Electronics Forum | Thu Sep 23 12:47:48 EDT 1999 | Earl Moon
| | | I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | | | The stencil is 6 mil thick, laser cut and electo-polished. | | | The apertures are 12 mil in diameter with 20 mil pitch.
Electronics Forum | Wed Sep 22 21:23:03 EDT 1999 | se
| | I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | | The stencil is 6 mil thick, laser cut and electo-polished. | | The apertures are 12 mil in diameter with 20 mil pitch. | | We
Electronics Forum | Mon Aug 30 16:10:10 EDT 1999 | Dave F
| I have looked through the IPC web page and surfed to frustration. Can somebody give me a lead? | Brian: We don't use an etched board. We use a special stencil, described below and print on bare copper laminate. 3 Solder Wetting Test. Recogniz
Electronics Forum | Fri Feb 20 13:55:32 EST 2004 | black5629
That will depend on so many factors: solder type / flux type sphericity of balls in paste stencil type (laser chem etch, electro form etc.) print paramaters I will tell you that it can be done.
Electronics Forum | Mon Nov 12 16:14:47 EST 2001 | davef
Yes!!! How can we assemble boards with 20 pitch when we allow 0.008� error to the master art? Excellent question!!! IPC-D-300G has nothing to do with assembler requirements. It is written by and for fabricators, so that they can be comfortable.
Electronics Forum | Thu Aug 12 21:08:39 EDT 1999 | ScottM
| | | | Hello | | | | | | | | Having a problem with bridging on 20mil pitch qfp, only on the lead groups where squeegee goes over width of apertures. Using MPM sp-200 semi-auto, chem-etch stencil, 9-10mil width opening | | | | 100 durometer blade. G
Electronics Forum | Thu Aug 12 20:31:57 EDT 1999 | Kelly Morris
| | Hello | | | | Having a problem with bridging on 20mil pitch qfp, only on the lead groups where squeegee goes over width of apertures. Using MPM sp-200 semi-auto, chem-etch stencil, 9-10mil width opening | | 100 durometer blade. Getting "tails" o
Electronics Forum | Thu Aug 12 20:48:05 EDT 1999 | JAX
| | | Hello | | | | | | Having a problem with bridging on 20mil pitch qfp, only on the lead groups where squeegee goes over width of apertures. Using MPM sp-200 semi-auto, chem-etch stencil, 9-10mil width opening | | | 100 durometer blade. Getting "
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 | Mon May 24 13:33:46 EDT 1999 | Dave F
| We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendor
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