Cylindrical Sputtering Target Assembly Defect Reduction
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Solution Overview
Problem
Conventional sputtering target assemblies for large-size flat panel displays (FPDs) suffer from defects such as particle adhesion due to the piece-bonding area, leading to reduced yield and productivity, as the existing technologies fail to effectively prevent nodule formation and particle occurrence during sputtering.
Innovation Solution
A sputtering target assembly comprising cylindrical sputtering target-backing tube bonded bodies, where the target pieces are bonded onto a cylindrical or columnar backing tube with dividing lines in the circumferential direction, ensuring that the dividing lines between adjacent bonded bodies are not aligned, thereby dispersing particles and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If target pieces are bonded onto a flat backing plate to form large-size targets, then the target size is increased to meet FPD production requirements, but dividing lines between target pieces align and cause nodule formation and particle adhesion
Solution Approach 1:
The patent applies curvature by changing the backing plate from a flat surface to a cylindrical surface. Target pieces are bonded onto the cylindrical backing plate such that their dividing lines are arranged circumferentially, preventing alignment of dividing lines between adjacent target pieces and eliminating nodule formation during sputtering.
Solution Approach 2:
The patent transitions from a two-dimensional flat arrangement to a three-dimensional cylindrical arrangement. By wrapping target pieces around a cylindrical backing plate, the dividing lines are distributed in the circumferential direction, preventing their alignment in any single location and reducing particle adhesion.
2Ease of manufacture
If target pieces are finely aligned on a flat backing plate for easy production, then manufacturing ease is improved, but dividing lines align and cause concentration of particle adhesion at specific positions
Solution Approach 1:
By using a cylindrical backing plate, the patent automatically prevents dividing line alignment while maintaining ease of assembly. The circumferential arrangement of target pieces on the curved surface ensures that dividing lines are distributed around the cylinder rather than concentrated at specific positions.
3Device complexity
If dividing lines between target pieces are aligned, then target assembly is simplified, but nodules are generated during sputtering and yield is reduced
Solution Approach 1:
The cylindrical backing plate provides a simple yet effective solution to prevent dividing line alignment. The curved surface naturally distributes dividing lines circumferentially, eliminating nodule formation and maintaining high film formation yield without complicating the assembly process.
4Area of stationary object
If large-size targets are produced by arranging multiple target-backing plate bonded bodies in the width direction, then target size is increased, but dividing lines align between adjacent bonded bodies and cause stripe-shaped particle adhesion
Solution Approach 1:
By transitioning from a flat two-dimensional arrangement to a three-dimensional cylindrical arrangement, the patent distributes dividing lines in the circumferential direction. This prevents dividing lines from aligning between adjacent target-backing plate bonded bodies, eliminating stripe-shaped particle adhesion patterns.
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 cylindrical sputtering target assembly significantly reduces particle defects, increases yield, and improves product quality by dispersing particles from the bonding area, achieving a film formation efficiency equivalent to large-size tabular targets while minimizing the target assembly's size and manufacturing complexity.
Implementation Method 1
a sputtering target-backing tube bonded body 8, in which a sputtering target composed of a plurality of cylindrical pieces 10 is bonded or placed on a cylindrical or columnar backing tube 5
Data Source
AI summary
Provided is a sputtering target assembly comprising two or more sputtering target-backing plate bonded bodies B aligned in the width direction, wherein the sputtering target-backing plate bonded bodies B each include a cylindrical target having a diameter of 100 mm or more and a length of 1000 mm or more and composed of three or more target pieces A being divided such that the dividing lines lie in the circumferential direction and being bonded or placed onto a cylindrical or columnar backing plate, wherein the bonded bodies B are arranged to form the sputtering target assembly in such a manner that the dividing lines between the three target pieces of one bonded body B are not present at the same positions of the dividing lines between fractional target pieces of adjacent another bonded body B. It is an object of the present invention to provide a sputtering target assembly that can reduce defects due to occurrence of particles originated from the piece-bonding area.