Electronics Forum | Fri Jul 06 18:17:34 EDT 2001 | davef
We find no solder balls after washing our boards. It works GREAT!!! ;-) Probably more to the point, look at "Circuits Assembly" 7/01, p 40, "Eliminating Solder Beads In No-Clean PCBs". "Solder mask type & composition are the greatest contributor t
Electronics Forum | Thu Apr 15 15:54:13 EDT 2004 | pjc
You ned to speak with an apps engineer from a paste supplier that can go through their alloys. I know Indium has such alloys. Any vendor should be able to supply you a list of alloys avbl in NC paste with their liquidous points.
Electronics Forum | Mon Jan 09 23:24:47 EST 2017 | saju86ece
Hi, We are doing pin in paste reflow process in one our product ( but paste printed on bottom side of the board and top side will be assembled through hole component)in which faced cold solder issue in THT capacitor location after reflow. The solder
Electronics Forum | Fri Sep 20 17:43:03 EDT 2019 | deanm
Looks like poor wetting/solderability to me. I don’t see heel fillets on the leads where the solder balls up. The solder has to go somewhere. It won’t flow where it won’t wet. Try printing a bare board and run through reflow. If the solder balls up o
Electronics Forum | Sun Jan 22 04:57:25 EST 2017 | robertwillis
If you look at my book on Pin In Hole Reflow there are many examples of may process defects. Its free to download and the first book on the technology. if you send a photo of the defect I may be able to point you in the right direction see http://pih
Electronics Forum | Mon Jul 01 15:37:56 EDT 2002 | pjc
Possible cause can be design related- if the solder land is too small. Check w/ IPC SM-782 Solder Land Design Guide Another is board finish. I have seen problems like this with Gold finished PWBs- which creates a more brittle solder joint.Another pos
Electronics Forum | Thu Feb 08 09:07:22 EST 2001 | Hussman
OK, without knowing the specifics, why does everyone blame the oven? Most solder balls occur around R's and C's in almost every shop I've been to. The best place to start looking is the screen printer - not the oven. Sure the oven is the last proc
Electronics Forum | Wed Aug 06 14:49:06 EDT 2014 | dyoungquist
Sn62Pb36Ag2 has a higher liquidus point of 189C as compared to Sn63Pb37 at 183C. You may need to slightly adjust your oven profiles to use it compared to SnPb. We have had good solder-ability and reliability with it in our IPC Class II products. A
Electronics Forum | Wed Nov 20 09:27:28 EST 2002 | davef
There's a fair number of issues with lead and bismuth solder alloys: * Lead and bismuth alloys can form a eutectic composition of Bi52Pb32Sn16 in the grain boundaries. Melting point of the eutectic alloy is 95�C [~96�C?]. * Fillet lifting of PTH du
Electronics Forum | Mon May 15 10:16:36 EDT 2006 | slaine
Hi Im trying to find a supplier for 30swg HMP solder wire idealy the alloy I want is 93.5Pb, 5Sn, 1.5Ag, 296 to 301 degrees C. Flux cored. 30swg or 0.3mm diamiter. but the critcal parts are the diameter and the melting point, 300 degrees +-20 degree
