Electronics Forum | Mon Jan 26 13:13:07 EST 2009 | rgduval
We've had this same problem with the solder wicking to the component terminations. However, in our case, we did not see the pads turning a silver-white color...rather, they exhibited a tarnishing/darkening of the gold. We determined that we had som
Electronics Forum | Mon Feb 18 07:52:09 EST 2019 | SMTA-Joe
Would increasing the thickness to compensate be a reasonable soulluction? This tarnishing is happening after the first time heat is applied. Could it be a factor of too long in ramp and/or soak?
Electronics Forum | Thu Apr 27 11:36:53 EDT 2000 | PeterB
Russ, We also use 'immersion silver' and have not had any impact on our processes. In fact there are a number of benefits i.e very flat pads (as good as electroless nickel/immersion gold but much cheaper and less unfriendly to the environment), good
Electronics Forum | Fri Jan 16 16:36:07 EST 2009 | boardhouse
i would not try to chemically clean the finish, you would just be asking for other problems. 1) I would ask your supplier their Hasl mix. Standard Lead hasl is 63/37 - it almost sounds like your boards have a higher content of Tin and your experien
Electronics Forum | Fri Apr 23 14:27:22 EDT 2010 | hegemon
I am concerned about a 'tarnishing' effect after moisture bake out that affects solderability on a batch of PCBs. This finish is new to us,and I am wondering if anyone has ideas about how to drive the moisture out of the boards without compromising
Electronics Forum | Wed Dec 22 01:39:06 EST 2010 | boardhouse
Hi Johan, As a Asian board supplier - I would not recommend using Lead free hasl on any product that has BGA, you would be just looking for issues, flatness being the main. I agree with one of the other replies - Your purchasing dept. should not be
Electronics Forum | Wed Nov 06 20:18:30 EST 2002 | davef
cvrgrrrl Your first thermal cycle with imm silver should be the easiest to solder. That you see copper indicates you did no soldering, got no wetting, produced no intermetallics, etc. Tell us again which components did not solder? Wuzzis "plug" t
Electronics Forum | Tue Jun 02 17:45:46 EDT 2009 | boardhouse
Hi Nicoleta, As a board shop, either are good choices but in my experience with my customers ENIG has alway been the favorite due to it is easier to work with in regards to not having to tweak your equipment. As long as the board shop that you are u
Electronics Forum | Thu Jun 16 17:02:40 EDT 2011 | boardhouse
The finish looks like Immersion Tin or Silver. if its lead free Hot air - could be issue of to high of a Tin Content. find out what brand of Hasl they are using. SL100 Example. Is this tarnished look only being seen after assembly or have you seen
Electronics Forum | Thu Oct 07 08:13:52 EDT 2010 | remullis
I just swapped from the HASL to Immersion Silver mainly because the board house we use could not maintain consistency in keeping the pads level. I was constantly battling bumps and bad finishes on the pads. They are able to give me a consistent board
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