To restate my question of earlier, if I have a .020" sphere before reflow, and my pad opening in the dielectric is .017", is there a rule of thumb to calculate the height of the sphere after reflow? We are using 62Sn/36Pb/2Ag spheres. This should help clearify my earlier question. Thanks in advance for any help.
Robert: Consider requesting samples of different sized solder balls from a variety of suppliers, solder them to dummy boards, and compare the size of reflowed balls to your spec. Then you could buy based on results. My2� Dave F