Encapsulation Resin Viscosity Control for Semiconductor Void Reduction
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Solution Overview
Problem
Existing semiconductor device fabrication techniques using ultrasonic vibrations to bond bump electrodes to conductor wiring often result in residual voids within the encapsulant, leading to performance declines due to high heating temperatures and repeated cooling of the bonding head, which reduces productivity.
Innovation Solution
An encapsulation resin composition with a reaction start temperature of 160°C or less and controlled melt viscosity is used, allowing for reduced void formation when subjected to ultrasonic vibrations, and is formulated with components like acrylic compounds and polyphenylene ether resins to enhance heat resistance and adhesion, facilitating a lower heating temperature and reduced voids in the encapsulant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic vibrations are applied to bond bump electrodes to conductor wiring, then electrical connection is achieved, but residual voids are formed in the encapsulant
Solution Approach 1:
The patent changes the physical parameters of the resin composition, specifically controlling the melt viscosity to be 200 Pa·s or less at the reaction start temperature. This parameter optimization allows the resin to flow more easily during ultrasonic bonding, filling voids more effectively while maintaining reliable electrical connections between bump electrodes and conductor wiring.
Solution Approach 2:
The patent uses a composite resin composition containing polyphenylene ether resin as the base resin, combined with other components in specific proportions. This composite formulation provides both the necessary flow characteristics for void reduction and the structural integrity for reliable bonding, resolving the contradiction between connection reliability and void formation.
2Strength
If heating temperature is increased to improve bonding, then adhesion is enhanced, but productivity decreases due to repeated cooling of bonding head
Solution Approach 1:
The patent lowers the reaction start temperature of the resin composition to 160°C or less by optimizing the resin formulation. This allows effective bonding at reduced temperatures, eliminating the need for repeated cooling of the bonding head and thereby maintaining high productivity while achieving sufficient adhesion strength.
Solution Approach 2:
The patent replaces the reliance on high thermal energy (heating) with optimized chemical composition and controlled viscosity. The resin's inherent flow properties at lower temperatures substitute for the need for high heating temperatures, reducing thermal cycling requirements and improving productivity.
3Productivity
If reaction start temperature is lowered to improve productivity, then heating time is reduced, but viscosity control becomes more difficult
Solution Approach 1:
The patent employs a specifically formulated composite resin system where polyphenylene ether resin serves as the base, combined with other components in precise proportions. This composite formulation ensures that the resin maintains appropriate viscosity characteristics across the lower temperature range, enabling both improved productivity and controlled manufacturing precision simultaneously.
Solution Approach 2:
The patent optimizes multiple parameters of the resin composition, including melt viscosity (200 Pa·s or less at reaction start temperature) and reaction start temperature (160°C or less). These coordinated parameter changes ensure that the resin remains manufacturable at lower temperatures while maintaining proper flow and bonding characteristics.
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 approach effectively reduces residual voids in the encapsulant, improves heat resistance and adhesion, and allows for lower heating temperatures, thereby enhancing semiconductor device reliability and productivity by eliminating the need for repeated cooling of the bonding head.
Implementation Method 1
the encapsulation resin composition has a reaction start temperature of 160° C. or less. A melt viscosity of the encapsulation resin composition is 200 Pa·s or less at the reaction start temperature
Implementation Method 2
even if an encapsulant is formed by heating the encapsulation resin composition placed in the gap between a base member and a semiconductor chip and subjecting the encapsulation resin composition to ultrasonic vibrations
Data Source
AI summary
An encapsulation resin composition is used to hermetically seal a gap between a base member and a semiconductor chip bonded onto the base member. The encapsulation resin composition has a reaction start temperature of 160° C. or less. A melt viscosity of the encapsulation resin composition is 200 Pa·s or less at the reaction start temperature, 400 Pa·s or less at any temperature which is equal to or higher than a temperature lower by 40° C. than the reaction start temperature and which is equal to or lower than the reaction start temperature, and 1,000 Pa·s or less at a temperature lower by 50° C. than the reaction start temperature.