Electronics Forum | Tue Oct 07 12:35:10 EDT 2008 | andy_pal
Hi All, I am using COB on my DOUBLE SIDED PCB. lastly we used Eletrolytic Ni / Flash Gold Plating. Our Boards vias Failed the UL corrosion Test. we did some cross-section analysis and found 10.75 �m of Nickel and 0.022 um of Gold and as the Process
Electronics Forum | Tue Dec 01 07:24:44 EST 1998 | Earl Moon
| 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. Our inspection
Electronics Forum | Tue Dec 01 07:54:49 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. Our inspec
Electronics Forum | Mon Nov 25 09:06:15 EST 2002 | jax
You might want to check the tin thickness. I believe you have a minimum of .65 microns in order to achieve a good solder joint through 3 thermal passes. In an immersion tin process, the ability to solder is time and temperature dependant. As the int
Electronics Forum | Thu Jun 08 16:12:19 EDT 2017 | davef
Your plater's recommendation should work fine. Your simple copper plate will work, but you'll be stepping into fighting a copper tarnish battle. Silver over the copper is a better choice. I was thinking a silver thickness of a minimum of 3 microns
Electronics Forum | Thu Mar 23 10:02:09 EST 2006 | Joe
Check placement pressure. I agree with the "smushing" theory. If you can place the component with less pressure, I'd do that first. A switch to Type three paste is also a good idea, as long as your minimum aperture dimension remains at 0.009" as you
Electronics Forum | Thu Apr 22 15:27:44 EDT 1999 | Hugh M
| | I keep hearing about polyimide stencils, but what are they like in terms of registration and aperture accuracy? | | | You are hearing about polyimide as in polyimide film as Kapton (TM Dupont). This material is the stuff of flex and rigid/flex c
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 | 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 | Fri May 16 15:45:00 EDT 2003 | swagner
If the only difference between the two products is the board supplier I believe thats where I would start, we had a similar problem like this two months ago and it turned out to be a faulty (thin) HASL layer which did not meet our print tolerance. T
