how many revisions the design will be going through 
and making sure that ALL non standard design flows are carefully and 
fully documented within the project.

I have not tried it with sync, but would assume that the comments are 
over written there as well.

David W. Gulley
Destiny Designs


Dennis Saputelli wrote:

 WARNING
 after i sent this it occurred to me that the comment field may get
 trashed by a netlist load
 david can you confirm that this works?
 do you use the sync or netlist load?
 
 Dennis Saputelli



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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Ian Wilson

On 09:14 AM 24/04/2002 +1000, [EMAIL PROTECTED] said:
..snip..keeping sch and pcb numbers synced is to download and install a 
renumbering
server from the RSI website.

RSI www site or Qualecad web site?

I thought the re-numbering server was from John Williams at Qualecad.

http://www.qualecad.com/page3.html

Look at the Reference Designator Modifier freeware server.

Ian Wilson

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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Clive . Broome



Ah yes, Ian is right, bit of brain strain here!






Ian Wilson [EMAIL PROTECTED] on 04/24/2002 10:35:35 AM

Please respond to Protel EDA Forum [EMAIL PROTECTED]

To:   Protel EDA Forum [EMAIL PROTECTED]
cc:(bcc: Clive Broome/sdc)

Subject:  Re: [PEDA] Shortened Designator on Silkscreen



On 09:14 AM 24/04/2002 +1000, [EMAIL PROTECTED] said:
..snip..keeping sch and pcb numbers synced is to download and install a
renumbering
server from the RSI website.

RSI www site or Qualecad web site?

I thought the re-numbering server was from John Williams at Qualecad.

http://www.qualecad.com/page3.html

Look at the Reference Designator Modifier freeware server.

Ian Wilson






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Re: [PEDA] Shortened Designator on Silkscreen

2002-04-23 Thread Geoff Harland

 I have a small problem with small parts in a small area on a small board
 (so what else is new?).

 I have 4 parallel channels of a Quad Transimpedance Amplifier circuit,
 which is very high gain and requires good isolation. The circuit is all
 descrete analog components, mostly 0402, except for the S0-8 op-amps,
 and is packaged quite densely with only .020 between components in the
 tight spots, and no room for package outlines. The circuit is layed out
 very nicely, and is electrically excellent, but unfortunately, there is
 no room for designators.
snip
 Anyone out there got any useful ideas?

 JaMi Smith

To start off with, this could well be my last post (or else very nearly my
last post) from this email address. I'm currently looking for another job
(preferably in Sydney, Australia, where I am currently living), with my
current job finishing this week (the usual circumstances for this era). But
I have recently signed up to these forums from my home email address, so
other members of these forums will continue to hear from me on an ongoing
basis, but from a different email address.

Now on to this thread.

It is being wise after the event, and not necessarily the best way to do
it, but if you want components R1_1, R1_2, R1_3, and R1_4 (say), then add
component R1_1 to the PCB file, then append a R1 string (on the Top
Overlay layer) to this component (using the Menu item 'Tools/Convert/Add
Selected Primitives to Component'; the component's primitives need to be in
an unlocked state at the time), then create the R1_2, R1_3, and R1_4
components from copying the R1_1 component to the (Protel) clipboard and
then pasting back into the PCB file, then re-annotating the pasted
components as required.

The additional R1 string is part of each of these components, and will
thus move with its component whenever that component is moved. (Moving the
string *relative* to the component will require the component's primitives
need to be in an unlocked state at the time though, but keep in mind that
the global command feature can be used to unlock (or relock) the primitives
of more than one component at a time.)

All up though, a lot of extra work is called for, even if it is all planned
in advance (to minimise the amount of extra work required). But short of
creating a customised addon Process of some sort (for example, one which
acts upon currently selected free strings so that these are automatically
appended to appropriate components which are also currently selected), I am
not sure of any other way of doing it, other than the suggestion made by
others to use the component's Comment strings.

Concerning the use of Comment strings, the Schematic drawings could still be
implemented to display component values (e.g. 10k, 100nF, etc) for each
component by using one of the 16 Part Fields for this purpose, and setting
the corresponding string to be visible. The Part Type (field) (for each
component) could then be used to hold the desired abbreviated Designator
(e.g. R1 for components R1_1, R1_2, etc), with the corresponding string
set invisible (unless it was desired to keep this visible). When information
was passed from the Schematic File(s) to the PCB file, the Comment string of
each component would then acquire the desired abbreviated Designator for
this, and any subsequent re-synchronisation between the Schematic file(s)
and the PCB file would *not* result in these desired abbreviated Designators
being lost or over-written for *any* of the components (in the PCB file).

Some extra work called for with that method as well, but if planned in
advance, the amount of extra work required could again be reduced (and
probably substantially). If used, I would strongly recommend the addition of
an annotation to the Schematic file(s), documenting the usage of this
technique.

Regards,
Geoff Harland.
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