SiC-MOSFET Snubber Device Integrated on Single Conductive Substrate
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Solution Overview
Problem
Existing snubber devices for semiconductor modules are costly and require complex heat dissipation and low-inductance wiring designs, increasing size and complexity.
Innovation Solution
A semiconductor device with a snubber device integrated on a single conductive substrate, featuring a SiC-MOSFET, a Zener diode, and a resistor, which unifies cooling systems and minimizes parasitic inductance by mounting the snubber components directly on the switching transistor's lead frame, reducing the need for external snubber devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an external snubber device is provided separately from the switching transistor, then the surge voltage suppression function is achieved, but the package size increases and heat dissipation design becomes more complex
Solution Approach 1:
The patent combines the snubber device and switching transistor into a single integrated semiconductor device mounted on one lead frame. The snubber circuit (comprising resistor R, capacitor C, and diode D) is directly integrated with the switching transistor, eliminating the need for separate external snubber devices. This merging reduces package size, simplifies heat dissipation design by unifying cooling paths, and reduces the number of external connections required.
2Reliability
If an external snubber device is provided separately from the switching transistor, then the surge voltage suppression function is achieved, but the wiring design becomes more complex and costs increase
Solution Approach 1:
The patent integrates the snubber circuit components directly on the same lead frame as the switching transistor, with internal wiring connections between the snubber components and transistor terminals. This eliminates the need for complex external low-inductance wiring design, reduces the number of external connections, and simplifies the overall wiring architecture while maintaining effective surge voltage suppression.
3Reliability
If a traditional RC snubber circuit is used, then the surge voltage is absorbed, but the number of components increases and the device size grows
Solution Approach 1:
The patent integrates the RC snubber circuit (resistor R and capacitor C) directly with the switching transistor on the same lead frame, reducing the number of discrete external components. The diode D is also integrated into the circuit. This consolidation maintains the surge voltage absorption function while reducing the total component count and device footprint compared to traditional separate RC snubber implementations.
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 downsizes the package, reduces costs by minimizing the number of snubber devices required, and enhances protection performance by absorbing surge voltages effectively while simplifying cooling and reducing parasitic inductance.
Implementation Method 1
The Zener diode is connected between a gate terminal and a drain terminal of the SiC-MOSFET
Implementation Method 2
a SiC-MOSFET, which functions as an active element for clamp, is used
Implementation Method 3
the snubber device and the switching transistor are mounted on a single lead frame... unification of a cooling system for the snubber device with a cooling system for the switching transistor
Data Source
AI summary
A semiconductor device of the present invention includes a switching transistor, and a recovery diode and a snubber device which are mounted on a single conductive substrate (frame) on which the switching transistor is also mounted. The snubber device includes a SiC-MOSFET connected between an output terminal C and a reference terminal E of the switching transistor, a Zener diode formed between a gate terminal G and a drain terminal D of the SiC-MOSFET, and a resistor formed between the gate terminal G and a source terminal S of the SiC-MOSFET. The reference terminal E of the switching transistor, the source terminal S of the SiC-MOSFET, and an anode terminal of the recovery diode are commonly connected.