Electronics Forum | Thu Jul 12 10:15:12 EDT 2007 | swag
I've got a proto build (3 boards) that has a Xilinx FG456 fine-pitch BGA on it. Every BGA pad on the PCB has an unmasked via attached. Between the via and the pad is a thin soldermask strip, maybe .005" wide at best. I am very confident it will br
Electronics Forum | Thu Feb 19 19:34:52 EST 2004 | Tom B.
Jim, There are 2 thoughts to this technology. SMDP (Soldermask Defined Pads) Can achieve more uniform opening of the land, yet as you know Regisration shift of mask can become a problem. Also there has been debate as to whther SMDP cause crack p
Electronics Forum | Wed Apr 25 10:53:49 EDT 2001 | wbu
Zam_bri: If it were a mystery .... there can�t be any answers . Possible causes: - Short is in the PCB ( not very propable, cause you�ve checked that ) - Short is in the BGA ( not very propable, cause you�ve checked that ) - Short occurs due to so
Electronics Forum | Fri Oct 15 09:11:39 EDT 2004 | mattkehoe
Hi Justin, Thanks for the feedback. We are inspecting with the naked eye. Most of what we do are prototype quantities, in this case 6 pcs, so AOI or measurement equipment has never seemed justified. The release looked uniform during the printing a
Electronics Forum | Fri Oct 15 17:11:45 EDT 2004 | HOSS
Matt, Had a similar problem with HASL that wasn't fluxed properly during fab. The appearance of the HASL looked dull and/or mottled (sp?). Solder was curled under on the edges where it should have been smoothly joined to the pad. Almost like a pu
Electronics Forum | Fri Jun 09 17:34:08 EDT 2000 | Melanie Mulcahy
I need some information regarding the acceptability/unacceptability of using tented vias with LPI soldermask. Long story on all involved, but basically I have a board that I have had manufactured with no problems which has BGA/uBGA parts, tented via
Electronics Forum | Wed Jul 09 04:57:11 EDT 2003 | Matt Kehoe
Our company applies solid solder to surface mount lands. While processing a micro BGA design we had some pads fall off, peel, whatever you might call it, from the surface of the board when touched "GENTLY" with the tip of a blade to remove a small s
Electronics Forum | Wed Oct 20 07:09:12 EDT 2004 | mattkehoe
Not really. Our process is a solid solder deposition application so we are not placing components into the wet paste prior to reflow. We print the paste then reflow is without components, trying to create a meniscus which is then washed, flattened,
Electronics Forum | Thu Mar 03 08:06:36 EST 2011 | scottp
I've seen this with through hole via in pad with soldermask plugging from the opposite side. Baking the boards solved it. Not using such a horrible via in pad method would also have solved it, but that wasn't an option. Is this ball sitting on a v
Electronics Forum | Thu May 28 15:54:45 EDT 2009 | elmerito
Hello, We have designed a 160ball bga substrate. Now we want to use the same substrate for the 145ball version of the product. All are the same, the package size, ball pitch, solder ball size only the number of balls will change. We will use a new s
.gif)
