Ryan, What you have described is a problem for anyone who is using selective solder pallets. The openings should always be chamfered and as large as possible to allow the solder to flow into and out of the opening. The copper tape may also work for you and I have seen others attach stainless steel strips to the pallet as a permanent fix. If you have already tweaked the process and can't eliminate the problem there is one other thing you can try. Reduce the lead length of the connectors that are bridging so there is only about .020 protruding through the bottomside of the board. If your board is .062 then the lead length should be .085. You can find connectors from some vendors cut at this length. You can also get a lead prep machine that will cut the leads to the required length. The type and amount of flux you are using may be a factor here also. Good luck. Ken Kirby Process Specialist Speedline Technologies (Embedded image moved Ryan Jennens <[log in to unmask]> to file: 07/26/99 09:36 PM pic24561.pcx) To: [log in to unmask] cc: (bcc: Kenneth Kirby/ElectrovertUS/Cookson) Subject: [TN] Selective Wave Solder Pallet Problems Hey all- We use selective wave solder pallets extensively to solder through-hole leads, as almost all our boards are mixed tech. A couple types boards consistently show a single short on the trailing edge of large through-hole connectors. One board always shorts on the trailing pins of a PGA socket, while the other always shorts on the trailing edge of a 40-pin dual-row female header. No amount of tweaking the wave machine settings affects the short. My theory is this: When the solder leaves the larger pallet openings, it has nothing to "snap" to. Therefore, it "snaps" to the last couple of pins it leaves. I have made sure that the solder flows off the back of the wave at the same speed as the conveyer. Has anybody else seen, or heard, of this problem with selective solder pallets? The advantages of reflowing bottom-side components make wave soldering the whole bottom-side unfeasible. Speaking with the pallet house has left us with grooved pallet bottoms and chamfered openings; but the problem remains. Is there a way to alter the selective wave solder pallet openings to avoid these "snap-back" shorts?