Electronics Forum | Thu Sep 07 08:50:45 EDT 2006 | Grant
Hi, We have seen a slight rise in failures in a product, and on investigation, the BGA ball has cracked off the PCB. It's below the intermetalic layer in the ball. Reflow otherwise looks good, and the raw components are clean. I am wondering what c
Electronics Forum | Sun Oct 29 22:47:03 EST 2006 | LMPH
We are going to start doing rework of Lead Free BGA's. Have always used flux for SN/Pb boards/BGA's with good results. Can flux be used fro lead free as well? Boards were originally assembled using lead free paste and components. Hence, the BGA w
Electronics Forum | Tue Oct 31 22:13:48 EST 2006 | davef
We never run raw solder paste through our board cleaner, because: * Flux floats on the water in the tank and contaminates everything, including the boards being 'cleaned'. [Prove this to yourself by observing the location of gray schmutz on the insid
Electronics Forum | Fri Nov 03 15:31:18 EST 2006 | Steve
Mika, It's not my company, I've used them in the past to re-ball some BGA's for me. They always do a moisture removal bake on moisture sensitve devices prior to ball attach, and then pack them in a vacuum sealed moisture barrier bag when they retu
Electronics Forum | Wed Dec 06 22:35:05 EST 2006 | davef
Questions are: * When you say, "corner of some board's BGA chips", is it on the top of the package or between the board and the bottom of the package? * If between the board and the bottom of the package, does it span the distance between the board a
Electronics Forum | Wed Jan 03 10:41:47 EST 2007 | Rob
Consider this: The inner balls will be at a lower temperture than the outer balls in reflow, so if you cannot inpsect them then that may be where your problem lies. Are you reworking with a specialist machine that is directing the right amount of h
Electronics Forum | Wed Feb 28 00:12:22 EST 2007 | Muhammad Haris
hi, Consider BGA1= bigger one BGA2= smaller one CONSIDERATION : 1. If bga2 is inside the bga1 then bga1 balls should not touch the bga2 upper surface i.e. the inside balls of bag1 package should b in ur mind, so choice is urs. METHOD: m
Electronics Forum | Tue Jun 26 21:36:48 EDT 2007 | davef
While your peak temperature measurement is probably correct, you probably ripped the pads from the board long before reaching that temperature. By using a steep temperature ramp, you are causing the corners of the BGA to curl away from the board and
Electronics Forum | Wed Jul 25 11:55:21 EDT 2007 | ck_the_flip
Zoinks!! Doing the homeplate design on 0402 will actually make your tombstones WORSE! Think about it. Your wetting forces are now on the ENDS of the device with no solder paste toward the middle of the device to tack the part down - a gauranteed f
Electronics Forum | Tue Nov 06 07:34:26 EST 2007 | scottp
I'm not sure what kind of marginal joint you're trying to identify, but when we went through a serious ball-in-cup problem a few years ago we tried hot & cold functional test as well as a day or two of -40/+125C thermal cycling and all were pretty po