Semiconductor Package Stacks with Differential Adhesive Thermal Expansion
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Solution Overview
Problem
The increasing demand for miniaturization and multi-functionality in electronic devices has led to a need for semiconductor packages with vertically stacked semiconductor chips, where existing solutions face challenges in managing thermal expansion and warpage due to differences in chip sizes and surface roughness.
Innovation Solution
A semiconductor package design featuring two stacks of semiconductor chips with different widths, each with its own adhesive layers, where both adhesive layers have the same coefficient of thermal expansion, and a molding member covers the stacks to manage warpage by varying the distribution of adhesive layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor chips of different sizes are vertically stacked to achieve miniaturization and multi-functionality, then the package density and functionality are improved, but thermal expansion differences and warpage occur due to size variations
Solution Approach 1:
The patent applies local quality by using adhesive layers with different coefficients of thermal expansion at different locations. Specifically, the first adhesive layer (between chips of different sizes) has a different thermal expansion coefficient than the second adhesive layer (between chips of similar sizes), allowing each region to compensate for thermal stress locally. This resolves the contradiction by maintaining structural stability while preserving the high-density stacked configuration.
Solution Approach 2:
The patent changes the parameter of thermal expansion coefficient in the adhesive layers to address warpage issues. By selecting adhesive materials with appropriate thermal expansion coefficients that match the adjacent semiconductor chips, the patent compensates for thermal stress caused by size variations, thereby maintaining structural stability in the miniaturized stacked package.
2Stability of the object's composition
If adhesive layers with different coefficients of thermal expansion are used to compensate for size differences, then warpage is reduced, but the manufacturing complexity increases
Solution Approach 1:
The patent segments the adhesive structure into multiple adhesive layers with different thermal expansion coefficients. The first adhesive layer is positioned between semiconductor chips of different sizes, while the second adhesive layer is positioned between chips of similar sizes. This segmentation allows each layer to be optimized for its specific location, controlling warpage effectively while maintaining a manageable manufacturing process.
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
This design reduces warpage by ensuring greater shrinkage in one portion of the package, preventing smile or crying warpage, and allows for efficient stacking of chips with different sizes, enhancing the package's structural integrity and functionality.
Implementation Method 1
The plurality of first adhesive layers and the plurality of second adhesive layers have the same coefficient of thermal expansion
Data Source
AI summary
A semiconductor package is provided including a first semiconductor chip stack and a second semiconductor chip stack that are adjacent to each other. The first semiconductor chip stack includes a plurality of first semiconductor chips and a plurality of first adhesive layers. The second semiconductor chip stack includes a plurality of second semiconductor chips and a plurality of second adhesive layers. Each of the first semiconductor chips includes a first cell region and a first scribe lane that surrounds the first cell region. Each of the second semiconductor chips includes a second cell region and a second scribe lane that surrounds the second cell region. An area of the first scribe lane is greater than an area of the second scribe lane. The plurality of first adhesive layers and the plurality of second adhesive layers have the same coefficient of thermal expansion.