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 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *