Electronics Forum | Mon Aug 17 02:50:44 EDT 1998 | Bob Willis
| Have an SRT w/preheat, 18 layer board all copper, 456 BGA needs to be removed and replaced. The manufacturer is Chip Express and during reflow it warps up or down. Causing either opens or shorts on the corners. I was using gel flux with multiple
Electronics Forum | Thu Mar 05 23:33:53 EST 1998 | Ron Costa
| | Hello everyone! | | Does any know anything about bare board size variations? | | Is there a spec. or tolerance? | | I'm running small lots of boards and during the screen printing process | | I find that I cannot paste each board perfectly.I've t
Electronics Forum | Thu May 17 07:36:40 EDT 2001 | Bob Willis
Here is a copy of a draft document on PIHR Inspection I have jotted down on a flight to Scotland yesterday, any comments suggestions etc ? I have already most of the photos for the standard but as you know there is nothing in the IPC document it just
Electronics Forum | Sun Sep 12 10:08:55 EDT 1999 | Earl Moon
| hello | | having a problem with one customers bare boards not matching my stencil apertures. i design stencils based on gerber data and reduce up to 15% on some pads. do some board houses reduce pads after receiving gerber data???why would they d
Electronics Forum | Thu May 10 16:17:59 EDT 2001 | davef
I am unaware of any industry standard for specifying apertures for SM stencils. I am aware of IPC-7525, Stencil Design Guidelines. You can obtain it from IPC [http://www.ipc.org]. Further, it seems like there is an article on stencil design ever
Electronics Forum | Sat Mar 25 10:13:18 EST 2000 | Robert Hutton-Squire
I am assembling a board with 2 x ALTERA FineLine PBGA devices. (256-pin and 100-pin) These devices have: surface pad size = 0.41mm (16) ball size = 0.48mm (18.9) ball pitch = 1.0mm (40) For my FIRST attempt I screen printed a fine pitch water solub
Electronics Forum | Mon Mar 27 20:48:25 EST 2000 | Dave F
Robert: Howya doin' bud? You say "BGA Shorting!!!" I say "Too Much Solder!!!" So, earlier comments about aperture design are appropriate, make good points, and I think we both agree that improvements could be made in your stencil design, but I'm
Electronics Forum | Tue Sep 01 19:31:36 EDT 1998 | Kallol Chakraborty
| 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 | Thu Apr 16 11:50:24 EDT 1998 | Gary Simbulan
| O.K., somebody read a probably hand-written 3 as 8. | Under these numbers, I can find at IBM's Patent Server the following other topics: | USP 4,312,692 | http://www.patents.ibm.com/details?patent_number=4312692: | USP 4,314,870 | http://www.pat
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