At 09:47 PM 4/25/2012, Lee Mulvogue wrote: > Now, I'm looking at connecting two PCBs edge-to-edge, and am havi= ng >difficulties finding a cheap solution for this. I only need about 8 >connections. My latest thought is, can I use a double-row 1.27mm >through-hole header system, and straddle it over the edge of the PCB >(thickness: 1mm? 1.2mm?), soldering to tracks top and bottom? So >using straight male headers on one board, straight female on the >other; been having a whole heap of trouble finding right-angle female >to suit. I've done this dozens of times in the past, except using 0.1" spacing=20 Double Row Headers and receptacles. You want to use 0.050" pin=20 pitch, which means that your PCB material has to be thin (0.031"=20 instead of 0.062"). This has been reliable for me for at least a couple of decades=20 now. Part of what makes it reliable is that both rows of pins are=20 soldered on both sides of the PCB, which pretty much eliminates=20 torsion or twisting problems that would cause the solder joints to=20 fracture and fail. For What Its Worth, longer connectors with more pins seem (to me) to=20 be inherently more reliable than short connectors with only a few=20 pins. The smallest number of pins that I've done this with is 16 (2=20 rows of 8 pins each). I would mock up a sample and bend and twist it to see if it=20 fails. Because you have significantly less surface area for the=20 solder to adhere to, you may in fact have a problem with either the=20 solder joints failing or the traces lifting away from the substrate. But I think that its worth trying to see. By the way - you can order both single-row and double-row headers and=20 female receptacles in right-angle style, in both through-hole and SMT=20 style. I routinely design boards that use right-angle, through-hole=20 double-row connectors and receptacles. Obviously, through-hole=20 connectors with plated-through-holes are dramatically more reliable=20 than the SMT equivalents. dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .