Importance

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Abstract

Integrated circuit packages that connect solder balls between solder ball pads of a die and substrate pads of a printed circuit board (PCB). The solder balls are electrically disconnected from any circuit of the die, i.e., 'dummy' solder balls, and are used to temporarily hold the die in position with respect to the PCB until the circuit is wire bonded and an underfill material is cured between the die and the PCB to more permanently connect them together. The underfill material is selected to have a coefficient of thermal expansion (CTE) that is substantially equal to the CTE of the solder balls to prevent thermal mismatch problems. An overmolding compound is disposed about the die and the underfill material and about the wire bonds to complete the package. Various arrangements of the solder ball pads on the die include columnar and row, corner, diagonal, cross, and periphery arrangements.

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First Claim