Redistribution Structure in Semiconductor Packages for Thermal Mismatch
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Solution Overview
Problem
The semiconductor industry faces challenges in bonding integrated circuit chips directly onto substrates due to increased integration density and thermal expansion mismatches, leading to warping and electrical coupling issues in three-dimensional packaging.
Innovation Solution
The integration of a redistribution structure between the semiconductor chip and the interposer, along with a molding compound that surrounds the chip, reduces thermal expansion mismatches and enhances physical and electrical connectivity, improving the reliability and performance of the integrated circuit package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If integrated circuit chips with increased integration density are bonded directly onto substrates, then the area occupied by components is reduced, but thermal expansion mismatches cause warping and reliability issues
Solution Approach 1:
The patent introduces a redistribution structure as an intermediary component between the integrated circuit chip and the substrate. This redistribution structure serves as a mediator that decouples the thermal expansion mismatch between the chip and substrate, allowing the chip to be bonded with reduced stress while maintaining electrical connectivity. The redistribution structure absorbs the differential thermal expansion, preventing warping and reliability issues.
Solution Approach 2:
The patent employs composite material structures in the redistribution layer and molding compound to manage thermal expansion. By using materials with intermediate thermal expansion coefficients between the chip and substrate, the composite structure gradually transitions the thermal stress, reducing the mismatch effect and preventing warping while maintaining the compact area.
2Device complexity
If chips are bonded directly to substrates, then the packaging structure is simplified, but warping and electrical coupling issues occur due to thermal expansion mismatches
Solution Approach 1:
The redistribution structure acts as a stabilizing intermediary between the chip and substrate. While it adds a layer to the packaging structure, it provides crucial mechanical stability by absorbing differential thermal expansion, preventing warping and maintaining the structural integrity of the package throughout temperature variations.
Solution Approach 2:
The patent changes the physical parameters of the packaging structure by introducing layers with specific thermal expansion coefficients that differ from both the chip and substrate. This parameter adjustment creates a gradient that gradually transitions the thermal stress, stabilizing the package composition against warping while maintaining acceptable structural complexity.
3Quantity of substance
If integration density is increased through 2D arrangements, then more components fit in a given area, but the ability to bond chips directly onto substrates is surpassed
Solution Approach 1:
The patent transitions from direct 2D chip-to-substrate bonding to a multi-layer 3D architecture involving the redistribution structure and molding compound. This dimensional change allows higher integration density to be achieved while maintaining manufacturability, as the redistribution structure provides a larger, more manageable bonding interface and the molding compound protects the complex interconnections.
Solution Approach 2:
The redistribution structure serves as a manufacturing intermediary that facilitates the bonding process for high-density configurations. It provides a larger bonding area with redistributed contact points, making the bonding process more manageable and less prone to defects compared to direct high-density chip-to-substrate bonding.
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 solution reduces warping and the risk of electrical shorting, thereby enhancing the reliability and performance of the integrated circuit package by addressing thermal expansion mismatches and ensuring stable connectivity.
Implementation Method 1
reduces warping and the risk of electrical shorting, thereby enhancing the reliability and performance of the integrated circuit package by addressing thermal expansion mismatches
Implementation Method 2
a redistribution structure that is electrically and physically coupled to a bottom surface of the semiconductor chip, such that the redistribution structure is disposed between the semiconductor chip and the interposer
Data Source
AI summary
A method includes forming a first redistribution structure over a carrier, where forming the first redistribution structure includes forming a plurality of first organic polymer layers over the carrier, and forming a plurality of first conductive lines in the plurality of first organic polymer layers, attaching a first package structure to the first redistribution structure, the first package structure including a first semiconductor die, a molding material that surrounds an entirety of a perimeter of the first semiconductor die, and a second redistribution structure on bottom surfaces of the first semiconductor die and the molding material, dispensing a first underfill into a first gap between the plurality of first conductive lines and the first package structure, bonding a substrate to the first redistribution structure using first conductive connectors, and dispensing a second underfill into a second gap between the substrate and the first redistribution structure.