Pirani gauge, filament manufacturing method thereof, and evaporation apparatus

Abstract

This application provides a Pirani vacuum gauge, its filament manufacturing method, and vapor deposition equipment. The Pirani vacuum gauge includes a housing, a connecting structure, a filter unit, and a filament. The housing has an air inlet communicating with the space to be monitored. The connecting structure is fixed inside the housing. The filter unit is located inside the air inlet and adsorbs at least some molecules in the gas entering the housing from the space to be monitored. The filament is located inside the housing and fixed to the connecting structure. The filament includes a filament body, a first protective layer covering the surface of the filament body, and a second protective layer covering the side of the first protective layer away from the filament body. The first protective layer effectively resists oxidation to reduce the oxidation of the filament body, which helps increase the filament's lifespan. The second protective layer reduces the adhesion of carbon particles to the filament, thus reducing the impact of carbon deposition on the filament's thermal conductivity and further increasing the filament's lifespan.

Description

Technical Field

[0001] This application relates to the field of vacuum monitoring technology, and in particular to a Pirani vacuum gauge, its filament manufacturing method, and vapor deposition equipment. Background Technology

[0002] Flat panel displays based on organic light-emitting diode (OLED) technology have become the mainstream display technology due to their advantages such as high image quality, energy saving, thin body and wide range of applications, and are widely used in various consumer electronics products such as mobile phones, televisions, laptops, and desktop computers.

[0003] The primary production method for OLED products currently involves depositing multiple independent OLED light-emitting units onto a substrate using evaporation equipment. Because the evaporation process requires very strict vacuum control, the vacuum level within the evaporation chamber of the equipment needs to be monitored in real time during the evaporation process. In existing technologies, a Pirani vacuum gauge is typically used to monitor the vacuum level within the evaporation chamber in real time.

[0004] The working principle of a Pirani vacuum gauge is to detect vacuum levels by measuring the thermal conductivity of a heated filament (usually tungsten filament in current technology). Specifically, when low-temperature gas molecules collide with a high-temperature solid, they absorb heat from the solid. The low-temperature gas molecules refer to the gas molecules in the space being monitored, while the high-temperature solid refers to the filament of the Pirani vacuum gauge. The lifespan of a Pirani vacuum gauge is limited by the lifespan of its filament. Frequent start-ups and shutdowns of the vapor deposition equipment or fluctuations in ambient temperature cause repeated thermal expansion and contraction of the filament, easily leading to micro-cracks and affecting its lifespan. At high temperatures, the filament reacts with oxygen, water vapor, or oil vapor, causing oxidation on its surface, which also affects its lifespan. Furthermore, carbon deposition on the filament surface reduces its thermal conductivity, requiring an increased heating current to maintain the filament temperature. However, increased heating current accelerates material evaporation on the filament, further reducing its lifespan. Therefore, improving the lifespan of the Pirani vacuum gauge's filament is crucial for extending the overall lifespan of the Pirani vacuum gauge. Summary of the Invention

[0005] In view of this, embodiments of this application provide a Pirani vacuum gauge, a method for manufacturing its filament, and an evaporation equipment to at least partially solve the above-mentioned problems.

[0006] According to a first aspect of the embodiments of this application, a Pirani vacuum gauge is provided, which is used to monitor the vacuum level of a space to be monitored and includes:

[0007] A housing, wherein an air inlet is provided on the housing, and the air inlet is connected to the space to be monitored so that gas in the space to be monitored enters the housing through the air inlet;

[0008] A connecting structure is fixed inside the housing.

[0009] A filtration unit is disposed inside the air inlet. The filtration unit adsorbs at least a portion of the polluting particles in the gas entering the housing from the space to be monitored. The gas entering the housing from the space to be monitored includes oxidizing molecules and organic molecules.

[0010] The filament is disposed inside the housing and fixed to the connecting structure. The filament includes a filament body, a first protective layer covering the surface of the filament body, and a second protective layer covering the side of the first protective layer away from the filament body. The filament body is maintained at a monitored temperature under the action of a heating current. The first protective layer prevents the oxidizing molecules from contacting the filament body to provide antioxidant protection for the filament body. The second protective layer is used to reduce the adhesion of carbon-containing particles to the filament. The carbon-containing particles are formed by the transformation of organic molecules under the heating of the filament body.

[0011] In one optional embodiment, the filament body is made of a tungsten alloy doped with 5% rhenium, the first protective layer is made of alumina nanoceramics or silicon carbide nanoceramics, and the second protective layer is made of graphene.

[0012] In one optional embodiment, the thickness of the first protective layer is 20 nm to 100 nm.

[0013] In one optional embodiment, the thickness of the second protective layer is 2 nm to 10 nm.

[0014] In an optional embodiment, the connection structure includes two brackets and two springs. The brackets are fixed to the inner side of the wall panel of the housing, and the two wall panels of the housing on which the brackets are fixed are arranged opposite to each other. The two ends of the springs are respectively connected to the brackets and one end of the filament.

[0015] In one alternative implementation, the support is a flexible ceramic support.

[0016] In one optional embodiment, the filtration unit includes at least one molecular sieve layer and at least one activated carbon layer.

[0017] In an alternative embodiment, the housing is fitted with a silicone damping layer.

[0018] According to a second aspect of the embodiments of this application, a vapor deposition apparatus is provided, the vapor deposition apparatus including the above-mentioned Pirani vacuum gauge, wherein the space to be monitored is the vapor deposition chamber of the vapor deposition apparatus.

[0019] According to a third aspect of the embodiments of this application, a method for manufacturing a filament of a Pirani vacuum gauge is provided. The Pirani vacuum gauge is used to monitor the vacuum level of a space to be monitored. The gas entering the Pirani vacuum gauge from the space to be monitored includes oxidizing molecules and organic molecules. The manufacturing method includes:

[0020] A filament body is fabricated, and the filament body is maintained at a monitored temperature under the action of a heating current;

[0021] A first protective layer is formed on the filament body by atomic layer deposition. The first protective layer prevents the oxidation molecules from contacting the filament body to provide antioxidant protection for the filament body.

[0022] A second protective layer is formed on the first protective layer. The second protective layer is used to reduce the adhesion of carbon-containing particles to the filament. The carbon-containing particles are formed by the transformation of organic molecules under the heating of the filament body.

[0023] According to the solution provided in the embodiments of this application, the filament in the Pirani vacuum gauge adopts a structure of filament body / first protective layer / second protective layer. The first protective layer can effectively resist oxidation to reduce the oxidation of the filament body, which is beneficial to increasing the service life of the filament. The second protective layer is used to reduce the adhesion of carbon particles (such as hydrocarbons) to the filament, thereby reducing the impact of carbon deposition on the filament's thermal conductivity. Therefore, it can improve the problem of increased evaporation rate of filament material caused by increased heating current to compensate for increased filament thermal conductivity, which can further increase the service life of the filament. The increased service life of the filament can effectively improve the service life of the Pirani vacuum gauge. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 A schematic diagram of an exemplary structure of a Pirani vacuum gauge provided in an embodiment of this application;

[0026] Figure 2 A schematic diagram of the filament structure in a Pirani vacuum gauge provided in this application embodiment;

[0027] Figure 3 A schematic diagram of the structure of a filter unit in a Pirani vacuum gauge provided in this application embodiment;

[0028] Figure 4 A schematic diagram of the assembly structure of the central connection structure and the filament of a Pirani vacuum gauge provided in an embodiment of this application;

[0029] Figure 5 A schematic diagram of the assembly structure of the central connection structure and the filament of another Pirani vacuum gauge provided in an embodiment of this application;

[0030] Figure 6 A schematic diagram illustrating another exemplary structure of a Pirani vacuum gauge provided in an embodiment of this application;

[0031] Figure 7 This is a schematic diagram of the frame structure of a vapor deposition apparatus provided in an embodiment of this application;

[0032] Figure 8 A schematic flowchart illustrating a method for manufacturing the filament of a Pirani vacuum gauge, provided in an embodiment of this application;

[0033] Figure 9 for Figure 8 A schematic diagram of the process of step S1 in the manufacturing method shown;

[0034] Figure 10 for Figure 8 A schematic diagram of the process of step S2 in the manufacturing method shown;

[0035] Figure 11 for Figure 8 A schematic diagram of step S3 in the manufacturing method shown.

[0036] Figure label:

[0037] 1-Shell; 11-Air inlet;

[0038] 2-Connecting structure; 21a-Circular ring; 21b-Support rod; 22-Spring;

[0039] 3-Filter unit; 31-Molecular sieve layer; 32-Activated carbon layer;

[0040] 4-Filament; 40-Filament end; 401-Mounting hole; 40a-Filament body end; 40b-Filament body end with first protective layer; 41-Filament body; 42-First protective layer; 43-Second protective layer;

[0041] 5-Silicone damping layer;

[0042] 1000 - Evaporation equipment; M - Pirani vacuum gauge; Q1 - Evaporation chamber. Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0044] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in the embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0045] It should be understood that in the description of the embodiments of this application, the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the scheme of the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0046] Furthermore, when an element or layer is referred to as being "on" another element or layer, "connected to," or "bonded to" another element or layer, the element or layer may be directly on the other element or layer, directly connected to, or directly bonded to the other element or layer, or there may be intermediate elements or layers. However, when an element or layer is referred to as being "directly on" another element or layer, "directly connected to," or "directly bonded to" another element or layer, there are no intermediate elements or layers.

[0047] The terms First, Second, etc., are used to describe various elements, components, regions, layers, and / or parts, but these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, and / or part from another element, component, region, layer, and / or part.

[0048] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] Based on practical experience with OLED evaporation processes, it is necessary to monitor the vacuum level within the evaporation chamber of the evaporation equipment during the evaporation process, typically using a Pirani vacuum gauge. Since the organic materials need to be heated during evaporation, they vaporize during this process. These gases enter the housing through the air inlet, causing contamination (oxygen, water vapor, or oil vapor, etc.) and potentially damaging the filament's lifespan.

[0050] Specifically, the contamination caused by the gas entering the housing of the Pirani vacuum gauge from the vapor deposition chamber is mainly due to the oxidation of the filament, which is the primary cause of filament life loss. Simultaneously, the contamination caused by the gas entering the housing of the Pirani vacuum gauge from the vapor deposition chamber is due to the presence of organic materials in these gases. These organic materials may produce hydrocarbons during heating, which easily deposit on the filament surface—a phenomenon known as carbon deposition. Carbon deposition reduces the thermal conductivity of the filament, requiring an increase in heating current to maintain its temperature. However, increasing the heating current accelerates the evaporation of material on the filament, thus reducing its lifespan and consequently shortening the lifespan of the Pirani vacuum gauge.

[0051] Meanwhile, during the actual vapor deposition process, the vapor deposition equipment will be frequently started and stopped, and the ambient temperature of the vapor deposition equipment will also fluctuate. This causes the filament to repeatedly expand and contract due to heat. The repeated expansion and contraction of the filament can easily cause micro-cracks in the filament, which will seriously affect the service life of the filament.

[0052] To address the aforementioned technical problems, this application provides a Pirani vacuum gauge, its filament fabrication method, and vapor deposition equipment. The specific implementation of this application's embodiments is further described below with reference to the accompanying drawings.

[0053] This application provides a Pirani vacuum gauge, such as Figure 1 As shown, the Pirani vacuum gauge is used to monitor the vacuum level of the space to be monitored, and the Pirani vacuum gauge includes a housing 1, a connecting structure 2, a filter unit 3, and a filament 4.

[0054] like Figure 1As shown, in the Pirani vacuum gauge provided in this embodiment, an air inlet 11 is provided on the housing 1, and the air inlet 11 is connected to the space to be monitored 200; the connecting structure 2 is fixed inside the housing 1. Specifically, the Pirani vacuum gauge monitors the vacuum degree of the space to be monitored 200 in a medium to low vacuum state. For example, the Pirani vacuum gauge is used to monitor the vacuum degree in positive vacuum systems such as food packaging and electronic product packaging, and to monitor the vacuum degree in the vapor deposition chamber of vapor deposition equipment.

[0055] like Figure 1 As shown, in the Pirani vacuum gauge provided in this embodiment, the filter unit 3 is disposed inside the air inlet 11, and the filter unit 3 adsorbs at least a portion of the polluting particles in the gas entering the housing 1 from the space to be monitored 200. The gas entering the housing 1 from the space to be monitored 200 includes oxidizing molecules and organic molecules. Specifically, the polluting particles include one or more of oil vapor, water vapor, and acidic gases (e.g., SO2); the oxidizing molecules are molecules that have the ability to oxidize the filament, such as water vapor, oil vapor, and oxygen.

[0056] like Figure 1 and Figure 2 As shown, in the Pirani vacuum gauge provided in this embodiment, the filament 4 is disposed inside the housing 1 and fixed on the connecting structure 2. The filament 4 includes a filament body 41, a first protective layer 42 covering the surface of the filament body 41, and a second protective layer 43 covering the side of the first protective layer 42 away from the filament body 41. The filament body 41 is maintained at the monitoring temperature under the action of the heating current. The first protective layer 42 prevents oxidation molecules from contacting the filament body 41 to provide anti-oxidation protection for the filament body 41. The second protective layer 43 is used to reduce the adhesion ability of carbon-containing particles to the filament 4. The carbon-containing particles are organic molecules transformed under the heating of the filament body 41.

[0057] Specifically, organic molecules are transformed into carbon-containing particles such as hydrocarbons under high temperature conditions. The second protective layer 43 has a low adsorption of carbon-containing particles such as hydrocarbons, thereby improving the carbon deposition phenomenon on the surface of the filament 4.

[0058] In the Pirani vacuum gauge provided in this embodiment, the filament adopts a structure of filament body 41 / first protective layer 42 / second protective layer 43. The first protective layer 42 can effectively resist oxidation to reduce the oxidation of the filament body 41, which is beneficial to increasing the service life of the filament. The second protective layer 43 is used to reduce the adhesion of carbon particles (such as hydrocarbons) to the filament 4, thereby reducing the impact of carbon deposition on the filament's thermal conductivity. Therefore, it can improve the problem of increased evaporation rate of filament material caused by increased heating current to compensate for increased filament thermal conductivity, which can further increase the service life of the filament. The increased service life of the filament can effectively improve the service life of the Pirani vacuum gauge.

[0059] It should be noted that, although not shown in the accompanying drawings, the Pirani vacuum gauge provided in this application also includes a controller. The controller controls the heating current of the filament body 4 to maintain the filament temperature at the monitoring temperature. Specifically, the controller adjusts the monitoring temperature according to different monitoring environments and the conditions of the space to be monitored. Simultaneously, the controller processes the filament monitoring data to obtain the vacuum level of the space to be monitored.

[0060] Specifically, the shape of the housing can be cylindrical or prismatic (e.g., cuboid, hexagonal prism, etc.), and the shape of the housing can be designed according to the installation space of the Pirani vacuum gauge.

[0061] Specifically, with Figure 1 Taking the Pirani vacuum gauge shown as an example, the air inlet 11 can be set on the wall plate of the housing 1, which is parallel to the length direction of the filament 4. For example, in a Pirani vacuum gauge where the housing 1 is cylindrical, the air inlet 11 is set on the side wall of the housing 1, i.e., on the curved surface; in a Pirani vacuum gauge where the housing 1 is prismatic, the air inlet 11 is also set on the side wall of the housing 1. It should be noted that in order to ensure that the gas entering the housing 1 through the air inlet 11 can be fully monitored, the air inlet 11 should be set at the end of the side wall.

[0062] Of course, the air inlet 11 can also be located on a wall panel of the housing 1 perpendicular to the length direction of the filament 4. For example, in a Pirani vacuum gauge where the housing 1 is cylindrical, the air inlet 11 is located on one of the bottom surfaces of the housing 1; in a Pirani vacuum gauge where the housing 1 is prismatic, the air inlet 11 is also located on the bottom surface of the housing 1. Having the air inlet 11 located on the bottom surface of the housing 1 ensures that the gas entering the housing 1 through the air inlet 11 can be adequately monitored.

[0063] The location of the air inlet 11 in the housing 1 should be selected to ensure that the gas entering the housing 1 through the air inlet 11 can be fully monitored, and the installation space of the Pirani vacuum gauge should be fully considered to facilitate the connection between the Pirani vacuum gauge and the space to be monitored 200.

[0064] like Figure 2 As shown, in the Pirani vacuum gauge provided in this embodiment, the filament body 41 is made of a tungsten alloy doped with 5% rhenium. It should be noted that the rhenium doping amount refers to the mass content. Specifically, the filament 4 in the prior art is usually made of yttrium iridium oxide or metallic tungsten lamp materials, while in this embodiment, the filament body 41 is made of a tungsten alloy doped with 5% rhenium, which has better high-temperature creep resistance. Even with repeated thermal expansion and contraction, it is not prone to microcracks, reducing the impact of frequent start-stop cycles and ambient temperature fluctuations on the filament. This helps reduce the risk of filament 4 breakage, thereby extending the service life of filament 4.

[0065] like Figure 2 As shown, in the Pirani vacuum gauge provided in this embodiment, the material of the first protective layer 42 is alumina nanoceramic or silicon carbide nanoceramic. Specifically, alumina nanoceramic or silicon carbide nanoceramic easily forms a dense film layer and both have good oxidation resistance.

[0066] like Figure 2 As shown, in the Pirani vacuum gauge provided in this embodiment, the material of the second protective layer 43 is graphene. Specifically, graphene has good thermal conductivity, so using graphene to form the second protective layer 43 does not reduce the thermal conductivity of the filament 4. Graphene has a low adsorption capacity for nonpolar molecules such as hydrocarbons, thus reducing the adhesion of nonpolar molecules such as hydrocarbons to the surface of the filament 4. This helps to reduce the impact of carbon-containing particles such as hydrocarbons on the thermal conductivity of the filament 4.

[0067] Optionally, in the Pirani vacuum gauge provided in this embodiment, the thickness of the first protective layer 42 is 20 nm to 100 nm. In one specific embodiment, the thickness of the first protective layer 42 is 20 nm; in another specific embodiment, the thickness of the first protective layer 42 is 50 nm; in yet another specific embodiment, the thickness of the first protective layer 42 is 80 nm; and in yet another specific embodiment, the thickness of the first protective layer 42 is 100 nm.

[0068] Optionally, in the Pirani vacuum gauge provided in this embodiment, the thickness of the second protective layer 43 is 2nm to 10nm. The thickness of the second protective layer 43 is 2nm; in another specific embodiment, the thickness of the second protective layer 43 is 6nm; in yet another specific embodiment, the thickness of the second protective layer 43 is 8nm; and in yet another specific embodiment, the thickness of the second protective layer 43 is 10nm.

[0069] The specific selection of the thickness of the first protective layer 42 and the second protective layer 43 should take into account the size of the filament body 1 and the application scenario of the Pirani vacuum gauge (gas composition, operating temperature, etc. in the space to be monitored).

[0070] like Figure 3 As shown, in the Pirani vacuum gauge provided in this embodiment, the filter unit 3 includes at least one molecular sieve layer 31 and at least one activated carbon layer 32. It should be noted that, although... Figure 3The filter unit 3 shown includes only one molecular sieve layer 31 and one activated carbon layer 32. However, in practical applications, different numbers of molecular sieve layers 31 and activated carbon layers 32 can be selected according to the specific conditions of the polluting gas and particles in the space to be monitored. Of course, additional gas filtration layers can also be added according to the specific conditions of the polluting gas in the space to be monitored, such as filtration layers for acidic gases (such as SO2) or alkaline gases (such as NH3).

[0071] Specifically, the molecular sieve material used in the molecular sieve layer 31 can be selected according to the gas composition in the space to be monitored Q. If the composition of the pollutant gas in the space to be monitored Q is simple, the molecular sieve layer 31 includes one type of molecular sieve material. However, if the composition of the pollutant gas in the space to be monitored is complex, the molecular sieve layer 31 can include multiple types of molecular sieve materials to filter different pollutant gases. The activated carbon layer 32 mainly utilizes the adsorption properties of activated carbon to absorb some molecules in the gas entering the inlet 11 from the space to be monitored Q.

[0072] During the use of the Pirani vacuum gauge, the filter unit 3 is snapped into the air inlet 11 and is replaced periodically according to the gas composition in the space Q to be monitored, so as to ensure that the filter unit 3 can have a good filtration effect.

[0073] The inventors also discovered that Pirani vacuum gauges are typically used in vibrating environments, such as pump vibration. Therefore, vibration stress can easily cause filament 4 to break, thus reducing its lifespan. Based on this, the inventors considered that reducing vibration stress would also help extend the lifespan of filament 4. The following describes the technical solution for improving vibration stress in the Pirani vacuum gauge.

[0074] like Figure 4 and Figure 5 As shown, in the Pirani vacuum gauge provided in this embodiment, the connecting structure 2 includes two brackets and two springs 22. Both brackets are fixed to the inner wall of the housing 1 and are each connected to one end of a spring 22. The other ends of the two springs 22 are respectively connected to both ends of the filament 4. Specifically, the other ends of the two springs 22 are respectively connected to both ends of the filament 4, that is, the other ends of the two springs 22 are respectively connected to the two filament ends 40. Specifically, due to the design of the springs 22 in the connecting structure 2, most of the vibration stress in the length direction of the filament 4 is released by the springs 22, which can effectively reduce the tension of vibration stress on the filament 4, thereby reducing the risk of filament breakage.

[0075] Optionally, the support is a flexible ceramic support. Flexible ceramic material is mainly composed of ceramic and polymer composites. The ceramic, as the main component, provides the material's hardness and wear resistance, while the polymer plays a crucial role in bonding and preventing breakage. During manufacturing, ceramic particles are uniformly coated with polymer, constructing a multi-layered, stable structure. This means the flexible ceramic support has a certain deformation capacity, which can further release vibration stress, thereby further reducing the tensile stress on the filament 4 and lowering the risk of filament 4 breakage.

[0076] Optionally, the two supports are as follows: Figure 4 The ring 21a is fixed to two opposing wall plates of the housing 1. One end of the spring 22 is hooked into the ring 21a, and the other end of the spring 22 is hooked into the mounting hole 401 at the end 40 of the filament 4. In this specific embodiment, the length direction of the filament 4 is perpendicular to the two opposing wall plates of the housing 1, which are fixed with brackets. It should be noted that the filament 4 is usually located at the center of the housing 1. For example, if the housing 1 is cylindrical, the axis of the cylindrical housing 1 should pass through the filament 4 under non-vibration stress. Based on this, if the air inlet 11 is located on the surface of the housing 1 perpendicular to the filament 4, the orthographic projection of the air inlet 11 on the plane of the wall plate of the housing on which the air inlet 11 is installed does not overlap with the orthographic projection of the filament 4 on the plane of the wall plate of the housing on which the air inlet 11 is installed. That is, the position of the air inlet 11 should avoid the connecting structure 2 to ensure that the filament 4 is located at the center of the housing 1.

[0077] Optionally, the support is as follows Figure 5 As shown, two support rods 21b are fixed to the end of a wall panel parallel to the length direction of the filament 4. One end of the spring 22 is hooked onto the support rod, and the other end of the spring 22 is hooked into the mounting hole 401 at the end 40 of the filament 4. It should be noted that the support rod 21b can be straight or cross-shaped, as long as the support rod 21b can ensure the stable connection of the filament 4. Furthermore, the support rod 21b is provided with a fixing structure to prevent the spring 22 from shifting. The fixing structure can be a hole penetrating the support rod 21b, the through direction of which is perpendicular to the axis of the support rod 21b and allows one end of the spring 22 to be hooked. The fixing structure can also be a limiting groove or a limiting plate. The limiting groove restricts the spring hooked onto the support rod 21b within the limiting groove range, and there are two limiting plates, with the two limiting plates restricting the spring hooked onto the support rod 21b between the two limiting plates.

[0078] Specifically, the spring 22 can be a helical spring and the spring 22 is made of a material with good corrosion resistance.

[0079] like Figure 6As shown, in the Pirani vacuum gauge provided in this embodiment, a silicone damping layer 5 is attached to the inner side of the housing 1. Based on the elastic characteristics of silicone, the silicone damping layer 5 can absorb the vibration stress generated by external vibration (such as pump vibration) on the housing 1, thereby reducing the impact of external vibration on the filament 4, and further reducing the risk of filament 4 breaking due to vibration.

[0080] Based on the same inventive concept, embodiments of this application also provide a vapor deposition apparatus, such as... Figure 7 As shown, the vapor deposition equipment 1000 provided in this embodiment includes any of the Pirani vacuum gauges M in the above embodiments, and has the beneficial effects of the Pirani vacuum gauges in the above embodiments, which will not be repeated here.

[0081] Specifically, the space to be monitored in the above embodiments is the vapor deposition chamber Q1 of the vapor deposition equipment 1000. The gas in the vapor deposition chamber Q1 includes vapor deposition materials, solvents, and other organic materials. Organic materials easily form hydrocarbons under high temperatures. Carbon deposition on the surface of the filament 4 of the Pirani vacuum gauge M will affect the thermal conductivity of the filament 4. In addition, SO2 and other polluting gases may be generated in the vapor deposition chamber Q1, which will also affect the service life of the filament 4. Therefore, the Pirani vacuum gauge M provided in the above embodiments can effectively improve the service life of the filament 4 when applied to the vapor deposition equipment 1000.

[0082] Based on the same inventive concept, this application also provides a method for manufacturing the filament of a Pirani vacuum gauge. The Pirani vacuum gauge is used to monitor the vacuum level of a space to be monitored. The gas entering the Pirani vacuum gauge from the space to be monitored includes oxidizing molecules and organic molecules. Figures 8 to 11 As shown, the method for manufacturing the filament of the Pirani vacuum gauge provided in this embodiment includes:

[0083] S1: Fabricate the filament body 41, which is maintained at the monitored temperature under the action of a heating current. Specifically, the filament body 41 is fabricated using a tungsten alloy doped with 5% rhenium. Figure 9 As shown, the two ends of the filament body 41 are provided with filament body end 40a, which becomes filament end 40 after the formation of the first protective layer 42 and the second protective layer 43.

[0084] S2: A first protective layer 42 is deposited on the filament body 41 using atomic layer deposition (ALD). The first protective layer 42 prevents oxidation molecules from contacting the filament body 41, thus providing antioxidant protection. Specifically, a dense alumina ceramic layer or silicon carbide ceramic layer is deposited on the filament body 41 using ALD as the first protective layer 42. By controlling the ALD process, the thickness of the first protective layer 42 is controlled between 20 nm and 100 nm. Figure 10As shown, after step S2, the end 40a of the main body forms the filament end 40b with the first protective layer.

[0085] S3: A second protective layer 43 is formed on the first protective layer 42. The second protective layer 43 is used to reduce the adhesion of carbon-containing particles to the filament 4. The carbon-containing particles are organic molecules transformed under heating of the filament body 41. Specifically, a graphene layer is coated on the first protective layer 42 as the second protective layer 43, and the thickness of the second protective layer 43 is controlled between 2 nm and 10 nm. In specific implementation, methods such as spraying or electrostatic adsorption can be used to coat the graphene onto the first protective layer to form a graphene layer. Graphene material has a low adsorption capacity for non-polar molecules such as hydrocarbons, thus reducing the adhesion of non-polar molecules such as hydrocarbons to the surface of the filament 4, i.e., improving the carbon deposition phenomenon on the filament surface. Since graphene material has good thermal conductivity, using a graphene layer as the second protective layer can effectively reduce the influence of hydrocarbons on the thermal conductivity of the filament 4.

[0086] It should be noted that, although Figures 9 to 11 While not shown in the diagram, in practical applications, the filament end 40 should be provided with a structure that facilitates connection with the connecting structure 2, such as a mounting hole 401 that facilitates hooking with the spring 22.

[0087] The fabrication method of the filament 4 of the Pirani vacuum gauge provided in this embodiment is relatively simple, and the obtained filament 4 has a structure of filament body 41 / first protective layer 42 / second protective layer 43. The first protective layer 42 can effectively resist oxidation to reduce the oxidation of the filament body 41, which is beneficial to increasing the service life of the filament. The second protective layer 43 is used to reduce the adhesion of carbon particles (such as hydrocarbons) to the filament 4, thereby reducing the impact of carbon deposition on the filament's thermal conductivity. Therefore, it can improve the problem of increased evaporation rate of filament material caused by increased heating current to compensate for increased filament thermal conductivity, which can further increase the service life of the filament. The increased service life of the filament can effectively improve the service life of the Pirani vacuum gauge.

[0088] To investigate the impact of the technical solution provided in this application on the service life of the Pirani vacuum gauge, the inventors conducted a comparative experiment. Details are as follows.

[0089] The inventors conducted filament life tests in a simulated testing environment using both the filament of an existing Pirani vacuum gauge and the filament of the Pirani vacuum gauge provided in this application. Specifically, an atmosphere comprising water vapor, oxygen, SO2, blue OLED organic light-emitting material, and a solvent for the blue OLED organic light-emitting material was used as the simulated gas components. To accelerate the test, the test environment pressure was atmospheric pressure, and the filament temperature was the temperature at which the Pirani vacuum gauge tested the vacuum level within the vapor deposition chamber.

[0090] For ease of description, in the following description, the filament in the Pirani vacuum gauge in the prior art will be referred to as Sample 1, and the filament in the Pirani vacuum gauge provided in this technical solution will be referred to as Sample 2.

[0091] First, the inventors conducted observational experiments on carbon deposition. Under the simulated conditions described above, when sample 1 showed obvious carbon deposition, sample 2 showed no obvious carbon deposition after the same testing time. Furthermore, microscopic observation revealed microcracks in sample 1, while sample 2 showed virtually no microcracks after the same testing time. This demonstrates that the Pirani vacuum gauge provided by this technical solution significantly improves the carbon deposition phenomenon on the filament surface. This is a crucial factor in extending the filament's lifespan.

[0092] Meanwhile, the inventors also conducted vibration stress experiments on the Pirani vacuum gauge in the prior art and the Pirani vacuum gauge provided by this technical solution under the same vibration environment. Due to the design of the bracket + spring in the connection structure of the Pirani vacuum gauge in this technical solution, as well as the design of the silicone damping layer inside the shell, vibration stress can be effectively released. After the filament in the Pirani vacuum gauge in the prior art breaks, the filament in the Pirani vacuum gauge provided by this technical method is still not significantly damaged.

[0093] Since the conductivity of metals is stable at the same temperature, a sudden increase in the resistance of the filament during the test indicates that the filament has deteriorated due to oxidation, microcracks, or other defects. Therefore, the resistance of the filament is monitored during the experiment. Once a sudden increase in the resistance of the filament is detected, the lifespan of the filament under the simulated test conditions is determined to have ended.

[0094] The inventors analyzed the results of multiple sets of experimental data and found that, under the simulated test conditions, the lifespan of Sample 2 was greater than that of Sample 1, and the lifespan of Sample 2 was 1.5 to 3 times that of Sample 1. Based on the statistical data that the lifespan of the filament in existing Pirani vacuum gauges is approximately 2 years, and considering only the improvements to the filament structure in this technical solution, theoretically, the lifespan of the filament in the Pirani vacuum gauge provided by this technical solution is approximately 3 to 6 years. However, considering that this technical solution also addresses the vibration stress problem, the lifespan of the filament in the Pirani vacuum gauge provided by this technical solution is not only 1.5 to 3 times that of the filament in existing Pirani vacuum gauges, but should theoretically be extended further. Therefore, this technical solution can significantly improve the lifespan of the filament in the Pirani vacuum gauge.

[0095] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A Pirani vacuum gauge for monitoring the vacuum level of a space to be monitored, characterized in that, The Pirani vacuum gauge includes: A housing, wherein an air inlet is provided on the housing, and the air inlet is connected to the space to be monitored so that gas in the space to be monitored enters the housing through the air inlet; A connecting structure is fixed inside the housing. A filtration unit is disposed inside the air inlet. The filtration unit adsorbs at least a portion of the polluting particles in the gas entering the housing from the space to be monitored. The gas entering the housing from the space to be monitored includes oxidizing molecules and organic molecules. The filament is disposed inside the housing and fixed to the connecting structure. The filament includes a filament body, a first protective layer covering the surface of the filament body, and a second protective layer covering the side of the first protective layer away from the filament body. The filament body is maintained at a monitored temperature under the action of a heating current. The first protective layer prevents the oxidizing molecules from contacting the filament body to provide antioxidant protection for the filament body. The second protective layer is used to reduce the adhesion of carbon-containing particles to the filament. The carbon-containing particles are formed by the transformation of organic molecules under the heating of the filament body.

2. The Pirani vacuum gauge according to claim 1, characterized in that, The filament body is made of a tungsten alloy doped with 5% rhenium, the first protective layer is made of alumina nanoceramics or silicon carbide nanoceramics, and the second protective layer is made of graphene.

3. The Pirani vacuum gauge according to claim 2, characterized in that, The thickness of the first protective layer is 20nm to 100nm.

4. The Pirani vacuum gauge according to claim 2, characterized in that, The thickness of the second protective layer is 2nm to 10nm.

5. The Pirani vacuum gauge according to claim 1, characterized in that, The connection structure includes two brackets and two springs. The two brackets are fixed to the inner wall of the housing and are respectively connected to one end of one of the springs. The other ends of the two springs are respectively connected to both ends of the filament.

6. The Pirani vacuum gauge according to claim 5, characterized in that, The support is a flexible ceramic support.

7. The Pirani vacuum gauge according to claim 1, characterized in that, The filtration unit includes at least one molecular sieve layer and at least one activated carbon layer.

8. The Pirani vacuum gauge according to claim 1, characterized in that, The inner side of the housing is covered with a silicone damping layer.

9. A vapor deposition apparatus, characterized in that, The Pirani vacuum gauge according to any one of claims 1-8, wherein the space to be monitored is the vapor deposition chamber of the vapor deposition equipment.

10. A method for manufacturing a filament for a Pirani vacuum gauge, the Pirani vacuum gauge being used to monitor the vacuum level of a space to be monitored, wherein the gas entering the Pirani vacuum gauge from the space to be monitored comprises oxidizing molecules and organic molecules, characterized in that... The manufacturing method includes: A filament body is fabricated, and the filament body is maintained at a monitored temperature under the action of a heating current; A first protective layer is formed on the filament body by atomic layer deposition. The first protective layer prevents the oxidation molecules from contacting the filament body to provide antioxidant protection for the filament body. A second protective layer is formed on the first protective layer. The second protective layer is used to reduce the adhesion of carbon-containing particles to the filament. The carbon-containing particles are formed by the transformation of organic molecules under the heating of the filament body.

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