Electronics Forum | Fri Oct 08 09:43:27 EDT 2004 | davef
First, don't get too excited about the thermal capabilities of conductive epoxy. An epoxy like DuPont CB-100 increases the amount of heat conducted through the barrel, but many over estimate what it can do. Calculations show for a 0.020" drilled
Electronics Forum | Fri Oct 08 07:38:48 EDT 2004 | Paddy
Hello, I am wondering if anybody has process experiance of designs which use the above. I understand that the filled via is an excellent thermal cnductor, which is great from a design point of view, but how do these solder through the reflow ovens
Electronics Forum | Wed Nov 30 12:44:54 EST 2005 | ppwlee
Dave, Do you know if such thermal transfer study with CB-100 (or equivalent) is available for review? My customer is pursuing this option and I am curious on how much improvement I would see by specifying a conductive via fill on the board. Rgds, P
Electronics Forum | Wed Nov 30 22:25:03 EST 2005 | davef
The authors of this article might get you started http://www.protoengineering.com/documents/viaplug.pdf Other information is: * http://www.dupont.com/pcm/techinfo/general/general9.html *
Electronics Forum | Sun Dec 15 22:31:43 EST 2002 | craigj
Has anyone heard of vias cracking (barrel from pad) when being wave soldered. Was told this was a big problem by contract pcb designer, he always tent vias because of this. The reason was that the solder filling the vias caused stressing and then sep
Electronics Forum | Mon Dec 16 09:36:54 EST 2002 | russ
I have never had this problem. It sounds like you are right in imagining that there must have been a bad supplier of PCBS or an inadequate design rule being followed, or a very bad wave process to have this cracking over wave solder. Some books requ
Electronics Forum | Fri Aug 22 09:41:49 EDT 2003 | davef
Mantis: Kenny reflows paste on [wave solders] all via, not just the test via, to plug the via and provide for a pressure seal between the board and the test fixture. Beyond that, since solder is softer than copper [and fills the hole better], solde
Electronics Forum | Fri May 25 08:06:19 EDT 2007 | davef
Soldering PTFE boards * Exposure to the high temperatures needed for solder reflow poses no problem of loss of peel strength since the exposure times are relatively short. * There are many different types of PTFE based products that may perform diff
Electronics Forum | Mon Feb 06 10:02:14 EST 2006 | Yash Sutariya
Sorry. I actually should clarify those slides. Black pad is not associated with tented vias. Also, you can tent vias with soldermask, but this requires the immersion gold process to be completed prior to soldermask. As such, all copper features (
Electronics Forum | Tue Sep 14 14:52:22 EDT 2004 | Carol
During processing, the solder in the vias reflows and forms solder balls. PCBs have solder in random PBGA vias from the board manufacturer.The manufacturer says this is a result of the HASL process and is unavoidable. We use HASL finish, multilayer,
