Nickel-Carbon Braze Alloys for Lower-Temperature Ceramic Joining
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Solution Overview
Problem
Current methods for joining ceramic materials are costly, require high temperatures and pressures, and often result in non-hermetic seals, making them unsuitable for applications like semiconductor manufacturing where materials like sapphire and yttrium oxide would provide better performance but are limited by manufacturing and cost constraints.
Innovation Solution
The use of Nickel-Carbon and Nickel-Cobalt-Carbon alloys for brazing ceramics to ceramics, ceramics to metals, and metals to metals, allowing for hermetic seals and cost-effective manufacturing of components that can withstand high temperatures and corrosive environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If liquid phase sintering is used to join ceramic materials, then strong bonds are achieved, but very high temperatures and very high contact pressures are required
Solution Approach 1:
A braze alloy layer comprising nickel and carbon acts as an intermediary material between the ceramic components. The braze alloy has a lower melting point than the ceramics being joined, enabling bonding at reduced temperatures. The braze layer wetts the ceramic surfaces and forms strong metallurgical bonds, serving as a mediator that transfers and distributes the bonding forces without requiring the extreme temperatures and pressures of liquid phase sintering.
2Strength
If diffusion bonding is used to join pieces, then strong structural bonds are achieved, but the pieces are altered such that they form new compounds near the joint
Solution Approach 1:
The braze alloy layer serves as a protective intermediary between the ceramic components, preventing direct diffusion bonding and the formation of unwanted interfacial compounds. The braze layer composition is controlled to be stable and compatible with both ceramics, acting as a barrier that maintains the original composition of the ceramic pieces while still providing strong bonding through the braze material itself.
3Reliability
If specialized fixturing and high temperatures are used for joining, then ceramic pieces are joined, but manufacturing costs increase
Solution Approach 1:
The joining process parameters are changed by using a braze alloy with a lower melting point than traditional methods. This allows the joining temperature to be reduced from very high temperatures to a more moderate range, enabling the use of conventional furnaces rather than specialized high-temperature equipment. The process time is also reduced, and standard fixturing can be used instead of specialized equipment, significantly reducing manufacturing costs while maintaining reliable joints.
4Stability of the object's composition
If Kovar is used to match the coefficient of thermal expansion of ceramic insulator, then thermal expansion match is achieved, but expensive e-beam welding must be used
Solution Approach 1:
The braze alloy comprising nickel and carbon acts as an intermediary joining material between the Kovar metal and ceramic insulator. This braze layer provides both thermal expansion compatibility and a joining mechanism that does not require expensive e-beam welding. The braze process can be performed using conventional equipment, and the braze alloy composition is selected to match the thermal expansion characteristics of both Kovar and ceramic, providing a cost-effective alternative to e-beam welding while maintaining the thermal stability of the assembly.
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 the creation of durable, hermetic joints that can operate at elevated temperatures and resist corrosion, extending the lifespan of components in semiconductor processing and reducing manufacturing costs by leveraging the properties of advanced ceramic materials like sapphire and yttrium oxide.
Implementation Method 1
The joining of ceramic materials may involve processes which require very high temperatures and very high contact pressures
Implementation Method 2
The use of Nickel-Carbon and Nickel-Cobalt-Carbon alloys for brazing ceramics to ceramics, ceramics to metals, and metals to metals
Implementation Method 3
provides a hermetic seal
Implementation Method 4
resist corrosion, extending the lifespan of components in semiconductor processing
Implementation Method 5
provides a joining method for joining ceramic pieces at a lower temperature
Data Source
AI summary
A brazing process using Nickel(Ni)-Carbon as graphite(Cg) alloys, Ni-Cg-Molybdenum(Mo) alloys, and Ni-Cobalt(Co)-Cg-Mo alloys for brazing together ceramics, ceramics to metals, metals to metals. Semiconductor processing equipment made with the use of Ni-Cg alloys, such as heaters and chucks. Semiconductor processing equipment components and industrial equipment components using a highly wear resistant surface layer, such as sapphire, joined to a substrate such as a ceramic, with a Ni-Cg alloy braze.