Electronics Forum | Mon Oct 14 17:59:45 EDT 2002 | russ
When I used the micro-stencils, We purchased the holder from the stencil manufacturer. As far as design we used 5mil stencils for uBGAs,6-7 mil for larger 63/37 balls, and 8 mil for CBGAs. Aperture openings used were slightly smaller than what we wo
Electronics Forum | Tue Nov 11 09:19:17 EST 2008 | davef
By the way you asked the question, we assume that by "reballing" you mean bumping, we should be able to figure that out: * Volume of the ball = ( pi*d^�)/6 = [355/113] *0.6*0.6*0.6]/6 = 0.11mm^3 * Volume of solder required = 2*volume of ball = 2*0.11
Electronics Forum | Tue Sep 01 20:36:05 EDT 1998 | Rin Or
| We are experiencing shorting on a BGA. The part has a 1mm pitch with a 196 I/O count. The problem seems to pop up without warning & disappear in the same manner. | Our pad design is .020" diameter pads with .025" solder resist diameter. The ce
Electronics Forum | Fri Apr 29 17:49:22 EDT 2005 | Woodsmt
I have used many of these devices recently and have used them several times over the last few years. I have been successful using a type 4 paste on a 5 mil stencil. The 13 mil round aperture should provide you with an area ratio just adequate for r
Electronics Forum | Fri Apr 29 17:49:26 EDT 2005 | Woodsmt
I have used many of these devices recently and have used them several times over the last few years. I have been successful using a type 4 paste on a 5 mil stencil. The 13 mil round aperture should provide you with an area ratio just adequate for r
Electronics Forum | Wed Dec 14 08:08:42 EST 2005 | Champ Kind
Snaggletooth, I spent a good portion of my career fighting solder shorts on BGA's and QFP's, tombstones on 0402's, solderballs on passives, etc.. I've solved just about all those issues, and didn't solely rely on my stencil manufacturer... Your ste
Electronics Forum | Thu Jan 31 15:13:20 EST 2008 | chef
You will need to develop your reflow profile which includes drilling a hole through the fab and into the ball for accurate temp measure. During profile/process development you will probably want 3D x-ray (consider contracting that out). Once in prod
Electronics Forum | Mon May 07 16:07:05 EDT 2012 | davef
Start with targets based on the stencil thickness (for height) and stencil thickness times the aperture size (for volume). * Set reasonable upper and lower control limits (+ 25% and –25 % of the targets, for example). * Next, check the printer set-u
Electronics Forum | Fri Oct 18 07:14:51 EDT 2002 | cyber_wolf
Have you tried using a paste with a more aggressive flux? Our main paste is Indium, but whenever we run into oxidized parts or have soldering problems due to oxidation on pads we use an older Alpha WS paste called WS609. The drawback of this paste is
Electronics Forum | Mon Aug 14 12:08:35 EDT 2006 | cuculi54986@yahoo.com
I agree with using the homeplate design on chips. Some Pb-free solder paste manufacturers recommend 1:1 apertures. This, in my experience, is not a good idea with any of the SAC305 pastes I've tried. I've been using the same stencil design guideli
