Power Converter Module Cooling With Thin TIM and Resin Buffer
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Solution Overview
Problem
Existing power conversion apparatuses face issues with height variations due to overmolding, leading to pump out of thermal interface material (TIM) and decreased reliability, while also requiring costly grinding processes to manage these variations.
Innovation Solution
A power conversion apparatus with a semiconductor module sealed in resin and a semisolid thermal conductive material between the module and cooling member, where the resin thickness is greater than the thermal conductive material, absorbing height variations and preventing pump out.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the TIM is thickened to absorb height variation, then height variation is absorbed, but pump out of TIM occurs and reliability decreases
Solution Approach 1:
The patent introduces a resin layer as an intermediary substance between the heat exchanger plate and the TIM. This resin layer absorbs the height variation through its compressibility and flow characteristics during molding, while the TIM layer can be kept thin to prevent pump out. The resin acts as a mediator that takes up the dimensional variation without requiring the TIM to be thickened.
Solution Approach 2:
The patent changes the parameter of TIM thickness from thick to thin, and instead adjusts the resin layer thickness and molding pressure to achieve height variation absorption. By changing the state parameters (thickness, pressure, temperature) of the resin during the molding process, the system absorbs dimensional variations without compromising TIM reliability.
2Temperature
If grinding is performed to expose heat exchanger plate surface, then thermal conductivity is improved, but height variation increases and productivity decreases
Solution Approach 1:
The patent performs the height adjustment action during the molding process itself, before final assembly. The resin is molded to a predetermined thickness that compensates for expected height variations, eliminating the need for subsequent grinding operations. This preliminary action integrates the height adjustment into the manufacturing process.
Solution Approach 2:
The patent extracts the height adjustment function from the TIM layer and transfers it to the resin layer. By separating the functions of thermal conduction (TIM) and height adjustment (resin), the system eliminates the need for grinding while maintaining both thermal performance and dimensional stability.
3Reliability
If TIM layer is made thin to prevent pump out, then reliability improves, but height variation absorption capability decreases
Solution Approach 1:
The resin layer serves as an intermediary that absorbs height variation, allowing the TIM layer to remain thin for reliability while still achieving dimensional compensation. The resin's viscoelastic properties enable it to fill gaps and absorb variations without requiring the TIM to be thick.
Solution Approach 2:
The patent creates a composite structure with two distinct layers: a resin layer for height adjustment and a TIM layer for thermal conduction. Each layer is optimized for its specific function, with the resin providing dimensional stability and the TIM providing thermal performance, achieving both goals simultaneously.
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 configuration enhances reliability, improves productivity, and reduces costs by suppressing TIM pump out and eliminating the need for grinding, while maintaining thermal conductivity.
Implementation Method 1
a thermal conductive material having a semisolid shape disposed between the semiconductor module and a cooling member that cools the semiconductor module
Implementation Method 2
a thickness of the resin between the thermal conductive material and the heat exchanger plate is larger than a thickness of the thermal conductive material
Data Source
AI summary
A power conversion apparatus is a semiconductor apparatus including: a semiconductor module in which a semiconductor element and the heat exchanger plate connected to the semiconductor element are molded and sealed with resin; and a thermal conductive material having a semisolid shape disposed between the semiconductor module and a cooling member that cools the semiconductor module, in which a thickness of the resin between the thermal conductive material and the heat exchanger plate is larger than a thickness of the thermal conductive material.