Electronics Forum | Tue Sep 01 09:02:24 EDT 1998 | Justin Medernach
| 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 | Wed Sep 27 08:50:51 EDT 2000 | Dreamsniper
Hi Guys, I've compared stencil printing adhesive versus acquiring a dispensing equipment. Had breakdown all the costs against each other. It end up that Stencil Printing Adhesive is more costly than equipment dispensing machine in the long term (5 y
Electronics Forum | Thu Dec 08 15:27:54 EST 2005 | Samir Nagaheenanajar
Yes, yes, I agree with American man, URL, on all his points about having to know the overall process 1st. I'm surprised he doesn't have his own free consulting website. Other things you can try are: * "Dog-bone" apertures... taper down the apertur
Electronics Forum | Wed Jun 08 13:41:56 EDT 2011 | swag
Two thoughts from me: 1)Are you sure the balls are collapsed? Have you looked at the perimeter from the side with a scope? From your x-ray, it appears you are correct in saying they are collapsed as the balls get smaller in a uniform fashion as you
Electronics Forum | Wed Jan 22 13:17:48 EST 2003 | slthomas
We're considering stenciling SMT adhesive to increase throughput. This is an as-of-yet unproven process and for that matter pcb design (we've never done anything with more than about 50 SMT parts on the bottom, this board has in excess of 1200, but
Electronics Forum | Thu Jul 15 08:34:54 EDT 1999 | Mark Quealy
I use a Transition Automation Semi- Automatic stencil printer with laser cut frameless stencils. My solder paste is an SN63/PB37 RMA 291. I do not operate with in a controlled humidity enviroment. The room temp generally runs around 70 deg's but humi
Electronics Forum | Mon Jul 29 15:24:07 EDT 2002 | OhioD
Interesting. From the reaction we got from DEK, I thought we were the only ones with pumpprint woes. We've tried 1 stencil with Bioact SC10, Hydrex SP&WS, Axarel, and Loctite remover on both Heraeus and Loctite glues. Some we spray, some we work-in m
Electronics Forum | Mon Jul 16 21:25:26 EDT 2001 | davef
Sure, use of U-shape apertures is another way to reduce the amount of paste that you apply. That and similar schemes mentioned in the article are not a function of the flux used. We have used U-shaped apertures for MELF and mini-MELF. They are sug
Electronics Forum | Thu Apr 22 15:27:44 EDT 1999 | Hugh M
| | I keep hearing about polyimide stencils, but what are they like in terms of registration and aperture accuracy? | | | You are hearing about polyimide as in polyimide film as Kapton (TM Dupont). This material is the stuff of flex and rigid/flex c
Electronics Forum | Wed Oct 25 10:11:09 EDT 2000 | Wolfgang Busko
Paddesign, aperture size and stencil thickness determine the amount of solder for your joint. Once you have found suitable parameters you need to control the volume of your paste deposit which is influenced by printer settings, paste condition, stenc