Rotatable Sputtering Target Compressible Joint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The jointing process of rotatable sputtering targets is complex and prone to thermal stress, leading to detachment and reduced sputtering efficiency, as conventional low-melting-point solders and different thermal expansion coefficients between materials cause stress and cracking.
Innovation Solution
A compressible joint piece with electrically and thermally conductive adhesive, featuring multiple through holes, is used to securely bond the target material and back tube, providing deformability and enhanced conductivity to manage thermal and volume discrepancies, thereby reducing the risk of cracking and improving sputtering power tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low-melting-point metal solder is used to joint the target material and back tube, then the jointing process is simplified, but the joint strength is weak and the target material is prone to detachment during sputtering
Solution Approach 1:
The patent changes the material parameters of the joint piece by using a compressible material with specific physical properties (compressibility, thermal conductivity, electrical conductivity) instead of traditional solder. This allows the joint piece to maintain strong bonding while accommodating thermal expansion differences and providing adequate mechanical strength during sputtering operations.
Solution Approach 2:
The joint piece is designed as a composite structure that combines multiple properties: compressibility to accommodate thermal stress, thermal conductivity to manage heat during sputtering, and electrical conductivity to maintain electrical continuity. This composite approach resolves the contradiction between ease of manufacture and joint strength.
2Ease of manufacture
If materials with different coefficients of thermal expansion are used for back tube, solder, and target material, then the jointing process is simplified, but thermal stress occurs during soldering or sputtering causing target material rupture
Solution Approach 1:
The patent changes the physical parameters of the joint piece material to include compressibility and matched thermal expansion characteristics. This allows the joint piece to absorb thermal stress through compression while maintaining dimensional stability, preventing target material rupture during temperature changes in soldering and sputtering processes.
Solution Approach 2:
The compressible joint piece acts as a pre-designed cushioning element that anticipates and absorbs thermal stress before it can cause damage. The compressibility provides a buffer zone that accommodates expansion and contraction cycles, protecting the target material from rupture.
3Reliability
If a compressible joint material is used to replace solder, then thermal stress is reduced, but the joint piece cannot transfer heat accumulated on the target material during sputtering, deteriorating sputtering power tolerance
Solution Approach 1:
The joint piece combines compressibility for thermal stress management with high thermal conductivity for heat transfer. This composite material property combination resolves the contradiction by allowing the joint piece to simultaneously cushion thermal expansion while efficiently conducting heat away from the target material during sputtering.
Solution Approach 2:
The patent changes the thermal parameters of the joint piece by selecting materials with appropriate thermal conductivity values. This ensures that while the joint piece remains compressible for stress management, it also maintains sufficient thermal conductivity to transfer heat during sputtering operations, preserving power tolerance.
4Ease of manufacture
If solder volume shrinks during solidification, then the jointing process is simplified, but shrinking stress causes the joint layer to detach from the back tube and target material
Solution Approach 1:
The patent changes the physical state parameters of the joint piece by using a compressible material that can undergo controlled compression without phase change. This eliminates the volume shrinkage problem associated with solder solidification while maintaining the ability to fill gaps and provide strong adhesion through compression during 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
The solution simplifies the jointing process, enhances joint strength, and increases sputtering power tolerance, leading to improved efficiency and extended target lifetime by effectively managing thermal stress and maintaining a strong, conductive bond between the target material and back tube.
Implementation Method 1
the electrically and thermally conductive adhesive is filled into the through holes and is formed between the target material and the back tube
Implementation Method 2
the back tube, the solder and the target material are made of materials with different coefficients of thermal expansion
Implementation Method 3
a compressible joint piece with electrically and thermally conductive adhesive, featuring multiple through holes, is used to securely bond the target material and back tube, providing deformability
Implementation Method 4
the electrically and thermally conductive adhesive is filled into the through holes and is formed between the target material and the back tube
Data Source
AI summary
A rotatable sputtering target has a target material, a back tube and a joint piece. The joint piece is disposed between the target material and the back tube. The joint piece has a compressible structure and an electrically and thermally conductive adhesive. Particularly, the compressible structure being a compressible blanket or a compressible sheet has multiple through holes and thus the electrically and thermally conductive adhesive is filled in the through holes and then directly formed between the target material and the back tube. Using the joint piece to joint the target material and the back tube not only maintains the joint strength but also elevates the tolerable power of the rotatable sputtering target, which can increase the sputtering efficiency.