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