Electronics Forum | Mon Aug 14 05:45:16 EDT 2023 | dimamalin
First, this is the result of bad printer setup. Adjust knife pressure, PCB gap, separation speed, tooling, and stencil cleaning. Pay attention to the coating of contacts pad and height of solder mask of PCB.
Electronics Forum | Mon Aug 14 13:08:00 EDT 2023 | dimamalin
Similar issues arose for me in cases where the contact pads of components were located below the solder mask level. Ordering a thinner stencil might potentially solve the problem.
Electronics Forum | Mon Aug 14 13:51:37 EDT 2023 | calebcsmt
I'm actually currently in the process of discussing with stencil MFG regarding the apertures and reduction to see if perhaps it was not optimal for this fine pitch QFN, as just as you mentioned, we have similar products with similar QFNs that do not
Electronics Forum | Tue Aug 15 17:17:26 EDT 2023 | emeto
This one picture would help us so much to assess. Step stencil to 6mil for the connector area.If this doe not resolve it, start thinking about part contamination, insufficient heat in reflow profile and a few other
Electronics Forum | Wed Nov 29 12:12:27 EST 2023 | proceng1
I think the laser etcher is the way to go. Practice on some obsolete stencils so you can determine the correct settings for the material.
Electronics Forum | Fri Jan 19 20:31:39 EST 2024 | dwl
If it works with a mylar stencil, I don't see why it wouldn't work with a stainless steel stencil. I agree that rubber squeegees would work better then metal.
Electronics Forum | Wed Jan 24 21:56:57 EST 2024 | fortunetech
You could also try something like a Radian desktop fiber laser as a smaller, low cost alternative to accurately and permanently engrave each stencil frame!
Electronics Forum | Wed Feb 07 15:04:57 EST 2024 | ttheis
We commonly put two images on a stencil 180 deg apart to save space and reduce cost. We keep the image centered left/right because the machines don't like it when they are offset, but turning them around front to back is no issue.
Electronics Forum | Wed Oct 11 16:24:35 EDT 2000 | John Thorup
Hello Antonio ASPECT RATIO = the ratio of one dimension to another as in the ratio of the thickness of a stencil to the width of the aperture. For instance, a 10 mil aperture in a 5 mil stencil will have an aspect ratio of 2. This is aperture width
Electronics Forum | Thu Mar 22 16:52:10 EST 2001 | kaopsahl
Yes, there are adhesives designed just for stencil application. Usually plastic squeegee blades are recommended for best printing results. Plastic stencils are also available for this application. Both Alpha Metals and Loctite have articles on this s
