Electronics Forum | Thu Oct 02 17:55:16 EDT 2008 | davef
~le sigh~ makes a good point about forcing bent leads into the solder, letting the solder cool, and releasing the force on the lead. On the other hand, reforming leads of components prior to assembly is dangerous, also, because the "bending of a lead
Electronics Forum | Mon Aug 29 22:48:09 EDT 2011 | davef
Rich Here's what Humiseal says: Thermal Properties The coating must be able to withstand localized thermal 'hot spots' generated by components. High temperatures can cause short-term changes in coating characteristics, such as softening and lowered e
Electronics Forum | Fri Jun 06 06:11:18 EDT 2014 | paulg
I have a large monoblock ceramic filter on a PTFE based pcb material. The filter has a metal casing soldered onto the ceramic filter. I am concerned that if the heating rate is to rapid, then thermal shock / differential expansion could cause the fil
Electronics Forum | Thu Jul 25 18:41:52 EDT 2019 | myke03o
Hi I have solved the issue. The component cracking are the big 1210, 0603 and 0402 capacitors. After studying and testing in many type of solder. The best to use is SnPb and the components are the key - there are component which will tend to expand
Electronics Forum | Sun Dec 10 20:17:51 EST 2017 | myke03o
Hi Dave, thanks for the response. * Improve your products that are used for thermal cycling testing of products of other companies? Yes we want to improve our products to pass thermal cycling and prolong the lifespan of the baord. * Change your pr
Electronics Forum | Wed Aug 10 10:41:23 EDT 2005 | patrickbruneel
Bob, Great theory if you're selling SN100C, but I have to disagree that an alloy being 4�C off eutectic will cause cracks. When a solder joint exits the solder wave, there is an immediate drop in temperature of 100�C. so being off 4�C is irrelevant.
Electronics Forum | Tue Jul 22 03:56:24 EDT 2003 | A.G.
Are there existing acceptability dedicated criteria for ALIVH bare boards? (Equivalent to IPC-A-600) In particular, how can we assess copper foil cracking after thermal stress?
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 Oct 31 21:52:10 EDT 2007 | davef
We wouldn't expect the ceramic of the capacitor to conduct very much heat. [We're surprised how high the thermal conductivity of Al2O3 is: (30W/m-�C).] Can we assume that you're talking about parts that are defective at incoming inspection?
Electronics Forum | Tue Jun 22 08:37:52 EDT 2010 | davef
Dennis: These "terminal detach failures" probably are caused by thermal shocking of the components. * Preheat the components * Use a hot air pencil rather than a soldering iron
