Segmented Diode Structure for Edge Current Concentration Control

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Solution Overview

Problem

Conventional diodes suffer from high current concentration at the curved edge, leading to overheating and potential burning due to the curvature effect and electric field concentration, which reduces their reliability.

Innovation Solution

The diode design incorporates a structure with a first and second electrode region separated by an insulation trench, where the second region is connected to the power supply through a resistor, reducing carrier injection efficiency and current concentration, and includes features like field limiting rings and semiconductor layers to disperse electric fields and enhance breakdown voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the diode uses a conventional structure with a curved edge, then the manufacturing is simple, but the current concentration at the curved edge causes temperature rise and burning risk

Engineering Contradiction:
Improveburning riskVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrode layer is divided into a first electrode region and a second electrode region, which are separated by an insulation trench. This segmentation allows the first region to handle high current density while the second region has reduced carrier injection efficiency, preventing current concentration at the edge and reducing burning risk.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the electrode layer are designed with different properties: the first electrode region has high carrier injection efficiency for main current conduction, while the second electrode region has low carrier injection efficiency to reduce current concentration. This local differentiation optimizes both reliability and current distribution.

Inventive Principle:
Principle #3Local quality

2Power

If the diode operates with high current density, then the power handling capability is improved, but the curvature effect causes electric field concentration and avalanche generation

Engineering Contradiction:
Improvepower handling capabilityVSAvoidelectric field concentration
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The harmful curvature effect and electric field concentration at the electrode edge are extracted and isolated by introducing an insulation trench between the first and second electrode regions. This removes the source of avalanche generation while preserving the high current density capability of the first electrode region.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The insulation trench acts as an intermediary structure that separates the high current density region from the edge region. It prevents the direct interaction that causes electric field concentration and avalanche, while still allowing the diode to operate at high power levels.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If the curved edge extracts holes efficiently, then the turn-off speed is improved, but the current concentration increases and temperature rises sharply

Engineering Contradiction:
Improveturn-off speedVSAvoidedge temperature
Core Design Contradiction:
SpeedVSTemperature

Solution Approach 1:

The electrode layer is segmented into two functional regions: the first electrode region maintains efficient hole extraction for fast turn-off, while the second electrode region has reduced carrier injection to prevent current concentration and temperature rise during the extraction process.

Inventive Principle:
Principle #1Segmentation

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 design effectively reduces the risk of burning and improves reliability by minimizing current concentration and enhancing breakdown voltage, ensuring consistent performance.

Implementation Method 1

a second electrode layer (200) disposed on the other side of the active region away from the drift layer (300), the second electrode layer (200) including a first region (110) and a second region (120), the second region (120) being connected to a power supply through a resistor

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

An insulation trench (130) is disposed between the first region (110) and the second region (120)

Methodology Applied
Scientific EffectElectrical Insulation: Electrical Resistance

Implementation Method 3

includes features like field limiting rings and semiconductor layers to disperse electric fields and enhance breakdown voltage

Methodology Applied
Scientific EffectElectric Field: Electric Field

Data Source

PatentEP4246588B1Diode and power circuit
Publication Date: 2025.07.30 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4246588B1 patent drawingFigure 1~2
  • EP4246588B1 patent drawingFigure 3~4A
  • EP4246588B1 patent drawingFigure 4B

AI summary

A diode and a power circuit are provided. The diode may include: a first electrode layer; a drift layer located above the first electrode layer, where the drift layer and the first electrode layer are doped with impurities of a same property, and a doping concentration of the drift layer is less than that of the first electrode layer; and the drift layer includes an active region and a terminal region surrounding the active region; a second electrode layer disposed in the active region, where the second electrode layer and the drift layer are doped with impurities of different properties; and the second electrode layer includes a first region and a second region surrounding the first region, and the first region and the second region are separated by a first insulation trench, where the first region is connected to a power supply through a first conductor, and the second region is connected to the power supply through a second conductor, a first resistor, and the first conductor sequentially. The diode has good conduction characteristics and high reliability.