Of course Hans, the producers are trusted people, better keep him quiet, then in the QMX power supply PCB design phase it was necessary to calculate Q104 1 millimeter more spaced, and what I think, I wouldn't want to be wrong.? The card printers do what was previously loaded by the designers so it is obvious that there are errors.? Thanks Hans for all the information you give us.
Il Lun 21 Ago 2023, 20:11 Donald S Brant Jr <dsbrantjr@...> ha scritto:
On Mon, Aug 21, 2023 at 12:57 PM, Hans Summers wrote:
it would be nice if the manufacturers didn't have this degree of slop?in the angle of the AOD403.
Perhaps the PCB footprint of the part(s) needs to be changed, to shrink the ground pad and its solder mask opening, which will constrain the movement of the part.?? Remember that during reflow soldering the part is literally floating on liquid solder and the only thing constraining its movement is surface tension.?? I had a product with some large Mini-Circuits surface mount amplifiers; the first pass had ~25% shorts using the MCL-recommended pattern.? When we shrank the ground pad (by about 25%) and widened the solder mask clearances we had 0 shorts.? Making the pad and solder mask openings symmetrical with respect to the centerline of the part will also help avoid skewing. 73, Don N2VGU
