Semiconductor Module with Encased Circuit Board
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Solution Overview
Problem
Existing power semiconductor modules face challenges with epoxy molding processes that are not compatible with pins sticking out vertically, leading to longer auxiliary connections with higher inductance and less favorable switching behavior, and require expensive CuNiSi material for press-fit connections.
Innovation Solution
A semiconductor module design featuring a substrate with a molded encasing, protruding power terminals, and an encased circuit board with press-fit receptacles for external connections, allowing for epoxy molding without vertical pins and enabling cost-effective, high-reliability connections with low inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pins stick out vertically from the power semiconductor module for auxiliary connections, then the module structure is simple and easy to manufacture, but the epoxy molding process becomes incompatible and the auxiliary connections have larger inductances
Solution Approach 1:
The patent transitions from vertical pin orientation to horizontal trace routing on the circuit board. The auxiliary connections are routed as traces on the circuit board surface rather than vertical pins, changing the dimensional orientation of the connections. This allows epoxy molding to be applied uniformly while maintaining electrical connectivity and reducing inductance through optimized trace paths.
Solution Approach 2:
The patent introduces a circuit board as an intermediary component between the power semiconductor devices and the auxiliary connection points. The circuit board with its trace routing system mediates the connection, allowing for optimized electrical paths with lower inductance while enabling proper epoxy molding application over the entire module surface.
2Ease of manufacture
If a single lead frame is used for both power and auxiliary terminals, then manufacturing is simplified, but expensive CuNiSi material must be used for all terminals
Solution Approach 1:
The patent segments the terminal functions by separating power terminals from auxiliary terminals. Power terminals continue to use the lead frame structure, while auxiliary connections utilize circuit board traces and separate terminal structures. This segmentation allows different materials to be used for different functions, reducing overall material costs while maintaining manufacturing efficiency.
Solution Approach 2:
The patent applies local quality by using different materials and structures for different parts of the module. The lead frame uses CuNiSi where high-current carrying capability is needed, while auxiliary connections use cheaper materials appropriate for low-current signal paths. This localized material selection optimizes both cost and performance.
3Device complexity
If lead-frame terminals are used with long auxiliary connections, then the module structure is simplified, but the inductances increase and switching behavior deteriorates
Solution Approach 1:
The patent changes the dimensional approach of auxiliary connections from long vertical lead-frame extensions to short horizontal traces on the circuit board. This dimensional change significantly reduces the length of auxiliary connections and their associated inductances, improving switching behavior while maintaining structural simplicity through the integrated circuit board design.
Data Source
AI summary
A semiconductor module comprises a semiconductor device; a substrate, on which the semiconductor device is attached; a molded encasing, into which the semiconductor device and the substrate are molded; at least one power terminal partially molded into the encasing and protruding from the encasing, which power terminal is electrically connected with the semiconductor device; and an encased circuit board at least partially molded into the encasing and protruding over the substrate in an extension direction of the substrate, wherein the encased circuit board comprises at least one receptacle for a pin, the receptacle being electrically connected via the encased circuit board with a control input of the semiconductor device.