Electronics Forum | Sat Mar 01 08:17:40 EST 2003 | davef
You're correct that the FR4 is probably the best choise. The majority of the problems in developing your reflow recipe is going to come from the CTE mismatches in the CCBGA , CBGA and PBGA that you put on the board. The other side says given the pr
Electronics Forum | Fri Feb 28 01:10:32 EST 2003 | MA/NY DDave
Hi I don't know what FR4 you are using, so check it out to make sure 125 isn't too high. I have seen this done occassionally when the PCBs have bad moisture or other problemx where baking helps prior to assembly and solder, yet I haven't seen it do
Electronics Forum | Thu Feb 27 12:27:10 EST 2003 | stevel
Hi all, We got some bare pwb in our incoming inspecion looked really wrapped. The maximum twist of the pwb we messured is 0.056inch by following the method in IPC-TM-650 2.4.22 C. (The diagonal size of our pwb is 7.5inch) According to the IPC standa
Electronics Forum | Wed Mar 05 11:54:44 EST 2003 | ruggi
Hi JFB, I think this is an unnecessary activity, but it may depend on your RH. We are in the Spokane, WA area, and the RH avg year round is about 25-30%. We have never baked our PCBs in the 9 years I've been here across 800+ varieties, including
Electronics Forum | Fri Mar 07 14:48:34 EST 2003 | gdstanton
Pretty much everything under the sun. For example if Company A wanted to hire Company B to build printed circuit cards designed by Company A; What type of T & C might Company B seek in their contract/agreement with Company A? The following things c
Electronics Forum | Mon Mar 24 04:00:34 EST 2003 | emeto
Hi mantis, this effect you are talking about is very interesting.I guess there is a difference in technology of both vendors.It;s obvious.But we should find the reason. One question and one simple sudgestion:What excatly is your oven? And have you pa
Electronics Forum | Sun Mar 23 00:09:02 EST 2003 | MA/NY DDave
Know the specs your assembly is supposed to meet 2>Runs some lot soldering samples to minimize cost if you do decide to scrap or bake or ?? 3>Do at least a little post soldering analysis to assure yourself that the results are similar to experien
Electronics Forum | Mon Mar 24 10:02:44 EST 2003 | ksfacinelli
I have a board that has a few TO220 packages with the 5 lead style. The problem I am encountering is forming the the leads. The TO220 package needs a 90 degree bend with pins 2 and 4 staggered. I am "not" doing thousands but would like to find a co
Electronics Forum | Wed Apr 09 09:48:49 EDT 2003 | iman
after oven bake dry the PCB, we process within 4-hrs, else need to rebake again under same baking parameter. taking a look, the exact pads with the blowholes are full ENIG pads with no via holes under the solder-intend land areas. In event there is
Electronics Forum | Tue Apr 01 13:01:27 EST 2003 | cnotebaert
I have NOT done 0402's yet but also have no trouble with 0603's. Did you try any thinner stencils? I don�t know this for a fact just speculating, I would think the 0402's have a smaller brd to chip gap and that you might be able to get away with a 4