Metal Substrate Terminal Welding Without Dielectric Layer Damage
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Solution Overview
Problem
Conventional insulated metal substrates face challenges in high voltage power module applications due to mechanical and thermal stress during welding processes, leading to potential damage and delamination of the resin isolating layer, which can result in crack formation and unreliable module performance.
Innovation Solution
A manufacturing method for a metal substrate structure that involves welding terminals to the metal top layer separately and then coupling the metal top and bottom layers with a dielectric layer, using techniques like ultrasonic or laser welding, while avoiding direct stress on the dielectric layer, and forming the dielectric layer through molding with materials like epoxy and ceramic fillers to enhance thermal conductivity and insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If terminals are welded to the metal top layer using conventional methods (ultrasonic or laser welding), then reliable electrical connection is achieved, but mechanical and thermal stress damages the dielectric layer causing cracks and delamination
Solution Approach 1:
The patent divides the manufacturing process into two separate stages: first welding terminals to the metal top layer, then subsequently coupling the metal layers with the dielectric layer. This segmentation isolates the welding stress from the dielectric layer, preventing crack formation while maintaining reliable electrical connections.
Solution Approach 2:
The terminal welding is performed as a preliminary action before the dielectric layer is coupled to the metal structure. By completing the welding operation first on the bare metal top layer, the dielectric layer is not exposed to welding-induced mechanical and thermal stress, thereby preventing damage.
2Ease of manufacture
If conventional insulated metal substrates are used for low and medium power applications, then manufacturing is simple and cost-effective, but they cannot reliably support high voltage power module applications
Solution Approach 1:
The patent changes the manufacturing parameters and sequence: welding terminals first to the metal top layer, then coupling the dielectric layer afterward. This parameter change enables the structure to withstand high voltage applications by preventing dielectric layer damage, while maintaining the simplicity and cost-effectiveness of conventional insulated metal substrate manufacturing.
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 method prevents damage to the dielectric layer, ensuring a stable semiconductor power module capable of operating reliably in high voltage ranges (0.5 kV to 10.0 kV) by minimizing mechanical and thermal stress, thus reducing the risk of crack formation and delamination.
Implementation Method 1
especially ultrasonic welding provides a strong impact of thermal and mechanical stress combined with heat on the substrate structure due to friction and pressure between a terminal foot and the substrate
Implementation Method 2
thermal and mechanical stress combined with heat on the substrate structure due to friction and pressure
Implementation Method 3
a strong thermal impact must be considered as well, when joining terminal feet to substrates by laser welding, for example
Data Source
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AI summary
A method for manufacturing a metal substrate structure (10) for a semiconductor power module (1) comprises providing at least one terminal (15), providing a metal top layer (11), providing a dielectric layer (12), and providing a metal bottom layer (13). The method further comprises coupling the at least one terminal (15) with the metal top layer (11) by means of welding, and coupling the metal top layer (11) with the dielectric layer (12) and with the metal bottom layer (13) such that the dielectric layer (12) is coupled with both the metal top layer (11) and the metal bottom layer (13) in between. The coupling of the at least one terminal (15) with the metal top layer (11) is done beforehand to the coupling of the metal top layer (11) with the dielectric layer (12) and the metal bottom layer (13).