Electronics Forum | Fri May 31 10:15:30 EDT 2019 | davef
Major sources of crack in the solder connection after thermal cycling are: * Thermal heating caused by differences in thermal expansion between the board and the component * Lead-free solder is more rigid and brittle than eutectic solder in simila
Electronics Forum | Mon Mar 31 11:10:43 EST 2003 | davef
First, most �thermal shock� recipes are not a reliability test. There is no relationship between the failures seem in these tests and in-use application. These tests show you the failures in these tests. That�s it!!! Second, accelerated life test
Electronics Forum | Thu Dec 15 12:10:07 EST 2005 | muse95
It should be the other way around. A Pb BGA ball will fully melt in a Pb free process, but a Pb free BGA ball will not fully melt in a Pb process, which means the Pb from the paste on the board will not fully diffuse through the ball. This leads to
Electronics Forum | Wed Feb 02 20:39:07 EST 2000 | Dave F
AF, Buddy: I know someone "set you up" to ask this question, but: 1 What kind of "thermal excursions" are you interested in? Solder cycles, rework cycles, thermal shock, thermal cycling ... 2 What are you talking about boards, components, assembl
Electronics Forum | Sun Jan 21 16:42:35 EST 2001 | davef
I just can not get over the size of these crystals. What is the chronology of and the span of the thermal cycles this BGA has seen.[Just guess at the fabrication cycles, if it's difficult to determine]
Electronics Forum | Tue Oct 04 12:49:59 EDT 2005 | patrickbruneel
The amount of times the tin/lead solder can be melted and solidified is unlimited and the heat cycles do not affect the solder characteristics. The only reason for changing the solder pot is when impurities are at or over the maximum levels.
Electronics Forum | Fri Jan 27 07:30:54 EST 2012 | scottp
We're in the high rel market and use a lot of 5 mil stencils. They give plenty of paste to meet IPC class 3 and survive over 1000 cycles of -40/+125C thermal cycle testing.
Electronics Forum | Fri Jul 29 19:12:30 EDT 2005 | Jason Fullerton
In the true sense of the term, tombstoning can only occur during reflow. Now, if your solder joints are cracking during thermal cycling and opening on one end you still have a problem - it just isn't "tombstoning". What laminate are you using on yo
Electronics Forum | Thu Sep 14 14:37:45 EDT 2000 | Serrena Carter
Does anyone know where I can find good rule of thumb information on soldering/brazing. I am most interested learning the maximum recommended CTE mismatch between two different materials that thermally cycle between 25-100C.
Electronics Forum | Tue Mar 31 08:08:32 EST 1998 | Michael Mallery
I am looking for information on TSOP encapsulating materials. Also, any manufacturing companies that sell TSOP's daisy chained for electrical functional thermal cycling.
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