阅读说明：本技术 打拿极型光电倍增管阴极和打拿极瓦片镀膜设备及镀膜方法 (Dynode type photomultiplier cathode and dynode tile coating equipment and coating method ) 是由 王亮 王兴超 孙建宁 司曙光 任玲 顾燕 金睦淳 徐海洋 纪路路 周新 于 2021-06-28 设计创作，主要内容包括：本发明涉及光电倍增管制作技术领域,具体而言涉及打拿极型光电倍增管阴极和打拿极瓦片镀膜设备及镀膜方法,包括：多个罩体,每个罩体均被设置成具有密封状态和开放状态,所述罩体处于密封状态时,内部形成镀膜腔室；镀膜系统,被设置在所述镀膜腔室内；主抽系统,包括主抽泵和连接到主抽泵抽气端的主抽管道,所述主抽管道第二端连接到所述镀膜腔室。对主抽泵进行隔离而不停机,破坏镀膜腔室的真空状态后使用预抽系统建立真空度优于10Pa的负压环境,再打开主抽泵的隔离,无需破除整个镀膜机系统的真空,无需频繁停启主抽泵,极大缩短了单轮次镀膜的装卸瓦片及排气抽真空时间,提高镀膜效率。(The invention relates to the technical field of photomultiplier manufacturing, in particular to a device and a method for coating a cathode and a dynode tile of a dynode type photomultiplier, which comprise the following steps: the mask comprises a plurality of mask bodies, a plurality of mask bodies and a plurality of mask bodies, wherein each mask body is set to have a sealing state and an opening state, and a coating cavity is formed inside the mask bodies when the mask bodies are in the sealing state; the coating system is arranged in the coating chamber; and the main pumping system comprises a main pumping pump and a main pumping pipeline connected to the pumping end of the main pumping pump, and the second end of the main pumping pipeline is connected to the coating chamber. The main pump is isolated without stopping, a pre-pumping system is used for establishing a negative pressure environment with the vacuum degree superior to 10Pa after the vacuum state of the coating chamber is destroyed, the isolation of the main pump is opened, the vacuum of the whole coating machine system does not need to be broken, the main pump does not need to be stopped and started frequently, the tile loading and unloading and exhaust vacuumizing time of single-wheel secondary coating is greatly shortened, and the coating efficiency is improved.)

1. The utility model provides a dynode type photomultiplier negative pole and dynode tile coating film equipment which characterized in that includes:

the mask comprises a plurality of mask bodies, a plurality of mask bodies and a plurality of mask bodies, wherein each mask body is set to have a sealing state and an opening state, and a coating cavity is formed inside the mask bodies when the mask bodies are in the sealing state;

the coating system is arranged in the coating chamber;

the main pumping system comprises a main pumping pump and a main pumping pipeline connected to the pumping end of the main pumping pump, and the second end of the main pumping pipeline is connected to the coating chamber;

the pre-pumping system comprises a pre-pumping pump and a pre-pumping pipeline connected to the pumping end of the pre-pumping pump, and the second end of the pre-pumping pipeline is connected to the coating chamber;

the air inlet valve is connected to the coating chamber and is used for providing trace process gas into the coating chamber;

the air release valve is connected to the coating cavity and used for destroying the vacuum environment in the coating cavity;

and the main pumping pipeline and the pre-pumping pipeline are both provided with isolating valves for controlling the on-off state of the main pumping pipeline or the pre-pumping pipeline.

2. The dynode photomultiplier cathode and dynode tile coating apparatus of claim 1 wherein the isolation valve in the main pumping line includes a proximal isolation valve and a distal isolation valve forming a main line therebetween and a branch line between the distal isolation valve and the coating chamber.

3. The dynode-type photomultiplier cathode and dynode tile coating apparatus of claim 2 wherein the pre-pumping system comprises a two-way pre-pumping system, the first pre-pumping system comprising a first pre-pump and a first pre-pump line, the first pre-pump line connected to the main pipe, the second pre-pumping system comprising a second pre-pump and a second pre-pump line, the second pre-pump line connected to the branch pipe.

4. The dynode-type photomultiplier cathode and dynode tile coating apparatus of claim 3 wherein the first pre-pump line is provided with a first isolation valve and the second pre-pump line is provided with a second isolation valve.

5. The dynode-type photomultiplier cathode and dynode tile coating apparatus of claim 2 wherein the air inlet valve is connected to the main pipe and the air release valve is connected to the branch pipe.

6. The dynode-type photomultiplier cathode and dynode tile coating apparatus of any one of claims 1 to 5, wherein the coating system comprises:

an evaporation source connected to an evaporation power source through an evaporation electrode for evaporating an evaporation material;

the annular clamp is positioned at the periphery of the evaporation source and used for placing a workpiece to be plated so that the evaporation material is plated on the workpiece;

wherein, the inside of the annular clamp is provided with a preformed groove for the evaporation source and the evaporation electrode to pass through, and the annular clamp can be driven by a driving source to rotate relative to the evaporation source.

7. The dynode-type photomultiplier cathode and dynode tile coating apparatus according to claim 6, wherein the axis of rotation of the ring jig is in a vertical direction, the ring jig is provided in at least two layers distributed in parallel in the vertical direction, the number of the evaporation sources is the same as that of the ring jig, and a baffle plate is provided between two adjacent evaporation sources to prevent series coating between different layers.

8. A method for coating a dynode-type photomultiplier cathode and a dynode tile, characterized by using the coating apparatus of any one of claims 1 to 7, comprising the steps of:

step 1, preparation: the cover body is in an open state, the evaporation material and the tiles to be plated are respectively assembled on the evaporation boat and the annular fixture, and then the cover body is in a sealed state;

step 2, the film coating environment is achieved: closing the main pumping pipeline isolation valve and the main pumping pump, opening the pre-pumping pipeline and the pre-pumping pump, closing the pre-pumping pipeline isolation valve and the pre-pumping pump when the vacuum degree of the film coating chamber is lower than 10Pa, starting the main pumping pump, opening the main pumping pipeline isolation valve, and pumping the vacuum degree of the film coating chamber to a state lower than 0.01 Pa;

step 3, coating treatment: rotating an annular clamp in the film coating cavity at a preset rotating speed, starting an evaporation power supply, adjusting evaporation current to a preset state, and evaporating an evaporation material to coat a film on a tile to be coated;

step 4, replacing the workpiece to be plated: closing the main extraction pipeline isolation valve, opening a vent valve to destroy the vacuum environment of the coating chamber, enabling the cover body to be in an open state, unloading the evaporation material and the coated tiles, newly preparing the evaporation material and the tiles to be coated, and enabling the cover body to be in a sealed state;

step 5, achieving the film coating environment again: and (3) starting the pre-pumping pipeline and the pre-pumping pump, closing the pre-pumping pipeline isolation valve and the pre-pumping pump when the vacuum degree of the film coating chamber is lower than 10Pa, opening the main pumping pipeline isolation valve, pumping the vacuum degree of the film coating chamber to a vacuum state lower than 0.01Pa by the main pumping pump, and repeating the step (3-5) until the film coating of the workpiece is finished.

9. The method of claim 8, wherein in step 4-5, when the tiles in any one of the coating chambers are coated, the remote isolation valve connected to the corresponding coating chamber is closed, and the vacuum state of the coating chamber is broken and the tiles are replaced separately, and after the replacement is completed, the pre-pumping system is used to pre-pump the coating chamber until the degree of vacuum is better than 10Pa, the pre-pumping system is closed, the remote isolation valve is opened, and the main pump is used again to pump vacuum.

10. The method of claim 8, wherein in step 3, a slight amount of process gas is introduced into the coating chamber through an air inlet valve to adjust the degree of vacuum in the coating chamber, the degree of vacuum being in the range of 0.01Pa to 20 Pa.

Technical Field

The invention relates to the technical field of photomultiplier tubes, in particular to a dynode type photomultiplier tube cathode and dynode tile coating equipment and a coating method.

Background

The dynode type photomultiplier is a photoelectric detector widely applied to the fields of biological medical treatment, spectral analysis, environmental monitoring and the like. Before the dynode type photomultiplier is assembled and activated, a metal antimony film layer is plated on a cathode and a dynode tile (hereinafter referred to as a tile) in advance. The batch coating of tile is required to be realized to volume production dynode type photomultiplier, still need ensure rete thickness homogeneity simultaneously, realizes that the compactness is adjusted, and wherein, the lateral wall of side window type photomultiplier contains the negative pole incident window and the dynode tile, and the lateral wall of end window type photomultiplier only contains the dynode tile.

In mass production of dynode-type photomultiplier tubes, thousands of tiles need to be coated every day, and ten or more coating cycles are often required using a conventional thermal evaporation coating machine (such as a vacuum coating machine shown in patent document 2). Generally, after the coating is finished, the molecules need to be stopped, gas is injected to balance the internal pressure and the external pressure, and the high vacuum state of the real equipment is broken, so that the coated tiles can be dismounted, and the tiles to be coated and evaporation materials can be loaded. And the dry pump and the molecular pump are started again to exhaust and vacuumize, so that the vacuum degree of the equipment is better than 0.01Pa, and the film can be coated.

Obviously, a large amount of time is wasted when the molecular pump is turned off and the molecular pump is started again for coating, the vacuum in the whole equipment is broken after the coating is finished, and when the coating is performed again, the gas in a coating chamber and a pipeline can be exhausted within 1h of air exhaust time, so that the vacuum degree reaches the vacuum degree required by the coating, and the coating efficiency is low.

In addition, because the concentration of the evaporation material evaporated from the evaporation source into the space is greatly different, the uniformity of the thickness of the tiles or cathodes arranged in all directions is often poor, and the sensitivity and gain difference between the cathodes and the dynodes are easily large.

Prior art documents:

patent document 1: method and device for regulating vacuum degree in preparation process of cathode of photomultiplier tube by CN107706071A, and manufacturing method of photomultiplier tube and photocathode

Patent document 2 CN109930128A vacuum coating machine

Disclosure of Invention

The invention aims to provide a dynode type photomultiplier cathode and a dynode tile coating device and a coating method, wherein when tiles are replaced, a main pump is isolated without stopping the machine, a pre-pumping system is used for establishing a negative pressure environment with the vacuum degree superior to 10Pa after the vacuum state of a coating chamber is destroyed, the isolation of the main pump is opened, the vacuum of the whole coating machine chamber does not need to be destroyed, the main pump does not need to be stopped frequently, the tile loading and unloading and exhaust vacuum pumping time of single-round coating is greatly shortened, and the coating efficiency is improved.

In order to achieve the above object, the present invention provides a dynode-type photomultiplier cathode and dynode tile plating apparatus, comprising:

the mask comprises a plurality of mask bodies, a plurality of mask bodies and a plurality of mask bodies, wherein each mask body is set to have a sealing state and an opening state, and a coating cavity is formed inside the mask bodies when the mask bodies are in the sealing state;

the coating system is arranged in the coating chamber;

the main pumping system comprises a main pumping pump and a main pumping pipeline connected to the pumping end of the main pumping pump, and the second end of the main pumping pipeline is connected to the coating chamber;

the pre-pumping system comprises a pre-pumping pump and a pre-pumping pipeline connected to the pumping end of the pre-pumping pump, and the second end of the pre-pumping pipeline is connected to the coating chamber;

the air inlet valve is connected to the coating chamber and is used for providing trace process gas into the coating chamber;

the air release valve is connected to the coating cavity and used for destroying the vacuum environment in the coating cavity;

and the main pumping pipeline and the pre-pumping pipeline are both provided with isolating valves for controlling the on-off state of the main pumping pipeline or the pre-pumping pipeline.

Preferably, the isolation valve located in the main pumping pipeline comprises a proximal isolation valve and a distal isolation valve, a main pipe is formed between the proximal isolation valve and the distal isolation valve, and a branch pipe is formed between the distal isolation valve and the coating chamber.

Preferably, the pre-pumping system comprises two pre-pumping systems, the first pre-pumping system comprises a first pre-pumping pump and a first pre-pumping pipeline, the first pre-pumping pipeline is connected to the main pipe, the second pre-pumping system comprises a second pre-pumping pump and a second pre-pumping pipeline, and the second pre-pumping pipeline is connected to the branch pipe.

Preferably, the first pre-pumping pipeline is provided with a first isolation valve, and the second pre-pumping pipeline is provided with a second isolation valve.

Preferably, the air intake valve is connected to the main pipe, and the air release valve is connected to the branch pipe.

Preferably, the coating system includes:

an evaporation source connected to an evaporation power source through an evaporation electrode for evaporating an evaporation material;

the annular clamp is positioned at the periphery of the evaporation source and used for placing a workpiece to be plated so that the evaporation material is plated on the workpiece;

wherein, the inside of the annular clamp is provided with a preformed groove for the evaporation source and the evaporation electrode to pass through, and the annular clamp can be driven by a driving source to rotate relative to the evaporation source.

Preferably, the rotation axis of the ring-shaped fixture is along the vertical direction, the ring-shaped fixture is arranged into at least two layers which are distributed in parallel along the vertical direction, the number of the evaporation sources is the same as that of the ring-shaped fixture, and a baffle plate is arranged between every two adjacent evaporation sources to prevent series plating between different layers.

The invention provides another technical scheme, and provides a method for coating a dynode type photomultiplier cathode and a dynode tile, wherein the coating equipment in the scheme is used, and comprises the following steps:

step 1, preparation: the cover body is in an open state, the evaporation material and the tiles to be plated are respectively arranged on the evaporation boat and the annular fixture, and then the cover body is in a sealed state;

step 2, the film coating environment is achieved: closing the main pumping pipeline isolation valve and the main pumping pump, opening the pre-pumping pipeline and the pre-pumping pump, closing the pre-pumping pipeline isolation valve and the pre-pumping pump when the vacuum degree of the film coating chamber is lower than 10Pa, starting the main pumping pump, opening the main pumping pipeline isolation valve, and pumping the vacuum degree of the film coating chamber to a state lower than 0.01 Pa;

step 3, coating treatment: rotating an annular clamp in the film coating cavity at a preset rotating speed, starting an evaporation power supply, adjusting evaporation current to a preset state, and evaporating an evaporation material to coat a film on a tile to be coated;

step 4, replacing the workpiece to be plated: closing the main extraction pipeline isolation valve, opening a vent valve to destroy the vacuum environment of the coating chamber, enabling the cover body to be in an open state, unloading the evaporation material and the coated tiles, newly preparing the evaporation material and the tiles to be coated, and enabling the cover body to be in a sealed state;

and 5, reaching the coating environment again: opening a pre-pumping pipeline and a pre-pumping pump, closing a pre-pumping pipeline isolation valve and the pre-pumping pump when the vacuum degree of the film coating chamber is lower than 10Pa, opening a main pumping pipeline isolation valve, and pumping the vacuum degree of the film coating chamber to a vacuum state lower than 0.01Pa by using a main pumping pump; and then repeating the steps 3-5 until the workpiece is coated.

Preferably, in step 4-5, after the tiles in any one of the coating chambers are coated, the far-end isolation valve communicated with the corresponding coating chamber is closed, the vacuum state of the coating chamber is separately broken, the tiles are replaced, after the replacement is completed, the pre-pumping system is used for pre-pumping the coating chamber, and when the vacuum degree is better than 10Pa, the pre-pumping system is closed, the far-end isolation valve is opened, and the main pumping pump is used again for vacuum pumping.

Preferably, in step 3, a minute amount of process gas is filled into the coating chamber through the air inlet valve to adjust the vacuum degree in the coating chamber, wherein the vacuum degree adjustment range is 0.01 Pa-20 Pa.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below can be considered as part of the inventive subject matter of this disclosure unless such concepts are mutually inconsistent. In addition, all combinations of claimed subject matter are considered a part of the presently disclosed subject matter.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description taken in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of specific embodiments in accordance with the teachings of the present invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic structural view of a dynode-type photomultiplier cathode and a dynode tile coating apparatus according to the present invention;

FIG. 2 is a schematic diagram of the structure of the vapor deposition system in the cathode of the dynode-type photomultiplier and the dynode tile coating apparatus of the present invention;

FIG. 3 is a schematic structural view of an annular fixture in the cathode and dynode tile coating apparatus for a dynode-type photomultiplier according to the present invention;

FIG. 4 is a schematic diagram showing the structure of the evaporation source in the cathode of the dynode type photomultiplier and the dynode tile coating apparatus of the present invention.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

In this disclosure, aspects of the present invention are described with reference to the accompanying drawings, in which a number of illustrative embodiments are shown. Embodiments of the present disclosure are not necessarily intended to include all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described in greater detail below, may be implemented in any of numerous ways with any of the dynode-type photomultiplier tube cathodes and dynode tile coating apparatus and coating methods, as the disclosed concepts and embodiments are not limited to any implementation. In addition, some aspects of the present disclosure may be used alone, or in any suitable combination with other aspects of the present disclosure.

Generally, after coating is finished, a molecular pump (a main pump) needs to be stopped, gas is flushed to balance internal and external pressures, the high vacuum state of the whole equipment is broken, the coated tiles can be dismounted, the tiles to be coated and evaporation materials can be loaded, then a mechanical pump and the molecular pump are started again to exhaust and vacuumize, and the molecular pump can rotate at 2 ten thousand revolutions and is slow in starting and stopping speed.

Referring to fig. 1, the present embodiment provides a dynode type photomultiplier cathode and dynode tile coating apparatus, which mainly includes an apparatus body, a plurality of cover bodies 11 (three shown in the figure), and a vacuum pumping system and a coating system 24, where the apparatus body supports and protects the vacuum pumping system and the coating system.

The cover 11 is configured to have a sealed state and an open state, and a plating chamber is formed inside when the cover 11 is in the sealed state. Optionally, the cover 11 is a quartz bell jar or a stainless steel bell jar, and the cover 11 is a stainless steel bell jar and is equipped with a glass observation window 29.

Further, in order to facilitate adjustment of the sealed state and the opened state of the cover 11, the cover 11 is lifted and lowered by the mechanical lifting arm 28. When the cover body 11 is lifted up, the operation of replacing tiles can be carried out on stations in the cover body 11, and when the cover body 11 is lowered to the proper position, the cover body 11 is in self-sealing connection with a flange (not shown) of the corresponding station through a sealing rubber ring (not shown in the figure) to form a coating cavity.

Referring to fig. 2-4, the coating system is disposed within the coating chamber; the coating system comprises: an evaporation source 242 connected to the evaporation power source 26 through an evaporation electrode 244 for evaporating the evaporation material; the annular clamp 241 is positioned at the periphery of the evaporation source 242 and used for placing a workpiece to be plated so that the evaporation material is plated on the workpiece; the inside of the ring holder 241 is provided with a pre-groove for passing the evaporation source 242 and the evaporation electrode 244, and can be driven by the driving source 30 to rotate relative to the evaporation source.

In an alternative embodiment, as shown in fig. 2, taking the illustrated three-set coating system in each coating chamber as an example, the evaporation source 242 is a tungsten wire spiral boat, the positive and negative electrodes of the evaporation source 242 are connected to the evaporation power supply 26 through 3 positive electrodes 2441, 2442, 2443 and 1 negative electrode 2444, the adjustment precision of the evaporation power supply 26 is 0.1A, and the current of each evaporation source 242 can be individually adjusted.

Thus, during vapor deposition, a vapor deposition material, in this example, metallic antimony particles, is placed in the tungsten filament screw boat. The positive electrode of the evaporation power supply 26 is in circuit communication with any one of positive electrodes 2441, 2442 and 2443 of the 3 evaporation sources 242 through a rotary knob (not shown in the figure), so that independently controlled evaporation of the 3 evaporation sources 2421, 2422 and 2423 is realized.

In an alternative embodiment, as shown in fig. 2, the rotation axis of the ring clamp 241 is along the vertical direction, the ring clamp 241 is arranged in at least two layers distributed in parallel along the vertical direction, the number of the evaporation sources 242 is the same as that of the ring clamps 241, and the ring clamp 241 is fixed by two struts 2451, 2452 to limit the spacing and relative position between the two ring clamps 241.

Further, the upper and lower ends of the two struts 2451, 2452 are connected to the fixed plate 245, the lower fixed plate 245 is provided with a circular slot 2453 for the vapor deposition electrode 244 to pass through, and the upper fixed plate 245 is connected to the driving source 30 of the mask body 11 through the driving rod 246.

Wherein, the driving rod 246 is detachably connected with the cover body 11. The drive source 30 is a motor that can be fixed to the inside or outside (shown as the outside) of the cover 11.

In this way, during the evaporation process, the motor rotates to drive the fixing plate 245 to rotate, so that the tile workpieces on the ring fixture 241 rotate around the evaporation source 242, and the coating uniformity is improved. And a multilayer tower-shaped coating structure is formed relative to the coating clamp with a single-layer structure, so that the number of workpieces coated at one time can be greatly increased.

Further, a baffle 243 is disposed between two adjacent evaporation sources 242, and three baffles 2431, 2432, 2433 are disposed above the illustrated three evaporation sources 2421, 2422, 2423 to prevent different layers from being plated in series.

Further, as shown in fig. 1, the main pumping system includes a main pump 16 and a main pumping pipe connected to the pumping end of the main pump 16, and the second end of the main pumping pipe is connected to the coating chamber. The pre-pumping system comprises a pre-pumping pump and a pre-pumping pipeline connected to the pumping end of the pre-pumping pump, and the second end of the pre-pumping pipeline is connected to the coating chamber. And the main pumping pipeline and the pre-pumping pipeline are both provided with isolating valves for controlling the on-off state of the main pumping pipeline or the pre-pumping pipeline.

The main pump 16 adopts a molecular pump and a dry pump, the rotating speed of the molecular pump can reach 2 ten thousand revolutions, the starting and stopping time is long, the dry pump firstly pumps vacuum until the vacuum degree is better than less than 10Pa, and the molecular pump pumps vacuum again.

Therefore, when the coating chamber is vacuumized, the pre-pumping system is firstly used for vacuumizing the coating chamber, when the vacuum degree is higher than and lower than 10Pa, the main pumping system is used for vacuumizing the coating chamber, so that the coating chamber reaches the coating condition (lower than 0.01 Pa), especially after one round of coating, the main pump 16 can be isolated, then the vacuum state of the coating chamber is destroyed, the tile is replaced, the cover body 11 is in a sealed state again, then the pre-pumping system is used for enabling the vacuum degree to be higher than and lower than 10Pa, and then the isolation of the main pump 16 is released.

Therefore, the main pump 16 does not need to be stopped and started frequently when the coating is carried out for multiple times repeatedly, the high vacuum state of the pipeline does not need to be broken, the tile loading and unloading and exhaust vacuumizing time of the single-time coating is shortened from more than 1 hour to less than 25 minutes, and the coating efficiency is greatly improved.

In an alternative embodiment, shown in connection with fig. 1, the isolation valves in the main pumping line include a proximal isolation valve 15 and a distal isolation valve 12, with a main pipe 14 formed between the proximal isolation valve 15 and the distal isolation valve 12, and a branch pipe 13 formed between the distal isolation valve 12 and the coating chamber. Three branch pipes 13 are arranged corresponding to the coating chambers.

Further, the pre-pumping system comprises a two-way pre-pumping system, the first pre-pumping system comprises a first pre-pumping pump 18 and a first pre-pumping pipe 25, the first pre-pumping pipe 25 is connected to the main pipe 14, the second pre-pumping system comprises a second pre-pumping pump 22 and a second pre-pumping pipe 20, and the second pre-pumping pipe is connected to the branch pipe 13.

In an alternative embodiment, first pre-pump 18 and second pre-pump 22 are dry mechanical vacuum pumps, such that first pre-pump 18 can simultaneously act as a dry pump in main pump 16.

In an alternative embodiment, in order to add evaporation stations, the branch pipes 13 are arranged in three, and are connected to the main pipe 14, during the first round of vacuum pumping, the first pre-pump 18 and the second pre-pump 22 both participate in the pre-vacuum pumping process, and during the subsequent pre-vacuum pumping process, in order to maintain the vacuum degree in the main pipe 14, the main pipe 14 is isolated by using the remote isolation valve 12, and only the second pre-pump 22 is controlled to pre-pump.

Furthermore, in order to control the on/off of the first pre-pumping pipeline 25 and the second pre-pumping pipeline 20, the first pre-pumping pipeline 25 is provided with a first isolation valve 19, and the second pre-pumping pipeline 20 is provided with a second isolation valve 23. In this way, the sealing performance of the first pre-pump 18 and the second pre-pump 22 can be increased when the pre-pump is not in operation.

Referring to fig. 1, an air inlet valve 21 is connected to the coating chamber for supplying a trace amount of process gas into the coating chamber; the air release valve 27 is connected to the coating chamber and is used for destroying the vacuum environment in the coating chamber; in an alternative embodiment, the inlet valve 21 is connected to the main pipe 14 and the bleed valve 27 is connected to the branch pipe 13.

Therefore, because the metal coating layers have different compactness under different coating vacuum degrees, process gases (such as nitrogen and argon) can be injected through the air inlet valve 21 to adjust the vacuum degree during coating, so that the compactness of the coated layer is adjusted and controlled, and the adjustment range of the vacuum degree is 0.01 Pa-20 Pa.

When the vacuum environment is broken after the plating is completed, the vacuum environment in the plating chamber can be broken only by the air release valve 27 on the branch pipe 13, and the vacuum environment in the main pipe 14 is maintained, and the main pump 16 is isolated and kept without stopping.

And because a plurality of stations are arranged, the independence of each coating chamber can be kept, and the independent operation can be realized under the condition that the main pump 16 does not stop.

The invention provides another technical scheme, and provides a method for coating a dynode type photomultiplier cathode and a dynode tile, wherein the coating equipment in the scheme is used, and comprises the following steps:

step 1, preparation: the lifting device 28 is used for driving the cover body 11 to lift up, so that the evaporation space in the cover body 11 is in an open state, evaporation materials (such as metal antimony particles) and dynode tiles to be plated are prepared, then the cover body 11 is lowered, and the evaporation space in the cover body 11 is in a sealed state;

step 2, coating environment: closing the near-end isolation valve 15 and the main pump 16, opening the pre-pumping pipelines (the first pre-pumping pipeline 25 and the second pre-pumping pipeline 20) and the pre-pumping pumps (the first pre-pumping pump 18 and the second pre-pumping pump 22), closing the pre-pumping pipeline isolation valve and the pre-pumping pumps (the second pre-pumping pump 22) when the vacuum degree of the film coating chamber is lower than 10Pa, starting the main pump 16, opening the near-end isolation valve 15, and pumping the vacuum degree of the film coating chamber to a state lower than 0.01 Pa;

step 3, coating film: rotating the annular clamp 241 at a preset rotating speed (the rotating speed of the annular clamp 241 is 5 rad/min-10 rad/min), starting the evaporation power supply 26, adjusting the evaporation current to a preset state, evaporating the coating steam from the evaporation material to the evaporation space, and coating the tile to be coated;

step 4, replacing the workpiece to be plated: closing the near-end isolation valve 15 and the far-end isolation valve 12, opening the air release valve 27 to destroy the vacuum environment of the coating chamber, lifting the mask body 11 to enable the evaporation space to be in an open state, unloading the evaporation material and the coated tiles, re-preparing new evaporation material and tiles to be coated, and then lowering the mask body 11 to enable the evaporation space to be in a sealed state;

and 5, reaching the coating environment again: the pre-pumping pipeline (a second pre-pumping pipeline 20) and the pre-pumping pump (a second pre-pumping pump 22) are started, when the vacuum degree of the coating chamber is lower than 10Pa, the second isolation valve 23 and the second pre-pumping pump 22 are closed, the near-end isolation valve 15 is opened, and the main pumping pump 16 enables the vacuum degree of the coating chamber to be pumped to a vacuum state lower than 0.01 Pa; and then repeating the steps 3-5 until the workpiece is coated.

Specifically, as shown in fig. 1, in step 1, when the cover 11 is lowered to a proper position, the cover 11 is self-sealed and connected to a flange (not shown) of a corresponding station through a sealing rubber ring (not shown), so as to form a relatively sealed coating chamber, so that a vacuum environment with a vacuum degree of less than 0.01Pa can be formed in the coating chamber; when the mask body 11 is raised to the right position, the evaporation parts on the inner side are exposed, so that the evaporation materials and the tiles can be conveniently replaced by workers.

In an alternative embodiment, in step 1, when the photomultiplier is a side window type photomultiplier, the evaporation target (tile to be plated) includes a dynode tile and a photocathode entrance window; when the photomultiplier is an end-window type photomultiplier, the vapor deposition portion (the tile to be plated) is a dynode tile. Wherein the tiles of dynodes are fixed to a ring jig and the evaporation material is placed in an evaporation boat.

In an alternative embodiment, in step 2, if the main pump 16 and the pre-pump share the first pre-pump 18, the first pre-pump 18 is kept not to be turned off, and the vacuum degree is kept to be better than 10Pa to be vacuumized together with the molecular pump of the main pump 16.

In an optional embodiment, in step 3, a minute amount of process gas is filled into the coating chamber through the air inlet valve 21 to adjust the vacuum degree in the coating chamber, wherein the vacuum degree adjustment range is 0.01 Pa-20 Pa.

In an optional embodiment, in step 4-5, after the tiles in any one of the coating chambers are coated, the distal isolation valve 12 communicated with the corresponding coating chamber is closed, and the coating chamber is independently broken from a vacuum state and replaced with tiles, after the replacement is completed, the coating chamber is pre-pumped by using the second pre-pump 22, and when the vacuum degree is higher than 10Pa, the second pre-pump 22 is closed, the distal isolation valve 12 is opened, and the main pump 16 is reused for vacuum pumping.

Referring to fig. 1, after coating is finished at first at any one of the 3 stations, the air release valve 27 of the corresponding station can be closed, gas is directly filled to break vacuum, the coated tiles are taken down and assembled, the tiles to be coated are pre-vacuumized by the second pre-pump 22, and the tiles in the current station can be assembled and disassembled without waiting for the coating of the rest stations. Namely, 3 stations can independently break vacuum and pre-vacuumize, thereby greatly shortening the time for loading and unloading workpieces and improving the film coating efficiency.

[ Evaporation Process ]

Starting up a first wheel for film coating: putting an evaporation material (metal antimony particles) into the evaporation source 242, preparing tiles to be plated, and lowering the mask body 11; starting the first pre-pump 18 and the second pre-pump 22, opening the first isolation valve 19, the far-end isolation valve 12 and the second isolation valve 23, and closing the first isolation valve 19, the second isolation valve 23 and the second pre-pump 22 when the vacuum degree is better than 10 Pa; and starting a main pump 16, opening a near-end isolation valve 15, vacuumizing the main pump 16 and a first pre-pump 18 together, and plating the film after the vacuum degree is better than 0.01 Pa.

Before film coating, the motor is adjusted to control the fixed disc 245 to rotate, the rotating speed of the annular clamp 241 is made to be 5 rad/min-10 rad/min, the tiles to be coated rotate around the evaporation source 242, the evaporation power supply 26 is started, the evaporation current is adjusted, and each layer of tiles to be coated of each station is sequentially coated. The evaporation source 242 has a large difference in the concentration of the evaporation material evaporated into space, so that the uniformity of the thickness of the tiles placed in all directions is often poor, and the tiles to be plated rotate around the evaporation source 242 during the plating process, so that the uniformity of the plating of the tiles can be improved.

In addition, because the compactness of the plated metal film layer is different under different plating vacuum degrees, process gas (such as nitrogen and argon) can be injected through the air inlet valve 21 to adjust the vacuum degree during plating, so that the compactness of the plated film layer is adjusted and controlled, and the adjustment range of the vacuum degree is 0.01 Pa-20 Pa.

Repeatedly coating films for multiple times:

after the first round of coating is finished, the near-end isolation valve 15 is closed to isolate the main pump 16, the far-end isolation valve 12 is closed to isolate the coating chamber from the main pipe 14, the high vacuum state of the coating chamber is broken through deflation of the deflation valves 27 at all stations, the cover body 11 is lifted, loading and unloading of tiles and replacement of evaporation materials are finished, and the bell jar 11 is lowered. And opening a second isolation valve 23 and a second pre-pumping pump 22 to pre-pump the coating chamber. And when the vacuum degree is better than 10Pa, closing the second isolation valve 23 and the second pre-pump 22, and opening the near-end isolation valve 15 and the far-end isolation valve 12 for vacuum-pumping and film-coating. The subsequent coating process is consistent with the first-wheel coating process of the startup, and the description is omitted here.

And (3) replacing the tiles to be plated with the transparent borosilicate glass sheets to test the film plating uniformity, assembling 20 transparent borosilicate glass sheets on the annular clamp 241, and testing the optical transmittance of the coated glass sheets after film plating so as to represent the thickness uniformity and consistency of the coated film of 20 borosilicate sheets.

Table 1: optical transmission of 20 clear glass borosilicate glass sheets

Each borosilicate glass sheet was taken up in the upper, middle and lower three positions for transmittance testing. The test results are shown in table 1, the transmittance of 20 borosilicate glass sheets after coating is about 6.1%, and the uniformity and consistency of the coating are high.

Based on the above embodiment, when the tile is replaced, the main pump 16 can be isolated only by closing the near-end isolation valve 15, and the main pump 16 does not need to be shut down. The coating chamber is isolated from the main pipe 14 by simply closing the distal isolation valve 12 on the branch pipe 13. And then the vacuum degree of the coating chamber is broken through the deflation of the deflation valve 27 at each station, and the cover body 11 is lifted, thus the loading and unloading of the tiles and the replacement of the evaporation materials can be completed. The main pump 16 does not need to be stopped and started frequently when the coating is carried out for multiple times repeatedly, the high vacuum state of the main pipe 14 does not need to be broken, the tile loading and unloading and exhaust vacuumizing time of the single-time coating is shortened from more than 1 hour to less than 25 minutes, and the coating efficiency is greatly improved.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.