Electronics Forum | Wed Feb 07 18:40:39 EST 2007 | bill
What is an acceptable mismatch for smt components and pcb. We are having cracked solder joints from fatigue after repeated thermal cycling 25 deg. c to 125 deg.c.
Electronics Forum | Wed Feb 28 15:09:57 EST 2007 | Hussman
Some no-cleans will pool flux on the top of the solder joint which acts like an insulator. I normally do not paste "contact" pads. You can have your board house HASL them if you need the extra bump on the pad.
Electronics Forum | Fri Apr 20 09:45:19 EDT 2007 | patrickbruneel
Here�s another article on lead free solder joint embrittlement http://uic.com/wcms/WCMS2.nsf/index/Resources_75.html
Electronics Forum | Thu Apr 19 02:49:07 EDT 2007 | ray
I observed some black dot or some oxidation occured on chip termination on pcba reflowed fews weeks ago as buffer stock. The solder joint and fillet wetting is good and shinning. It is an acceptable or defect condition per IPC standard/requirement? W
Electronics Forum | Tue Apr 24 17:39:05 EDT 2007 | Cmiller
I would not really say green, but muddy, yes. It does not look like tin/lead dross. You should not see it on you solder joints though.
Electronics Forum | Wed May 16 11:27:40 EDT 2007 | patrickbruneel
Can�t help but just notice that RoHaaS affects more then just solder joint reliability. As long as the mat is �green� all should be just fine. For more info check http://www.rohaas.com Sorry couldn�t resist
Electronics Forum | Thu Sep 06 15:57:36 EDT 2007 | grantp
Hi, Vapor phase is an incredibly process, apart from the tombstoning, that we just could never eliminate. So we had to dump it and go with convection. It's a shame, as the solder joints were incredible! Regards, Grant
Electronics Forum | Wed Sep 05 08:56:42 EDT 2007 | stepheniii
One of our customers does a drop test. They hold the final unit five feet above a concrete floor and drop it.
Electronics Forum | Thu Sep 06 10:12:27 EDT 2007 | slthomas
"...but it would also be testing if they had enough mechanical strength to hold the components on." Only if you take the time to observe the results. :) Your point is well taken, but these guys were only interested in seeing if any failure modes pro
Electronics Forum | Mon Sep 10 13:46:26 EDT 2007 | mobytahoe
One of our customers bangs the assembly on his table top to see if parts will fall off. Darwin is alive and well in the OEM world...