Si Circuit Double-Sided Cooling via Ceramic Substrates

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Solution Overview

Problem

Existing components with Si circuits are only cooled on one side, limiting their thermal management efficiency, as they lack effective double-sided cooling solutions with high thermal and electrical conductivity.

Innovation Solution

A component design featuring a ceramic flat substrate with metal-filled thermal-electrical vias and cooling channels on the top side of the Si circuit, connected to a second ceramic substrate via metallization, enabling double-sided cooling using high thermal conductivity materials like aluminum nitride and copper.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a Si circuit is cooled on only one side using conventional single-sided metallization and heat sink attachment, then the structure is simple and easy to manufacture, but the thermal management efficiency is limited and heat dissipation is insufficient

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidstructure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent transitions from single-sided cooling to double-sided cooling by adding a second ceramic substrate with metallization on the opposite side of the first substrate. This dimensional change allows heat to be dissipated from both the top and bottom surfaces of the Si circuit, effectively doubling the heat dissipation pathways and improving thermal management efficiency without requiring completely new cooling architectures.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs composite material structures including DCB-Cu (dual copper bonded) metallization layers, sintered silver interconnects, and aluminum nitride ceramic substrates with high thermal conductivity. These composite materials combine different properties (electrical conductivity, thermal conductivity, mechanical strength) to achieve efficient heat transfer from the Si circuit to the heat sinks on both sides while maintaining structural integrity.

Inventive Principle:
Principle #40Composite materials

2Reliability

If high thermal conductivity materials are used for cooling elements, then heat transfer efficiency improves, but manufacturing complexity and process difficulty increase

Engineering Contradiction:
Improvethermal management performanceVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent divides the cooling system into separate modular components: first and second ceramic substrates, independent metallization layers on each substrate, and separate heat sink attachments. This segmentation allows each component to be manufactured and optimized independently using established processes, then assembled together. The DCB-Cu metallization can be applied to each substrate separately, and heat sinks can be attached to both sides independently, simplifying the overall manufacturing process while maintaining high thermal conductivity.

Inventive Principle:
Principle #1Segmentation

3Temperature

If double-sided cooling with metal-filled vias and cooling channels is implemented, then thermal management efficiency increases, but the device complexity and manufacturing steps increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidassembly complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent designs the ceramic substrates to serve multiple functions simultaneously: they provide mechanical support for the Si circuit, conduct heat from the circuit to the heat sinks, provide electrical isolation between components, and contain embedded cooling channels for liquid coolant flow. The metallization layers serve both electrical connection and thermal conduction purposes. This multi-functionality reduces the need for separate dedicated cooling components, thereby reducing overall assembly complexity despite the advanced features.

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

Enhances the thermal management efficiency of Si circuits by allowing heat dissipation from both sides, improving the assembly's performance through effective heat transfer and electrical connectivity.

Implementation Method 1

the ceramic flat substrate 6 being metal-filled thermally contains electrical through-connections (vias) 11... With the help of the ceramic flat substrate with metal-filled vias, which touches the free upper side of the Si circuit via the connecting means, better heat dissipation can take place on both sides.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the substrates are made of aluminum nitride. Aluminum nitride has high thermal conductivity... If aluminum nitride is chosen as the substrate material, its coefficient of expansion of approx. 4.7 ppm/K is close to the silicon of the chip with approx. 4.2 ppm/K.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the ceramic flat substrate 6 being metal-filled thermally contains electrical through-connections (vias) 11 and/or cooling channels for guiding a coolant.

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3360158B1Circuit cooled on two-sides
Publication Date: 2021.01.13 CERAMTEC GMBH
  • EP3360158B1 patent drawingFigure 1~2

AI summary

The invention relates to a component (9) comprising a first ceramic substrate (1) with an upper side (1b) and a lower side (1a), wherein a metallization (2) is applied on the upper side (1b), on which metallization an Si circuit (4) is mounted by its lower side via a connecting means (3). In order that the Si circuit (4) is cooled on both sides by elements with a high thermal conductivity and simultaneously a high electrical conductivity, and in order that the efficiency of the assembly is increased, according to the invention, a connecting means (5) is applied on the upper side (1b) of the Si circuit (4), on which connecting means a ceramic flat substrate (6) is attached by its lower side, and a second cermaic substrate (8) is arranged on the flat substrate (6) via a metalization (7), wherein the ceramic flat substrate (8) contains metal-filled thermal electrical vias (11) and/or cooling ducts for guiding a coolant.