IGBT Module Heat Dissipation with Variable Copper Thickness
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Solution Overview
Problem
Conventional IGBT modules with DBC substrates suffer from limited heat dissipation efficiency due to inadequate heat transfer and high interface impedance caused by solder layers, leading to potential chip damage from excessive temperature.
Innovation Solution
An IGBT module with a heat dissipation structure featuring copper layers of different thicknesses and a thermally-conductive, electrically-insulating layer that replaces the solder layer, allowing direct heat transfer to a heat dissipation layer without interface impedance issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a solder layer is used to connect the DBC substrate and heat dissipation metal layer, then the structure is easy to manufacture, but the interface impedance increases and heat dissipation efficiency deteriorates
Solution Approach 1:
The patent removes the solder layer from the heat dissipation path by directly bonding copper layers to the DBC substrate. This extraction eliminates the interface impedance caused by soldering, resolving the contradiction between ease of manufacture and heat dissipation efficiency.
Solution Approach 2:
The patent introduces a copper layer as an intermediary between the DBC substrate and heat dissipation metal layer. This copper intermediary provides both electrical connectivity and thermal conduction without the interface impedance problems of solder joints.
2Device complexity
If a uniform thickness copper layer is used, then the manufacturing process is simple, but the heat dissipation uniformity deteriorates due to varying chip densities
Solution Approach 1:
The patent applies different copper layer thicknesses in different regions according to local heat generation needs. Areas with higher chip density receive thicker copper layers for enhanced heat dissipation, while areas with lower density receive thinner layers, optimizing thermal performance without excessive complexity.
Solution Approach 2:
The patent transitions from a two-dimensional uniform copper layer to a three-dimensional variable thickness structure. This dimensional change allows the copper layer thickness to be optimized locally, improving heat dissipation uniformity while managing structural complexity.
3Reliability
If the copper layer thickness is increased to improve heat dissipation, then the heat dissipation efficiency is improved, but the copper material cost increases
Solution Approach 1:
The patent uses variable thickness copper layers that are thicker only where needed for high heat dissipation areas and thinner in low heat generation areas. This local optimization improves heat dissipation efficiency while minimizing overall copper material usage.
Solution Approach 2:
The patent applies copper material partially and selectively rather than uniformly across the entire substrate. By concentrating copper thickness where heat dissipation is most critical, the patent achieves high heat dissipation efficiency without excessive copper material consumption.
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 heat dissipation uniformity and efficiency, reducing the risk of chip damage while minimizing copper material costs by optimizing copper layer thickness based on chip density.
Implementation Method 1
a thermally-conductive and electrically-insulating layer (14), wherein the thermally-conductive and electrically-insulating layer (14) is disposed on the heat dissipation layer (15)
Implementation Method 2
a thermally-conductive and electrically-insulating layer (14), wherein the thermally-conductive and electrically-insulating layer (14) is disposed on the heat dissipation layer (15)
Implementation Method 3
the first copper layer (13a) and the second copper layer (13b) are disposed on the thermally-conductive and electrically-insulating layer (14) at intervals
Data Source
AI summary
An IGBT module with a heat dissipation structure includes a first layer of chips, a second layer of chips, a first bonding layer, a second bonding layer, a first copper layer, a second copper layer, a thermally-conductive and electrically-insulating layer, and a heat dissipation layer. The first copper layer and the second copper layer are disposed on the thermally-conductive and electrically-insulating layer at intervals. The first layer of chips and the second layer of chips are disposed on the first bonding layer and the second bonding layer, respectively. The number of chips of the first layer of chips is larger than that of the second layer of chips such that the first copper layer has a greater thickness than the second copper layer.