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
> 
> * * * * * * * * * * * * * * * * * * * * * * * * * *
> * * * *
> * 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
> * * * * * * * * * * * * * * * * * * * * * * * * * *
> * * * *


__________________________________________________
Do You Yahoo!?
Yahoo! Games - play chess, backgammon, pool and more
http://games.yahoo.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
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to