Parylene Coating Vacuum Pump Staging for Faster Pump-Down
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Solution Overview
Problem
Current parylene coating systems face challenges with slow pump down times and high costs, making them impractical for wide-scale application due to inefficient use of single oil pumps and other pumping systems that are ineffective at lower pressures.
Innovation Solution
Integration of multiple turbo pumps into the pumping system, including a controller to manage the switching between different pumps based on pressure levels, optimizing the pump down process to achieve and maintain target pressures efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single oil pump is used for vacuum pumping, then the system structure is simple, but the pump down time is long and the pumping efficiency is low
Solution Approach 1:
The patent divides the vacuum pumping process into two distinct stages: rough pumping (using a mechanical pump to achieve initial vacuum) and high vacuum pumping (using a turbomolecular pump to achieve final vacuum). This segmentation allows each pump type to operate in its optimal pressure range, significantly reducing total pump down time compared to using a single pump for the entire range.
Solution Approach 2:
The system dynamically switches between different pump configurations based on the current pressure level. The controller automatically transitions from mechanical pump-only operation to combined turbomolecular and mechanical pump operation when the cutoff pressure is reached, optimizing pumping speed at each stage of the vacuum process.
2Productivity
If a turbomolecular pump is used alone for high vacuum, then the pumping speed at low pressure is high, but the pump cannot operate effectively at atmospheric pressure
Solution Approach 1:
The patent creates a universal pumping system that can handle the entire pressure range from atmospheric to high vacuum. The mechanical pump provides broad pressure range coverage, while the turbomolecular pump enhances performance in the high vacuum regime. Together, they form a multi-functional system that adapts to different operating conditions through automatic switching.
Solution Approach 2:
The mechanical pump acts as an intermediary that prepares the system for turbomolecular pump operation by first establishing the cutoff pressure. This intermediate step enables the turbomolecular pump to operate effectively in its optimal pressure range, while the mechanical pump continues to provide backing pressure and handles the broader pressure range.
3Loss of time
If multiple pumps are integrated into the pumping system, then the pump down time is reduced, but the system complexity increases
Solution Approach 1:
The system incorporates pressure sensors and controllers that continuously monitor the vacuum level and automatically switch between pump configurations based on the cutoff pressure. This feedback mechanism simplifies operation by eliminating manual intervention, allowing the system to manage its increased complexity through automated control while achieving faster pump down times.
4Productivity
If a mechanical pump is used for the entire vacuum range, then the system is cost-effective, but the pumping speed at low pressure is insufficient
Solution Approach 1:
The patent applies different pump technologies to different pressure ranges based on their optimal performance characteristics. The mechanical pump handles the rough vacuum range where it is most effective and cost-efficient, while the turbomolecular pump is deployed for the high vacuum range where it provides superior pumping speed and vacuum quality. This localized application of appropriate technologies optimizes both performance and cost.
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
Reduces pump down time and costs, making parylene coating more accessible and feasible for a variety of parts and substrates by enhancing pumping speed and efficiency.
Implementation Method 1
a pumping system including at least a mechanical pump and a turbomolecular pump... continue, using the turbomolecular pump, the pump down operation of the deposition chamber until the internal pressure is at or below a target pressure for thin-film deposition
Implementation Method 2
monitor an internal pressure of the deposition chamber... determine a cut-in pressure for switching operation from the first pump to the second pump
Data Source
AI summary
A method for providing a parylene deposition comprises a coating system including a chamber, a pumping system having a first and a second pump, where a pumping speed of the first and second pumps is based at least in part on an operating pressure; and a controller, the controller configured by machine-readable instructions to control activation of the first pump to initiate a pump down operation of the chamber, determine a cut-in pressure for switching operation from the first to the second pump, monitor an internal pressure of the chamber, switch operation to the second pump based at least in part on determining that the internal pressure of the chamber is at or below the cut-in pressure; and continue, using the second pump, the pump down operation of the deposition chamber until the internal pressure is at or below a target pressure for parylene deposition.