Electronics Forum | Thu Nov 22 08:30:59 EST 2001 | krs
I have heard of this but do not have direct experience. Immersion tin is susceptible to moisture absorption particularly after washing off solder paste. So it sounds like your boards are picking up the solvent off the screen. Water rinse or degrease
Electronics Forum | Thu May 30 11:37:27 EDT 2002 | Ron Costa
Hi Ray, A couple of things to look into: 1.date code of reel 2. what is the termination made up of tin/lead or tin/lead/palladium. Check with part manufacturer. 3.paste volume/aperture openings 4.PCB plating 5.solder paste formulation Good luck R
Electronics Forum | Tue Sep 24 12:30:11 EDT 2002 | Claude_Couture
I'm just shooting ideas here, but maybe a via hole in the middle of the solder pad would drain the excess solder by capillary force? Or using a tin plated PCB and printing flux only, then place and reflow. depending on the thickness of the tin plati
Electronics Forum | Mon May 12 23:28:33 EDT 2003 | dehlers
To the best of my knowledge and experience the 2 % Ag component is not for embrittlement but rather to reduce gold scavenging caused by the propensity for tin to react with the gold. I have seen eutectic tin/lead actually disolve gold wire after a f
Electronics Forum | Fri Sep 12 22:57:13 EDT 2003 | Dean
What is the surface finish of the PCB? Tin? Imersion Silver? What flux is used in wave solder and / or SMT? I have much experience with silver migration and tin wiskers. Both can disappear during a reqork cycle. Both can be extremely difficult
Electronics Forum | Wed Jun 04 09:15:06 EDT 2003 | davef
We used to use 260+-5C (500+-10F) for Sn63, now we use 240-260C (460-480 F). You probably could get away with 232C (450F) in all cases, since there is no thermal mass to a lead being tinned. We keep our tinning temperature the same as our solder po
Electronics Forum | Mon Jun 23 11:02:33 EDT 2003 | Kris
Hi, No Major issue using lead-free plated components in tin-lead as long as Sn/Bi is not the finish. I think some customer might be worried about low melting phase. More voiding may be seen in case of ceramic capacitors used with tin-lead. It is
Electronics Forum | Wed Jul 23 08:21:55 EDT 2003 | James
Here we go again. I tried changing paste and that did nothing. Literally solder balled up and flew to the next pad. What would be a short term fix to use up all baards with white tin. Is there a fix if the board house did not manufacturer the boards
Electronics Forum | Tue Sep 09 15:22:39 EDT 2003 | gdstanton
Anyone have any experience with immersion white tin over copper plating? We are seeing opens develop under BGAs after we bake and conformal coat. And when we lift the parts the pads are 60% of the original size. Need some advice on possible causes
Electronics Forum | Mon Apr 26 17:12:14 EDT 2004 | babe
Take a solder iron with some wire solder and attempt to tin the leads of the component. Look under magnifier or microscope. Did they wet? If not try fluxing them with liquid flux and then soldering again. Did they wet? If they did not then you may wa
