Electronics Forum | Fri Dec 04 20:26:34 EST 1998 | kallol Chakraborty
| | | | Hi folks , | | | | Lately we are seeing a lot of rawcards with black spots on the pads - most of them have Au finish(immersion gold) . We did a lot of inspecton after wave solder and found that only (fine pitch) QFP are affected the most. Ou
Electronics Forum | Fri Dec 04 20:37:45 EST 1998 | kallol chakraborty
| | | | | Hi folks , | | | | | Lately we are seeing a lot of rawcards with black spots on the pads - most of them have Au finish(immersion gold) . We did a lot of inspecton after wave solder and found that only (fine pitch) QFP are affected the most
Electronics Forum | Tue Aug 21 22:24:36 EDT 2001 | davef
Root around here http://www.kns.com/resources/library/lib-wirebonding.asp
Electronics Forum | Thu Jun 14 15:29:29 EDT 2012 | davef
That you can get good solder flow when hand soldering seems to indicate that the temperature of your solder pot is too low. Still, I'm uneasy that you see gold on the pads after passing the board across the solder pot. Gold is so thin with ENIG. So
Electronics Forum | Fri Aug 17 11:55:31 EDT 2001 | davef
5uin. Your nickel thickness is fine. Although if you wanted to trade costs, consider giving-up nickel to 150uin thickness, while increasing the gold thickness. Gold over electroless nickel creates brittle joints because of phosphorous in the nicke
Electronics Forum | Thu Jun 14 04:24:32 EDT 2012 | brettrenishaw
Yes pads are still gold after the wave soldering process even if you wave solder a pcb several times. I have tried soldering using an iron and the solder takes to the pad as you would expect. This happens on all boards of this type and all boards are
Electronics Forum | Fri Aug 17 01:40:55 EDT 2001 | V.RAMANAND KINI
We are in the watch & clock Business. We have a Watch IC chip that has to be wirebonded using Ultrasonic aluminium wedge bonder. The wire dia is 1.25mil. The PCB is made of G10 Glass epoxy copper clad laminate. The copper thickness is 18 microns. The
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 | 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 | Tue Sep 05 05:25:27 EDT 2017 | heros_electronics
Hi, I think your friend wrongly changed the D code so that the finger width doesn't meet your requirements. And the fingers have long and short ones, which is hard to do selective gold plating because of not easy to add plating wires. Of course, you
