Microchannel Heat Sink Thermal Bonding to Prevent Channel Deformation

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Solution Overview

Problem

Conventional microchannel heat sinks face issues with interlayer connection reliability, deformation, and leakage due to brazing and diffusion welding processes, which affect the heat dissipation efficiency of high power density chips.

Innovation Solution

A method involving thermal bonding with upper and lower cover plates processed to match the microchannel structure, aligned and stacked under pressure in a reducing atmosphere, eliminating the need for adhesives and reducing deformation, thereby enhancing bonding strength and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If brazing process is used to join plates, then bonding strength is improved, but brazing filler flows into channels causing blockage and galvanic corrosion reducing reliability

Engineering Contradiction:
Improvebonding strengthVSAvoidreliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent removes the brazing filler material from the joining process entirely, extracting the harmful element that causes channel blockage and galvanic corrosion while maintaining plate bonding through alternative mechanisms

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a diffusion barrier layer as an intermediary between plates during diffusion bonding, preventing material contamination while enabling strong bonding without requiring brazing filler

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If diffusion welding process is used to achieve stronger bonding, then bonding strength is improved, but high pressure causes channel deformation in soft metal materials

Engineering Contradiction:
Improvebonding strengthVSAvoidchannel shape
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The patent performs preliminary actions by creating a diffusion barrier layer and preparing plate surfaces before diffusion bonding, enabling bonding at reduced pressures that prevent channel deformation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent modifies process parameters by conducting diffusion bonding at lower pressures compared to conventional diffusion welding, changing the pressure parameter to prevent channel deformation while achieving sufficient bonding strength

Inventive Principle:
Principle #35Parameter changes

3Shape

If insufficient pressure is applied during diffusion welding, then channel deformation is reduced, but bonding strength between plates becomes weak causing leakage

Engineering Contradiction:
Improvechannel shapeVSAvoidleakage resistance
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The diffusion barrier layer acts as a mediator that enables effective bonding at lower pressures by preventing material interdiffusion and contamination, ensuring leakage resistance without requiring high pressure that would deform channels

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method improves the bonding strength and reliability of microchannel heat sinks by directly applying pressure without adhesives, reducing deformation and leakage, and maintaining high heat dissipation efficiency.

Implementation Method 1

placing the upper cover plate, the each of the plates, and the lower cover plate that are aligned and stacked in a reducing atmosphere, and heating the upper cover plate, the each of the plates, and the lower cover plate that are aligned and stacked, and performing heat preservation

Methodology Applied
Scientific EffectThermal bonding: Heating

Implementation Method 2

applying a pressure on the upper cover plate and/or the lower cover plate

Methodology Applied
Scientific EffectPressure application: Compression

Data Source

PatentEP4135134B1Manufacturing method for a microchannel heat sink
Publication Date: 2024.12.25 FOSHAN HUAZHI ADVANCED MATERIALS CO LTD
  • EP4135134B1 patent drawingFigure 1
  • EP4135134B1 patent drawingFigure 2~3
  • EP4135134B1 patent drawingFigure 4~5

AI summary

The apresnt application adopts the thermal bonding process to process the microchannel heat sink. By placing the upper cover plate and the lower cover plate on the plates of the microchannel heat sink, the pressure is directly applied, and there is no need to add other adhesives. It can avoid the problems of blockage, galvanic corrosion etc. inside the channel caused by the brazing process, and improve the reliability of the microchannel heat sink product. Before welding, the upper cover plate and the lower cover plate are processed according to the microchannel structure to form a hollow structure, and then aligned and stacked with the microchannel heat sink, and then subjected to pressure welding, which not only accurately and effectively applies the pressure on the walls of the microchannel, but also can greatly relieve the pressure on the microchannel heat sink during the pressure welding process, and reduce the deformation of the cooling liquid channel portion of the microchannel heat sink. Compared with the conventional diffusion welding process, under the same conditions, this process can apply greater pressure to the microchannel heat sink, improve the bonding force between the plates of the microchannel heat sink and improve product stability.