Electronics Forum | Fri Aug 13 13:47:52 EDT 1999 | Brian Wycoff
| | | | | 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
Electronics Forum | Fri Aug 13 13:50:53 EDT 1999 | Brian Wycoff
| | | | | | 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 du
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
Electronics Forum | Thu Mar 05 23:52:26 EST 1998 | Ron Costa
| Hi Ron, | Your question really opens up a "Pandora's box", but when you say you're not able to print perfectly, what is it exactly that you mean? Is the print lacking volume? Is it mis-registered? Are you bridging? Also, what printers have you used
Electronics Forum | Fri Nov 19 22:48:26 EST 1999 | mark
Steve, your comments from your stencil vendor are very interesting. Any decent laser cutter automatically cuts a trapezoidal aperture. This is just the nature of the cutting. We have a bunch of lasers (and chem-etch). You have to polish your laser cu
Electronics Forum | Thu Sep 02 07:22:03 EDT 1999 | Earl Moon
| I'd like to know the advantages and disadvantages between the two. | | Thanks and regards, | | Both have their place. When using less fine pitch (.025" +) with fine pitch (.020" or less and BGA's) a .007" thick stencil may be used. This would re
Electronics Forum | Sat Aug 14 07:01:44 EDT 1999 | Earl Moon
| Has anybody adopted the method of stencil printing with the board at a 45 degree angle to the squeegee blade? What are the benefits and drawbacks? I've heard you get better fine pitch results. | | TX | Mark | I know we all seek easy/better solut
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 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
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