Electronics Forum | Fri Dec 17 15:11:34 EST 1999 | Alvin Kevichusa
Let's look at it this way... Imagine a multileaded component sitting on a flat surface. If all the leads touch the flat surface, they are all in the same plane (that of the flat surface) and are coplanar. Coplanarity is desirable because if a lead is
Electronics Forum | Wed Jan 03 12:33:37 EST 2001 | Terry Burnette
John, There is one process issue that occurs with the larger BGA packages which have coplanarity near the high end of the .2mm spec.. The defect is commonly referred to as "ball in cup" and "head in pillow". It is an open solder connection whereby th
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 | Tue Jun 13 08:17:06 EDT 2006 | davef
The solder alloy does not change based on the flux. Your potential for embrittlement is the same [providing the metal of the solders are the same] with either solder. We would guess the OA flux is [and drag tinning are] removing corrosion from the
Electronics Forum | Mon Jun 12 07:42:56 EDT 2006 | brian.perry@suntroncorp.com
We are placing a gold plated device (LCC) to a NiAu PCB using a SnPb No-clean solder. We're noticing quite a bit of difficulty with reliable joints (intermittent connectivity) and if we have to rework a particular device, adjacent devices of this sa
Electronics Forum | Fri Dec 03 19:44:34 EST 1999 | Russ
Hello all, I am in the process of converting our facility to noclean processes. So far I am experiencing troubles with soldering to gold finishes. The finish is an H.P. type1. The solder joints appear dull and grainy. They seem to be very strong
Electronics Forum | Mon Dec 13 00:05:28 EST 1999 | Dennis O'Donnell
I can't figure out why everyone is plating everything with gold. According to the J Standard, gold plating should be removed before soldering to the surface. The gold, when left on the surface to be soldered will contaminate the solder joint and ca
Electronics Forum | Wed Jul 12 11:26:12 EDT 2006 | flipit
Hi, I believe you have classic gold imbrittlement here. With 80 microinches of gold you are way over the limit. You can try to reflow longer time and at a higher temperature. The gold does not melt into the solder joint. The gold dissolves into
Electronics Forum | Wed Jul 12 11:46:00 EDT 2006 | flipit
Hi, One other note. You don't want gold to be more than 1% to 2% of the the solder joint. Above this percentage you will have embrittlemant issues. Lots of information on gold embrittlement on this site and on the Internet. I estimate your produ
Electronics Forum | Mon Dec 06 09:16:22 EST 1999 | Dave F
Russ: Three things: 1 Wolfgang is 100% correctamundo about the slow dissolution rate of gold 2 Shear stength of the gold 63/37 solder connection decreases rapidly, as the gold content of the solder connection increases above 2%. 3 There are many
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