Electronics Forum | Mon Feb 04 12:30:25 EST 2002 | fmonette
Dave highlighted all the elements that must be considered to determine the optimal temperature and duration for a pre-rework PCBA bake process. As far as the component is concerned, it really depends if you care about not damaging the package for r
Electronics Forum | Sun Feb 03 08:44:25 EST 2002 | davef
There is no standard for baking an assembled board prior to BGA rework, nor should there be. The amount of time required to bake a board varies with: * Board material. * Board construction and layers. * Board size. * Components on the board. If som
Electronics Forum | Thu Apr 25 09:34:24 EDT 2002 | fmonette
Michael, By the way, the default bake duration should be 48 hours at 125C instead of 24 hours. The shorter duration was based on a standard that is now obsolete. The current revision of J-STD-033 includes a variable duration bake table, based on co
Electronics Forum | Tue Apr 23 14:39:49 EDT 2002 | mkallen
Here's a related question: How hot can a PBGA get before popcorn delamination becomes a concern? 100 C? 150C? I realize that the answer will depend upon the conditioning of the part, so let's assume that the part is saturated with moisture. A pra
Electronics Forum | Wed Apr 24 21:35:34 EDT 2002 | davef
Ooooo, much better. Tough to say, because of all the variables [ie, different materials, moisture level, temperature, etc]. Plastic encapsulated devices, especially IC, absorb water from the air, which is violently released during soldering. Typica
Electronics Forum | Thu Apr 25 09:27:03 EDT 2002 | fmonette
Michael, This concern is well covered in J-STD-033, section 8.6 Board Rework. "...If the component temperature exceeds 200C, the board may require a bakeout prior to rework..." In other words, you only need to worry about moisture related defects w
Electronics Forum | Thu Feb 07 09:07:10 EST 2002 | fmonette
Dason, Please be aware that weight gain is only a very crude estimate of the component moisture content. This is only accurate when the moisture is uniformly distributed inside the component (which is actually never). This measurement is usually no
Electronics Forum | Fri Aug 12 03:54:03 EDT 2005 | Mika
Does the pcba:s comes directly from the assembly line, You are going to do rework on? If faulty pcba:s comes back from, let say a customer from outside or the pcba:s has been on Your shelf for some days/weeks, exposed to open environment (humidity in
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