Electronics Forum | Wed Jul 17 11:45:48 EDT 2002 | fmonette
The current IPC/JEDEC standard J-STD-033 for moisture-sensitive devices does not include a bake cycle at 90C (it includes cycles at 40C and 125C for non-assembled components in reels or trays). However, the upcoming revision, which should be release
Electronics Forum | Fri Oct 04 11:34:42 EDT 2002 | Bob Willis
Some additional comments from a paper may be of interest. Baking Printed Circuit Boards - Why and How Baking printed boards prior to conventional and surface mount assembly should not be necessary. Often boards are baked for historical reasons; in
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 | 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 | 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 | 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 | 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 | Tue Dec 08 17:55:51 EST 1998 | Dave F
1. What is the best way to remove polyurethane conformal coating from selected areas? Your conformal coat material supplier is best equipped to tell you how to remove the coating. Polyurethane conformal coating is not easy to remove. Without in-pu
Electronics Forum | Wed Jan 27 09:00:56 EST 1999 | Chris Fontaine
| | I have boards coated with Humiseal 1B73. At a late point mfg. site we need to remove a series of 0603 resistors for optioning purposes. I have been trying to determine the fastest, easiest way to re-coat the pads after removal. Drying time of the
Electronics Forum | Wed Jul 15 10:25:26 EDT 2015 | shahrat
Hi brothers, Can anyone give me some clear ideas that which surface finishing is the best for PCBs used for LED TV motherboard production? Some says that OSP is good but it is not good for double sided board. So I am a bit confused in between HASL,O
