Electronics Forum | Tue Feb 19 11:34:04 EST 2002 | AndyC
Do you mean middle height slice ? . This is a term used to describe the x-ray taken at a mid-ball position on a BGA ball , ie , the "fattest/widest" part if the ball . This is generally done to see if voids contained within have led to fracture acros
Electronics Forum | Tue Nov 10 07:35:04 EST 2009 | scottp
Step 1 is to find out what kind of opens you're getting through a cross-section or die & pry. Are they head in pillow, brittle fracture at the intermetallic, bulk solder cracks, ball separation from interposer? Without some basic failure analysis a
Electronics Forum | Fri Feb 01 14:23:47 EST 2002 | delnosa
Looking for help on getting information on understanding the physics of micro-fracture growth rate within the BGA ball (or solder joints in general). Hoping to find a fairly straight forward study on the concept/theory of this topic. I'm not a meta
Electronics Forum | Wed Sep 30 11:32:45 EDT 2009 | pbarton
What type of conformal coating are you using and are you allowing the coating to migrate under the device in question? If you are allowing the coating unbder the BGA the problem could be CTE of coating is much greater than that of the BGA balls/sold
Electronics Forum | Wed Sep 14 15:42:45 EDT 2011 | nowak18
During temperature cycling we have determined that the conformal coating wicking underneath our BGAs has caused fractures in our solder balls. One proposed solution is to run an RTV dam around the parameter of the BGA to prevent the CC from wicking u
Electronics Forum | Thu Apr 03 11:57:38 EST 2003 | davef
R4: We see the ball left on the PCB with a flat top and the BGA pad appears to be virgin. D4: Not good. The flat top indicates that the ball melted at one time or another. This pad and ball have seen at least two solder cycles with solder and flux. S
Electronics Forum | Sun Feb 04 15:06:20 EST 2007 | Scotty
Profile should have a longer cool soak. Verify as was mentioned all pin/fixture support through out the entire process. Print, Place, pre reflow hand load, post reflow, carriers, ICT, Depanel and FCT. Conformal Coated or Potted? Mylars work well for
Electronics Forum | Tue Apr 01 11:50:08 EST 2003 | rdr
Dave, thanks for the info. This sounds like it would verify the presence of an open. We have verified that these balls are open and I am trying to figure out if we are fracturing or not wetting. causing these opens. I would use the die method on ne
Electronics Forum | Tue Apr 01 18:42:18 EST 2003 | rdr
Well, here is what I have found so far. I have removed the top of the BGA and found that the ball had detached from the package. Three balls were removed with the two adjacent balls pulling the pads off the board and stayed attached to the BGA while
Electronics Forum | Thu Apr 03 11:17:17 EST 2003 | rdr
Well, first off now I'm just starting to believe that we are fracturing again. But here is some more input D1 ENIG? I would not have thought that they would be but as usual you are probably right. D2 Again I would have to agree about it should affe
