Electronics Forum | Wed Jun 01 13:29:34 EDT 2022 | emeto
It is almost like attempt to advertise something or dig into market opinion for future development of something. In both cases looks like scheme - not clear what they ask for, not clear what they want to achieve.
Electronics Forum | Thu Oct 27 20:46:35 EDT 2022 | emeto
Also solder paste type, optimized printer parameters suitable for this paste, correct apertures design on the stencil, stencil thickness, proper AAR, mounting accuracy and placement profile, oven profile, board thickness and a few other.
Electronics Forum | Tue Jan 03 13:34:08 EST 2023 | dontfeedphils
Just to add some more caveats, the rate at which the paste leaves the tube will also be dependent on the (somewhat) fluctuating variables of temp and humidity. This is why a height measurement of the paste roll on the screen works better.
Electronics Forum | Mon Jul 17 09:09:42 EDT 2023 | tommy_magyar
Things I would check: - solder paste - reflow profile - stencil printing parameters including support, stencil itself and squeegee - MSL procedures - inspection between pick and place and reflow to check paste printing (ideally SPI) Hope this h
Electronics Forum | Mon Jul 31 18:34:30 EDT 2023 | emeto
I have done some of these. Pin in paste process with generous amount of paste to fill the barrel properly. Pick and place process is tricky too, but if you get them on tape and reel, you can have a custom nozzle and have them placed.
Electronics Forum | Sat Oct 07 12:52:11 EDT 2023 | ttheis
I don't know why you would NOT use a no clean paste. You're just adding time and cost to the assemblies, not to mention potential problems. Changing paste is the best option here unless you have a very compelling reason not to.
Electronics Forum | Fri Oct 20 11:16:14 EDT 2023 | tommy_magyar
I agree, and also, assuming you have SPI (if the solder paste roll is measured by laser) the SPI should not fail a board for such amount of missing paste.
Electronics Forum | Fri Feb 23 09:35:36 EST 2024 | emanuel
We have the standard profile as a template made according to the solder paste specs. For some boards we measure the result at 2 points, on the board itself and on top of a sensitive SOT263 module and adjust accordingly. The solder paste is well kept,
Electronics Forum | Fri Feb 23 14:51:48 EST 2024 | carl_p
Just another thought - how long is the printer idle for between boards? is it long enough to have the chemicals start to separate within the paste?
Electronics Forum | Wed Feb 28 17:07:50 EST 2024 | emeto
Once you warm it up to room temperature, use it or lose it. Paste should always be brought to a room temperature before use. If it is not ready, don't use it.