Heat Dissipation Substrate with Gradient Thermal Vias

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Solution Overview

Problem

Existing heat dissipation substrates for electronic components in electric power steering devices face challenges in efficiently managing heat distribution and dissipation, particularly in high-temperature environments and during varying operational conditions, leading to potential component failure.

Innovation Solution

A heat dissipation substrate with a unique arrangement of thermal vias, where the surface density is highest at the inner edge of the electronic component projection region and gradually decreases, allowing for efficient heat conduction through the substrate thickness direction, with varying intervals and diameters to optimize heat transfer based on temperature conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If thermal vias are uniformly distributed across the substrate, then manufacturing is simplified, but heat dissipation efficiency is reduced due to inadequate targeting of high-heat regions

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidvia arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by varying the surface density of thermal vias across different regions of the substrate. The first region (higher heat generation) has a higher surface density of thermal vias, while the second region (lower heat generation) has a lower surface density. This non-uniform distribution optimizes heat dissipation efficiency by concentrating thermal conduction pathways where heat generation is highest, rather than using a uniform via distribution across the entire substrate.

Inventive Principle:
Principle #3Local quality

2Reliability

If thermal vias are concentrated in the center of the electronic component projection region, then heat dissipation from the center is improved, but edge regions experience insufficient heat dissipation

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidheat dissipation area coverage
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent addresses this contradiction by implementing a gradient distribution of thermal vias. The first region, corresponding to the center of the electronic component projection region, has a higher surface density of thermal vias to handle the concentrated heat generation. The second region, corresponding to the edge portions, has a lower surface density. This gradient approach ensures that heat dissipation capacity is matched to the local heat generation characteristics, optimizing overall heat dissipation efficiency while maintaining appropriate coverage across the entire component area.

Inventive Principle:
Principle #3Local quality

3Reliability

If the surface density of thermal vias is increased throughout the substrate, then heat dissipation capacity is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improveheat dissipation capacityVSAvoidvia density variation
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent resolves this contradiction by applying local quality through region-specific via density optimization. Instead of uniformly increasing via density across the entire substrate, the invention concentrates the higher via density only in the first region where heat generation is highest. The second region maintains a lower via density, reducing unnecessary manufacturing complexity and material usage. This localized approach achieves optimal heat dissipation capacity while minimizing overall device complexity and manufacturing cost.

Inventive Principle:
Principle #3Local quality

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

This configuration enhances heat dissipation properties by balancing the shortest distance and heat dissipation area, effectively suppressing temperature rises in electronic components, even under varying operational conditions, thereby preventing component failure.

Implementation Method 1

a plurality of thermal vias which passes through the heat dissipation substrate between the mounting surface and the rear surface

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3386277B1Heat-dissipating substrate and electrically driven power steering device
Publication Date: 2022.07.06 NSK LTD
  • EP3386277B1 patent drawingFigure 1
  • EP3386277B1 patent drawingFigure 2
  • EP3386277B1 patent drawingFigure 3~4

AI summary

Provided are a heat dissipation substrate capable of improving heat dissipation properties of an electronic component, and an electric power steering device. In the heat dissipation substrate, a plurality of thermal vias are disposed at least in an electronic component projection region in which a region of a bottom surface portion of the electronic component is projected to a mounting surface in a direction perpendicular to the mounting surface, and a surface density of the thermal vias which occupy the mounting surface per unit area is at least partially different. The plurality of thermal vias are disposed so that the surface density of the thermal vias becomes the greatest in a dense region on an inner side of an edge portion of the electronic component projection region.