Power Module Terminal Protrusion for Creeping Discharge Suppression
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Solution Overview
Problem
The challenge is to suppress creeping discharge between electrical terminals in power modules, which is exacerbated by high-speed operation and size constraints, making it difficult to maintain insulation performance while reducing the distance between high-voltage terminals.
Innovation Solution
The design incorporates electrical terminals with protrusions having a circular or oval cross-section on one side and a flat plate shape on the leading end, ensuring equal cross-sectional areas to minimize electrical field concentration and facilitate efficient current passage, thereby reducing creeping discharge and enhancing insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the insulation distance between electrical terminals is reduced to downsize the power module, then the size of the power module is reduced, but creeping discharge occurs between terminals
Solution Approach 1:
The protrusion of the electrical terminal is configured with a circular cross-section instead of a flat or sharp edge. This curved geometry distributes the electrical field more uniformly, preventing field concentration at sharp corners that would initiate creeping discharge. The circular shape allows for reduced insulation distance while maintaining insulation reliability.
2Speed
If the power module operates at high speed, then the power device performance is improved, but high surge voltage is caused by parasitic inductance making insulation design more difficult
Solution Approach 1:
The circular cross-section of the terminal protrusion reduces parasitic inductance by eliminating sharp edges and corners that create magnetic field concentration. This smoother geometry allows for faster switching operations with reduced surge voltage, enabling high-speed operation while maintaining insulation integrity.
3Ease of manufacture
If the cross-section of the protrusion has sharp edges or corners, then the manufacturing is simpler, but electrical field concentration occurs increasing creeping discharge
Solution Approach 1:
The protrusion is designed with a circular cross-section that can be manufactured using standard extrusion or molding processes. The curved shape is achieved through conventional manufacturing techniques without requiring complex multi-step processes, thus maintaining ease of manufacture while eliminating electrical field concentration at sharp edges.
Data Source
AI summary
A semiconductor device includes: at least one power semiconductor element; a sealing resin disposed so as to seal the power semiconductor element; and a plurality of electrical terminals each electrically connected to the power semiconductor element and each including a protrusion protruding from a surface of the sealing resin. The protrusion includes a first part that is provided on a side of the sealing resin in a protrusion direction of the protrusion and of which a cross-section intersecting the protrusion direction has one of a circular shape and an oval shape.