Interposer Thermal Expansion Reinforcing Pattern for TSV Package Stability
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Solution Overview
Problem
Semiconductor packages face challenges in maintaining structural integrity due to thermal expansion differences between various materials, leading to deformation issues as temperature changes, particularly in stack-type multi-chip packages using through-silicon vias (TSVs).
Innovation Solution
Incorporating thermal expansion reinforcing patterns with a high coefficient of thermal expansion (CTE) materials, such as insulating polymers like BCB and polyimide, on the interposer surface between TSVs to offset stress caused by thermal changes, preventing deformation of the interposer and ensuring package stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple semiconductor chips are vertically stacked to increase storage capacity, then chip density is improved, but thermal expansion stress causes interposer deformation
Solution Approach 1:
The patent applies thermal expansion principle by incorporating a thermal expansion reinforcing pattern made of material with high coefficient of thermal expansion (CTE) on the back surface of the interposer. This pattern compensates for the thermal stress generated by the stacked chips, balancing the expansion forces and preventing interposer deformation while maintaining the high chip density achieved through vertical stacking.
Solution Approach 2:
The patent uses composite materials by combining the interposer substrate with a thermal expansion reinforcing pattern made of different material properties. The reinforcing pattern material has high CTE to counterbalance the thermal stress from the chip stack, creating a composite structure that maintains structural stability under thermal conditions while supporting high chip density.
2Reliability
If through-silicon vias (TSVs) are used to couple stacked chips, then electrical coupling is improved, but thermal stress from material expansion differences causes deformation
Solution Approach 1:
The patent addresses the thermal stress issue by introducing a thermal expansion reinforcing pattern that actively compensates for the differential thermal expansion between TSV materials and the interposer substrate. The high CTE material in the pattern expands more under heat, creating counterbalancing stress that prevents the interposer from deforming, thereby maintaining shape stability while preserving the reliable electrical coupling provided by TSVs.
Solution Approach 2:
The patent applies preliminary anti-action by pre-installing the thermal expansion reinforcing pattern on the interposer back surface before chip stacking. This pattern is designed to generate counterbalancing thermal stress that opposes and neutralizes the deformation forces that will arise from TSV thermal expansion during operation, preventing shape changes before they occur.
3Stability of the object's composition
If thermal expansion reinforcing patterns are added to the interposer, then structural stability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by placing the thermal expansion reinforcing pattern only on the back surface of the interposer, specifically in regions where thermal stress compensation is most needed. This localized approach provides the necessary thermal stability without adding complexity to the entire package structure, maintaining simplicity in areas where it is not required while enhancing stability where it is critical.
Solution Approach 2:
The patent simplifies manufacturing by using a thermal expansion reinforcing pattern that can be formed using standard photolithography and deposition processes, copying existing manufacturing techniques rather than requiring new complex processes. The pattern design leverages conventional fabrication methods, reducing the increase in manufacturing complexity while achieving the desired thermal stability enhancement.
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 use of thermal expansion reinforcing patterns effectively mitigates deformation by balancing thermal expansion across the package, maintaining structural integrity and preventing bending or warping of the interposer, even under temperature fluctuations.
Implementation Method 1
thermal expansion reinforcing patterns with a high coefficient of thermal expansion (CTE) materials... to offset stress caused by thermal changes
Data Source
AI summary
A semiconductor package includes an interposer, first and second semiconductor chips horizontally arranged over a first surface of the interposer, the second semiconductor chip being adjacent to the first semiconductor chip, and a thermal expansion reinforcing pattern disposed over a second surface of the interposer.