| 摘要 |
A fluxless method for fusing preformed solder balls (24) to contact pads on a semiconductor package substrate (10) wherein a masking plate (18) having one or more vertical holes (23) corresponding to the contact pads is placed over the package substrate, oxide-free solder balls are placed in holes, the assembly is preheated to a temperature less than the melting point of the solder, and an energetic beam (32) is directed onto the preformed solder balls to melt them and fuse them to the contact pads. |
