Patent ID: 9735125
Date: 2017-08-15
CPC Classifications: H01L

Claim:
1. A method of assembling a semiconductor chip to a substrate comprising: providing a semiconductor chip having pads; providing a substrate having pads to receive the semiconductor chip; providing solder bumps on at least one of the semiconductor chip pads and substrate pads; aligning the semiconductor chip pads with the substrate pads; applying a compression force to the semiconductor chip to cause the solder bumps to deform against, and make contact with, the substrate pads and the semiconductor chip pads, the compression force being applied while the semiconductor chip and substrate are held at a temperature above room temperature and below a temperature at which any liquid will form in at least one of the solder bumps, and wherein at least another one of the solder bumps are melted or reflowed to make a metallurgical bond between the semiconductor chip pads and the substrate pads; after applying a compression force, applying an underfill material to fill the gap between the semiconductor chip and the substrate, the underfill material not penetrating between the deformed solder bumps, the semiconductor chip pads and the substrate pads; and after applying the underfill material, heating the assembled semiconductor chip and substrate to an elevated temperature to cause the solder bumps to melt and reflow and form a plurality of metallurgical bonds between the semiconductor chip pads and the substrate pads.