Ceramic Member Voltage Supply Rod Heat Dissipation
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Solution Overview
Problem
The existing ceramic members with voltage supply rods experience uneven temperature distribution due to heat dissipation, leading to local temperature variations on the surface, which affects the uniform heating of Si wafers.
Innovation Solution
A ceramic member design incorporating a voltage supply rod with a heat-transfer reducing portion having lower thermal conductivity and cross-sectional area at its far end, compared to the base end, to minimize heat dissipation and maintain a uniform temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid round bar voltage supply rod made of highly electrically conductive metal is used, then electrical conductivity is improved, but heat dissipation increases causing local temperature drop
Solution Approach 1:
The voltage supply rod is divided into two portions with different cross-sectional areas: a base end portion with larger cross-section for electrical connection and a far end portion with smaller cross-section to reduce heat dissipation. This local variation in geometry allows the rod to maintain high electrical conductivity where needed while minimizing thermal conduction to the substrate, thereby resolving the contradiction between electrical conductivity and temperature uniformity.
Solution Approach 2:
The invention changes the geometric parameter (cross-sectional area) of the voltage supply rod along its length. By reducing the cross-sectional area from the base end to the far end, the thermal conductivity parameter (k·A) is reduced at the far end, decreasing heat dissipation to the substrate and preventing local temperature drop, while maintaining sufficient electrical conductivity through the rod.
2Temperature
If the heat capacity of the voltage supply rod is reduced to prevent uneven temperature distribution, then temperature uniformity is improved, but electrical conductivity decreases
Solution Approach 1:
The voltage supply rod employs different cross-sectional dimensions at different locations: the base end portion maintains a larger cross-section to ensure adequate electrical conductivity and mechanical strength, while the far end portion uses a smaller cross-section to reduce heat capacity and minimize heat dissipation to the substrate. This localized differentiation resolves the contradiction between maintaining electrical conductivity and achieving temperature uniformity.
3Ease of manufacture
If a uniform cross-section voltage supply rod is used throughout, then manufacturing simplicity is maintained, but heat dissipation causes local temperature drop above the rod
Solution Approach 1:
The voltage supply rod is designed with a stepped cross-section, where the base end portion has a larger cross-sectional area than the far end portion. This local variation in geometry is achieved through conventional manufacturing processes and effectively reduces heat dissipation at the far end, preventing local temperature drop on the substrate while maintaining manufacturing feasibility.
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 design effectively reduces the local temperature drop on the ceramic base and Si wafers, improving temperature uniformity and reducing heat dissipation through the voltage supply rod.
Implementation Method 1
the heat-transfer reducing portion has thermal conductivity k2 and a cross-sectional area A2 in a cross section taken perpendicularly to the longitudinal direction. The thermal conductivity k2 and the cross-sectional area A2 satisfy a formula k2·A2 < k1·A1
Data Source
AI summary
A ceramic member includes a voltage supply rod capable of reducing a local temperature drop of the ceramic member. The ceramic member comprises a ceramic base, a metal body disposed inside the ceramic base, and a voltage supply rod made of an electrically conductive material and having a far end portion electrically connected to the metal body. The far end portion is located at an end of the voltage supply rod in a longitudinal direction. The voltage supply rod also includes a heat-transfer reducing portion continuous with the far end portion. The heat-transfer reducing portion has thermal conductivity k2 and a cross-sectional area A2 in a cross section taken perpendicularly to the longitudinal direction. The thermal conductivity k2 and the cross-sectional area A2 satisfy a formula k2·A2<k1·A1, where k1 denotes thermal conductivity of the base end portion, and A1 denotes a cross-sectional area of the base end portion.