Power Module Base Plate Sidewalls to Contain Solder Overflow

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Solution Overview

Problem

The overflow of connecting materials such as solder on semiconductor module surfaces leads to contamination, reduced adhesion of encapsulation materials, and unstable connections, necessitating additional manufacturing processes and increased costs.

Innovation Solution

A base plate with integral sidewalls and optional grooves is designed to prevent overflow by acting as barriers, maintaining a stable connection and adhesion while reducing material loss, and enhancing the mechanical stability of the semiconductor module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If solder resist coating is applied to prevent overflow, then overflow prevention is improved, but manufacturing cost increases and adhesion of encapsulation material deteriorates

Engineering Contradiction:
Improveoverflow of connecting materialVSAvoidmanufacturing cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent uses a simple, cost-effective barrier structure made of the base plate material itself rather than expensive solder resist coatings. The barrier is formed by the base plate geometry (elevated edges or protrusions) that naturally prevents solder overflow without requiring additional protective layers.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the geometric parameters of the base plate by adding elevated edges or protrusions with specific height and width dimensions. These dimensional changes create a physical barrier that controls solder flow while maintaining compatibility with encapsulation material adhesion.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If solder resist coating is applied to prevent overflow, then overflow prevention is improved, but adhesion of encapsulation material deteriorates

Engineering Contradiction:
Improveoverflow of connecting materialVSAvoidadhesion of encapsulation material
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent eliminates the need for solder resist coatings by using the base plate's own geometric structure as a barrier. This removes the layer that would interfere with encapsulation material adhesion while still preventing solder overflow effectively.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent applies the barrier function locally at the edges and corners of the base plate where solder overflow is most likely to occur. The elevated edges or protrusions are positioned specifically at these critical locations to prevent overflow without covering the entire base plate surface, thus preserving adhesion areas for encapsulation material.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If large grooves are formed to collect overflow, then overflow prevention is improved, but mounting area is reduced

Engineering Contradiction:
Improveoverflow of connecting materialVSAvoidmounting area
Core Design Contradiction:
Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

Instead of creating grooves to collect overflow (adding material removal), the patent inverts the approach by creating elevated edges or protrusions that prevent overflow before it occurs. This additive approach preserves the mounting area while achieving the same overflow prevention goal.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The elevated edges or protrusions are formed in advance during base plate manufacturing to preemptively block solder overflow. This preliminary barrier prevents the need for large grooves to collect overflow, thereby preserving maximum mounting area.

Inventive Principle:
Principle #10Preliminary action

4Object-affected harmful factors

If large grooves are formed to collect overflow, then overflow prevention is improved, but connecting material loss increases

Engineering Contradiction:
Improveoverflow of connecting materialVSAvoidconnecting material
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent inverts the conventional groove-based approach by using elevated edges to block overflow proactively. This prevents connecting material from accumulating in large volumes anywhere, thereby reducing material loss while still preventing harmful overflow.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts the potential harm of unrestricted solder flow into a beneficial controlled overflow pattern by using elevated edges as guides. The solder is directed to flow in controlled amounts to specific areas rather than accumulating in large grooves, reducing material waste.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 prevents contamination and material loss, improves adhesion, and enhances the reliability and stability of the power semiconductor module without additional manufacturing costs.

Implementation Method 1

the basic body has at least one elevated integral part forming at least one sidewall projecting beyond the mounting area by a vertical height

Methodology Applied
Scientific EffectPhysical barrier: Physical Containment

Data Source

PatentEP4057339B1Base plate having sidewall, power semiconductor module comprising the base plate and method for producing the base plate
Publication Date: 2026.05.06 HITACHI ENERGY LTD
  • EP4057339B1 patent drawingFigure 1A~1B
  • EP4057339B1 patent drawingFigure 1C~1D
  • EP4057339B1 patent drawingFigure 2A~2B

AI summary

A base plate (10) for a power semiconductor module is provided, wherein the base plate (10) comprises a basic body (1) formed in one piece. The basic body (1) has a front side (1A) and a rear side (1B), wherein the front side (1A) comprises a mounting area (1M) of the base plate (10). Along at least one of its edges (IE), the basic body (1) has at least one elevated integral part forming at least one sidewall (11) which projects beyond the mounting area (1M) by a vertical height (11H). At regions of the mounting area (1M), the basic body (1) has a vertical thickness (IT) extending between the front side (1A) and the rear side (1B), wherein the vertical thickness (IT) is larger than the vertical height (11H) of the sidewall (11). Moreover, a power semiconductor module (100) comprising such base plate (10) and method for producing such a base plate (10) are provided.