Semiconductor Device Metal Support Holding-Down Portion

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Solution Overview

Problem

Semiconductor devices with a baseless structure have low rigidity, leading to upwardly convex bending when secured to a heat sink, which can cause substrate cracking and increase thermal resistance.

Innovation Solution

A semiconductor device design featuring a metal support with a holding-down portion that prevents upward convex bending of the insulating substrate, secured to a case with adhesive, and a metal support above the substrate to maintain contact and reduce thermal expansion differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a baseless structure is used to reduce device complexity, then ease of manufacture is improved, but rigidity deteriorates causing upwardly convex bending of the insulating substrate

Engineering Contradiction:

Improvestructure complexityVSAvoidrigidity

Core Design Contradiction:

Device complexityVSStrength

Solution Approach 1:

The support structure is segmented into a case portion and a separate support portion that extends into the case. This segmentation allows the support portion to provide localized reinforcement to the insulating substrate without requiring a complete baseplate, thus maintaining rigidity while avoiding full baseless structure complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The support portion is nested within the case structure, with the support portion extending downward into the case from the insulating substrate. This nesting arrangement allows the support to be integrated within the existing device architecture, providing reinforcement without adding external complexity

Inventive Principle:

Principle #7Nested doll (Nesting)

2Strength

If screws are used to secure the device to a heat sink, then fixing strength is improved, but the insulating substrate bends into an upwardly convex shape due to applied force

Engineering Contradiction:

Improvefixing strengthVSAvoidsubstrate shape

Core Design Contradiction:

StrengthVSShape

Solution Approach 1:

The support portion extends downward into the case to provide preliminary support to the insulating substrate before the device is secured to the heat sink. This preliminary anti-action counteracts the upward bending force that would otherwise be applied by the screws, preventing substrate deformation

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The support portion acts as an intermediary element between the insulating substrate and the case. It distributes and absorbs the mechanical stress from screw fastening, preventing direct transmission of bending forces to the substrate while still allowing secure mounting to the heat sink

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If the insulating substrate bends upwardly convex, then device assembly is simplified, but substrate cracking occurs and thermal resistance increases

Engineering Contradiction:

Improveassembly simplicityVSAvoidsubstrate integrity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The support portion provides beforehand cushioning by extending into the case to support the insulating substrate before operational stresses are applied. This prevents substrate cracking under thermal and mechanical loads while maintaining the baseless structure's assembly simplicity

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The device employs a composite structure combining the insulating substrate with the support portion extending into the case. This composite arrangement enhances substrate integrity and thermal resistance performance while preserving the manufacturing advantages of a baseless design

Inventive Principle:

Principle #40Composite materials

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 minimizes upwardly convex bending, prevents substrate cracking, and maintains low thermal resistance by ensuring consistent contact between the substrate and heat sink, even under temperature changes.

Implementation Method 1

an adhesive bonding the insulating substrate and the case together

Methodology Applied

Scientific EffectAdhesive bonding: Adhesive

Implementation Method 2

a holding-down portion extending downward from the metal support so as to prevent upwardly convex bending of the insulating substrate

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Implementation Method 3

maintains low thermal resistance by ensuring consistent contact between the substrate and heat sink

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS9633918B2Semiconductor device

Publication Date: 2017.04.25 MITSUBISHI ELECTRIC CORP

AI summary

A semiconductor device includes an insulating substrate, a semiconductor element secured to a top surface of the insulating substrate, a case formed of a resin and having a frame portion surrounding the semiconductor element, a metal support located above the insulating substrate and having an end secured to the frame portion, a holding-down portion extending downward from the metal support so as to prevent upwardly convex bending of the insulating substrate, and an adhesive bonding the insulating substrate and the case together.