Hi d1wang,
I appreciate that you took the time to generate these footprints, however, I would suggest you look up some white papers on how pad shape defines the surface tension of the resulting melted solder shape. A rectangular pad will result in surface tension of the solder to "pull" the pad to the center of the pad, centering the device being soldered. The solder actually makes a sort of trapezoid shape with a "center line" to it. When you round of the corners you create a more rounded ball of solder that can pull the device of center. As I said, there are many white papers from TI, Analog, Linear Tech, Vishay: most of the big companies have extended info on soldering SMD components and why one shapes the pad in which they do. If you look at the IPC spec (which in my opinion spells out worst case and their pad designs with the space around them (courtyards, etc.) is complete overkill and flies in the face of a good analog board design, but I digress).
Again, I congratulate you helping others out by posting footprints, however, if one does this, they should be done according to something like IPC so that manufacturability of the PCB will be successful.
B'rgds,
Mike Tripoli
Statistics: Posted by mtripoli — 07 Jan 2019, 17:49
