Electronics Forum | Fri Oct 29 10:02:28 EDT 1999 | John Thorup
Chris A lot of people have reported sudden, fab lot related problems with Ni/Au pads. These are usually characterized by a discoloration of the gold and called cheerful names like "black pad disease". This can be a process problem at your fab house
Electronics Forum | Mon Aug 27 15:06:29 EDT 2001 | davef
This otta push Wolfgang over the top ... Recommended reading G.G. Harman, Wire Bonding in Microelectronics : Materials, Processes, Reliability, and Yield, 2nd edition, McGraw-Hill Electronic Packaging and Interconnection Series, 1997. G.G. Harman, R
Electronics Forum | Mon May 17 13:21:45 EDT 2021 | SMTA-64387881
PWB Bake out or other elevated temperture processes can cause issues with oxidation of that Nickel layer. The gold porosity can vary from batch to batch, but also process changes can contribute. Are you baking the boards or have previous reflow pro
Electronics Forum | Tue Oct 26 08:17:54 EDT 1999 | William
Dave, Last question(s). What do I do about a gold porosity problem? Dave: How would I approach the board house to check for this? They use a very well known chemistry, but is that where the pblm lies? Or would it be in their process, cycle times
Electronics Forum | Mon Nov 01 11:07:36 EST 1999 | William
Thank you so much Dave for all of your wonderful help. You know, all I really wanted to know was a little more about the gold porosity problem. Since I am not an expert on gold immersion, nor do I claim to be, I just wanted some information so that
Electronics Forum | Mon Apr 26 17:09:05 EDT 2021 | kwalker
Sounds like you are getting oxidation of the nickel under the gold layer. If the gold is porous it will allow the nickel underneath to oxidize, which is the dark dull layer you are seeing, and why when you apply flux it solders just fine - the flux i
Electronics Forum | Mon Oct 27 20:01:00 EDT 2014 | rangarajd
Hello, We are facing solderability issues on a particular lot of board. THe Nickel thickness measured with an XRF is around 400 U inches. Spec calls out for 130 u inches Nickel and 3 - 5 U inches gold over it. Assuming there is no porosity on the g
Electronics Forum | Wed Sep 26 12:16:44 EDT 2012 | bwjm
Hi Guys,recently i am facing an issue. Refer to the attached photo. This PCB is high RF speed, gold immersion single layer. After reflow, my solder seems to have black stains on it. I tried with SAC305 paste water soluble and no-clean, both results a
Electronics Forum | Thu Nov 10 20:39:44 EST 2022 | SMTA-64386598
The solderability shelf life of ENIG is related almost entirely to diffusion of O2 through the gold plating. When O2 diffuses through the gold, the underlying nickel is oxidized rendering it unsolderable (with ENIG - you solder to Ni, the gold dissol
Electronics Forum | Fri Dec 09 02:20:47 EST 2005 | Mike_Kennedy
Grant, I dont quite understand the implications my self yet on gold deposit using FLASH or ENIG. However the important part of the gold finish is that it is kept under 3% of the total solder joint, so normally its safe. With the FLASH process it is m