| 摘要 |
PURPOSE:To eliminate poor connection between leads and pads by a method wherein a continuous layer of solder paste is placed on a lineup of bonding pads including dummy pads and the sloder is melt to coat the pads by means of the reflow solder method. CONSTITUTION:At the both ends of a region wherein bonding pads 4 are arranged, dummy pads 10 are juxtapositioned with the same pitch, made of the same substance and assuming the same configuration but not participating in the formation of an electric circuit. A belt-shaped solder paste 5 is printed on the pads 4, 10. Application of heat to the layer 5 in a reflow process melts the layer 5 and the molten solder moves toward affinity-rich metal surface of the pads 4 due to self-alignment. Accordingly, the part of the substrate 3 exposed between pads 4 gets rid of solder, for the removal of short circuits between the pads 4. Reduction in solder layer thickness is observed only in the vicinity of pads 10 where the two extremities of the layer 5 sag. |
