Diffusion Bond Layer for Low-Temperature Substrate Joining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current bonding methods for substrates, particularly in semiconductor applications, face challenges such as high energy consumption, thermal stress-induced damage, and contamination due to high temperatures, which can lead to structural destruction and reduced bond strength, especially when dealing with materials of different thermal expansion coefficients.
Innovation Solution
A method involving the application of a diffusion bond layer with a fine microstructure on the substrates, where the grain boundaries are oriented normally to the substrate surfaces, allowing for bonding at low temperatures and enhancing bond strength by increasing the grain boundary surface area for atomic diffusion, using controlled deposition techniques and minimizing thermal and mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high temperatures are used for bonding substrates, then bond force is improved, but thermal stress and structural damage increase
Solution Approach 1:
The patent changes the temperature parameter from high (>400°C) to low (room temperature to 200°C) bonding conditions. This is achieved by introducing a diffusion bond layer with specific microstructure (grain size 0.1-10 μm) that enables atomic diffusion at lower temperatures, thereby resolving the contradiction between achieving strong bonds and avoiding thermal stress damage to existing structures
Solution Approach 2:
The patent uses a composite structure consisting of the substrate and a diffusion bond layer with different material properties. The bond layer is designed with specific grain size and orientation (grain boundaries normal to substrate surface) to facilitate diffusion bonding at low temperatures, allowing strong bonding without subjecting the substrate to high thermal stress
2Strength
If high temperatures are used for bonding, then bond force is improved, but energy consumption increases
Solution Approach 1:
The patent fundamentally changes the temperature parameter from high (>400°C) to low (room temperature to 200°C) bonding conditions. The diffusion bond layer with controlled grain size (0.1-10 μm) enables sufficient atomic diffusion at these lower temperatures, dramatically reducing energy consumption while maintaining strong bond forces
3Strength
If high temperatures are used for bonding, then bond force is improved, but contamination and structural destruction increase
Solution Approach 1:
The patent reduces the bonding temperature from high (>400°C) to low (room temperature to 200°C), which prevents thermal degradation and contamination of the bond layer and surrounding structures. The diffusion bond layer's microstructure enables sufficient bonding at these lower temperatures without generating harmful thermal effects
Solution Approach 2:
The patent applies a diffusion bond layer with pre-controlled microstructure (grain size 0.1-10 μm, grain boundaries normal to surface) before bonding. This preliminary preparation of the bond layer interface enables low-temperature bonding that avoids contamination and structural damage while achieving strong bonds
4Productivity
If rapid temperature changes are used for bonding, then bonding speed is improved, but thermal stress and voiding increase
Solution Approach 1:
The patent changes the temperature parameter from high and rapidly changing to low and gradually changing conditions. The diffusion bond layer enables sufficient atomic diffusion at low temperatures even with gradual heating, eliminating thermal shock and stress-induced voiding while maintaining acceptable bonding speeds
Solution Approach 2:
The patent introduces a diffusion bond layer with specific microstructure as a buffer between the bonding process and the substrate. This layer cushions against rapid temperature changes by enabling diffusion at low temperatures, preventing thermal shock and stress-induced voiding in the substrate and existing structures
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 enables a strong, permanent bond between substrates at lower temperatures, reducing the risk of thermal stress and contamination, while maintaining the integrity of existing structures and components, with bond strengths exceeding 1.5 J/m2, and can be achieved within a short time frame.
Implementation Method 1
diffusion bond layer which has an average grain diameter H parallel to the contact surface or substrate surface smaller than 1 μm
Data Source
AI summary
A method for coating of a first substrate with a first diffusion bond layer by deposition of a first material which forms the first diffusion bond layer on a first surface of the first substrate such that the first diffusion bond layer forms a grain surface with an average grain diameter H parallel to the first surface smaller than 1 μm. The invention further relates to a method for bonding of a first substrate which has been coated as described above to a second substrate which has a second diffusion bond layer, the method of the bonding comprising the following steps: bring a first diffusion bond layer of a first substrate into contact with a second diffusion bond layer of a second substrate, pressing the substrates together to form a permanent metal diffusion bond between the first and second substrates.