Power Semiconductor Device Metal Plate Oxide Film Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power semiconductor devices face issues with warped modules and increased electrical resistance due to gaps between metal plates and base plates, exacerbated by oxide films, leading to high electrical resistance and ineffective radiation noise suppression.
Innovation Solution
The power semiconductor device incorporates a metal plate with a cut-off portion and protrusions or a metal foil bonded to its edges, which inserts into a convex portion on the base plate, damaging the oxide film and establishing a direct electrical connection, reducing resistance and enhancing noise suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a metal plate is inserted between radiation fins and base plate to suppress radiation noise, then radiation noise suppression is improved, but electrical resistance between metal plate and base plate increases due to gaps and oxide films
Solution Approach 1:
The invention divides the metal plate into multiple segments with protrusions that can independently contact the base plate at multiple discrete points, ensuring reliable electrical connection while maintaining the shielding function
Solution Approach 2:
The invention applies preliminary action by pre-forming protrusions on the metal plate before assembly, which automatically damage the oxide film upon contact with the base plate, ensuring low electrical resistance without requiring additional processing steps
2Ease of manufacture
If heating and cooling is carried out during resin sealing, then power semiconductor elements are sealed, but modules become warped or metal plates warp, generating gaps
Solution Approach 1:
The invention applies local quality by providing protrusions at specific locations on the metal plate that can accommodate local warping while maintaining contact with the base plate, allowing the rest of the structure to undergo thermal deformation without compromising the electrical connection
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 reduces electrical resistance between the metal plate and base plate, effectively suppressing radiation noise and malfunctions in power semiconductor elements.
Implementation Method 1
A plurality of protrusions are formed on edges of the opening, and the protrusions scrape a convex portion when the convex portion is inserted into the opening, thereby damaging an oxide film on a surface of the base plate
Implementation Method 2
an electrical contact between the metal plate and the base plate is realized by placing the metal plate between the radiation fins and the base plate... a ratio of portions that are made conductive as a result of the contact of the metals is low, disadvantageously resulting in a high electrical resistance
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A power semiconductor device includes: a mold unit that includes a power semiconductor element, a base plate, and a mold unit, the power semiconductor element being mounted on one surface of the base plate, a convex portion being formed on an other surface of the base plate, the convex portion including a plurality of grooves, the power semiconductor element being sealed with the mold resin in such a manner as to expose the convex portion; a plurality of radiation fins inserted into the grooves, respectively, and fixedly attached to the base plate by swaging; and a metal plate (3) that includes a opening (31) into which the convex portion is inserted, the metal plate being arranged between the mold unit and the radiation fins with the convex portion inserted into the opening (31), wherein the metal plate (3) includes a protrusion (32) that protrudes from an edge of the opening (31) and that digs into a side surface of the convex portion when the convex portion is inserted into the opening (31).