| 摘要 |
PURPOSE:To equalize the heights of bumps and the top surfaces of the bumps to the same plane by providing hole group having the prescribed volume at the position corresponding to the pad arranging position, placing a metal mask having a surface which is not wetted with solder, and filling solder paste. CONSTITUTION:An oxidized film to cover the entire surface is formed, a metal mask 18 which is not wetted with solder at all is accurately positioned and placed on the back surface of a chip substrate via pin holes 21 and the pins 20 of positioning jig 19. Solder molten to pad 7a on the chip substrate directly under pattern holes 14 can be readily draped. When solder paste 13 is coated on the mask 18, the paste 13 is fully filled in the hole 14. The substrate 1, the jig 19 and the mask 18 are heated by heating means such as an electric furnace, solder in the paste 13 is melted, and cooled. The solder is fusion-bonded to the pads 7a on the substrate 1, solidified to substantially spherical state to form a bump 8. |
