Liquid Storage Device Pressure Control via Differential Gas Compensation
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Solution Overview
Problem
Conventional liquid storage devices for semiconductor manufacturing face issues with pressure instability due to mechanical sensitivity loss in interlock mechanisms, leading to potential damage and contamination risks, especially with the use of chemical liquids like ST250 and ammonia, which require high purity and stable conditions.
Innovation Solution
A liquid storage device incorporating a gas compensating tube with a differential pressure mechanism, comprising a gas storage tank and a spring-activated sealing plate, automatically controls gas flow into the liquid storage tank to maintain pressure stability and prevent contamination, replacing the need for a liquid seal container.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure relief valve and vacuum breaking valve are used to control pressure in liquid storage tank, then pressure control function is provided, but mechanical sensitivity is lost after certain time leading to unstable pressure
Solution Approach 1:
The patent removes the mechanical interlock mechanism (pressure relief valve and vacuum breaking valve) from the system and replaces it with a liquid seal mechanism. The liquid seal container with liquid seal (typically de-ionized water) provides pressure control through liquid column height without moving parts, eliminating the sensitivity loss problem while maintaining pressure control functionality throughout the service life.
Solution Approach 2:
The patent substitutes the mechanical interlock system with a hydraulic/liquid-based system. The liquid seal mechanism uses liquid pressure and column height to control the opening and closing of the liquid seal container, replacing mechanical valves and interlocks with a fluid-based control mechanism that has no moving parts subject to wear or sensitivity loss.
2Stability of the object's composition
If liquid seal container with de-ionized water is used to maintain stable pressure, then pressure stability is improved, but bacterial growth is encouraged requiring quality control
Solution Approach 1:
The patent introduces nitrogen gas into the liquid seal container to create an inert atmosphere that prevents bacterial growth in the de-ionized water. The nitrogen gas layer above the liquid seal eliminates oxygen and other contaminants that would support bacterial proliferation, while maintaining the liquid seal's pressure stability function. This allows the use of de-ionized water without the harmful effects of bacterial contamination.
3Reliability
If overflow tube extends into liquid seal container to prevent liquid flow back, then liquid backup is prevented, but depth adjustment is required to avoid flow back into storage tank
Solution Approach 1:
The patent designs the liquid seal container with a specific structure where the liquid seal automatically maintains the correct level without requiring manual adjustment of the overflow tube. The container geometry and liquid seal volume are designed to self-regulate the liquid level, eliminating the need for operational adjustment while preventing liquid flow back into the storage tank.
4Device complexity
If conventional liquid storage device is used, then simple structure is maintained, but chemical liquids may be damaged and discharge may be affected under pressure instability
Solution Approach 1:
The patent nests the liquid seal container within the liquid storage tank system, with the liquid seal container positioned inside or integrated with the main storage tank. This nested structure provides pressure stabilization and chemical liquid protection without adding significant external complexity, as the liquid seal mechanism is incorporated into the existing storage device architecture.
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 ensures stable pressure conditions, prevents chemical liquid damage, and facilitates smooth discharge of chemicals by rapidly supplying protective gas, thereby enhancing the reliability and efficiency of chemical liquid storage in semiconductor manufacturing processes.
Implementation Method 1
a differential pressure mechanism having one end connected with the liquid storage tank and the other end connected with the gas storage tank for controlling the connection or disconnection between the liquid storage tank and the gas storage tank according to the pressure difference therebetween
Implementation Method 2
a spring-activated sealing plate
Data Source
AI summary
The present invention provides a liquid storage device relates to the field of semiconductor manufacturing technology comprising: a liquid storage tank, a liquid intake tube, a liquid discharge tube and a gas discharge tube; the liquid intake tube, the liquid discharge tube and the gas discharge tube are all connected with the liquid storage tank; the liquid storage device also comprises a gas compensating tube connected with the liquid storage tank; the gas compensating tube comprises a differential pressure mechanism and a gas storage tank; one end of the differential pressure mechanism is connected with the liquid storage tank, and the other end is connected with the gas storage tank; the differential pressure mechanism is used for controlling the connection or disconnection between the liquid storage tank and the gas storage tank according to the pressure difference therebetween.