Electronics Forum | Sat Mar 25 10:13:18 EST 2000 | Robert Hutton-Squire
I am assembling a board with 2 x ALTERA FineLine PBGA devices. (256-pin and 100-pin) These devices have: surface pad size = 0.41mm (16) ball size = 0.48mm (18.9) ball pitch = 1.0mm (40) For my FIRST attempt I screen printed a fine pitch water solub
Electronics Forum | Wed Jan 17 20:48:14 EST 2001 | davef
We find that the raw BGA's pad sheared surface has the SnPb solder at various Z heights whereas the assembled BGAs pad leave a smooth layer of SnPb along the pad. Like to understand the cause for the difference. Who could guess? Solder joint streng
Electronics Forum | Tue Apr 13 19:14:25 EDT 2004 | Dreamsniper
Hi DaveF, To explain. The BGA that we have is from Motorola. The solder balls of these BGA's are Eutectic Solder and processed using a NC flux (as per info from supplier). So this means that the BGA pad and solder connections had NC flux process. W
Electronics Forum | Tue Nov 14 21:27:26 EST 2006 | davef
"Hidden pillow" seems to be a a variant of "pillow effect" or "head in pillow". Pillow effect is an open, with non-wetting between the lead and the solder on the pad. Here the lead sags into the solder without any bonding or wetting. Poor wetting c
Electronics Forum | Fri Jan 19 17:43:30 EST 2001 | davef
Intermetalic Layer (IL). A compound formed at the interface of two different metals, whose atoms have an extremely high natural attraction for each other, so high, that they do not bond to other elements by any other means. Also, intermetalic compo
Electronics Forum | Tue Oct 31 14:52:25 EST 2000 | Dr. Kantesh Doss
Hi Antonio: You clearly have printed excessive amount of solder paste on the pad. You can reduce the amount of paste by one or two methods: 1. Switchover to 5 mil thick stencils. 2. Change the design of your stencil openings (at the discrete compone
Electronics Forum | Sat Sep 23 15:13:40 EDT 2000 | Francois Racine
Hi Sophia, I`m responsible of SMT line and we solved this problem with a complete automatic solder paste printer machine. In the past we had problem with off alignment and solder height too.... at that time we used a semi-auto printer machine and w
Electronics Forum | Wed Aug 23 08:32:32 EDT 2000 | Earl Moon
Well Sun, This is Moon and you are out of phase with reality. I have nothing against advertising as long as it does not prohibit free technical intercourse as it did me and the investment I made several years ago. Free my ass. I mean, let them make
Electronics Forum | Tue Oct 10 12:56:15 EDT 2000 | Ken Van ZIll
I agree that homplate is a good design, but also this could be caused by the stencil thickness and aperture size, if you are at 7-9 mils thick stencil and a 1:1 ratio on aperture size then 2 things i know of will happen, one a squishing out of past o
Electronics Forum | Wed Feb 21 18:07:00 EST 2001 | billschreiber
Hi Ramon, The obvious answer you might expect to here from me is that you could probably reduce your misprint problem if you had a good stencil cleaning process. Please see my response to the question by MarkT on �Cleaning Materials� because it i
