Electronics Forum | Wed Mar 03 18:42:29 EST 2010 | 89jeong
Hello Graham Copper. Thanks for yr comment. I will review the pad size and component placement with our engineer. It looks that the placement of lead is wrong. But what i want to hear from you is about solder lump on the right.As you can see, the sol
Electronics Forum | Fri Mar 05 04:19:03 EST 2010 | aungthura
Ya, that could be happened bcoz of reflow profile.I think, in this case, each lead got the different temperature during the reflow process. If the solder had melted properly,the hot lead would have attracted the solder to cover itself.
Electronics Forum | Wed Mar 03 23:07:59 EST 2010 | davef
If your "engineer reviewed the reflow profile and said this was not related to reflow conditions," then what does he think it's related to? We think that a increased effort to improve the thermal recipe to solder this part is required, because: * S
Electronics Forum | Wed Mar 03 01:48:57 EST 2010 | 89jeong
Hello Sir. Our customer asked me why the solder did not cover the surface of the potocopuler lead. There are 2 ea of photocopuler on pcb and the leads are totally 8ea. But only one is showing this problem. When i reviewed the reflow profile, there
Electronics Forum | Mon Mar 08 05:03:24 EST 2010 | grahamcooper22
Hi, I fully agree with isd.jww. The difference in the solder joint appearance of the 2 joints highlighted could be down to a few reasons...reflow profile (I know you've checked, but have you stuck a thermocouple on this actual joint ? ), contaminatio
Electronics Forum | Wed Jan 28 01:27:30 EST 2004 | Martin Silberkuhl
First of all, sorry for my bad english (I'm german)!!! We have the following problem: we assemble 6pcs. smd 30pin connectors on one of our boards that we produce. These connectors have a top cover, that the pick&place machine can put it on the board
Electronics Forum | Fri Dec 16 18:37:10 EST 2005 | mdemos1
Hi. I am trying to understand Tg and how it relates to reflow. With the higher temperatures of lead free, we have been looking toward laminates with a Tg of 180 instead of the current 140. My question is a little more general. In either lead free
Electronics Forum | Tue May 02 15:29:14 EDT 2000 | M. F. Roe
I am looking for public papers or articles on intermetallic formation as a function of reflow profile. Most solder paste vendors specify peak temperature and time above liquidus, but I am particularly interested in what happens to intermetallic grow
Electronics Forum | Mon Dec 19 07:29:30 EST 2005 | jax
Tg is just a way to say when the board goes limp... or a quick way to rank laminates... who cares. For lead free you want to look at Td, Decomposition Temperatures. ( Temp at which the material weight changes by 5% )
Electronics Forum | Mon Dec 19 07:49:33 EST 2005 | davef
=330*C is good advice. Search the fine SMTnet Archives for earlier discussions on Td, like http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=32430
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