On 22 Sep 97 at 19:20, Harold Hallikainen wrote: > On Mon, 22 Sep 1997 11:09:32 +0000 Lawrence Lile > writes: > > >Man, you got guts! I've never run traces between DIP pads for fear > >they'd never work in production. Does anybody else do work this fine > >with success? > > > >HOW SMALL do you dare make a trace on a board? My rule has always > >been to make them as wide as I can, and to avoid tight spacings and > >small traces. The board houses that mass produce my stuff are all low > >budget and I don't trust their process to reproduce fine traces. I > >generally use .060" traces width when I've got a Texas-sized space to > >run in, .030" if I'm cramped. That would never fit between a pair if > >DIP pads. > > > Wow... Doesn't sound like much board density! I usually > run 12 > mil traces with 13 mil spaces. I also run a ground plane or ground > grid on both sides of the board. Power is usually distributed on 25 > or 50 mil traces, depending on space available. These are on double > sided, plated thru, solder mask over bare copper. The local PCB houses complain if I thread more than 2 traces between 0.1" IC pads. > We've had very few problems, but when there are problems, > it's > usually a short instead of an open. And... they are a pain to find! > We'll probably be going to bare board testing on future runs. The > PC house charges another $1.00 per board for that. > This idea of plotting prototype boards directly, especially > surface mount, is intriguing. How about plotting conductive ink, > letting it dry, then plotting the next layer with an slightly wider > insulating trace followed by the narrower conductive trace. We otta > be able to make multilayer boards with no chemicals (other than > ink). Drilling is still a pain, and I guess we'd have trouble > soldering to ink... The PTH technology exists already - how long before the 'plate' occurs for the entire board? Or - use some kind of electron beam deposit? Thin tracks, forsooth! MikeS (remove the you know what before replying)