Electronics Forum | Wed Feb 07 16:20:46 EST 2007 | davef
Bismuth is a low-melting metal with poor mechanical properties; if you melt the bismuth wire into a standard tin-lead solder joint, then the bismuth alloys with the solder, and forms a material that will crumble if you scrape it with your fingernail.
Electronics Forum | Mon Dec 27 12:24:47 EST 1999 | RICK_EEI
Hi everyone. We use a small ultrasonic aqueous cleaner. After each PCB we hand solder, (water soluble) we place it in the cleaner immediately. Lately we have had some problems with the solder joints appearing to be corroding away. We tried lowering t
Electronics Forum | Sat May 24 00:43:59 EDT 2003 | iman
Our engineers did a study on our medical product with 1mils standoff height, and one issue was 100% of the boards that underwent ultrasonic failed due to failure of the package wirebonding. Poor reflow control would be one area to review in any event
Electronics Forum | Thu Jul 28 22:35:58 EDT 2011 | davef
The consequences of poor heel formation in solder connections include: * Lower solder joint strength * Possible intermittent short circuits * Reduced first-pass yields * Increased inspection cost * Increased rework cost * Likely field failures * Like
Electronics Forum | Wed Sep 25 15:58:36 EDT 2002 | bschreiber
Hello Dave, I hope that electronic slap didn�t hurt too much. Robf, I am sorry that you did not agree with my initial response, but the answer is very detailed and most of the support material I have is only in paper format so I need to either snai
Electronics Forum | Mon Sep 11 04:23:49 EDT 2000 | Wolfgang Busko
Adam: I would say that you do have a reliability problem. - check parts for solderability - check your board finish - check your profiles - check your paste - check your processes with focus on cleanliness - do some mechanical tests, you should rath
Electronics Forum | Thu Jan 07 15:28:52 EST 2010 | cbart
did the boards get built by hand or via smt process (through reflow oven)? Someone asked earlier if some one touched up the adjacent joint. The answer to that question is yes. Look at how the solder tails off the smt pad away from that joint! I suspe
Electronics Forum | Tue Nov 05 00:51:39 EST 2002 | yngwie
How to measure the max allowable force when we press the heatsink at the attachment process. I was posted with question by my customer, " how to I ensure that the force I use to attach the heatsink does not causing any damage to the solder joint on t
Electronics Forum | Fri Nov 07 16:00:45 EST 2003 | Don A
It would depend on how many boards and parts you need to build. I would prefer an etch cut as it leaves the the part intact and you get the strength of the solder joint. It also reduces the handling of the BGA and associated damage from that
Electronics Forum | Mon Jul 17 13:37:35 EDT 2006 | carln
Here is something I copied from Circuitnet.com. This appears to answer your question and then some... http://www.circuitnet.com/experts/ Ask the Experts Jul 17, 2006 What type of cleaner method is preferred for lead-free stencils? What type of s
