Vacuum pump gas ballast device

Abstract

The invention relates to the technical field of vacuum pump accessories, and particularly discloses a vacuum pump gas ballast device which is arranged on a vacuum pump, an exhaust end is arranged on the vacuum pump, the vacuum pump gas ballast device is arranged in front of a tail end outlet of the exhaust end in a communicating mode, the vacuum pump gas ballast device comprises an adapter pipe body, and the adapter pipe body is connected into the vacuum pump. A control valve body is arranged on the adapter pipe body, the control valve body is used for opening and closing the adapter pipe body, and silencing filter cotton is arranged at the tail end of the adapter pipe body. Dry gas can be introduced near the exhaust end of the vacuum pump, so that condensed gas can be discharged, and the exhaust end can exhaust smoothly.

Description

Technical Field

[0001] This invention relates to the field of vacuum pump accessories technology, specifically a vacuum pump gas ballast device. Background Technology

[0002] To address the challenges of vacuum pumps used in the semiconductor industry, it's crucial to understand the extremely high demands placed on dry vacuum pumps by the industry's processes. While ensuring high vacuum levels, stringent requirements exist for pumping speed and chamber cleanliness. Furthermore, they must possess corrosion resistance (capable of withstanding corrosive gases such as HF, Cl2, and SiH4). However, current dry vacuum pumps used in the semiconductor industry suffer from significant drawbacks, primarily three major issues: 1. Poor process vacuum and low pumping speed: During the process, once the pressure of the gas being pumped exceeds the saturated vapor pressure of the gas at that time, condensable gases will condense. When the condensed gas returns to the low-pressure end, it will evaporate again, causing the vacuum performance and pumping efficiency of the vacuum pump to decrease.

[0003] 2. Vacuum lubricating oil emulsification: The condensed and liquefied gas generated in the process will cause pump oil contamination. Over time, pump oil emulsification will occur, causing it to lose its lubricating and protective function. This will lead to wear on bearings and other linkage parts, resulting in reduced pump performance and damage after long-term operation.

[0004] 3. Poor cleanliness of the vacuum process chamber: Because condensable and liquefiable gases are generated during the process, and cannot be completely removed under vacuum conditions, the cleanliness between the process chamber and the pump body cannot be guaranteed. This may result in substandard quality of the partially completed product. Summary of the Invention

[0005] The purpose of this invention is to provide a vacuum pump gas ballast device to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: a vacuum pump gas ballast device, which is installed on a vacuum pump. The vacuum pump is provided with an exhaust end. The vacuum pump gas ballast device is connected to the end outlet of the exhaust end. The vacuum pump gas ballast device includes a transfer pipe body, which is connected to the vacuum pump. A control valve body is provided on the transfer pipe body, which is used to open and close the transfer pipe body. A sound-absorbing filter cotton is provided at the end of the transfer pipe body.

[0007] Furthermore, the transfer pipe includes a first pipe and a second pipe that are connected to each other, the first pipe and the second pipe are arranged perpendicularly, the control valve body is arranged on the first pipe, and the sound-absorbing filter cotton is arranged at the end of the second pipe.

[0008] Furthermore, the first pipe and the second pipe are connected by an adapter.

[0009] Furthermore, the first pipe is positioned near the rotor of the vacuum pump.

[0010] Furthermore, the control valve body can control the gas flow rate entering the first pipeline.

[0011] The present invention has the following beneficial effects: This invention allows for the intake of dry gas near the exhaust end of a vacuum pump via negative pressure or by actively introducing it, which helps to expel condensed gas and ensures smooth exhaust from the exhaust end. After shutting down the gas ballast device, a vacuum test was conducted, and the actual test showed a significant improvement in vacuum level, as well as a slight increase in pumping speed at different vacuum levels.

[0012] This invention uses a gas ballast to timely inject dry, permanent gas, causing the overall pressure inside the pump chamber to reach the exhaust pressure in advance for discharge, thereby preventing the condensable gas from condensing and ensuring the cleanliness of the vacuum chamber.

[0013] This invention ensures that the vacuum pump chamber is relatively clean and dry, resulting in less residual corrosive gas compared to vacuum pumps without gas ballast devices. This effectively extends the replacement cycle of vacuum pump sealing components such as O-rings and easily corroded metals, thus reducing the maintenance and operating costs of the vacuum pump. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the vacuum pump gas ballast device combined with a vacuum pump in Example 1; Figure 2 for Figure 1 An enlarged schematic diagram of a vacuum pump gas ballast device. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 like Figures 1-2As shown, the vacuum pump gas ballast device in this embodiment is installed on the vacuum pump 10. The vacuum pump is provided with an exhaust end, especially in the area near the rotor. The vacuum pump gas ballast device is connected to the end outlet of the exhaust end. It can draw in external air or a specific gas source at the negative pressure position of the exhaust channel and then discharge it with the exhaust end.

[0018] Here, the vacuum pump gas ballast device includes a transfer pipe body 11, which is connected to the vacuum pump 10. A control valve body 12 is provided on the transfer pipe body 11, which is used to open and close the transfer pipe body 11. A sound-absorbing filter cotton 13 is provided at the end of the transfer pipe body 11.

[0019] Furthermore, the adapter body 11 includes a first pipe 111 and a second pipe 112 that are connected to each other. The first pipe 111 and the second pipe 112 are arranged perpendicularly. The control valve body 12 is arranged on the first pipe 111. The sound-absorbing filter cotton 13 is arranged at the end of the second pipe 112. The first pipe 111 and the second pipe 112 are connected by an adapter 14.

[0020] Meanwhile, the control valve body 12 can be manually opened and closed, or it can be a solenoid valve structure that electrically controls the flow rate of the dry gas.

[0021] It should be noted that if a process is to be carried out under high vacuum conditions, the gas ballast must be turned off. Therefore, the gas ballast must be used before a high vacuum process. If conditions are limited, the air inlet of the gas ballast device can be connected to the air. The outside air is drawn into the chamber by the pump body itself to achieve the gas ballast effect. If the outside air is relatively humid, drying and filtering components must be installed at the air inlet of the gas ballast for use.

[0022] Of course, if the process vacuum requirement is low, the gas ballast device can be kept running for a long time, and the flow rate of the drying gas such as nitrogen can be controlled. Usually, the flow rate is controlled at 5 to 20 L / min, which effectively reduces the cost of using the vacuum pump and has minimal impact on its working efficiency.

[0023] After multiple tests, it was determined that adding a gas ballast device to the first-stage rotor at the high-pressure end of the vacuum pump has the best purging effect, the greatest improvement in the ultimate vacuum after gas ballast purging, the least amount of condensable gas residue in the process test chamber, and also a significant advantage in pumping speed.

[0024] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A vacuum pump gas ballast device, mounted on a vacuum pump, wherein the vacuum pump is provided with an exhaust end, characterized in that, The vacuum pump gas ballast device is connected and installed before the end outlet of the exhaust end. The vacuum pump gas ballast device includes a transfer pipe body, which is connected to the vacuum pump. A control valve body is provided on the transfer pipe body, which is used to open and close the transfer pipe body. A sound-absorbing filter cotton is provided at the end of the transfer pipe body.

2. The vacuum pump gas ballast device according to claim 1, characterized in that: The transfer pipe includes a first pipe and a second pipe that are connected to each other. The first pipe and the second pipe are arranged perpendicularly. The control valve body is arranged on the first pipe, and the sound-absorbing filter cotton is arranged at the end of the second pipe.

3. The vacuum pump gas ballast device according to claim 2, characterized in that: The first pipe and the second pipe are connected by an adapter.

4. The vacuum pump gas ballast device according to claim 1, characterized in that: The first pipe is located near the rotor of the vacuum pump.

5. A vacuum pump gas ballast device according to claim 1, characterized in that: The control valve body can control the gas flow rate entering the first pipeline.

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