Electronics Forum | Tue Jun 01 10:11:00 EDT 2004 | davef
Intermetallic growth is a diffusion process, the thickness of the intermetallic is given by: z^2 = (Do)(t)exp[-Q/RT] Where Do (m2 s-1) is the diffusion coefficient, T(�K) is the temperature, Q (J mol-1) is the activation energy and R (8.314 J mo
Electronics Forum | Mon Jul 05 03:44:53 EDT 2004 | johnwnz
Dave, I'm going to disagree with you on the ENIG, it's my 3rd choice only just beating out OSP for that 4th spot. 1. Immersion Silver - cheaper than ENIG, as flat and no issues with Brittle interface (black pad) or Gold Embrittlement) Longer shelf l
Electronics Forum | Fri Aug 13 16:54:20 EDT 2004 | davef
If the terminations on your components are not barrier plated, you must be very careful about the amount of time you stay above liquidous. As you'd expect, longer is not better. The longer you stay at liquidous, the more of the component terminatio
Electronics Forum | Tue Mar 15 22:04:56 EST 2005 | KEN
The hasl joint looks fuller (and is easier to inspect)because it has more solder volume. Think about it. Your pre-plating your board with solder (before you add more solder). I doubt your getting 0.3 mils of hasl.....probably more like 1.3 to 3.0
Electronics Forum | Tue Mar 21 20:25:30 EST 2000 | Dave F
John: What�s the matter? Free gold � good thing for you, bad thing for your supplier. :^) Pre-tinning of gold plated leads is important to: � Prevent gold embrittlement of the solder joint � Determine if the leads are solderable prior to assembly (
Electronics Forum | Tue Nov 07 21:49:05 EST 2000 | Dave F
Cheers to you Your gold plating is specified for the gold wire bonding between the die of your BGA and the pads on the BGA substrate. For solderable surfaces this is heavy on gold for use on pads. Gold SB thinner on pads to limit the amount of gol
Electronics Forum | Mon Sep 13 06:23:06 EDT 1999 | Earl Moon
| | We have a product, with various PWBs, with over 600 parts each one (We are a low Volume/high mix company with an average component placement per PCB between 250 to 300 parts). This PWBs have 7 to 10, 20 mils pitch parts. We are having problems wi
Electronics Forum | Fri Jan 15 11:28:50 EST 1999 | Bob Willis
| | Folk's, | | | | I'm looking for information of how long you cna store a gold finish PCB before building it. I know there are problems with the gold disappearing into the underlying nickle over time / temperature etc but exactly how long do you h
Electronics Forum | Fri Jan 15 14:45:48 EST 1999 | Earl Moon
| | | Folk's, | | | | | | I'm looking for information of how long you cna store a gold finish PCB before building it. I know there are problems with the gold disappearing into the underlying nickle over time / temperature etc but exactly how long do
Electronics Forum | Fri Jun 19 10:03:46 EDT 1998 | Earl Moon
| Has anyone had experience with placing BGA on gold plated boards. I thought I read a while ago there was a problem with embrittlment causing cracked joints. If anyone has experience with this your feedback would be great. | Mike Mike, We and ind
