Electronics Forum | Mon Feb 19 22:56:20 EST 2007 | davef
Russ We agree with your comments on plugging from one side only. But... We believe that it IS possible to trap process chemicals [technically, not flux] in a blind [or any other] via. This can be done by plating the via closed, rather than pluggi
Electronics Forum | Sat Aug 27 09:47:05 EDT 2005 | davef
From the pic, we see blistering, but none so close to via that we'd attribute the blistering to via, via plugging, or anything of the sort. When we see blisters like this, we think of a surface contaminant being present on the boards at the time of
Electronics Forum | Tue Feb 01 21:53:06 EST 2000 | Dave F
Emmanuel: You have choices to prevent the solder paste from flowing to the second side during reflow: 1 Have your board fabricator plug the vias. 2 Put a temporary solder mask on the secondary side vias. 3 Have your designer relay-out the vias unde
Electronics Forum | Thu Oct 27 11:45:06 EDT 2005 | Jeffm
I have a multi layer (8) PWB with blind vias going from 1 to 7 that is experiencing occasional blistering (delam). It is only on perhaps 15% of the boards run. We vacuum baked (85C, not sure what pressure) a sample lot and still had a few exhibit the
Electronics Forum | Tue Nov 20 12:48:40 EST 2001 | tony_sauve
We recently experienced a problem w/voids (up to 65%) in uBGA solder joints. The only joints that have the problem correlated to pads which had blind 0.006" via's in them. The via's only extend down 2 layers, of the 18. 21 BGA's on the PCB, only expe
Electronics Forum | Tue Aug 23 13:10:29 EDT 2005 | davef
We've never heard of this [but all of our gold is electroless, not electrolytic]. If the delamination is caused by the electroylic gold finishing and the via plug process during fabrication, something is wrong. Either your supplier: * Is goofy ...
Electronics Forum | Mon Feb 26 20:02:42 EST 2001 | davef
First, I don�t understand why your board fabricator can�t do a good job plugging your vias. Additionally, when you consider that they forgot to plug the first batch of boards, it makes me wonder if they are desirable as a supplier. Generally, we us
Electronics Forum | Fri Dec 12 01:06:02 EST 2003 | kenny
Dear folks; I am currently looking a PCB manufacturer who can fabricate PCB with the following specification:- Board sizes: _20000__ x _20000__ mils Thickness: 125 mils PCB material: FR4 Surface finish: 30 microinches Gold over 200 micro inches Nic
Electronics Forum | Sat Jan 23 13:29:40 EST 1999 | Earl Moon
| Hi Everyone, | We plan to build, for reliability/experimental/research purpose some CSPs (namely Tessera microBGA 46-I/O 0/75mm pitch and TI 64 I/O 0/8 mm pitch). the various factors that we plan to evaluate are the reliability and assembly concern
Electronics Forum | Fri Apr 12 17:22:47 EDT 2002 | davef
First, splitting hairs on parlance. * Conformal Coating. A thin electrically nonconductive protective coating that conforms to the configuration of the covered assembly to provide environmental and mechanical protection. * Solder Mask. Coating mate
winsouce.jpg)
