SiC Schottky Diode PFC Module for High Voltage Loss Reduction
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Solution Overview
Problem
Conventional power factor correction (PFC) modules using silicon Schottky barrier diodes experience increased losses and higher manufacturing costs when operating at high voltages due to high forward voltage drop, while SiC devices offer low loss and excellent recovery characteristics but are more expensive.
Innovation Solution
A semiconductor module with a diode bridge comprising SiC Schottky barrier diodes in the upper arm and silicon diodes and switching elements in the lower arm, where only the SiC diodes are formed as SiC devices, reducing overall loss and cost while maintaining low forward voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If Schottky barrier diodes made of Si are used in high-voltage control, then the device complexity is reduced and manufacturing cost is lowered, but the forward voltage increases considerably leading to increased loss
Solution Approach 1:
The patent applies different semiconductor materials to different positions in the diode bridge circuit. Specifically, SiC Schottky barrier diodes are used in the upper arm (first and second diodes) where low loss and excellent recovery characteristics are critical, while Si diodes are used in the lower arm (third and fourth diodes). This local differentiation of material quality resolves the contradiction by optimizing performance in critical areas while controlling overall manufacturing cost.
2Loss of energy
If Schottky barrier diodes made of SiC are used in high-voltage control, then the forward voltage is maintained at a low level and recovery characteristics are excellent, but the manufacturing cost increases
Solution Approach 1:
The patent selectively applies SiC material only to the upper arm diodes (first and second diodes) where low forward voltage and excellent recovery characteristics provide the greatest benefit for loss reduction. The lower arm diodes use conventional Si material. This localized application of high-performance material optimizes power loss reduction while controlling manufacturing cost increase.
Solution Approach 2:
Instead of using SiC for all diodes in the bridge (excessive action), the patent uses SiC only for the critical upper arm diodes (partial action). This partial application achieves sufficient loss reduction and performance improvement without incurring the full manufacturing cost penalty of complete SiC conversion.
3Loss of energy
If all diodes are formed as SiC devices, then the loss is significantly reduced and recovery characteristics are excellent, but the manufacturing cost increases and size reduction is limited
Solution Approach 1:
The patent implements local quality differentiation by using SiC Schottky barrier diodes specifically in the upper arm positions (first and second diodes) where their low loss and excellent recovery characteristics have the greatest impact on overall module performance. The lower arm diodes use conventional Si material. This selective application achieves significant loss reduction and enables size reduction in critical areas while controlling overall manufacturing cost.
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 significantly reduces loss and cost by leveraging SiC devices' low loss and high recovery characteristics, while suppressing cost increase and allowing size reduction of the PFC module.
Implementation Method 1
A first and second diodes D1R and D1S are Schottky barrier diodes formed by using a wide bandgap semiconductor
Implementation Method 2
A semiconductor element using a wide bandgap semiconductor is regarded as a promising element to function as a next-generation switching element capable of realizing high breakdown voltage, low loss, and high resistance to heat
Data Source
AI summary
A PFC module includes: a diode bridge having first and second diodes in the upper arm, and third and fourth diodes in the lower arm; and first and second switching elements for power factor correction. The first and second diodes are Schottky barrier diodes formed by using a wide bandgap semiconductor. The third and fourth diodes, and the first and second switching elements are diodes and switching elements respectively formed by using silicon.