Electronics Forum | Sat Aug 05 09:06:40 EDT 2000 | Dave F
I'm confused ... Land Grid Array (LGA). An alternative to the BGA for device manufacturers is to package their devices without any terminations on the bottom. Although not technically accurate, the easiest way to envision an LGA device is to pictu
Electronics Forum | Thu Jun 29 11:52:23 EDT 2000 | JAX
sree, There is no Definite. You have to make the call. If you think the previous info was on target, use the info provided to find out the appropriate percentage relation between ball diameter, pad diameter, and aperture size. If you already run BGA,
Electronics Forum | Mon Feb 07 13:00:06 EST 2000 | Jose RG
Hi, Last Friday, we had a new defect in our line. We found a nice and shiny solder fillet completelly attached to some component leads (in a SPLCC 84) but the solderjoints were not solder to the pads. (Hasl finishing) Any idea ?? Some contamination
Electronics Forum | Wed Jan 28 10:25:20 EST 1998 | Chris Fontaine
I have not been able to find a standard which governs component lead sweep. We use an internal standard of 4 mils here at Sanders, and your 6 mil sweep would definitely be unacceptable. I believe the reason there is no standard governing sweep is b
Electronics Forum | Tue Jan 21 16:28:02 EST 2003 | tony_sauve
Sorry I didn't close this one off last year... We had some failure analysis done on these PCB's ( 3D x-ray,microsectioning,SEM) and the results definitively proved that there was some contamination @ the base of the uvia's that had the voiding. It ap
Electronics Forum | Tue May 31 09:40:23 EDT 2005 | mattkehoe
We have some boards that exhibit poor solder wetting when reflowed. Nothing fancy, smallest pitch size .050. See photo's at http://www.sipad.net/SnPbwetting.htm Is this ; Contamination on the HASL finish? Insufficient solder,not enough to cover pad
Electronics Forum | Tue Sep 08 23:12:57 EDT 2020 | SMTA-64387687
Have you tried rotating the board 90 or 180 going into the oven? With inductive components there's a possibility of magnetic current buildup, that pulls the component to one of the pads. Although, I've only seen it on larger inductors. Also, the pres
Electronics Forum | Mon Feb 07 13:40:41 EST 2000 | Dave F
Jose: Those are good guesses. Without knowing more, ask yourself: 1 There is probably adequate heat available, but that portion of the substrate that�s not soldering well is not receiving proper heating. Why is the component getting so hot, relati
Electronics Forum | Thu Feb 10 09:43:42 EST 2000 | Glenn Robertson
Russ - I agree with Dave and Wolfgang that the boards are the top suspect. The idea of "rework" from Gold to HASL sounds scary. Are you sure the Gold is electroplate and not immersion? Resolve that and then check the archives for "dark pad" or
Electronics Forum | Sun Sep 10 14:43:59 EDT 2000 | David Harper
Just from my experience in seeing a problem like this is as follows The part has not been centered over the pads when placed, and during reflow the part is dragged over the the side with the most contact. Two, the parts are being dropped into the Pc
