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://email@example.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://firstname.lastname@example.org * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *