Power Module Groove Interlocking for Insulation Reliability

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Solution Overview

Problem

Conventional power modules face insulation failure and increased thermal resistance due to displacement of insulating and metal layers when external forces are applied, leading to thermal runaway and bonding issues.

Innovation Solution

A power module design featuring a groove on the metal layer to securely insert and bond the insulating layer, using a flexible resin with high thermal conductivity fillers, which enhances the bonding strength and prevents layer deviation, eliminating the need for liquid thermal compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an insulating layer and a metal layer are contacted on a flat surface, then the manufacturing process is simple, but the layers may be deviated from each other when external force is applied, causing insulation failure

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidinsulation reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies a curvature principle by forming a groove (concave structure) on the metal layer surface instead of using a completely flat surface. This groove structure provides mechanical interlocking with the insulating layer, preventing deviation under external force while maintaining manufacturing feasibility through standard molding processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The groove structure creates a form of controlled void space that allows the insulating layer to be inserted and mechanically locked. This interlocking structure significantly improves bonding strength and prevents layer deviation without requiring additional complex fastening mechanisms.

Inventive Principle:
Principle #31Porous materials

2Ease of manufacture

If an insulating layer and a metal layer are contacted on a flat surface, then the manufacturing process is simple, but thermal resistance increases when layers are deviated, causing thermal runaway

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidthermal management reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The groove structure ensures continuous contact between the insulating layer and metal layer by providing mechanical interlocking. This prevents gaps that would increase thermal resistance, ensuring efficient heat dissipation from the semiconductor device while maintaining simple manufacturing processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Device complexity

If external force is applied to flat-contacted layers, then the structure is simple, but bonding strength decreases causing layer deviation

Engineering Contradiction:
Improvestructural complexityVSAvoidbonding strength
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The groove (concave) structure on the metal layer creates mechanical interlocking with the insulating layer. This interlocking significantly enhances bonding strength and prevents layer deviation under external force, while the overall structure remains relatively simple and manufacturable.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The groove structure creates a mechanical lock that increases bonding strength between layers. The interlocking geometry provides resistance to external forces without requiring additional fastening components, maintaining structural simplicity while dramatically improving strength.

Inventive Principle:
Principle #31Porous 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 solution improves the reliability of the power module by preventing layer deviation, maintaining thermal conductivity, and reducing thermal resistance, thus preventing thermal runaway and bonding failures.

Implementation Method 1

a groove into which a part of the insulating layer is inserted is formed on a surface of the metal layer facing the insulating layer

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Implementation Method 2

a mold resin formed so as to cover the semiconductor chip and at least a part of the metal layer

Methodology Applied
Scientific EffectEncapsulation:

Data Source

PatentEP3026701B1Power module and manufacturing method thereof
Publication Date: 2022.11.16 ROHM CO LTD
  • EP3026701B1 patent drawingFigure 1~2
  • EP3026701B1 patent drawingFigure 3~4
  • EP3026701B1 patent drawingFigure 5

AI summary

A power module includes: an insulating layer; a leadframe disposed on the insulating layer; a semiconductor chip disposed on the leadframe; and a mold resin formed so as to cover the semiconductor chip and at least a part of the metal layer, wherein a groove into which a part of the insulating layer is inserted is formed on a surface of the leadframe facing the insulating layer. There can be provided the power module with improved reliability so that the insulating layer and the leadframe may be hardly deviated from each other even if external force is applied thereon; and a fabrication method for such a power module.