Power Semiconductor Device With Cylindrical Terminal
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Solution Overview
Problem
Conventional power semiconductor devices sealed with transfer molding resin have external terminals that protrude from the side surfaces, limiting miniaturization and current capacity due to the need for sufficient insulation distance and the bending process used for lead frames, which restricts the increase in current application.
Innovation Solution
The power semiconductor device features a cylindrical external terminal communication section perpendicular to the wiring pattern surface, allowing external terminals to be inserted and connected within the device's projection area, eliminating the need for protruding lead frames and enabling increased current capacity without size constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If external terminals protrude from side surfaces near the resin-sealed portion, then the device structure is simple, but the device size cannot be reduced due to insufficient insulation distance
Solution Approach 1:
The patent changes the protrusion direction of external terminals from the horizontal dimension (side surfaces) to the vertical dimension (perpendicular to the mounting surface). The external terminals now protrude from the upper surface of the resin-sealed portion, which allows closer spacing between terminals while maintaining adequate insulation distance, thereby reducing the overall device footprint.
2Device complexity
If lead frames are used for external terminals, then the device structure is simple, but the current capacity is limited due to the bending process requirements
Solution Approach 1:
The patent extracts the bending process requirement from the external terminal structure by eliminating the lead frame component. External terminals are now directly connected to the wiring pattern without requiring bending, allowing the use of thicker terminal structures that can handle higher current capacities while simplifying the manufacturing process.
3Reliability
If multiple manufacturing processes (bonding external casing, filling silicon gel, injecting heat-hardening resin) are used, then the device reliability is improved, but the manufacturing time is prolonged
Solution Approach 1:
The patent merges multiple manufacturing processes into a single transfer molding operation. The external casing, silicon gel filling, and heat-hardening resin injection are combined into one integrated process where all components are molded simultaneously in a single step, dramatically reducing manufacturing time while maintaining device reliability through the use of transfer molding technology.
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 design reduces the device's size, increases mounting density, and enhances productivity by eliminating the need for lead frame dimensions in molding, while allowing larger current applications through arbitrary external terminal cross-sectional sizes.
Implementation Method 1
a high thermal conductive insulation layer joined to one surface of the metallic heat dissipator
Implementation Method 2
power semiconductor elements are sealed with transfer molding resin
Data Source
AI summary
A power semiconductor device in which transfer molding resin seals: a metallic circuit substrate; a power semiconductor element joined to a wiring pattern; and a side surface of a cylindrical external terminal communication section provided on the wiring pattern and to which an external terminal can be inserted and connected. The cylindrical external terminal communication section is substantially perpendicular to a surface on which the wiring pattern is formed. An outer surface of a metal plate of the metallic circuit substrate and a top portion of the cylindrical external terminal communication section are exposed from the transfer molding resin. The transfer molding resin is not present within the cylindrical external terminal communication section.