Electronics Forum | Sun Sep 27 22:39:55 EDT 2009 | rajeshwara
The same issue i faced 2 yrs before , i sugest 1. Use stencil of 4 mils ( Take care of Aspect Ratio and Area Ratio ). 2. Use Solder Paste of Type 4.5 and Viscosity in between 1100 to 1300. ( Try Solder Paste of Cookson or Alpha metals : OM338 T45-L
Electronics Forum | Mon Sep 17 16:03:13 EDT 2001 | jschake
The results from an experiment comparing 27 different combinations of pad dimensions concluded that the pad design with 15 mil pad length, 12 mil pad width, and 9 mil pad separation produced the best assembly yields. A 5 mil thick laser cut stencil
Electronics Forum | Tue Sep 16 16:55:51 EDT 2008 | rayjr1491
I am a doer myself but with the turn around and cost on EFORM stencils I prefer to be right and starting with math is always the best way. We have played with reducing apertures even stencil thickness as low as 4 mil. On the side that this component
Electronics Forum | Mon Dec 04 08:43:39 EST 2017 | bandjwet
If you are looking to rework (after all of the previous suggestions are taken and tried....you have some solid ones in there). When a device like this is placed and is hard to get to we use the 7721 bumping process using a controlled heat source (no
Electronics Forum | Tue Aug 20 09:26:36 EDT 2013 | proceng1
I believe that Rain-X contains silicone and Nano-ProTek solution does not. I did speak with a field service guy for Nano-Protek and he told me the special coating test pen that they offer is just a sharpie with their logo on it. Thats how I test to
Electronics Forum | Tue Oct 09 20:27:13 EDT 2001 | davef
That�s a 672 BALL BGA, bud!!! It�s a BIG Mutha!!! [I know. I know. For some reason suppliers call balls "pins".] Let�s focus on: * Clarifying the units on your PCB and aluminum plate thickness measurements. * Describing your use of the aluminum pl
Electronics Forum | Wed Jun 29 11:09:26 EDT 2011 | swag
That is all we have ever used ("Zelflex" by LPKF). They work great. We have 300+ stencils stored in print drawers, probably 3'x3'x5' area. The stencils are also cheaper by more than 1/2 from our supplier. The only stencils we have in permanent fra
Electronics Forum | Thu Oct 11 17:44:30 EDT 2001 | aaelect
OK, OK. 672 ball BGA. The pcbs are PC Card bus size and are .015 thick. There are 3 on a panel with about 1/2" between and rails. The aluminum plates are about 3" by 7". There are 3 cutouts which allow for the parts from either side to protrude du
Electronics Forum | Tue Nov 17 22:36:17 EST 2009 | rajeshwara
Hi All Plz help , we are manufacturer of Set Top Boxes , where we use ST BGA 5202 ,Paste : ALPHA METAL OM338-T45-LF & STENCIL : 4 MIL & we also tried 5 mil . Problem : At first Test BGA work fine but after some days Assembly dead functional and when
Electronics Forum | Fri Dec 01 12:56:33 EST 2017 | emeto
It seems that it will work with 5 mil stencil. To be safe use 4 mil if the rest of the design allows it. 10x20mil apertures for both rows. If you have bigger footprint in the corners, make bigger apertures there. For the ground plane, I would use ver
