Hi Techneters Does anyone know a good site/book/source , commercial/non-commercial for SMD footprints library. I have been assigned to update our footprint library, and I am not satisfied with footprints given in data books of component suppliers. I presume that those footprints are not optimized for IR reflow, nor carefully experimented. Does anyone know any mathematical formula to be used to check roughly dimensions of a pad ? We make multilayer FR4 boards, HAL/Immersion Gold finish, no clean flux, which is probably causing solder balls. This problem is coped by reducing the size of stensil apertures. How much it can be reduced ? Does anyone have comment on that ? Thanks for your time and cooperation. Brs, Johannes Sivula, Reliability Engineer, Tellabs Oy,