Thermal Barrier Struts for Capacitance Diaphragm Gauge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitance diaphragm gauges (CDGs) are highly sensitive to contamination and coating, affecting their accuracy and reliability, especially in semiconductor wafer processing, where maintaining the diaphragm at a higher temperature to prevent condensation is limited by the electronics' thermal management capabilities.
Innovation Solution
A thermal barrier system that separates the diaphragm, operating at a higher temperature, from the electronics, using a structure with a plurality of struts to reduce heat transfer while maintaining mechanical interconnection, allowing the diaphragm to be heated to a higher temperature without overheating the electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diaphragm temperature is increased to prevent condensation and contamination, then measurement accuracy and reliability are improved, but the electronics temperature increases causing thermal damage and reduced reliability
Solution Approach 1:
The housing is divided into a high-temperature section (first housing portion) containing the diaphragm and a low-temperature section (second housing portion) containing the electronics, connected by a thermal barrier. This segmentation allows each section to operate at its optimal temperature independently, preventing heat transfer from the heated diaphragm to the temperature-sensitive electronics.
Solution Approach 2:
A thermal barrier (intermediate structure) is introduced between the high-temperature diaphragm section and the low-temperature electronics section. This intermediary component blocks thermal energy transfer while maintaining mechanical connection and signal transmission, allowing the diaphragm to be heated without overheating the electronics.
2Measurement precision
If the diaphragm temperature is increased to minimize contamination, then measurement accuracy is improved, but heat transfer to electronics reduces system reliability
Solution Approach 1:
The housing is segmented into thermal zones with the diaphragm in a heated zone for contamination prevention and electronics in a cooled zone for reliability, connected through a thermal barrier that maintains measurement precision while protecting system reliability.
Solution Approach 2:
The thermal barrier acts as an intermediary that allows the diaphragm to operate at elevated temperatures for accurate pressure measurement while preventing heat transfer that would compromise system reliability through electronic component failure.
3Loss of energy
If thermal insulation techniques are used to separate diaphragm and electronics, then heat transfer is reduced, but the maximum heat differential is limited
Solution Approach 1:
Different sections of the housing have different thermal properties: the first housing portion is designed for high-temperature operation with contamination-resistant properties, while the second housing portion is designed for low-temperature electronic operation, with the thermal barrier providing localized thermal management at the interface.
Solution Approach 2:
The thermal barrier employs composite construction with multiple materials having different thermal conductivities, including insulating materials and structural materials, to achieve both thermal isolation and mechanical strength while withstanding significant heat differentials beyond the limits of single-material solutions.
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 solution effectively reduces heat transfer from the heated diaphragm to the electronics, enabling the diaphragm to be maintained at a higher temperature, thus minimizing contamination and maintaining accurate pressure measurements while keeping the electronics at a safe temperature.
Implementation Method 1
an intermediate thermal restriction and ventilation portion interconnecting the first wall and the second wall
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A capacitive diaphragm gauge (CDG) is positioned in a pressure sensing section of a pressure measuring unit. The CDG is heated to maintain the CDG at a temperature selected to reduce contamination build-up on the diaphragm of the CDG. The pressure sensing section is connected to a first mounting interface of a thermal barrier. A second mounting interface of the thermal barrier is connected to an electronics section. The thermal barrier includes a plurality of struts that mechanically interconnect the first mounting interface to the second mounting interface. The struts have sizes selected to be sufficiently large to cantilever the electronics section from the sensing section. The sizes of the struts are selected to be sufficiently small to reduce the heat transfer from the first mounting interface to the second mounting interface to maintain the second mounting interface below a selected maximum temperature.