Inverter Substrate Electrode Orientation for Current Balance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional semiconductor devices face issues with current unbalance among power elements due to varying current path lengths, leading to larger device sizes and increased complexity, while devices with uniform current paths require extensive space for terminals, resulting in larger dimensions.

Innovation Solution

The semiconductor device incorporates a substrate with arm elements arranged in series, where semiconductor elements are separated into groups with input and output electrodes positioned between these regions, minimizing current path length differences and reducing the need for extensive terminal space, thereby downsizing the device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electrode terminal and output terminal extend in the direction along which the semiconductor elements are arrayed to reduce current unbalance, then the current unbalance among semiconductor elements is reduced, but a large space for the electrode terminal and output terminal is required, resulting in a larger device size

Engineering Contradiction:
Improvecurrent unbalanceVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent changes the orientation of terminal extension from the second direction (parallel to semiconductor element array) to the first direction (perpendicular to semiconductor element array). This dimensional change allows current paths to be extended without increasing the area occupied by terminals, as terminals now extend in the direction perpendicular to the element array rather than parallel to it.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent divides semiconductor elements into multiple groups (first through sixth groups) arranged in a specific pattern, with different terminal groups extending in different directions. This segmentation allows optimization of current paths for different element groups independently, reducing overall current unbalance while maintaining compact terminal layout.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the current path length from electrode terminal to each power element is different, then the device structure is simplified, but the timings of current flowing into power elements are different, resulting in large current unbalance

Engineering Contradiction:
Improvestructure complexityVSAvoidcurrent unbalance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments semiconductor elements into multiple groups and provides different terminal extensions for different groups. This segmentation allows each group to have optimized current paths with appropriate lengths, ensuring simultaneous current arrival at all elements while maintaining overall structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs asymmetric terminal extensions where different terminal groups extend in different directions and have different lengths. This asymmetric design compensates for the different positions of semiconductor element groups, equalizing the current path lengths from terminals to elements despite the structurally simple layout.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2897275B1Inverter device
Publication Date: 2019.01.02 TOYOTA INDUSTRIES CORP
  • EP2897275B1 patent drawingFigure 1
  • EP2897275B1 patent drawingFigure 2(a)~2(b)
  • EP2897275B1 patent drawingFigure 3

AI summary

A plurality of arm elements is arrayed along a first direction of a substrate. Each arm element includes a plurality of semiconductor elements connected in parallel. Each arm element is configured such that a plurality of semiconductor elements is arrayed along a second direction of the substrate which is perpendicular to the first direction and separated into a first element group and a second element group. The substrate includes a first region where the semiconductor element included in the first element group is arranged and a second region where the semiconductor element included in the second element group is arranged, and the first region and the second region are separated along the second direction. An input electrode unit and an output electrode unit are arranged along the first direction in a region provided between the first region and the second region on the substrate.