Semiconductor Terminal Layout for Creepage Distance in Compact Packages
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Solution Overview
Problem
It is challenging to further downsize semiconductor devices while maintaining adequate insulation based on the creepage distance between terminals with different applied potentials.
Innovation Solution
The semiconductor device design incorporates a case member with a recess and protrusion configuration, where the terminal arrangement portion has a recess extending in a direction different from the housing portion, allowing for a reduced gap between main terminals while ensuring insulation through a controlled creepage distance, and a protrusion that separates the recess from the housing portion to prevent insulation material from flowing into the recess.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the gap between main terminals is reduced to downsize the semiconductor device, then the device size is reduced, but the insulation based on creepage distance is compromised
Solution Approach 1:
The recess extends in a second direction (depth direction) different from the first direction (planar direction) in which the terminals are arranged. This dimensional transition allows the creepage distance to be increased vertically rather than horizontally, enabling terminal miniaturization in the planar view while maintaining adequate insulation through the depth-direction extension of the recess
Solution Approach 2:
The recess is disposed within the terminal arrangement portion, creating a nested structure where the recess cavity provides the extended creepage path. The protrusion further nested within the recess structure prevents insulation material flow while maintaining the insulating barrier, allowing compact terminal spacing without compromising insulation reliability
2Reliability
If a deep recess is formed to ensure creepage distance, then insulation is improved, but the manufacturing complexity increases due to insulation material flowing into the recess
Solution Approach 1:
The protrusion acts as an intermediary structure that physically blocks the flow of insulation material into the recess cavity. By positioning the protrusion at the recess opening, it serves as a barrier that prevents material intrusion while maintaining the recess's insulating function, thereby simplifying the manufacturing process
Solution Approach 2:
The terminal arrangement portion is segmented into distinct functional zones: the recess cavity for creepage distance extension, the protrusion for material flow control, and the housing portion for structural support. This segmentation allows each element to perform its specific function independently, simplifying the overall manufacturing process by reducing material flow complications
Data Source
AI summary
A semiconductor device, including a circuit board, a case member, and first and second main terminals each having an outer terminal portion and an inner terminal portion. The case member includes a terminal arrangement portion having a recess formed between the outer terminal portions of the first and second main terminals and extending in a direction from a first end to a second end thereof, the first end being closer to a housing portion of the case member than the second end, and than first end portions of the outer terminal portions of the main terminals, and the second end being farther from the housing portion than second end portions of the outer terminal portion of the main terminals. A protrusion is formed on a wall surface of the terminal arrangement portion toward the housing portion, and is aligned with the recess and separates the recess and the housing portion.