Package-on-Package Semiconductor Stacking with Matching Substrates
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Solution Overview
Problem
Existing package-on-package (POP) semiconductor technologies face challenges in achieving high capacity and compactness while maintaining reliability, often resulting in low yield due to thermal expansion coefficient differences and complex stacking processes.
Innovation Solution
A POP semiconductor package design that includes a first and second substrate with semiconductor chips, connected by an internal connection member, where the substrates have matching thermal expansion coefficients and a reduced internal connection terminal size to minimize warping and enhance reliability, allowing for high-capacity stacking with improved electrical connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple semiconductor chips are vertically stacked to achieve high density, then capacity and compactness are improved, but reliability decreases due to thermal expansion coefficient differences
Solution Approach 1:
The patent changes the material parameter of the substrates by selecting materials with matching thermal expansion coefficients. This parameter change eliminates the thermal expansion mismatch that causes warping and reliability issues in multi-chip stacked packages, thereby improving package yield while maintaining high stacking density.
Solution Approach 2:
The patent employs composite material selection where the first and second substrates are made from materials specifically chosen to have compatible thermal expansion properties. This composite approach ensures that when chips are stacked vertically, the entire package structure expands and contracts uniformly during thermal cycling, preventing internal stress and warping.
2Reliability
If internal connection terminal size is reduced to minimize warping, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent changes the dimensional parameter of the internal connection terminals by reducing their size. This size reduction minimizes the thermal mass and stress concentration points, thereby preventing warping in the stacked package. The smaller terminals also reduce the number of materials and processing steps required, simplifying manufacturing despite the precision requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enables a low-height, high-capacity POP semiconductor package with improved reliability by minimizing thermal expansion issues and optimizing the internal connection process, preventing warping and ensuring efficient electrical connections between stacked packages.
Implementation Method 1
The internal connection member may be between the first back side and the second back side and may electrically connect the first package to the second package
Implementation Method 2
The first substrate may have a thermal expansion coefficient equal or similar to that of the second substrate
Data Source
AI summary
Provided is a semiconductor package including a first package and a second package. The first package includes a first substrate having a first front side and a first back side opposing the first front side. The first package further includes a first semiconductor chip on the first front side and an external connection member on the first semiconductor chip. The external connection member may be configured to electrically connect the first semiconductor chip to an external device. The second package includes a second substrate having a second back side facing the first back side of the first substrate and a second front surface opposing the second back side. The second package includes a second semiconductor chip on the second front side. The semiconductor package further includes an internal connection member between the first back side and the second back side to electrically connect the first package to the second package.