Nano-Scale Diffusion Bonding for Dissimilar Material Seals
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Solution Overview
Problem
Traditional methods for bonding dissimilar materials like sapphire and titanium, such as diffusion bonding and soldering, often result in weak bonds, contamination, and damage to internal components due to high temperatures and pressures, and are prone to crack generation from thermal expansion mismatches.
Innovation Solution
A kinetically limited nano-scale diffusion bond is formed using an electromagnetic beam to bond transparent and absorbent materials at room temperature, creating a thin, crack-free, and hermetic interface with properties similar to the bulk materials, minimizing thermal stress and undesirable compound formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional diffusion bonding is used to bond dissimilar materials, then bond strength is achieved, but high temperatures cause grain growth, alter physical properties, and generate cracks due to thermal expansion mismatch
Solution Approach 1:
The invention changes the bonding parameters from high temperature (600-1000°C) to low temperature (room temperature or slightly elevated), and from long duration to short duration (kinetically limited process). This resolves the contradiction by achieving bond strength without the harmful thermal effects that cause grain growth, property alteration, and crack generation.
Solution Approach 2:
The invention replaces the thermal field (heat-based diffusion bonding) with an electromagnetic field (laser or electron beam irradiation). This substitution enables bonding at low temperatures by using electromagnetic energy to drive the diffusion process locally at the interface, avoiding bulk heating and associated thermal damage.
2Strength
If high temperature diffusion bonding is used, then material bonding is achieved, but internal components within the package are damaged by high temperatures
Solution Approach 1:
The invention changes the temperature parameter from high (600-1000°C) to low (room temperature or slightly elevated), enabling bond formation without exposing internal components to damaging high temperatures. The kinetically limited process achieves bonding through short-duration electromagnetic irradiation rather than prolonged thermal exposure.
Solution Approach 2:
The invention substitutes thermal energy with electromagnetic energy (laser or electron beam) to achieve bonding. This allows the bonding process to occur at low bulk temperatures, protecting temperature-sensitive internal components while still providing sufficient energy at the bond interface to create strong joints.
3Area of stationary object
If traditional diffusion bonding creates large interaction zones, then bond coverage is achieved, but crack sizes increase and reliability decreases
Solution Approach 1:
The invention creates a localized bond interface with distinct properties: a thin diffusion zone (nanometer to sub-micrometer scale) with high atomic mixing and a sharp transition to undisturbed bulk materials. This local quality approach concentrates the bonding action at the interface while preserving the integrity of the bulk materials, thereby achieving adequate bond area without the crack propagation issues associated with large interaction zones.
Solution Approach 2:
The invention changes the spatial scale parameter of the interaction zone from micrometer/millimeter scale (traditional diffusion bonding) to nanometer/sub-micrometer scale (kinetically limited bonding). This dramatic reduction in interaction zone size, achieved through short-duration electromagnetic irradiation, prevents crack initiation and propagation while maintaining sufficient bond strength across the interface.
4Temperature
If intermediate layers like solder or glass frit are used for low temperature bonding, then bonding of dissimilar materials is achieved, but bond strength is inferior and susceptibility to corrosion increases
Solution Approach 1:
The invention extracts and eliminates the intermediate layer (solder, glass frit, or other bonding materials) from the bonding system. By using electromagnetic irradiation to directly induce diffusion bonding between the dissimilar materials at low temperatures, the process achieves strong, corrosion-resistant bonds without requiring separate bonding materials that would compromise strength or introduce corrosion vulnerabilities.
Solution Approach 2:
The invention uses electromagnetic radiation (laser or electron beam) as an intermediary energy source to enable direct bonding between dissimilar materials at low temperatures. This intermediary provides the necessary energy to drive diffusion at the interface without requiring thermal heating or intermediate bonding materials, thereby achieving both low temperature processing and superior bond strength with corrosion resistance.
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
The method produces bonds with strength equivalent to the bulk materials, providing a hermetic, corrosion-resistant, and bio-stable connection without damaging the components, and is applicable to materials with varying thermal expansion coefficients.
Implementation Method 1
The absorbent opaque material has properties that significantly absorb energy from the electromagnetic beam
Implementation Method 2
A kinetically limited nano-scale diffusion bond is formed using an electromagnetic beam to bond transparent and absorbent materials
Data Source
AI summary
Bulk materials having a kinetically limited nano-scale diffusion bond is provided. The bulk materials having a kinetically limited nano-scale diffusion bond includes transparent material, absorbent opaque material and a diffusion bond. The transparent material has properties that allow an electromagnetic beam of a select wavelength to pass there through without more than minimal energy absorption. The absorbent opaque material has properties that significantly absorb energy from the electromagnetic beam. The diffusion bond is formed by the electromagnetic beam bonding the transparent material to the absorbent opaque material. Moreover, the diffusion bond has a thickness that is less than 1000 nm.