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 | Mon Nov 08 11:11:16 EST 1999 | John Thorup
Believe it! Although it might be necessary in certain rare cases, and as Ray says, as a bandaid, to routinely bake your boards is a mistake. For much more info, search the IPC technet archives over the last few weeks. It was a popular thread
Electronics Forum | Wed Nov 10 09:42:05 EST 1999 | Boca
Generic fabs should not require baking. Some special cases like teflon and flex circuits take moisture very well, they often continue to require a trip to the oven. Best wishes, Boca
Electronics Forum | Fri Apr 23 17:00:31 EDT 2010 | davef
Hegeman: So you receive these boards in seal moisture barrier bags, store them in a controlled environment, and use them as needed; what is your goal in baking these poor babies?
Electronics Forum | Mon Apr 26 18:09:07 EDT 2010 | hegemon
Obviously knowledge in this area is still in a bit of a 'flux'. Dave, you had the right idea, the "putz"s signed off on the responsibility, and sent a new batch o'boards. FAST. This new batch were at least date code in 2010, and we had no issues so
Electronics Forum | Fri Apr 23 17:59:54 EDT 2010 | hegemon
Therein lies the issue. Unknown storage conditions before we received the PCBs, date codes just expired (2 weeks), first article is de-lam city! Had a bad feeling about it. Have read some studies showing that there is no linear tie in of visual cha
Electronics Forum | Sat Apr 24 10:43:31 EDT 2010 | davef
Hege: Sounds like this customer is a putz. Ask the putz to sign a release, acknowledging responsibility. Here's a couple more links on imm silver: * http://www.pcbdesignschool.com/wp-content/uploads/2009/08/the-study-measurement-and-prevention-of-t
Electronics Forum | Mon Apr 26 14:40:07 EDT 2010 | blnorman
We had one product that used immersion silver plating. There were a couple of instances where we saw tarnishing, and elemental analysis confirmed the presence of sulfur. These boards did have the anti-tarnish sheets between boards, but somehow they
Electronics Forum | Mon Jul 08 11:53:40 EDT 2002 | yngwie
Hi Guys, We prints solder paste on via hole as the holes are used as the test points. This is a clean process. In normal production, upon completion of a primary side, board will proceed to secondary process immediately. The problem happened when
Electronics Forum | Tue May 11 09:44:48 EDT 2010 | dyoungquist
Lower humidity: Pros: Helps with mositure sentative devices. Cons: 1)Paste exposed to the dry air during your porcess will dry out quicker. 2) Drier air promotes more ESD issues, i.e. more electrostatic generation.
