Electronics Forum | Thu Feb 20 17:18:24 EST 2003 | davef
Give us infortmation, please. What is [are]: * Height board to board side of the interposer on the low side of uBGA * Height board to board side of the interposer on the high side of uBGA * Alloy of solder balls, no paste was used correct? * Type of
Electronics Forum | Mon Jan 28 16:12:47 EST 2002 | Joe B.
Dave F, thank you for your reply and the references you included. You asked why I'm trying to understand this info, here's an answer: I'm working on an NSF-funded materials-related project, one aspect of which may lead to some advances in the forma
Electronics Forum | Tue May 01 09:51:51 EDT 2007 | slthomas
Where are you measuring your temperature at? Are you measuring pad/ball interface temp through a hole in the board, or a lead on a different part, or board surface, or.....?
Electronics Forum | Thu May 03 09:02:31 EDT 2007 | realchunks
Hi LC, Where are you getting your profile from? Are you actually attaching t-couples to the board? For BGAs the best place to measure is from the center of the device. This means drilling a hole in the board and placing the t-couple thru the hole
Electronics Forum | Tue Feb 18 22:15:04 EST 2003 | davef
Arturo, So, you're not shorting to a thermal pad. Given that you're shorting to outer balls, tell us about: * Location of the shorting among the outer balls. * Board construction. * BGA constuction. * Paste deposition. * Temperature measurements ta
Electronics Forum | Thu Oct 12 08:12:51 EDT 2006 | realchunks
I have, but not for what you are trying. Different ovens and styles react differently when you try this, so you have to experiment to see how far you can go. Why do you think different temps top and bottom will solve the coplanairty issue? Is this
Electronics Forum | Tue May 17 08:00:26 EDT 2005 | Bob R.
We went through this with one PBGA supplier recently and they were able to get the problem under control by fixing some of their molding processes that were inducing residual stresses. You can really see it in a thermal moire where you measure warpa
Electronics Forum | Wed Aug 27 14:41:49 EDT 2003 | Stephen
Have you checked the temperature profile at the balls? Just because a recipe works "fine most of the time" does not mean it is optimum. Do you have a machine that can measure co-planarity? If I get time I plan on using the MPA to look at co-plana
Electronics Forum | Mon Aug 28 12:41:35 EDT 2000 | JAX
MoonMan, I'll take a crack at the list. Feel free to answer the ones I don't! 1. Solderability is a parameter which indicates how well a component can be soldered. As far as Solder Termination Coatings go, here are some up�s and down�s of a few. Ha
Electronics Forum | Thu Apr 27 21:20:38 EDT 2000 | Dean
Here are some pointers to use during your X-ray inspection. Microcracking is virtually impossible to determine with X-ray. However, I suspect you are looking for "hard" opens. Those are much easier to find visually. If using a paste-and-place pro
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