Multilayer Brazed Joint Structure for Thermal Cycling Resistance
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Solution Overview
Problem
Brazed joints in semiconductor processing chamber components experience frequent maintenance due to component failures, necessitating improved reliability and longevity to reduce maintenance outages.
Innovation Solution
A multilayer brazed joint construction incorporating a mesh, insert, and brazing material, with features such as chamfers and expansion volumes to reduce stress concentrations, and a conformal layer of chromium, tungsten, titanium, or nitrides to enhance bonding and strength, is used, along with a deoxidization process and controlled heating and cooling to prevent excess stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional brazed joints are used in semiconductor processing chamber components, then the components can be assembled and operated, but the brazed joints experience frequent failures requiring maintenance
Solution Approach 1:
The patent applies composite materials by creating a multilayer brazed joint structure consisting of a ceramic body, metallic rod, mesh layer, insert, and conformal layer. This composite construction combines materials with different properties (ceramic for thermal stability, metal for structural strength, mesh for stress distribution) to achieve superior reliability and resistance to thermal cycling compared to conventional single-material brazed joints.
Solution Approach 2:
The patent implements local quality by adding specific features at critical locations within the brazed joint. The mesh is positioned within the brazing material to locally reinforce stress-prone areas, the conformal layer is applied specifically on the ceramic body surface to enhance bonding, and chamfers are added to the metallic rod to locally reduce stress concentration at geometric discontinuities.
2Productivity
If brazed joints are subjected to thermal cycling in semiconductor processing, then the processing operations can be performed, but stress-induced cracking occurs reducing joint durability
Solution Approach 1:
The patent applies parameter changes by modifying the geometric parameters of the brazed joint components. Chamfers are added to the metallic rod to change the stress distribution pattern, reducing peak stresses during thermal cycling. The mesh structure changes the local stiffness and stress distribution parameters within the brazing material, preventing crack initiation and propagation under thermal load.
Solution Approach 2:
The patent implements beforehand cushioning by incorporating the mesh layer within the brazing material and the conformal layer on the ceramic body before the brazing process. These layers act as pre-positioned stress distributors and bonding enhancers that cushion the joint against thermal stresses before they occur during semiconductor processing operations.
3Device complexity
If stress concentrations are present in brazed joints, then the joints can be formed with simple construction, but component failures occur frequently requiring maintenance
Solution Approach 1:
The patent applies segmentation by dividing the brazed joint into distinct functional layers: a ceramic body, a metallic rod, a mesh layer, an insert, and a conformal layer. This segmented construction allows each layer to perform its specific function (structural support, stress distribution, bonding enhancement) while collectively achieving high reliability without excessive overall complexity.
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 solution significantly reduces stress-induced cracking and enhances the durability of brazed joints, leading to increased resistance to thermal cycling and improved operational life of semiconductor processing chamber components.
Implementation Method 1
The metallic joint component and a brazing material are disposed within a recess in a ceramic body. The metallic component, the brazing material, and the ceramic body are heated to form the brazed ceramic joint.
Implementation Method 2
A method of creating a brazed joint includes deoxidizing the surfaces of a metallic joint component.
Data Source
AI summary
Methods of forming a metallic-ceramic brazed joint are disclosed herein. The method of forming the brazed joint includes deoxidizing the surface of metallic components, assembling the joint, heating the joint to fuse the joint components, and cooling the joint. In certain embodiments, the brazed joint includes a conformal layer. In further embodiments, the brazed joint has features in order to reduce stress concentrations within the joint.