Multilayer Substrate Cavities and Roughened Conductors for Heat Dissipation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing multilayer substrates face challenges in improving heat dissipation and electrical characteristics, particularly in transmission lines, which affect their performance in high-frequency signal transmission.

Innovation Solution

The multilayer substrate design includes a stacked body with insulator layers and conductor layers, featuring increased surface roughness on exposed portions and interior spaces filled with air or vaporizing fluids to enhance heat dissipation and reduce transmission loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional smooth conductor layers are used in multilayer substrates, then manufacturing is easier, but heat dissipation and electrical characteristics deteriorate

Engineering Contradiction:

Improveheat dissipationVSAvoidsurface roughness control

Core Design Contradiction:

TemperatureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating different surface roughness characteristics in different regions of the conductor layer. Specifically, the conductor layer has a first surface roughness on its first main surface and a second surface roughness on its second main surface, with the second surface roughness being greater than the first. This localized differentiation allows the exposed portion to enhance heat dissipation through increased surface area while maintaining smoother surfaces for reliable electrical connections.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by modifying the surface roughness parameter of the conductor layer. By controlling the second surface roughness to be greater than the first surface roughness, the invention transforms the conductor layer's thermal and electrical properties. The increased surface roughness on the exposed portion increases surface area for heat dissipation, while the parameter control ensures manufacturing feasibility.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If interior spaces are introduced for heat dissipation, then thermal performance improves, but device complexity increases

Engineering Contradiction:

Improveheat dissipationVSAvoidstacked body structure

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by utilizing the stacking direction (vertical dimension) to create interior spaces within the stacked body. The stacked body includes multiple insulator layers and conductor layers arranged in the stacking direction, with interior spaces positioned between these layers. This vertical arrangement allows heat dissipation functionality to be integrated without significantly increasing horizontal footprint or overall device complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The stacked body structure serves multiple functions simultaneously: it provides electrical insulation between conductor layers, creates interior spaces for heat dissipation, and maintains structural integrity. The insulator layers and conductor layers are arranged to fulfill both electrical and thermal management functions within a single integrated structure, reducing the need for separate components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design improves heat dissipation and electrical characteristics by increasing surface area for heat conduction and reducing dielectric loss, thereby enhancing the efficiency of high-frequency signal transmission.

Implementation Method 1

increasing surface area for heat conduction

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

reducing dielectric loss

Methodology Applied

Scientific EffectDielectric loss reduction: Dielectric

Data Source

PatentUS20250380350A1Multilayer substrate and electronic device

Publication Date: 2025.12.11 MURATA MFG CO LTD

AI summary

A multilayer substrate includes a stacked body and a first conductor layer. The stacked body includes insulator layers stacked in a stacking direction. The first conductor layer is provided in the stacked body. In the stacked body, interior spaces that are not connected to a space outside the stacked body are provided. The first conductor layer includes a first principal surface and a second principal surface including an exposed portion exposed to the interior spaces. A surface roughness of the exposed portion is greater than a surface roughness of the first principal surface.