Electronics Forum | Mon Nov 07 16:31:47 EST 2005 | CW
hi Bob, Thanks for the info. I understand your comments, but I am looking for specific guidance, If I am putting chip capacitors on a .063 FR4 board, what size package should we stay away from to avoid cracking? (I realize this is dependent on h
Electronics Forum | Tue Nov 28 15:10:50 EST 2006 | M. Sanders
Unfortunately, I don't have a copy of IPC-A-610 D on hand, however, I believe in IPC-610, this �floating height� between lead and pad has no maximum specification restriction. As long as there is no voiding, it is still acceptable for all 3 classes.
Electronics Forum | Wed Jul 01 04:54:28 EDT 2015 | jvercamm
hi, the last post on pad cratering dates from 2012. We have (likely similar) problems with a RoHS 783 solder ball BGA size 29x29mm^2 (organic package BT), pitch is 1mm and solder ball diam is 0.5mm the field failure is after 12 months, almost exclu
Electronics Forum | Wed Feb 18 12:42:43 EST 2004 | babe
OK, if the sphere of the ball and the paste on the pad are both eutectic, 63/37 then the paste will reflow first causing a drop of the component, after which the spheres will reflow causing a double drop and a good intermettalic. You can see this by
Electronics Forum | Thu Feb 12 11:35:17 EST 2004 | Kris
what is the composition of the paste and ball ? Interesting to know why the customer is asking you to look for it Thx
Electronics Forum | Fri Feb 13 11:19:07 EST 2004 | Evtimov
Hi Bryan The answer is in the paste compozition. Balls of the BGA are usually made by eutetic solder paste.
Electronics Forum | Fri Feb 20 15:07:31 EST 2004 | agp
I agree with Jay. The paste will reflow first before the balls. The main reason is the flux content and the dimension of the spheres.
Electronics Forum | Thu Feb 12 10:19:46 EST 2004 | Bryan
Hi all, These days our customer asks us to figure out ,during reflow,the BGA ball and solder paste,which will first melt? I think it's very hard to get the rusult.coz I think it'll vary at diffrent part of the BGA,and how can this affect the perf
Electronics Forum | Fri Feb 13 11:46:23 EST 2004 | Jack
Is your customer trying to reduce voiding? If the device is using Sn90 / Pb10 and the paste is Sn63/Pb37 the board will melt first. However, if both solders are 183C eutectic, it's a tossup? PCB design, copper weight, bga type (pbga, micro bga, Tbg
Electronics Forum | Fri Feb 27 11:33:32 EST 2004 | Bryan
Very strange question,but interesting.Is there anyone who have conducted any experiments to figure out the results?I made a profile board,one thermal couple on pad and other one drilled into the ball of BGA.the 2 points are perpendicular to conveyor
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