Semiconductor device
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Solution Overview
Problem
Power semiconductor modules, especially those using silicon carbide diodes, are prone to high short-circuit currents during faults, leading to potential explosions and fires due to the inability of existing protective elements to switch off the module in a timely manner, resulting in damage from residual currents and plasma formation.
Innovation Solution
A semiconductor component with a thyristor-like structure and strategically arranged short-circuit regions to absorb high fault currents, featuring a lower average density of short-circuit areas in the failure region compared to edge regions, which enhances the propagation speed of plasma and prevents unwanted plasma escape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical protective elements such as magnetic circuit breakers or fusible links are used, then the module can be protected from short circuit damage, but the switching time is too slow (around 500 μs) to reliably prevent damage in timely manner
Solution Approach 1:
The patent replaces mechanical protective elements (magnetic circuit breakers, fusible links) with a semiconductor-based protective device (thyristor or triac) that can switch off the module electrically in microseconds, eliminating the mechanical switching delay of around 500 μs and achieving reliable protection without time loss.
2Power
If silicon carbide diodes are used as freewheeling diodes, then power density is significantly increased, but the diodes have limited overload capacity and can explode under high short-circuit currents
Solution Approach 1:
The patent incorporates a protective device (thyristor or triac) that activates before the silicon carbide diode can be damaged by overcurrent. The device detects fault conditions and switches off the module in advance, cushioning the diode from the full impact of high short-circuit currents that would otherwise cause explosion.
3Object-affected harmful factors
If high density short-circuit regions are arranged throughout the entire active region, then plasma propagation is controlled, but the plasma may escape from the semiconductor component causing fire
Solution Approach 1:
The patent applies local quality by arranging short-circuit regions with different densities in different zones: higher density at the periphery to contain plasma, and lower density in the center to control propagation. This spatial variation in density creates a plasma confinement structure that prevents escape while maintaining controlled propagation.
Solution Approach 2:
The patent segments the active region into different zones (central region and peripheral region) with different short-circuit region densities. This segmentation allows independent optimization of plasma control in the center and plasma containment at the periphery, preventing plasma escape while maintaining controlled propagation.
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
The semiconductor component effectively switches off the module in a timely manner during faults, preventing damage and plasma escape, thereby ensuring reliable operation and protecting surrounding components.
Implementation Method 1
In the event of a fault, a very high short-circuit current can occur, which can lead to the explosion of the freewheeling diodes. Highly conductive plasma can escape
Implementation Method 2
Highly conductive plasma can escape, which can cause further short circuits in the converter
Data Source
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Figure 4
AI summary
A semiconductor device comprises a semiconductor body (100) having a first surface (101) and a second surface (102) opposite the first surface (101) in the vertical direction (y), a gate region (210), and an active region (220) arranged horizontally adjacent to the gate region (210). A first emitter (20) of a first conductor type, a first base (22) of a second conductor type, and a second base (24) of the first conductor type are arranged successively between the second surface (102) and the first surface (101) in the vertical direction (y). The semiconductor device further comprises a front-facing emitter (30) of the second conductor type located in the active region (220), extending from the first surface (101) in the vertical direction (y) to the second base (24), and a plurality of short-circuit regions (32) of the first conductor type.which extend from the first surface (101) through the front emitter (30) to the second base (24), wherein the active region (220) has a first edge region (310) adjacent to the gate region (210) in a horizontal direction, a failure region (320) adjacent to the first edge region (310) in a horizontal direction, and a second edge region (330) adjacent to the failure region (320) in a horizontal direction, and an average density of the short-circuit regions (32) arranged in the failure region (320) is lower than an average density of the short-circuit regions (32) arranged in the first edge region (310) and the second edge region (330), respectively.