Sinter-Bonded Heat Dissipation Structures for Microelectronic Modules

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Solution Overview

Problem

Microelectronic modules with high power microelectronic devices face challenges in heat dissipation, particularly at elevated power levels, as existing embedded metal coin structures are costly, prone to warpage, and inefficient in dissipating heat effectively.

Innovation Solution

The use of sinter-bonded heat dissipation structures composed of sintered materials bonded to a module substrate, which include thermally conductive pieces like heat pipes or metal slugs, providing enhanced thermal transfer paths and leveraging low-temperature sintering processes to form robust metallurgical bonds and reduce manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If embedded metal coin structures are used for heat dissipation, then thermal transfer is improved, but manufacturing cost increases and substrate warpage occurs

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The invention changes the manufacturing process parameters from traditional high-cost embedded metal coin techniques to a sintering process using paste application. This parameter change enables heat dissipation structures to be manufactured at lower cost while maintaining effective thermal transfer paths from the power device to the heat sink

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical embedding process of metal coins with a sintering-based system. Instead of mechanically pressing or embedding pre-formed metal coins into the substrate, the solution uses a paste containing metal particles that is applied and then sintered to form the heat dissipation structure, eliminating the need for complex mechanical embedding equipment and reducing manufacturing cost

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

2Temperature

If embedded metal coin structures are used for heat dissipation, then thermal transfer is improved, but substrate warpage increases

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidsubstrate warpage
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The invention changes the processing parameters from high-temperature metal coin embedding to low-temperature sintering (below the melting point of the metal particles). This parameter change reduces thermal stress on the substrate, preventing warpage while still achieving effective heat dissipation through the sintered metal structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the mechanical embedding system with a sintering system that uses controlled heating and pressure applied uniformly across the substrate. This substitution eliminates the localized mechanical stress and thermal gradient that cause warpage in traditional metal coin embedding, as the sintering process creates a more uniform stress distribution

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

3Power

If power levels are increased to meet application demands, then output power is improved, but heat concentration increases

Engineering Contradiction:
Improveoutput powerVSAvoidheat concentration
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The invention introduces a sintered metal structure as an intermediary heat transfer medium between the power device and the heat sink. This intermediary provides a high thermal conductivity path that efficiently conducts heat away from the power device, enabling high power operation without excessive heat concentration. The sintered structure acts as a thermal bridge that mediates the heat flow from the small-area power device to the larger heat sink surface

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 approach enhances heat dissipation capabilities, reduces manufacturing costs, and mitigates substrate warpage issues, while allowing the sintered structures to serve additional functions like electrical conductivity and RF shielding.

Implementation Method 1

transforming the sinter precursor material into a sintered metal body that bonds the power device to the module substrate

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 2

sinter-bonded heat dissipation structure... providing enhanced thermal transfer paths

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3327766B1Microelectronic modules with sinter-bonded heat dissipation structures and methods for the fabrication thereof
Publication Date: 2022.05.18 NXP USA INC
  • EP3327766B1 patent drawingFigure 1
  • EP3327766B1 patent drawingFigure 2~3
  • EP3327766B1 patent drawingFigure 4

AI summary

Methods for producing high thermal performance microelectronic modules containing sinter-bonded heat dissipation structures. In one embodiment, the method includes embedding a sinter-bonded heat dissipation structure in a module substrate. The step of embedding may entail applying a sinter precursor material containing metal particles into a cavity provided in the module substrate, and subsequently sintering the sinter precursor material at a maximum processing temperature less than a melt point of the metal particles to produce a sintered metal body bonded to the module substrate. A microelectronic device and a heatsink are then attached to the module substrate before, after, or concurrent with sintering such that the heatsink is thermally coupled to the microelectronic device through the sinter-bonded heat dissipation structure. In certain embodiments, the microelectronic device may be bonded to the module substrate at a location overlying the thermally-conductive structure.