Electronics Forum | Wed May 08 09:40:33 EDT 2002 | Hussman69
One thing most over look is the time between the last reflow and the second print. You don't want to print on a hot board.
Electronics Forum | Fri Sep 07 09:19:44 EDT 2001 | Hussman
Jean, A lot depends on your process. can you add a dot of adhesive after screen printing and before placement? This works well for larger heavier parts. A second suggeestion is to reprofile your board. Try keeping the bottom side cooler. I do t
Electronics Forum | Mon May 13 10:37:56 EDT 2002 | fmonette
The other important issue relates to moisture sensitive devices (MSD). If you have MSDs on the first side, you need to track the remaining floor life of the components on the partially assembled boards between the first and second reflow. Contrary to
Electronics Forum | Tue May 14 21:07:03 EDT 2002 | ianchan
Hi mates, Yes, the lighter mass is a valid reasoning. in addition to the "lighter (mass) than thou" point of view, 1) the first reason for mounting active Parts (eg. IC, QFP, LGA...) is to minimize the temperature exposure of the Parts to a single
Electronics Forum | Mon Jun 21 08:01:38 EDT 2010 | jm
Hello, need some help if anyone has any insight on this issue. Ran first side and ex-ray indicates BGA parts look normal. Ran the second side and now the BGA balls on first side appear to have broken free and moved under part. This board has BGA's
Electronics Forum | Thu Mar 25 09:27:08 EDT 2010 | stepheniii
Thanks I guess I got used to google where the "and" is implied. I searched various combinations and all I could find were threads regarding the pcb's not the components. Does anyone bake their boards after wash before second reflow because of MSD c
Electronics Forum | Wed Mar 24 17:09:34 EDT 2010 | davef
RE Search: Search can be tricky. Try MSD and wash
Electronics Forum | Wed Mar 24 16:54:38 EDT 2010 | stepheniii
J-STD-033B.1 Says "For cavity packages in which water may be entrpped, water clean processes after first reflow can be an additional source of moisture. This may present an additional risk, which should be evaluated." And it talks about derating if
Electronics Forum | Fri Jun 25 07:33:23 EDT 2010 | CL
Good Morning JM, Does anything come into physical contact with the BGA in question during the reflow event? Is this a RoHS process? If so, is the BGA in question also a RoHS part? Thanks Chris
Electronics Forum | Fri Jun 25 13:52:51 EDT 2010 | tate350
Are there any tantalum caps near the BGA? I have seen "wet" tant caps releasing moisture during reflow and disrupting the BGA balls. It may result in missing balls or bridging.
