Non-Oxide DBC Substrate Bonding With an Al2O3 Interlayer

Solution Overview

Problem

Current methods for fabricating DBC substrates on non-oxide ceramics are associated with high manufacturing costs and long processing times, limiting their adoption for power semiconductor devices due to challenges in achieving efficient bonding and adhesion.

Innovation Solution

A DBC substrate is fabricated using a ceramic workpiece with a non-oxide ceramic, where an Al2O3 intermediate layer is deposited between the ceramic and a copper-containing layer, utilizing atomic layer deposition and direct bonded copper processes to enhance adhesion and reduce manufacturing complexities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a DBC process is performed on non-oxide ceramic to achieve lower thermal resistance and better thermal expansion matching, then the performance for power semiconductor devices is improved, but the manufacturing cost and manufacturing time increase significantly

Engineering Contradiction:

Improvethermal management performanceVSAvoidmanufacturing cost and time

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by depositing aluminum-containing monolayers on the non-oxide ceramic surface before the copper bonding process. This preparatory step modifies the ceramic surface to enable subsequent copper deposition, thereby facilitating the DBC process on non-oxide ceramics without requiring complex alternative manufacturing procedures, thus reducing both cost and time while achieving the desired thermal performance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The aluminum-containing monolayers serve as an intermediary layer between the non-oxide ceramic and the copper layer. This intermediate layer enables effective bonding and adhesion between the ceramic substrate and copper, making the DBC process feasible on non-oxide ceramics with simplified procedures, thereby reducing manufacturing complexity, cost, and time while maintaining improved thermal management performance.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If conventional methods are used to deposit copper on non-oxide ceramic, then the process can be completed, but adhesion and bonding efficiency are insufficient leading to high manufacturing costs and long processing times

Engineering Contradiction:

Improveadhesion and bonding efficiencyVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by depositing aluminum-containing monolayers on the non-oxide ceramic surface before the copper bonding process. This preparatory step modifies the ceramic surface to enable subsequent copper deposition, thereby facilitating the DBC process on non-oxide ceramics without requiring complex alternative manufacturing procedures, thus reducing both cost and time while achieving the desired thermal performance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The aluminum-containing monolayers serve as an intermediary layer between the non-oxide ceramic and the copper layer. This intermediate layer enables effective bonding and adhesion between the ceramic substrate and copper, making the DBC process feasible on non-oxide ceramics with simplified procedures, thereby reducing manufacturing complexity, cost, and time while maintaining improved thermal management performance.

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 reduces material consumption, chemical waste, and ohmic losses, enabling energy and resource savings, and results in improved DBC substrates and power semiconductor devices with enhanced thermal management and efficiency.

Implementation Method 1

depositing one or more aluminum-containing monolayers on at least the first main side of the ceramic workpiece by atomic layer deposition

Methodology Applied

Scientific EffectAtomic layer deposition: Chemical Vapour Deposition

Implementation Method 2

depositing a copper-containing layer over the one or more aluminum-containing monolayers by a direct bonded copper process

Methodology Applied

Scientific EffectDirect bonded copper process: Welding

Data Source

PatentUS12119284B2DBC substrate for power semiconductor devices, method for fabricating a DBC substrate and power semiconductor device having a DBC substrate

Publication Date: 2024.10.15 INFINEON TECH AUSTRIA AG

AI summary

A DBC substrate for power semiconductor devices includes a ceramic workpiece of a non-oxide ceramic having first and second opposing main sides, the ceramic workpiece having a thickness of 10 μm or more measured between the first and second main sides, a copper-containing layer disposed over the first main side, the copper-containing layer having a thickness of 5 μm or more, and an intermediate layer comprising Al2O3 disposed between the ceramic workpiece and the copper-containing layer.