Sealing Resin Layer Gradient Fillers for Thermal Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing electronic components with a semiconductor chip mounted on a substrate and sealed with a sealing resin face reliability issues due to stress concentration at the interface between resin layers with different thermal expansion coefficients, leading to decreased performance under thermal changes.
Innovation Solution
An electronic component design featuring a sealing resin layer with two types of fillers dispersed in a binder, where the average particle diameter and density of the fillers differ, and the total volume density of the fillers decreases in the upward direction from the substrate, reducing stress concentration and improving thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing resin layer is formed by laminating resin sheets with different thermal expansion coefficients, then thermal conductivity is improved, but stress concentration occurs at the interface leading to decreased reliability
Solution Approach 1:
The patent applies local quality by creating a gradient structure where the filler concentration varies continuously from the substrate interface toward the top surface. The filler density is highest near the substrate and gradually decreases upward, eliminating abrupt interfaces between resin layers with different thermal expansion coefficients. This gradual transition locally adjusts the thermal expansion properties throughout the sealing resin layer, preventing stress concentration at any single interface while maintaining overall thermal conductivity.
Solution Approach 2:
The patent employs parameter changes by systematically varying the filler concentration parameter throughout the sealing resin layer. The filler density transitions from a high concentration near the substrate to a lower concentration at the top surface, creating a continuous gradient. This parameter variation allows the thermal expansion coefficient to change gradually through the layer thickness, resolving the stress concentration problem that arises from abrupt parameter changes at layer interfaces.
2Temperature
If filler concentration is increased to improve thermal conductivity, then heat dissipation performance is enhanced, but stress concentration due to thermal expansion differences is aggravated
Solution Approach 1:
The patent applies local quality by concentrating higher filler density in the lower portion of the sealing resin layer near the substrate, where heat generation from the semiconductor chip is most intense. This local concentration of fillers maximizes heat dissipation performance at the critical heat-generating region. Simultaneously, the filler density is reduced in the upper portions, decreasing thermal expansion differences and stress concentration in regions where heat generation is lower, thus maintaining reliability.
Solution Approach 2:
The patent employs parameter changes by creating a spatially varying filler concentration profile. The filler concentration parameter is highest near the substrate interface and gradually decreases toward the top surface. This parameter gradient enables optimized heat dissipation where needed (near the heat-generating chip) while reducing thermal expansion mismatch and stress in upper regions, thereby simultaneously improving heat dissipation performance and maintaining reliability.
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 design enhances thermal conductivity and reduces stress concentration, thereby improving the reliability and heat dissipation performance while maintaining cost-effectiveness by preferentially conducting heat to the substrate and moderating thermal expansion variations.
Implementation Method 1
the thermal conductivity of a filler is higher than the thermal conductivity of a binder resin. Thus, heat that is generated by a semiconductor chip is more likely to be conducted through a filler than through a binder resin
Implementation Method 2
In the case where the thermal expansion coefficient of the first resin layer and the thermal expansion coefficient of the second resin layer are different from each other, stress is generated at the interface between the first resin layer and the second resin layer due to the difference in thermal expansion coefficient
Data Source
AI summary
An electronic component whose reliability is less likely to decrease while its thermal conductivity is maintained. A semiconductor chip is mounted on a substrate. The semiconductor chip is sealed with a sealing resin layer. The sealing resin layer includes a binder and two types of fillers having a plurality of particles dispersed in the binder. As the two types of fillers, fillers at least one of whose physical quantities, which are average particle diameter and density, are different from each other are used. The total volume density of the fillers in the sealing resin layer decreases in an upward direction from the substrate, and a portion of the sealing resin layer in a height direction of the sealing resin layer has an area in which the two types of fillers are present in a mixed manner.