Electronics Forum | Fri Dec 16 08:16:41 EST 2005 | davef
Heat cycles deplete the pure tin layer. Each solder cycle reduces the tin thickness by ~0.1 micron (4 uin). So, if you start with a thin imm tin coating you'll have problems after multiple heat cycles. Steve Wentz says, "In almost every case I've
Electronics Forum | Fri Dec 16 13:31:28 EST 2005 | gpaelmo
Thanks for your response.
Electronics Forum | Fri Dec 16 13:31:03 EST 2005 | gpaelmo
Thanks for your response.
Electronics Forum | Fri Dec 16 03:47:46 EST 2005 | gpaelmo
Anyone have problems wave soldering white tin finish? We are an ems and our customer provides us the pcb's. SMT and TH components on the board. SMT is fine but when we wave solder, wetting to top side is very poor (solder only flows half way up). We
Electronics Forum | Fri Dec 16 08:00:26 EST 2005 | jax
What you are most likely dealing with: Insufficient Pure Sn layer ( multiple causes ) Because elevated temperatures accelerate the diffusion process, the thickness of the Pure Sn layer will reduce during every thermal cycle... ( bakeing PCBs, S
Electronics Forum | Wed Jul 29 13:44:45 EDT 1998 | David Spilker
We are investigating alternatives to HASL finishes for more dense PWBs. OSP is not a good choice because of low solid flux and possibly long shelf life. Immersion gold is expensive and so far has been more difficult to wave solder. Has anyone had
Electronics Forum | Mon Aug 07 09:04:09 EDT 2006 | molos21
Hi everyone, I am starting to use the lead free process and I had a few wetting problems (solder did not reach top side) at the wave soldering process once the pcb had passed our smt line (one heat pass). From what I understand, I have had a problem
Electronics Forum | Tue Aug 28 15:13:17 EDT 2007 | rgduval
Lead-free? White-tin finish? Even if it's not, it sounds like a moisture/contamination issue. If your boards must sit in stock between reflow/wave, consider giving them an alcohol bath to clean up any contamination, and a good baking to remove any
Electronics Forum | Thu Sep 27 10:40:46 EDT 2007 | rgduval
Joris, Yep, very common to have those small blow holes in lead-free alloys. We used to get them very consistently on white-tin finished boards, and less frequently with gold finished boards, for what ever that is worth. IPC-610 actually allows t
Electronics Forum | Thu Sep 27 10:53:59 EDT 2007 | gregoryyork
Joris, > > Yep, very common to have those small > blow holes in lead-free alloys. We used to get > them very consistently on white-tin finished > boards, and less frequently with gold finished > boards, for what ever that is worth. > > IPC-6
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