Electronics Forum | Tue Aug 27 08:12:35 EDT 2002 | jmaruska
Do you have some experience with solder paste WS1208. What is the "best" conditions for printing process? I mean type of stencil, apertures, squeegee. Do you have original data sheet of this solder paste? - life time, working time on the stencil, sh
Electronics Forum | Mon Jul 25 06:12:53 EDT 2005 | lloyd
Folks thanks for all the info, I'm gonna check out our pad geometries and see how they compare with industry standards. Brian, could you elaborate a bit more on the stencil design you have mentioned. Do you mean that you have offset the stencil aper
Electronics Forum | Fri Nov 09 10:37:38 EST 2007 | devajj
We have started using QFN packages in large volume and are having problems with no-solders. We are using 6mil stencil with 1x1 paste print to pad. These also have thermal pads with thru vias that we reduce the stencil aperture by 1/4. Board also ha
Electronics Forum | Mon Nov 26 22:05:34 EST 2007 | shy
currently i'm open my stencil aperture is 80% from the land pattern. is this will cause insufficient solder at the terminal component or not? the stencil thichness is 6mil and the board run using SMT pallet which i consider there will be no option f
Electronics Forum | Thu Mar 25 20:09:35 EDT 2021 | grahamcooper22
What is the QFP pitch ? What aperture dimensions have you chosen ? Is the stencil laser cut then polished ? Your AFTER stencil size looks promising...your BEFORE stencil aperture size looks disastrous...would surely give bridges.. Your pcb pad siz
Electronics Forum | Mon Dec 06 14:44:41 EST 2021 | dwl
1 to 1 stencil aperture to pad should be fine on the gull leads, and yield 100% coverage with leaded solder. The thermal pad is going to be a challenge though, if you truly need 100% coverage. There will be out gassing from the flux and this will nee
Electronics Forum | Fri Jul 07 13:37:46 EDT 2023 | davef
Use the volume of paste of your circular aperture as the starting point. Calculate: Volume = pi X (aperture diameter^2 / 4) X stencil thickness Determine the sides of your square aperture using the volume of paste that you calculated and the stencil
Electronics Forum | Wed Jul 15 12:22:57 EDT 1998 | Steve Moore
Electropolishing definitely improves the print characteristics of both Laser-cut and Chem-etch stencils. The caveat here is avoid over polishing which results in rounding of the edges and/or enlargement of the openings. Over polishing is typically th
Electronics Forum | Thu Feb 10 11:41:13 EST 2005 | ddhanashekar
thanks for your reply i have to try with a stencil wirh reduced aperture opening
Electronics Forum | Wed Sep 18 12:31:16 EDT 2002 | dragonslayr
My suggestion is to conduct a Design For Manufacturing (DFM)study on the assembly in question. Pay particular attention to the pad sizes, component lead dimensions and satisfy yourself that those two factors are correct. Given that pads match compone
