Vacuumizing pipeline

Abstract

The utility model relates to a vacuumizing pipeline, and relates to the technical field of semiconductor manufacturing, in the vacuumizing pipeline, a working cavity is connected with a first vacuum pump through a main pipeline, a first valve is arranged on the main pipeline and used for controlling the vacuumizing flow of the main pipeline, and a first branch pipeline is connected with the main pipeline on the two sides of the first valve. When vacuumizing is carried out, the first valve is closed, the second vacuum pump carries out pre-vacuumizing on the working cavity through the first branch pipe so as to achieve the vacuum degree for starting the first vacuum pump, then the first valve is opened, namely the main pipe is opened, and the working cavity is vacuumized through the first vacuum pump. Due to the fact that the pumping speed of the first vacuum pump is larger than that of the second vacuum pump and the cross section area of the main pipeline is larger than that of the first branch pipeline, the vacuumizing speed is obviously increased. And the first valve can control the flow, so that the stability in the working cavity during vacuumizing can be ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a vacuum pipeline. BACKGROUND

[0002] CDSEM (Critical Dimension Scanning Electron Microscope) machines play a crucial role in the semiconductor manufacturing process, which is used to measure the size of fine patterns on chips. In a scanning electron microscope, in order to obtain a high-resolution image and reduce the collision of the electron beam with gas molecules, a high vacuum state needs to be maintained in the sample chamber.

[0003] The existing vacuum pipeline of the CDSEM machine is connected to the molecular pump through the dry pump and then connected to the working cavity for vacuumizing. In order to ensure the stability of the pressure in the working cavity, the pipeline setting is relatively thin, so the vacuumizing rate is slow and the efficiency is low.

[0004] Therefore, how to increase the vacuumizing rate and ensure the stability of the pressure has become a technical problem to be solved by the person skilled in the art. CONTENT OF THE UTILITY MODEL

[0005] Therefore, it is necessary to provide a vacuum pipeline for increasing the vacuumizing rate and ensuring the stability of the pressure.

[0006] In order to achieve the above purpose, the utility model provides a kind of vacuum pipeline, comprising:

[0007] working cavity, main pipeline, first valve, first branch pipe, first vacuum pump and second vacuum pump;

[0008] The first end of the main pipeline is connected with the working cavity, and the second end of the main pipeline is connected with the first vacuum pump;The first vacuum pump is used to vacuumize the working cavity;

[0009] The first valve is located on the main pipeline, and is used to control the vacuumizing flow of the main pipeline;

[0010] The first branch pipe connects the main pipeline on both sides of the first valve;

[0011] The second vacuum pump is used to pre-vacuumize the working cavity through the first branch pipe to start the first vacuum pump;

[0012] Wherein, the pumping speed of the first vacuum pump is greater than the pumping speed of the second vacuum pump, and the cross-sectional area of the main pipeline is greater than the cross-sectional area of the first branch pipe.

[0013] In one of the embodiments, the vacuum pumping line further comprises:

[0014] A first detecting device is arranged between the first valve and the working chamber, and is used for detecting the chamber pressure of the working chamber.

[0015] In one of the embodiments, the vacuum pumping line further comprises:

[0016] A second valve is arranged on the first branch pipe, and is used for opening or closing the first branch pipe.

[0017] In one of the embodiments, the vacuum pumping line further comprises:

[0018] A second branch pipe, a first end of the second branch pipe is connected with the second vacuum pump, and a second end of the second branch pipe is connected with the main pipe between the first valve and the first vacuum pump.

[0019] In one of the embodiments, the vacuum pumping line further comprises:

[0020] A third valve is arranged on the second branch pipe, and is used for controlling the on-off of the second vacuum pump.

[0021] In one of the embodiments, the vacuum pumping line further comprises:

[0022] A fourth valve is arranged between the first valve and the first vacuum pump, and is used for opening or closing the main pipe.

[0023] In one of the embodiments, the vacuum pumping line further comprises:

[0024] A second detecting device is arranged between the fourth valve and the first valve, and is used for detecting the pressure of the main pipe.

[0025] In one of the embodiments, the vacuum pumping line further comprises:

[0026] A switching chamber and a third branch pipe, a first end of the third branch pipe is connected with the main pipe between the first valve and the first vacuum pump, and a second end of the third branch pipe is connected with the switching chamber, and the switching chamber is used for vacuum buffering.

[0027] In one of the embodiments, the vacuum pumping line further comprises:

[0028] A fifth valve is arranged on the third branch pipe, and is used for controlling the vacuum pumping flow of the third branch pipe.

[0029] In one of the embodiments, the vacuum pumping line further comprises:

[0030] A third detecting device is arranged between the fifth valve and the conversion cavity, and is used for detecting the cavity pressure of the conversion cavity.

[0031] Compared with the prior art, the above technical solution has the following advantages:

[0032] In the vacuum pipeline, the working cavity is connected with the first vacuum pump through the main pipeline, the first valve is arranged on the main pipeline, the first valve is used for controlling the vacuum flow of the main pipeline, and the first branch pipeline is connected with the main pipeline on both sides of the first valve. When vacuumizing, the first valve is closed, the second vacuum pump pre-vacuums the working cavity through the first branch pipeline to reach the vacuum degree of starting the first vacuum pump, and then the first valve is opened, that is, the main pipeline is opened, and the working cavity is vacuumized by the first vacuum pump. Since the pumping speed of the first vacuum pump is greater than that of the second vacuum pump, and the cross-sectional area of the main pipeline is greater than that of the first branch pipeline, the vacuumizing speed is obviously improved. Since the first valve can control the flow, the stability of the working cavity during vacuumizing can be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0034] Figure 1 A structural schematic diagram of a vacuum pipeline is provided for the embodiments of the present application;

[0035] Figure 2 Another structural schematic diagram of a vacuum pipeline is provided for the embodiments of the present application;

[0036] Figure 3 Another structural schematic diagram of a vacuum pipeline is provided for the embodiments of the present application.

[0037] Explanation of reference signs: 01-working cavity; 02-main pipeline; 03-first valve; 04-first branch pipeline; 05-first vacuum pump; 06-second vacuum pump; 07-first detecting device; 08-second valve; 09-second branch pipeline; 10-third valve; 11-fourth valve; 12-second detecting device; 13-conversion cavity; 14-third branch pipeline; 15-fifth valve; 16-third detecting device. DETAILED DESCRIPTION

[0038] For the purposes of the present application, the present application will be described with reference to the attached drawings. The drawings are provided for purposes of illustration only and merely depict typical or example embodiments of the present application. The present application can be implemented in numerous other ways, and the present application should not be limited to the embodiments described herein.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the present application.

[0040] It should be understood that when a layer is referred to as being "on" or "adjacent" or "connected to" another layer, it can be directly on, adjacent to or connected to the other layer, or intervening layers can also be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to" or "directly connected to" another layer, there are no intervening layers present.

[0041] As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It should be understood that the term "comprises or comprises" or "has" or "having" and the like, specifies the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but does not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

[0042] Based on the content in the background art, the CDSEM machine is currently designed as a dry pump connected to two molecular pumps, and the two molecular pumps are connected to the working cavity and the conversion cavity, respectively. Switching valves are provided between the molecular pump and the working cavity and between the molecular pump and the conversion cavity. In the vacuum pumping pipeline, the dry pump is first opened, and the vacuum is pumped to a certain pressure, then the dry pump is closed and the molecular pump is opened to pump the vacuum. However, in order to ensure the stability of the pressure in the working cavity during vacuum pumping, the pipeline is relatively thin, so the vacuum pumping rate is slow, the efficiency is low, and the rate is slow. After each opening, the working cavity needs to be pumped for more than ten hours.

[0043] Based on this, the application provides a vacuum pipeline, a working cavity of which is connected with a first vacuum pump through a main pipeline, a first valve is arranged on the main pipeline, the first valve is used for controlling the vacuum flow of the main pipeline, and a first branch pipeline is connected with the main pipeline on both sides of the first valve. When vacuumizing, the first valve is closed, the second vacuum pump pre-vacuums the working cavity through the first branch pipeline to reach the vacuum degree of starting the first vacuum pump, then the first valve is opened, i.e., the main pipeline is opened, and the working cavity is vacuumized by the first vacuum pump. Since the pumping speed of the first vacuum pump is greater than that of the second vacuum pump, and the cross-sectional area of the main pipeline is greater than that of the first branch pipeline, the vacuumizing speed is obviously improved. Since the first valve can control the flow, the stability in the working cavity during vacuumizing can be ensured.

[0044] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application will be further described in detail below in combination with the drawings and specific embodiments.

[0045] Reference Figure 1 , Figure 1 A structure schematic diagram of a vacuum pipeline is provided for the embodiments of the application; the vacuum pipeline comprises:

[0046] A working cavity 01, a main pipeline 02, a first valve 03, a first branch pipeline 04, a first vacuum pump 05 and a second vacuum pump 06.

[0047] The first end of the main pipeline 02 is connected with the working cavity 01, and the second end of the main pipeline 02 is connected with the first vacuum pump 05; the first vacuum pump 05 is used for vacuumizing the working cavity 01.

[0048] The first valve 03 is arranged on the main pipeline 02 and is used for controlling the vacuum flow of the main pipeline 02.

[0049] The first branch pipeline 04 is connected with the main pipeline 02 on both sides of the first valve 03.

[0050] The second vacuum pump 06 is used for pre-vacuumizing the working cavity 01 through the first branch pipeline 04 to start the first vacuum pump 05; wherein the pumping speed of the first vacuum pump 05 is greater than that of the second vacuum pump 06, and the cross-sectional area of the main pipeline 02 is greater than that of the first branch pipeline 04.

[0051] Specifically, in the embodiment of the present application, the working cavity 01 is connected with the first vacuum pump 05 through the main pipeline 02, and the first valve 03 is arranged on the main pipeline 02. The first valve 03 is a throttle valve, and the opening size of the first valve 03 can be controlled to control the flow of air during vacuum pumping. The first valve 03 can be arranged to more accurately control the pressure in the working cavity 01 and ensure the stability of the pressure in the working cavity 01 during vacuum pumping. It should be noted that the first vacuum pump 05 can be a cryogenic pump, and the second vacuum pump 06 can be a dry pump.

[0052] The first branch pipeline 04 is arranged on the main pipeline 02 on both sides of the first valve 03. The first end of the first branch pipeline 04 is connected to the main pipeline 02 between the first valve 03 and the working cavity 01, and the second end of the first branch pipeline 04 is connected to the main pipeline 02 between the first valve 03 and the first vacuum pump 05, that is, the main pipeline 02 is connected on the side. The cross-sectional area of the first branch pipeline 04 is smaller than that of the main pipeline 02, that is, the first branch pipeline 04 is thinner than the main pipeline 02. During vacuum pumping, the second vacuum pump 06 is first used to pre-vacuum the working cavity 01 through the first branch pipeline 04. The pre-vacuuming makes the pressure of the main pipeline 02 and the working cavity 01 reach a preset pressure. Since the vacuum pumping capacity of the second vacuum pump 06 is weak, the first branch pipeline 04 is relatively thin, which can improve the speed of vacuum pumping. It should be noted that the preset pressure can be 5 Pa, and the vacuum pumping process can be about 1 hour, which is not limited in detail.

[0053] When the main pipeline 02 and the working cavity 01 reach the preset pressure, the first vacuum pump 05 is started. After the first vacuum pump 05 is started, the first valve 03 is controlled to open the main pipeline 02. The main pipeline 02 is relatively thick, and the pumping speed of the first vacuum pump 05 is greater than that of the second vacuum pump 06, which can greatly increase the speed of vacuum pumping of the working cavity 01.

[0054] During the vacuum pumping process, the flow of air during vacuum pumping is controlled by the first valve 03, which can ensure the stability of the working cavity 01. Compared with the existing 10-12 hours of vacuum pumping, the vacuum pumping time is reduced to about 3 hours in the present application. In the case of ensuring the stability of the working cavity 01, the vacuum pumping time is obviously shortened.

[0055] Optionally, with reference to Figure 2 , Figure 2 Another structure diagram of the vacuum pumping pipeline provided by the embodiment of the present application; in another embodiment of the present application, the vacuum pumping pipeline further comprises:

[0056] The first detection device 07 is located between the first valve 03 and the working cavity 01 and is used to detect the cavity pressure of the working cavity 01.

[0057] Specifically, a first detection device 07 can be arranged between the first valve 03 and the working cavity 01. It should be noted that the first detection device 07 can be a pressure gauge or other detection device for detecting pressure, and the specific limitation is not made. The pressure of the working cavity 01 is the same as the pressure in the main pipeline 02 between the first valve 03 and the working cavity 01. By arranging the first detection device 07 on the main pipeline 02 between the first valve 03 and the working cavity 01, the cavity pressure of the working cavity 01 can be detected. The pressure of the working cavity 01 is detected in real time, and when the pressure change is unstable, the opening size of the first valve 03 can be adjusted to ensure the stability of the pressure in the working cavity 01.

[0058] Optionally, as shown in the first valve 03 and the working cavity 01, Figure 2 The vacuum pipeline further comprises:

[0059] The second valve 08 is arranged on the first branch pipeline 04 and used for opening or closing the first branch pipeline 04.

[0060] Specifically, the second valve 08 can be a switch valve. After the working cavity 01 is vacuumed to a preset pressure by the second vacuum pump 06 through the first branch pipeline 04, in order to ensure the stability of the vacuum flow controlled by the first valve 03, the first branch pipeline 04 can be closed. That is, the second valve 08 is closed, the first branch pipeline 04 is disconnected, and the second branch pipeline 09 is prevented from affecting the accuracy of vacuumizing by the first vacuum pump 05.

[0061] Optionally, as shown in the first valve 03 and the working cavity 01, Figure 2 The vacuum pipeline further comprises:

[0062] The second branch pipeline 09 is connected with the second vacuum pump 06 at a first end and connected with the main pipeline 02 between the first valve 03 and the first vacuum pump 05 at a second end.

[0063] Specifically, the second vacuum pump 06 and the main pipeline 02 can be connected by the second branch pipeline 09. The first end of the second branch pipeline 09 is connected with the second vacuum pump 06, and the second end of the second branch pipeline 09 is connected between the first valve 03 and the first vacuum pump 05. Compared with the connection between the existing dry pump and the molecular pump, when the pre-vacuumizing is performed in the application, the second vacuum pump 06 is directly connected with the main pipeline 02, and the vacuumizing speed is obviously improved.

[0064] Optionally, as shown in the first valve 03 and the working cavity 01, Figure 2 The vacuum pipeline further comprises:

[0065] The third valve 10 is arranged on the second branch pipe 09 and is used for controlling the on-off of the second vacuum pump 06.

[0066] Specifically, the third valve 10 is arranged on the second branch pipe 09, and the third valve 10 is an on-off valve. When the pre-evacuation of the second vacuum pump 06 is completed, the pressure in the working cavity 01 is in a relatively stable state, but the vacuumizing capacity of the second vacuum pump 06 is limited. In order to increase the vacuumizing rate, the second vacuum pump 06 can be closed at this time, and the first vacuum pump 05 is used for main evacuation. The vacuumizing mode through the two pumps can realize a lower vacuum degree and meet a more stringent vacuum requirement. The third valve 10 can also be closed in time when the second vacuum pump 06 is down, so as to ensure that the gas does not backflow and affect the pressure in the working cavity 01.

[0067] Optionally, as shown in FIG. 1, Figure 2 in another embodiment of the present application, the vacuumizing pipeline further comprises:

[0068] The fourth valve 11 is arranged between the first valve 03 and the first vacuum pump 05 and is used for opening or closing the main pipeline 02.

[0069] Specifically, in the embodiment of the present application, the fourth valve 11 is arranged between the first valve 03 and the first vacuum pump 05, and the fourth valve 11 can be an on-off valve. The fourth valve 11 can separate the working cavity 01 and the first vacuum pump 05. If the first vacuum pump 05 is down, the fourth valve 11 can be closed in time, so as to prevent the gas from backflowing and ensure the pressure in the working cavity 01 after the vacuumizing, thereby avoiding more time spent on vacuumizing again. At this time, only the first vacuum pump 05 needs to be replaced, and the vacuumizing or the vacuum degree can be continued on the basis of the previous vacuumizing.

[0070] Optionally, as shown in FIG. 1, Figure 2 in another embodiment of the present application, the vacuumizing pipeline further comprises:

[0071] The second detection device 12 is arranged between the fourth valve 11 and the first valve 03 and is used for detecting the pressure of the main pipeline 02.

[0072] Specifically, in the embodiment of the present application, the second detection device 12 is arranged between the fourth valve 11 and the first valve 03, and the second detection device 12 can be a pressure gauge, which is used for monitoring the pressure of the main pipeline 02 in real time. The monitoring of the pressure of the main pipeline 02 is helpful to ensure the normal operation of the entire device, and the second detection device 12 and the first detection device 07 can be linked. When an abnormality is detected, different valves can be adjusted in time, so as to ensure the vacuumizing effect of the entire vacuumizing pipeline.

[0073] Optionally, referring to FIG. 1, Figure 3 , Figure 3Another structure diagram of the vacuum pipeline provided by the embodiment of the present application is shown in the figure; in another embodiment of the present application, the vacuum pipeline further comprises:

[0074] The conversion cavity 13 and the third branch pipeline 14, the first end of the third branch pipeline 14 is connected to the main pipeline 02 between the first vacuum pump 05 and the first valve 03, and the second end of the third branch pipeline 14 is connected to the conversion cavity 13, and the conversion cavity 13 is used for vacuum buffering.

[0075] Specifically, the conversion cavity 13 is used for vacuum buffering, for example, before the sample enters the working cavity 01 or before the sample exits the working cavity 01, the sample first enters the conversion cavity 13, so that the sample adapts to a certain vacuum environment, provides buffering, and then is converted into the working cavity 01. The conversion cavity 13 can allow the sample to be put in or taken out without destroying the vacuum state of the working cavity 01. And by gradually adjusting the pressure in the cavity, the sample can enter the high vacuum environment without experiencing a sharp pressure change. This helps to protect the sample from damage caused by a sudden pressure change.

[0076] The conversion cavity 13 is connected to the main pipeline 02 through the third branch pipeline 14, the first end of the third branch pipeline 14 is connected to the main pipeline 02 between the first vacuum pump 05 and the first valve 03, and the second end of the third branch pipeline 14 is connected to the conversion cavity 13. It should be noted that since the required vacuum degree of the conversion cavity 13 is not as high as that of the working cavity 01, the cross-sectional area of the third branch pipeline 14 can be smaller than that of the main pipeline 02, and can be the same as that of the first branch pipeline 04.

[0077] Optionally, as shown in the figure, in another embodiment of the present application, the vacuum pipeline further comprises: Figure 3

[0078] The fifth valve 15 is located on the third branch pipeline 14 and is used for controlling the vacuum flow of the third branch pipeline 14.

[0079] Specifically, in the embodiment of the present application, the fifth valve 15 is further arranged on the third branch pipeline, the fifth valve 15 can be a throttle valve, the opening size of the fifth valve 15 can be controlled to control the flow of the vacuum pumping, thereby controlling the vacuum degree of the conversion cavity 13. The fifth valve 15 is arranged to more accurately control the pressure in the conversion cavity 13 and ensure that the pressure in the conversion cavity 13 is stable during vacuum pumping.

[0080] Optionally, as shown in the figure, in another embodiment of the present application, the vacuum pipeline further comprises: Figure 3

[0081] The third detection device 16 is located between the fifth valve 15 and the conversion cavity 13 and is used for detecting the cavity pressure of the conversion cavity 13. ​​

[0082] Specifically, the third detection device 16 can be arranged between the fifth valve 15 and the conversion cavity 13, and the third detection device 16 can be a pressure gauge, which is not limited. The third detection device 16 is arranged on the third branch pipe 14 between the fifth valve 15 and the conversion cavity 13, so that the cavity pressure of the conversion cavity 13 can be detected. The pressure of the conversion cavity 13 is detected in real time, and when the pressure change is unstable, the opening size of the fifth valve 15 can be adjusted to ensure the stability of the pressure in the conversion cavity 13.

[0083] Based on the above-mentioned vacuum pipeline, the application also provides an embodiment of using the vacuum pipeline to vacuum, which is described below. First, before starting, all the valves are in a closed state. After starting, the second valve 08, the third valve 10 and the fourth valve 11 are opened, and the second vacuum pump 06 is used to vacuum the working cavity 01 through the first branch pipe 04 to 5 Pa, and the working time is about 1 hour. After the first detection device 07 detects that the vacuum degree of the working cavity 01 is 5 Pa, the first vacuum pump 05 starts, the working cavity 01 is in a relatively stable state, the second valve 08 is closed, the fourth valve 11 and the fifth valve 15 are opened, and the first vacuum pump 05 performs main pumping action on the main pipeline 02 and the working cavity 01. The first valve 03 and the fifth valve 15 control the opening size to adjust the vacuum flow. When the main pumping is opened, the third valve 10 is closed, and the working cavity 01 and the conversion cavity 13 are pumped at the same time. The time used for pumping to 4x10 -5 Pa is 1.5-2 times shorter than the existing one, and the vacuum pumping process is about 2 hours. When the pressure reaches the specified pressure, the speed is reduced, and the cavity pressure is maintained by continuous pumping. Compared with the existing 10-12 hours of vacuum pumping, the total time of the vacuum pumping degree is reduced to about 3 hours, which significantly shortens the vacuum pumping time while ensuring the stability of the working cavity 01.

[0084] The application sets multiple valves to control the pressure change in the cavity more accurately during vacuum pumping. In addition, the main pipeline 02 has a larger cross-sectional area, so the vacuum pumping speed is faster, and the vacuum pumping efficiency is improved.

[0085] In the description of the present application, the description of the terms "some embodiments", "another embodiment" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In the description of the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0086] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, it is to be understood that the application encompasses all such possible combinations.

[0087] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, some modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A vacuuming line, characterized in that, The vacuum pumping pipeline comprises: a working cavity, a main pipeline, a first valve, a first branch pipeline, a first vacuum pump and a second vacuum pump; a first end of the main pipeline is connected with the working cavity, and a second end of the main pipeline is connected with the first vacuum pump; the first vacuum pump is used for vacuumizing the working cavity; the first valve is located on the main pipeline and is used for controlling the vacuumizing flow of the main pipeline; the first branch pipeline connects the main pipeline on both sides of the first valve; the second vacuum pump is used for pre-vacuumizing the working cavity through the first branch pipeline to start the first vacuum pump; wherein, the pumping speed of the first vacuum pump is greater than the pumping speed of the second vacuum pump, and the cross-sectional area of the main pipeline is greater than the cross-sectional area of the first branch pipeline.

2. The evacuation line of claim 1, wherein, The vacuum pumping pipeline further comprises: a first detection device located between the first valve and the working cavity and used for detecting the cavity pressure of the working cavity.

3. The evacuation line of claim 1, wherein, The vacuum pumping pipeline further comprises: a second valve located on the first branch pipeline and used for opening or closing the first branch pipeline.

4. The evacuation line of claim 1, wherein, The vacuum pumping pipeline further comprises: a second branch pipeline, a first end of the second branch pipeline is connected with the second vacuum pump, and a second end of the second branch pipeline is connected with the main pipeline between the first valve and the first vacuum pump.

5. The evacuation line of claim 4, wherein, The vacuum pumping pipeline further comprises: a third valve located on the second branch pipeline and used for controlling the on-off of the second vacuum pump.

6. The evacuation line of claim 1, wherein, The vacuum pumping pipeline further comprises: a fourth valve located between the first valve and the first vacuum pump and used for opening or closing the main pipeline.

7. The evacuation line of claim 6, wherein, The vacuum pumping pipeline further comprises: a second detection device located between the fourth valve and the first valve and used for detecting the pressure of the main pipeline.

8. The evacuation line of claim 1, wherein, The vacuum pumping pipeline further comprises: a conversion cavity and a third branch pipeline, a first end of the third branch pipeline is connected with the main pipeline between the first valve and the first vacuum pump, and a second end of the third branch pipeline is connected with the conversion cavity, and the conversion cavity is used for vacuum buffering.

9. The evacuation line of claim 8, wherein, The vacuum pumping pipeline further comprises: a fifth valve located on the third branch pipeline and used for controlling the vacuumizing flow of the third branch pipeline.

10. The evacuation line of claim 9, wherein, The vacuum pumping pipeline further comprises: a third detection device located between the fifth valve and the conversion cavity and used for detecting the cavity pressure of the conversion cavity.

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