Stacked chip package using warp preventing insulative material and manufacturing method thereof

Abstract

In a stacked chip configuration, and manufacturing methods thereof, the gap between a lower chip and an upper chip is filled completely using a relatively simple process that eliminates voids between the lower and upper chips and the cracking and delamination problems associated with voids. The present invention is applicable to both chip-level bonding and wafer-level bonding approaches. A photosensitive polymer layer is applied to a first chip, or wafer, prior to stacking the chips or stacking the wafers. The photosensitive polymer layer is partially cured, so that the photosensitive polymer layer is made to be structurally stable, while retaining its adhesive properties. The second chip, or wafer, is stacked, aligned, and bonded to the first chip, or wafer, and the photosensitive polymer layer is then cured to fully bond the first and second chips, or wafers. In this manner, adhesion between chips / wafers is greatly improved, while providing complete fill of the gap. In addition, mechanical reliability is improved and CTE mismatch is reduced, alleviating the problems associated with warping, cracking and delamination, and leading to an improvement in device yield and device reliability.

Description

RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. 119 to Korean Patent Application No. 10-2005-0080655 filed on Aug. 31, 2005, the content of which is incorporated herein by reference in its entirety. This application is related to U.S. patent application Ser. No. ______, entitled “Stacked Chip Package Using Photosensitive Polymer and Manufacturing Method Thereof”, by Yong-Chai Kwon, et al., filed of even date herewith and commonly owned with the present application, the content of which is incorporated herein by reference, in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to semiconductor device packages including a stacked chip package configuration that utilizes a photosensitive polymer including adhesive and warp prevention properties, and manufacturing methods thereof. BACKGROUND OF THE INVENTION [0003] Semiconductor manufacturing and packaging technology has evolved to the point where device packages can include multiple in...

AI Technical Summary

Benefits of technology

[0010] The present invention provides for a stacked chip package configuration, and manufacturing methods thereof, wherein the gap between a lower chip and an upper chip is filled completely using a relatively simple process that eliminates voids, and the cracking and delamination problems associated with such voids. The present invention is applicable to both chip-level bonding and wafer-level bonding approaches. A photosensitive polymer layer is applied to a first chip, or wafer, prior to stacking the chips or stacking the wafers. The photosensitive polymer layer is partially cured, so that the photosensitive polymer layer is made to be structurally stable, while retaining its adhesive properties. The second chip, or wafer, is stacked, aligned, and bonded to the first chip, or wafer, and the photosensitive polymer layer is then cured to fully bond the first and second chips, or wafers. In this manner, adhesion between chips / wafers is greatly improved, while providing complete fill of the gap. In addition, mechanical reliability is improved and CTE mismatch is reduced, alleviating the problems associated with cracking and delamination. This leads to an improvement in device yield and device reliability.

[0045] In another embodiment, the first coefficient of thermal expansion of the photosensitive polymer layer being higher than the second coefficient of thermal expansion of the substrate compensates for active devices formed on a top portion of the substrate opposite the photosensitive polymer layer having a third coefficient of thermal expansion that is higher than the second coefficient of thermal expansion of the substrate, to prevent warping of the semiconductor device during subsequent thermal cycles of the semiconductor device.

[0063] In another embodiment, the first coefficient of thermal expansion of the first photosensitive polymer layer being higher than the second coefficient of thermal expansion of the first substrate compensates for active devices formed on a top portion of the first substrate opposite the first photosensitive polymer layer having a third coefficient of thermal expansion that is higher than the second coefficient of thermal expansion of the first substrate, to prevent warping of the semiconductor device during subsequent thermal cycles of the semiconductor device.

Problems solved by technology

The resulting MSPs enjoyed widespread use in the past, but are relatively bulky and cumbersome for modern applications.

The resulting MCPs have characteristically high yield, however, process throughput is a problem, as each individual chip needs to be handled during alignment and bonding processes.

The resulting WL CSPs suffer from low yield.

Chip level bonding and wafer level bonding are generally complicated and unstable manufacturing processes.

The underfill process is unreliable, since the gap between the lower and upper chip substrates is small, for example on the order of 20 μm.

If the underfill process does not result in a complete and uniform fill of the gap, then any resulting voids can increase the likelihood of future generation of cracks.

Such cracks can propagate during future heating and cooling cycles, decreasing the reliability of the resulting chip stack device.

Such stress is typically caused by a mismatch in coefficient of thermal expansion (CTE) between two adjacent layers.

Such CTE mismatch can cause further cracking and delamination when subjected to numerous heating and cooling thermal cycles, negatively affecting device yield during manufacture, and device reliability during operation.

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