Elastically Deformable Pressing Member for Power Module Vibration

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Solution Overview

Problem

The reliability of power electronic modules in high-voltage battery inverters for electric vehicles is compromised due to untimely heating and vibration-induced degradation of screws used for pressing the modules against the casing, leading to reduced heat dissipation and module durability.

Innovation Solution

An elastically deformable pressing member with a spring mechanism is used to maintain contact between the power module and the casing, absorbing vibrations and maintaining a durable pressing force without being sensitive to tearing stresses, thereby enhancing the robustness and longevity of the power block.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If screws are used to press the power module against the casing, then the module is firmly fixed and heat dissipation is improved, but the screws degrade due to vibration-induced tearing forces, reducing pressing force and reliability over time

Engineering Contradiction:

Improvepressing force durabilityVSAvoidscrew service life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the screw-threaded mechanical connection system with a deformation-based mechanical system. Instead of relying on screws that engage through threads (which are sensitive to tearing forces), the invention uses an elastically deformable element that exerts pressing force through its deformation capability, making it insensitive to the direction and nature of applied forces including vibrations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and mechanical properties of the pressing element from rigid (screw) to elastically deformable. This parameter change allows the element to absorb vibrations and maintain consistent pressing force without degradation, as the elastic deformation absorbs the impact of vibrational forces rather than creating tearing stresses on threaded connections.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If rigid pressing elements are used to maintain contact between the module and casing, then heat dissipation is effective, but vibrations cause loss of contact and reduced heat dissipation over time

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidcontact maintenance

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent introduces dynamic characteristics to the pressing element by making it elastically deformable. This allows the element to dynamically respond to vibrational forces by deforming and absorbing energy, maintaining continuous contact between the power module and casing. The dynamic elasticity enables the system to adapt to varying vibration conditions while preserving thermal contact.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The elastically deformable element acts as a pre-configured cushioning mechanism that absorbs vibrational forces before they can cause loss of contact. The elastic deformation capacity is built into the pressing element beforehand, allowing it to cushion against upcoming vibrational impacts and maintain stable contact pressure for heat dissipation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 elastically deformable pressing member effectively maintains the power module in contact with the casing, improving heat dissipation and module durability by absorbing vibrations and maintaining a consistent pressing force, thus enhancing the reliability and lifespan of the power block.

Implementation Method 1

the vibrations, in particular in a direction orthogonal to the bearing surface, undergone by the part are absorbed by the deformable element

Methodology Applied

Scientific EffectVibration absorption: Damping

Implementation Method 2

said member comprising an elastically deformable element extending along an axis, said element having a first end intended to be in mechanical connection with said support, and a second end intended to exert a force on said part

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 3

In order to evacuate the heat formed in the casing of the electronic power module, it is known practice to press or press the electronic power module against a bottom of the casing and to choose the materials for the bottom of the casing of the electronic power module and for the bottom housing so that they are compatible in terms of thermal conductivity

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2756743B1Member for pressing a component firmly against a surface

Publication Date: 2016.01.20 VALEO SYSTEMES DE CONTROLE MOTEUR SAS

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AI summary

The invention relates to a member (250) for pressing a component (10) firmly against a surface (5) of a support, said member (250) comprising an elastically deformable element (22, 23) extending along an axis, said element having a first end intended to be connected mechanically to said support, and a second end intended to apply load to said component (10), said elastically deformable element comprising at least one spring (22, 23).