CTE-Engineering Die Pair for Semiconductor Warpage Control
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Solution Overview
Problem
The challenge in semiconductor packaging lies in the structural issues arising from the coefficient of thermal expansion (CTE) mismatch between components, leading to defects during the packaging process of larger semiconductor dies, particularly when integrating silicon dies with organic components in 3D packaging.
Innovation Solution
The solution involves engineering a CTE-engineering die, typically made of copper, to dominate the combined CTE of the semiconductor die and the CTE-engineering die pair, ensuring compatibility with organic components and improving thermal performance by using a eutectic gold-tin solder for bonding, thereby facilitating better warpage control and yield in fan-out processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the semiconductor die size is increased to include multi-functional components, then the functionality is improved, but the CTE mismatch defects increase during packaging
Solution Approach 1:
A CTE-engineering die is introduced as an intermediary component between the semiconductor die and the organic substrate. This intermediate die has engineered CTE properties that bridge the gap between the silicon semiconductor die and the organic substrate, reducing thermal stress and preventing packaging defects while allowing larger multi-functional dies to be packaged reliably
2Volume of moving object
If a coreless substrate is used to reduce package size, then the compactness is improved, but the warpage control deteriorates
Solution Approach 1:
The CTE properties of the die stack are engineered by selecting specific materials and thicknesses for the CTE-engineering die. By adjusting the CTE parameter of the intermediate die, the overall thermal expansion behavior of the package is controlled, enabling warpage compensation while maintaining the compact coreless substrate design
3Productivity
If silicon die is integrated with organic components in 3D packaging, then the circuit density is improved, but the CTE mismatch causes detrimental defects
Solution Approach 1:
A composite die stack is created consisting of the silicon semiconductor die bonded to the CTE-engineering die. This composite structure combines the high-performance silicon circuitry with the CTE-engineered intermediate layer, achieving both high circuit density and thermal expansion compatibility with organic substrates
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 approach enhances the thermal performance, reduces mechanical risks, and improves the compatibility with organic build-up technology, leading to improved yield and heat handling in semiconductor devices, particularly in bumpless build-up layer (BBUL) processing and coreless substrate applications.
Implementation Method 1
the effect of differences in the coefficients of thermal expansion (CTE) between components used in a semiconductor package can lead to detrimental defects
Implementation Method 2
using a eutectic gold-tin solder for bonding
Data Source
AI summary
Packaged semiconductor die and CTE-engineering die pairs and methods to form packaged semiconductor die and CTE-engineering die pairs are described. For example, a semiconductor package includes a substrate. A semiconductor die is embedded in the substrate and has a surface area. A CTE-engineering die is embedded in the substrate and coupled to the semiconductor die. The CTE-engineering die has a surface area the same and in alignment with the surface area of the semiconductor die.