Other

Miguel Albert Capote

Aguila Technologies Inc.

M. A. Capote

Xiaoqi Zhu

Zhiming Zhou

Ligui Zhou

Yong-Joon Lee

Robert Vinson Burress

A simplified process for flip-chip attachment of a chip to a substrate is provided by precoating the chip with an encapsulant underfill material having separate discrete solder columns therein to eliminate the conventional capillary flow underfill process. Such a structure permits incorporation of remeltable layers for rework, test, or repair. It also allows incorporation of electrical redistribution layers. In one aspect, the chip and pre-coated encapsulant are placed at an angle to the substrate and brought into contact with the pre-coated substrate, then the chip and pre-coated encapsulant are pivoted about the first point of contact, expelling any gas therebetween until the solder bumps on the chip are fully in contact with the substrate. There is also provided a flip-chip configuration having a complaint solder/flexible encapsulant understructure that deforms generally laterally with the substrate as the substrate undergoes expansion or contraction. With this configuration, the complaint solder/flexible encapsulant understructure absorbs the strain caused by the difference in the thermal coefficients of expansion between the chip and the substrate without bending the chip and substrate.

Semiconductor flip-chip package and method for the fabrication thereof

A simplified process for flip-chip attachment of a chip to a substrate is provided by pre-coating the chip with an encapsulant underfill material having separate discrete solder columns therein to eliminate the conventional capillary flow underfill process. Such a structure permits incorporation of remeltable layers for rework, test, or repair. It also allows incorporation of electrical redistribution layers. In one aspect, the chip and pre-coated encapsulant are placed at an angle to the substrate and brought into contact with the pre-coated substrate, then the chip and pre-coated encapsulant are pivoted about the first point of contact, expelling any gas therebetween until the solder bumps on the chip are fully in contact with the substrate. There is also provided a flip-chip configuration having a complaint solder/flexible encapsulant understructure that deforms generally laterally with the substrate as the substrate undergoes expansion or contraction. With this configuration, the complaint solder/flexible encapsulant understructure absorbs the strain caused by the difference in the thermal coefficients of expansion between the chip and the substrate without bending the chip and substrate.

A flip-chip device and process for fabricating the device employs a multilayer encapsulant that includes a first portion encapsulant having a coefficient of thermal expansion of at most 30 ppm/&deg; C. and an elastic modulus of 2-20 GPa and a second portion comprising a polymer flux having a coefficient of thermal expansion that may exceed 30 ppm/&deg; C.

A simplified process for flip-chip attachment of a chip to a substrate is provided by pre-coating the chip with an encapsulant underfill material having separate discrete solder columns therein to eliminate the conventional capillary flow underfill process. There is also provided a flip-chip configuration having a flexible tape lamination for underfill encapsulation. With this configuration, the complaint solder/flexible encapsulant understructure absorbs the strain caused by the difference in the thermal coefficients of expansion between the chip and the substrate and provides enhanced ruggedness.

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Vista, CA, United States of America

Xiaoqi Zhu