Bimetallic Valve Semiconductor Cooler for Temperature Distribution

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Solution Overview

Problem

The existing semiconductor devices face temperature distribution issues due to differences in semiconductor chip characteristics and operating conditions, leading to performance determination by the maximum operating temperature and potential heat expansion differences between components, which can impair reliability.

Innovation Solution

A cooler with a bimetallic valve system that automatically increases refrigerant flow rate when a semiconductor chip reaches high temperature, featuring a simple structure with inclined fins and a blocking plate to enhance cooling capacity, using liquid refrigerant with high specific heat, and bimetallic valves that change shape to increase refrigerant intake at high temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single cooler is used to cool multiple semiconductor chips, then the device structure is simplified, but temperature distribution becomes uneven due to differences in chip characteristics and operating conditions

Engineering Contradiction:
Improvecooler structureVSAvoidtemperature distribution
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The cooler is divided into multiple independent cooling channels, with each channel equipped with its own bimetallic valve. This segmentation allows independent temperature control for each semiconductor chip, addressing the uneven temperature distribution while maintaining overall structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each cooling channel is customized with a bimetallic valve that responds to the specific temperature conditions of its associated semiconductor chip. This local quality approach ensures that each chip receives appropriate cooling based on its individual operating characteristics, resolving the temperature distribution issue.

Inventive Principle:
Principle #3Local quality

2Temperature

If the refrigerant flow rate is increased to cool high-temperature chips, then cooling capacity improves, but the system cannot automatically adapt to localized temperature variations

Engineering Contradiction:
Improvecooling capacityVSAvoidtemperature adaptation
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

Bimetallic valves are installed in each cooling channel to automatically adjust refrigerant flow based on local temperature conditions. The valves self-regulate without external control, enabling the system to adapt to temperature variations in each chip independently while maintaining overall cooling capacity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The bimetallic valves change their physical parameters (opening degree) in response to temperature changes, automatically adjusting the refrigerant flow rate to match the cooling needs of each semiconductor chip, thus providing adaptive cooling capacity.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If bimetallic valves are added to each cooling channel for automatic temperature control, then temperature control precision improves, but device complexity increases

Engineering Contradiction:
Improvetemperature controlVSAvoidcooler structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

Complex electronic temperature sensing and control systems are replaced with simple bimetallic valves that use pure mechanical principles (thermal expansion) to automatically regulate refrigerant flow. This substitution achieves precise temperature control while minimizing structural complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The bimetallic valves utilize hydraulic principles to control refrigerant flow automatically. The valves respond to temperature changes by mechanically adjusting the flow path, providing precise temperature control through fluid dynamics rather than complex mechanical or electronic systems.

Inventive Principle:
Principle #29Pneumatics and hydraulics

4Temperature

If fins are made perpendicular to the refrigerant flow for maximum heat transfer, then heat transfer efficiency improves, but refrigerant flow resistance increases

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidrefrigerant flow resistance
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The fins are arranged at an inclined angle rather than perpendicular to the refrigerant flow, creating an asymmetric configuration. This asymmetry optimizes the balance between heat transfer efficiency and flow resistance by allowing the refrigerant to flow more smoothly while still maintaining effective thermal contact with the fins.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The fin surfaces are designed with curved profiles that follow the refrigerant flow pattern. This curvature allows the fins to maintain effective heat transfer contact with the flowing refrigerant while reducing flow resistance compared to sharp perpendicular edges.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

Effectively suppresses temperature rises in semiconductor chips, enhances cooling capacity, and simplifies assembly while maintaining reliability by uniformly cooling semiconductor devices and preventing heat expansion-related shape changes.

Implementation Method 1

a curved plate-like bimetallic valve (26), one end of which is connected to each respective heat transfer pin (25), and the other end of which is a free end

Methodology Applied
Scientific EffectBimetallic effect: Bi-Metallic Strip

Implementation Method 2

a top plate (20), a jacket (21), having a side plate (21a) and bottom plate (21b), the side plate (21a) of which is firmly fixed to the top plate (20), a refrigerant inflow port (23) through which the refrigerant flows into an inside of the jacket (21), a refrigerant outflow port (24) through which the refrigerant flows out from the inside of the jacket (21)

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3032580B1Cooling device and semiconductor device having said cooling device
Publication Date: 2018.06.20 FUJI ELECTRIC CO LTD
  • EP3032580B1 patent drawingFigure 1(a)~1(c)
  • EP3032580B1 patent drawingFigure 2(a)~2(b)
  • EP3032580B1 patent drawingFigure 3(a)~3(c)

AI summary

An object of the invention is to provide a cooler, having a small number of parts and a simple structure, which can automatically enhance cooling capacity when at high temperature, and a semiconductor device which is easy to assemble. A cooler which cools a semiconductor module includes a top plate; a jacket, having a side plate and a bottom plate, the side plate of which is firmly fixed to the top plate; a refrigerant inflow port through which a refrigerant flows into a space surrounded by the top plate and jacket; a refrigerant outflow port through which the refrigerant flows out from the space; a plurality of fins, firmly fixed to the top plate, a plurality of which are disposed separately on each of the left and right of a main refrigerant path in the jacket, and which are disposed inclined toward the inflow side of the main refrigerant path; heat transfer pins disposed in positions on the top plate on the refrigerant inflow sides of the fins; and a curved plate-like bimetallic valve, one end of which is connected to each respective heat transfer pin, and the other end of which is a free end.