RF Module Stacking Layout for GaAs Amplifier Heat Dissipation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Semiconductor modules using materials with low thermal conductivity, such as GaAs, experience increased operating temperatures due to poor heat dissipation, leading to degraded amplification characteristics and hindered size reduction.

Innovation Solution

A radio frequency module design featuring a module substrate with a first base part made of high thermal conductivity material (e.g., silicon) and a second base part made of low thermal conductivity material (e.g., gallium arsenide) stacked such that the amplifier circuit is positioned between the two, with connections via electrodes, facilitating heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a transistor of an amplifier is formed with a material having low thermal conductivity (e.g., GaAs), then the amplification characteristics can be maintained, but the operating temperature increases due to poor heat dissipation

Engineering Contradiction:

Improveamplification characteristicsVSAvoidoperating temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The base part is divided into a first base part made of high thermal conductivity material (silicon) and a second base part made of low thermal conductivity material (GaAs). The amplifier circuit is formed on the second base part while the first base part serves as a heat dissipation structure, separating the functional requirements of signal amplification and heat dissipation into different segments.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the base part are assigned different thermal conductivity properties. The first base part has high thermal conductivity to efficiently conduct heat away from the amplifier, while the second base part has low thermal conductivity to maintain the amplifier's performance characteristics. This local differentiation resolves the contradiction between heat dissipation and amplification performance.

Inventive Principle:

Principle #3Local quality

2Temperature

If a large heat dissipation area is secured to suppress temperature increase, then the operating temperature can be controlled, but the size of the semiconductor module cannot be sufficiently reduced

Engineering Contradiction:

Improveoperating temperatureVSAvoidsemiconductor module size

Core Design Contradiction:

TemperatureVSVolume of moving object

Solution Approach 1:

The heat dissipation function is merged with the structural support function. The first base part serves dual purposes: providing mechanical support for the amplifier circuit and acting as a heat dissipation pathway. This merging eliminates the need for separate heat dissipation structures, enabling compact module design while maintaining temperature control.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Instead of increasing the lateral heat dissipation area, the solution utilizes the vertical dimension by creating a layered structure with the first base part positioned beneath the second base part. Heat is conducted vertically through the first base part to a heat dissipation structure, achieving effective heat dissipation without increasing the module's lateral footprint.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Volume of moving object

If components are laid out on both sides of the wiring board to reduce module size, then the semiconductor module size is reduced, but heat dissipation becomes more difficult

Engineering Contradiction:

Improvesemiconductor module sizeVSAvoidheat dissipation

Core Design Contradiction:

Volume of moving objectVSTemperature

Solution Approach 1:

The base part is segmented into two functional regions: the second base part for amplifier integration and the first base part for heat dissipation. This segmentation allows the module to maintain compact dimensions while providing dedicated heat dissipation pathways, resolving the contradiction between size reduction and heat dissipation effectiveness.

Inventive Principle:

Principle #1Segmentation

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

Improves heat dissipation and reduces the size of the radio frequency module by effectively transferring heat generated by the amplifier circuit to the higher thermal conductivity base part, maintaining performance and enabling compact design.

Implementation Method 1

the first base part is joined to the second base part, and the first base part is connected to the second major surface via a second electrode... effectively transferring heat generated by the amplifier circuit to the higher thermal conductivity base part

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS12537549B2Radio frequency module and communication device

Publication Date: 2026.01.27 MURATA MFG CO LTD

AI summary

A radio frequency module includes a module substrate including major surfaces that face each other; a first base part that is at least partially comprised of a first semiconductor material and in which an electronic circuit is formed; a second base part that is at least partially comprised of a second semiconductor material having a thermal conductivity lower than the thermal conductivity of the first semiconductor material and in which an amplifier circuit is formed; and an external connection terminal disposed on or over the major surface. The first base part and the second base part are disposed on or over the major surface out of the major surfaces; and the second base part is disposed between the module substrate and the first base part, is joined to the first base part, and is connected to the major surface via an electrode.