Power Semiconductor Base Plate Projection Deformation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional power semiconductor devices experience high electrical resistance due to oxide films on metal and base plate surfaces, limiting effective noise reduction and malfunction suppression despite improved heat radiation performance.

Innovation Solution

A power semiconductor device design featuring a base plate with projections that deform to secure an electrically conductive member, damaging oxide films and exposing newly formed surfaces with low electrical resistance, ensuring stable earth potential and reduced noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a metal member is inserted between heat radiation fins and base plate to improve heat radiation performance, then heat radiation performance is improved, but electrical resistance between metal member and base plate becomes large due to oxide films

Engineering Contradiction:

Improveheat radiation performanceVSAvoidelectrical connection quality

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The projection is pre-formed on the base plate before assembling with the metal member. During assembly, this projection protrudes into the metal member to create intimate contact that damages oxide films, establishing low-resistance electrical connection pathways before the component is fully installed and oxidized.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The projection acts as an intermediary element between the base plate and metal member. It facilitates both mechanical connection and electrical conduction by deforming during assembly to break oxide films, thereby mediating the electrical contact between the two metal surfaces.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If metal member is placed between heat radiation fins and base plate for earth grounding, then noise reduction is achieved, but electrical conduction is insufficient due to small contact area of non-oxidized surfaces

Engineering Contradiction:

Improvenoise radiationVSAvoidelectrical conduction efficiency

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The projection undergoes a parameter change from a protruding state to a deformed state during assembly. This deformation changes the contact parameters between the base plate and metal member, increasing the effective contact area and reducing electrical resistance by breaking oxide film barriers.

Inventive Principle:

Principle #35Parameter changes

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 solution effectively lowers electrical resistance between the base plate and metal member, enhancing noise reduction and malfunction suppression in power semiconductor devices.

Implementation Method 1

by deforming the projection the electrically conductive member is fixed to the base plate and electrical conduction can be secured

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

a base plate that is made of electrically conductive material and is thermally connected to the power semiconductor element so as for heat generated from the power semiconductor element to be conducted to a heat radiation fin

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9685399B2Power semiconductor device

Publication Date: 2017.06.20 MITSUBISHI ELECTRIC CORP

AI summary

A power semiconductor device is provided with a base plate thermally connected to the power semiconductor element for heat generated from the power semiconductor element to be conducted to heat radiation fins. An electrically conductive member fixed to the base plate is electrically conducted to the base plate and is connected to ground, and has projections fitted into notches provided in the electrically conductive member. By deforming the projections, the electrically conductive member is fixed to the base plate and electrical conduction can be secured. With this arrangement, noise radiated from the power semiconductor element is reduced and malfunction of the power semiconductor element is suppressed.