On Mon, May 23, 2011 at 5:38 AM, V G wrote: > Hi all, > > I'm having three boards made for my university. The design is a SCADA > control system terminal that will sit inside a chamber and switch on and > off > heaters/humidifiers/stuff like that. It has all the necessary protection = in > place (MOV, zeners, fueses, optoisolators, etc), most of it on the board, > where it is needed. Unfortunately, due to all the protection, LEDs, and > stuff, the board is quite large (around 6x6 inches). It's also using only > through hole components. > > Here's a roughly (messily) laid out, unrouted picture of the board: > http://postimage.org/image/11z7x17dw/full/ > > I would like to save as much space as possible. This will probably mean > switching all the components to surface mount. There's also four huge > MOSFETS near the top right which probably wont be laying down on the boar= d > to save space, but are outlined as such in the picture. The huge DIP > package > in the middle is a UBW32 board. Other ICs are mostly 74 series logic > buffers, etc. Most of the 6 pin DIPs are optoisolators. > > Note: I wouldn't know how to route this beast by hand. The autorouter > routes > this thing fine in two layers. > > What suggestions would you guys have for saving space and designing for > better efficiency? > -- About a million things :-) I would suggest that you start with the understanding that the "perfect" design is impossible, then work to "functional". First, I see a classic newbie mistake - no mounting holes. You said the autorouter does it "fine", why is that not an acceptable solution? You want to "save as much space as possible" - why? If it physically doesn't fit in the mounting location, ok, that's a good reason. If you're trying to reduce costs on the board, you need to re-evaluate your motives. Saving $5 off the PCB on a total production run of three units, compared to the dozen hours or more it takes to lay out a space optimized version may not be your best choice. Also consider the future - if you were able to shrink this down to a 2" square using the tiniest parts available, how convenient would it be to assemble or debug? A little extra space at this stage can make your life a lot easier later. -Denny --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .