EGE-Type IGBT Structure for Parasitic Capacitance Reduction
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Solution Overview
Problem
In high-power applications, such as wind power generation systems, half-bridge circuits experience erroneous turn-on phenomena due to parasitic capacitance, leading to increased switching losses and reduced power conversion efficiency, which existing solutions attempt to mitigate by adding negative voltage generation circuits, increasing component count and cost.
Innovation Solution
The use of EGE-type (emitter-gate-emitter type) IGBT structures with specific driver configurations, including pull-up and pull-down transistors, reduces the number of components needed by minimizing parasitic capacitance and preventing erroneous turn-on without negative voltage generation circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional IGBT structures are used in half-bridge circuits, then the circuit can operate, but erroneous turn-on occurs due to parasitic capacitance, increasing switching losses and reducing power conversion efficiency
Solution Approach 1:
The patent changes the structural parameters of the IGBT by introducing the EGE-type structure with three trench gates (emitter-gate-emitter configuration) instead of conventional two-trench-gate structures. This structural parameter change reduces parasitic capacitance between collector and emitter, thereby reducing switching losses and preventing erroneous turn-on in half-bridge circuits.
Solution Approach 2:
The patent converts the harmful effect of parasitic capacitance by designing the EGE-type IGBT structure where the middle gate is positioned to minimize the parasitic capacitance between collector and emitter. By strategically positioning the gates and optimizing the drift region structure, the harmful parasitic capacitance is reduced to beneficial levels that prevent erroneous turn-on while maintaining device performance.
2Reliability
If components for preventing erroneous turn-on are added to half-bridge circuits, then reliability improves, but the number of components and cost increase
Solution Approach 1:
The EGE-type IGBT structure provides self-service by inherently preventing erroneous turn-on through its built-in structural characteristics. The three-trench-gate configuration with optimized drift region creates natural electrical isolation that prevents parasitic turn-on without requiring external protection circuits, negative voltage generation circuits, or additional components, thereby maintaining reliability while reducing device complexity.
Solution Approach 2:
The patent extracts and eliminates the need for external erroneous turn-on prevention components by incorporating the protection function directly into the IGBT structure itself. The EGE-type design removes the requirement for separate protection circuits, clamping diodes, or negative voltage generation circuits that would otherwise be needed to prevent parasitic turn-on in conventional designs.
3Ease of manufacture
If conventional IGBT structures are used, then device simplicity is maintained, but on-resistance is higher, increasing power loss in high-power applications
Solution Approach 1:
The patent changes the structural parameters of the IGBT by implementing the EGE-type structure with three trench gates and optimized drift region. This parameter change reduces the on-resistance by improving charge distribution and reducing parasitic capacitance, thereby reducing power loss in high-power applications while maintaining manufacturing feasibility through standard semiconductor fabrication processes.
Solution Approach 2:
The EGE-type IGBT structure can be viewed as a composite structure combining multiple functional regions (emitter regions, drift region, three trench gates) within a single device. This composite structure optimizes the electrical characteristics by combining the benefits of multiple regions working together to reduce both on-resistance and parasitic capacitance, achieving lower power loss without sacrificing ease of manufacture.
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 approach reduces the number of mounted components, lowers costs, and enhances power conversion efficiency by minimizing parasitic capacitance and preventing erroneous turn-on in high-power applications.
Implementation Method 1
The IE effect means that holes are made difficult to discharge from the emitter electrode side when the IGBT is in an ON state, whereby the concentration of charges stored in the drift region is increased to reduce the on-resistance.
Data Source
AI summary
To reduce the number of mounted components in the power conversion device and drive device.Each high-side transistor and low-side transistor has an EGE-type structure of (emitter-gate-emitter type). A high-side driver includes a first pull-up transistor configured to apply a first positive voltage to a gate based on an emitter of the high-side transistor, and a first pull-down transistor configured to couple the gate to the emitter. A low-side driver includes a second pull-up transistor configured to apply a second positive voltage to the gate based on an emitter of the low-side transistor, and a second pull-down transistor configured to couple the gate to the emitter.