Semiconductor Package Stiffener Layout for CTE Warpage Control
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving reliable packaging techniques that provide structural stability and mitigate stress due to coefficient of thermal expansion (CTE) mismatch between semiconductor components and wiring substrates, leading to warpage and reduced yield and reliability.
Innovation Solution
Incorporation of stiffeners with high Young's modulus and low CTE on both sides of the wiring substrate, surrounding the semiconductor component, to reinforce mechanical properties and prevent warpage, while maintaining electrical connectivity and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor components are integrated with higher density and miniaturization, then integration density and productivity are improved, but structural stability and reliability deteriorate due to CTE mismatch and warpage
Solution Approach 1:
The patent applies local quality by placing stiffeners at specific locations on the wiring substrate - specifically at peripheral regions and/or between semiconductor components - rather than uniformly across the entire substrate. This localized reinforcement provides targeted support to high-stress areas while maintaining overall package flexibility and electrical performance.
Solution Approach 2:
The patent employs composite material structure by combining the wiring substrate with stiffener elements that have different mechanical properties (higher Young's modulus and lower CTE). This composite approach creates a hybrid structure that leverages the electrical conductivity of the substrate and the mechanical stability of the stiffener material to achieve both high integration density and structural reliability.
2Reliability
If stiffeners are added to reinforce mechanical properties, then structural stability and reliability are improved, but device complexity increases
Solution Approach 1:
The stiffeners are positioned at specific locations (peripheral regions and/or between components) rather than covering the entire substrate, providing targeted reinforcement where stress concentration occurs during thermal cycling. This localized approach improves structural stability without unnecessarily complicating the overall package design.
Solution Approach 2:
The patent modifies key material parameters by selecting stiffener materials with specific properties (higher Young's modulus and lower CTE than the wiring substrate) to counteract thermal expansion mismatch. This parameter-based solution addresses reliability issues through material selection rather than complex structural modifications.
3Productivity
If minimum feature size is reduced to increase integration density, then productivity is improved, but manufacturing precision and reliability worsen due to increased stress concentration
Solution Approach 1:
The stiffeners are strategically positioned at peripheral regions and/or between closely-spaced semiconductor components to provide localized mechanical support in areas where stress concentration is most critical during thermal cycling, enabling better control of manufacturing precision in high-density configurations.
Solution Approach 2:
The composite structure of wiring substrate combined with high-modulus stiffener material creates a mechanically robust platform that can support reduced feature sizes and higher integration densities while maintaining manufacturing precision through enhanced structural stability and reduced thermal stress.
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 enhances the mechanical stability and reliability of semiconductor packages by reducing warpage and improving yield, ensuring consistent electrical and thermal performance under temperature changes.
Implementation Method 1
mitigate stress due to coefficient of thermal expansion (CTE) mismatch between semiconductor components and wiring substrates
Implementation Method 2
Incorporation of stiffeners with high Young's modulus and low CTE on both sides of the wiring substrate
Data Source
AI summary
A semiconductor package provided herein includes a wiring substrate, a semiconductor component, conductor terminals, a bottom stiffener and a top stiffener. The wiring substrate has a first surface and a second surface opposite to the first surface. The semiconductor component is disposed on the first surface of the wiring substrate. The conductor terminals are disposed on the second surface of the wiring substrate and electrically connected to the semiconductor component through the wiring substrate. The bottom stiffener is disposed on the second surface of the wiring substrate and positioned between the conductor terminals. The top stiffener is disposed on the first surface of the wiring substrate. The top stiffener is laterally spaced further away from the semiconductor component than the bottom stiffener.