Coating method for microchannel plate for 3rd generation image intensifier

Abstract

The application relates to a film coating method for a micro-channel plate of a third-generation image intensifier, which comprises the following steps: a film pasting tool configuration step, a film pasting environment configuration step, a micro-channel plate loading step, an organic film pasting step, an air drying step, a transfer step and a drying step. Through the above method, the organic film layer of the micro-channel plate is free of wrinkles, cracks and watermarks, the qualified rate of the organic film layer of the micro-channel plate is increased from 20% to more than 90%, the organic mask quality and the qualified rate of the micro-channel plate are effectively improved, the rapid production of the industry is realized, and the product production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of night vision, in particular to a film coating method for a microchannel plate of a third-generation image intensifier. BACKGROUND

[0002] In the third-generation low-light-level night vision device, the most important core electronic component is the image intensifier, which mainly consists of a gallium arsenide photocathode, an anti-ion feedback microchannel plate, and a fluorescent screen. The photoelectrons generated by the gallium arsenide photocathode are multiplied by the microchannel plate (MCP for short) channels, and a high-density electron cloud is formed at the output end. Due to the presence of residual gas in the vacuum device, the electron cloud ionizes the residual gas under high field strength, and the positive ions are accelerated in the electric field and move towards the photocathode, eventually colliding with the photocathode to form ion feedback, which produces additional photoelectric emission and forms ion spots on the fluorescent screen, thereby deteriorating the image and reducing the service life of the photocathode. Therefore, in order to reduce the ion feedback of residual gas in the device, a thin dielectric film is sputtered on the input surface of the microchannel plate in the third-generation low-light-level image intensifier to act as an ion barrier and prevent ion feedback.

[0003] Considering the porous characteristics of the microchannel plate, in order to form a continuous ultra-thin film on the input end of the microchannel plate, the channel holes on the input end of the microchannel plate must be flattened, and then the organic film layer is removed after the formation of the anti-ion feedback film (Al2O3 film). The requirements for the anti-ion feedback film in the third-generation low-light-level image intensifier are: ultra-thin, continuous, dense, high electron transmission rate, and high ion blocking rate. Therefore, the organic film layer, as a temporary substrate for the anti-ion feedback film, needs to have sufficient strength and good adhesion, and be smooth, flat, uniform, and tightly attached to the surface of the microchannel plate. The quality of the organic film layer determines the quality and yield of the anti-ion feedback film and directly affects the performance of the microchannel plate.

[0004] The organic mask film prepared in the market at present is divided into two kinds: dry film sticking and wet film sticking. However, the organic mask film has poor quality and low yield. The dry film sticking is also called pulling film sticking, which requires that the operator accurately judges the pulling time and pulling rate of the organic mask film, otherwise, the organic mask film cannot be extracted or is broken. The wet film sticking requires that the organic mask film is suspended above the microchannel plate, and the deionized water is drained to make the organic mask film settle on the surface of the microchannel plate. In this process, due to the inconsistent drainage rate of the deionized water accumulated between the microchannel plate and the organic mask film, wrinkles and water marks are generated on the film layer when the organic mask film is stuck on the surface of the microchannel plate. In addition, in the process of preparing the organic mask film, due to the specific toughness and strength requirements of the organic film layer, stress concentration is generated when the excess organic mask film is extracted or scraped, which causes the organic mask film to be broken. In addition, during the transportation and drying, the operator touching the film sticking clamp often introduces some particulate impurities, which cannot be eliminated by subsequent processes. The above defects directly affect the quality of the prepared organic film and reduce the performance of the third generation microchannel plate. SUMMARY

[0005] Therefore, it is necessary to provide a film coating method for a microchannel plate of a third generation image intensifier to avoid defects such as wrinkles, breakage, water marks and stripes of the organic film, so as to significantly improve the quality and yield of the organic film layer.

[0006] To achieve the above-mentioned purposes, the application adopts the following technical solutions.

[0007] The application provides a film coating method for a microchannel plate of a third generation image intensifier, which comprises the following steps:

[0008] A film sticking tooling is configured, the film sticking tooling comprises a carrier disc for carrying the microchannel plate, and the inclination angle of the carrier disc is adjusted to 3-4 degrees; a limiting groove is arranged at the center position of the carrier disc, and the microchannel plate is placed in the limiting groove; a flow guide groove is arranged between the limiting groove and the outer side surface of the carrier disc, and the flow guide groove is suitable for quickly draining the deionized water in the limiting groove;

[0009] A film sticking environment is configured, the debugged film sticking tooling is placed at the center of a tank containing deionized water, and the height of the deionized water is slowly controlled until the water surface is 1cm above the supporting surface of the carrier disc;

[0010] The microchannel plate is loaded, the side surface of the microchannel plate is clamped and placed on the film sticking tooling, so that the microchannel plate is tightly attached to the carrier disc;

[0011] The organic liquid is hung on the organic film at 1 cm above the center area of the micro-channel plate, and is left until the organic liquid is spread to form a thin film with no rainbow stripes; the deionized water in the tank is slowly drained at a rate of 1-1.5 L / min, so that the thin film is gradually attached to the micro-channel plate and the carrier plate from high to low and from top to bottom until it completely covers the entire micro-channel plate and the carrier plate;

[0012] Air drying, the film-attaching tooling and the micro-channel plate are taken out, and the deionized water between the micro-channel plate and the organic film is blown off using a nitrogen gun;

[0013] Transportation, the upper cover and the handle are installed on the carrier plate, and the micro-channel plate is enclosed in the sealed space between the upper cover and the film-attaching tooling; the carrier plate with the micro-channel plate is transferred to the vacuum drying oven through the handle;

[0014] Drying, the drying temperature and the drying time of the vacuum drying oven are set to dry the organic film on the micro-channel plate.

[0015] Preferably, the film-attaching tooling comprises a support seat and a carrier plate, the support seat has support feet that can adjust the inclination angle of the support seat, and the carrier plate is placed on the support seat.

[0016] Preferably, after the step of configuring the film-attaching environment, the method further comprises the step of:

[0017] After standing for a while, the surface of the deionized water is irradiated using a strong light flashlight to check whether there are impurities on the surface of the water and in the water, and if so, the impurities on the surface of the water and in the water are removed.

[0018] Preferably, before the step of air drying, the method further comprises the step of:

[0019] The organic film on the outer edge of the two flow guide grooves on the carrier plate is pierced using a sharp-tipped tweezers to prevent stress between the notch and the organic film from causing the film layer to break, and then the excess organic film is scraped along the 8 mm transition layer outer circle of the carrier plate to avoid wrinkles in the film layer extending to the effective area of the micro-channel plate.

[0020] Preferably, the step of air drying specifically comprises:

[0021] The flow rate of the nitrogen gun is adjusted to 0.01 sccm, and the deionized water between the micro-channel plate and the organic film is blown dry from top to bottom along the inclination direction of the micro-channel plate in a "Z" shaped path using the nitrogen gun.

[0022] Preferably, in the step of drying, the drying temperature of the vacuum drying oven is set to 70-80 degrees Celsius, and the drying time is 200-300 min.

[0023] Preferably, after the step of drying, the method further comprises the step of:

[0024] Take out the carrier plate, open the upper cover, check the film layer quality of the organic film in a ''Z'' shape, if there are wrinkles, breakage, watermark and stripe defects, remove the organic film layer and re-coat.

[0025] Preferably, the method for removing the organic film layer comprises placing the microchannel plate under the ultraviolet lamp for irradiation for 4 hours, so that the organic film layer is decomposed and falls off.

[0026] Compared with the quality of the organic mask prepared in the current market, the film layer prepared by the application has no wrinkles, breakage, watermarks, and the qualified rate of the organic film layer of the microchannel plate is increased from 20% to more than 90%, effectively improving the quality and qualified rate of the organic mask of the microchannel plate, realizing rapid production of the industry, and reducing the production cost of the product. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the film sticking tool in the embodiment.

[0028] The implementation of the application and its functions and principles will be further described in the specific implementation mode in combination with the drawings. DETAILED DESCRIPTION

[0029] The application will be further described below in combination with the drawings and specific embodiments.

[0030] The embodiment provides a film coating method for a microchannel plate of a III generation image intensifier, comprising the following steps:

[0031] S1: configuring a film sticking tool, the film sticking tool comprising a carrier plate for carrying the microchannel plate, and adjusting the inclination angle of the carrier plate to be 3-4 degrees;

[0032] S2: configuring a film sticking environment, placing the debugged film sticking tool in the center of a tank containing deionized water, and slowly controlling the height of the deionized water until the water surface is 1 cm above the supporting surface of the carrier plate;

[0033] S3: loading the microchannel plate, clamping the side surface of the microchannel plate and placing it on the film sticking tool, so that the microchannel plate closely adheres to the carrier plate;

[0034] S4: sticking the organic film, dropping the organic liquid at a position 1 cm above the center area of the microchannel plate, and standing until the organic liquid spreads to form a thin film without rainbow stripes; slowly discharging the deionized water in the tank, so that the thin film gradually sticks to the microchannel plate and the carrier plate from high to low and from top to bottom, until it completely covers the entire microchannel plate and carrier plate;

[0035] S5: air drying, taking out the film sticking tool together with the microchannel plate, and using a nitrogen gun to blow off the deionized water between the microchannel plate and the organic film;

[0036] S6: transport, install the upper cover and handle on the carrier plate, and seal the micro-channel plate in the sealed space between the upper cover and the film pasting tool; and transfer the carrier plate with the micro-channel plate to the vacuum drying box through the handle;

[0037] S7: drying, set the drying temperature and drying time of the vacuum drying box, and dry the organic film on the micro-channel plate.

[0038] As shown in Figure 1 The film pasting tool 100 of the embodiment includes a support base 10 and a carrier plate 20. The support base 20 is provided with support feet 30 that can adjust the inclination angle of the support base 10. The carrier plate 20 is placed on the support base 10. The center of the carrier plate 20 is provided with a limiting groove 21 in which the micro-channel plate is placed. A flow guide groove 22 is arranged between the limiting groove 21 and the outer side of the carrier plate 20. The flow guide groove 22 is used to quickly drain the deionized water in the limiting groove 21.

[0039] In the process of depositing the organic mask on the surface of the micro-channel plate, only when the two planes of the organic film layer and the micro-channel plate surface are completely parallel, the film layer can be flat and bubble-free. However, the current technology cannot achieve this effect. The embodiment takes a different approach. By adjusting the height of the front and back of the film pasting tool, the micro-channel plate is in an inclined state of 3-4 degrees. When the organic film is pasted on the surface of the micro-channel plate, a pre-contact is formed. Under the action of the inclination angle, the film layer is smoothly covered on the surface of the micro-channel plate, effectively avoiding the formation of bubbles between the organic film and the micro-channel plate. At the same time, two flow guide grooves 22 are designed at the edge of the film pasting clamp. Under the action of the flow guide grooves 22, the deionized water on the surface of the micro-channel plate can be quickly drained, preventing the occurrence of quality defects of the organic mask film layer caused by the accumulation of deionized water.

[0040] In addition, after step S2, the following steps are further included:

[0041] After standing for a while, use a strong light flashlight to irradiate the surface of the deionized water to check whether there are impurities on the water surface and in the water. If there are, remove the impurities on the water surface and in the water. In this way, bubbles and water marks can be prevented during film pasting.

[0042] The film layer rupture usually occurs in the process that the organic film starts to contact the microchannel plate until completely covers the surface of the microchannel plate. On the one hand, the problem of drainage rate, the rate is too fast to cause a certain impact on the organic film, thereby causing the rupture, the rate is too slow to cause the organic film to deform and bend; on the other hand, when the organic film completely covers the surface of the microchannel plate, the burr tip of the tool clamp also causes the film layer rupture, so that the organic film layer is rolled to the output surface of the microchannel plate, thereby causing the loss of the organic film on the input surface. The drainage throttle valve device is introduced to finely adjust the drainage rate, thereby preventing the film layer rupture caused by the too fast or too slow drainage. Therefore, in the organic film pasting step S4, the drainage rate of the deionized water is set to 1-1.5 L / min.

[0043] Similarly, before the film pasting on the microchannel plate, the microchannel plate also needs to be inspected to prevent the impurities on the surface of the microchannel plate from affecting the pasting quality of the organic film. Specifically as follows:

[0044] The microchannel plate package box is opened, the edge of the microchannel plate is clamped by using the carbon fiber tweezers, the input surface is placed in the limiting groove 21 of the inspection clamp with the input surface upward, under the 5X microscopic magnifying mirror, the input surface quality of the microchannel plate is inspected in turn from top to bottom in the "Z" type, if there are impurities on the surface of the microchannel plate, the impurities are picked up by using the felt until the surface of the microchannel plate is clean and free of particulate impurities.

[0045] In order to avoid secondary pollution, the input surface edges of the microchannel plate are clamped by using the stainless steel tweezers, and the microchannel plate is vertically clamped and placed in the limiting groove 21.

[0046] When the step S4 is performed, after the horizontal plane is stable, the automatic droplet device is used, for example, the rotary transfer gun knob is set, the transfer parameters are set to 10 μL, the transfer gun is vertically inserted into the gun head, 10 μL of organic liquid is sucked, the organic liquid is suspended on the microchannel plate center area 1 cm above, and the organic liquid is formed into a wrinkle-free and rainbow-free film after waiting.

[0047] Then, the negative pressure drainer switch is turned on, and the drainage is started. Under the action of the inclination angle and the two flow guide grooves, the deionized water on the surface of the microchannel plate is quickly guided away along the inclination angle and the flow guide groove 22 direction, the organic mask starts to settle on the surface of the carrier 20, and as the deionized water in the tank is uniformly sucked, the organic film starts to cover the surface of the microchannel plate until completely covers the entire microchannel plate and the carrier 20.

[0048] After the film covering is completed, the air drying step is entered, but before this, the following steps should be added:

[0049] The organic film on the outer edge of the two flow guide grooves 22 on the carrier 20 is punctured using a pointed tweezer to prevent stress between the notch and the organic film from causing the film layer to break, and the excess organic film is scraped off along the outer circle of the transition layer of the carrier 20 to avoid wrinkles extending to the effective area of the micro-channel plate.

[0050] The air-drying step of the embodiment specifically includes:

[0051] The flow of the nitrogen gun is adjusted to 0.01 sccm (standard cubic centimeter per minute), and the deionized water between the micro-channel plate and the organic film is blown dry from top to bottom along the inclined direction of the micro-channel plate using the nitrogen gun in a "Z" shape.

[0052] After the micro-channel plate is air-dried, the upper cover 40 of the carrier 20 is assembled, the upper cover step is inlaid at the position of the flow guide groove to form an assembly, so that the micro-channel plate is in a closed and clean independent space, reducing the risk of contamination of the micro-channel plate exposed to the air, and realizing safe and clean transfer of the micro-channel plate. After standing for 10 minutes, the handle 50 is installed, the handle 50 is combined with the side notch 23 of the carrier 20, and the carrier 20 with the micro-channel plate is transferred to a vacuum drying oven for drying.

[0053] The detachable combined film sticking tool 100 is used in the embodiment, the support seat 10 and the carrier 20 are used as independent bodies, after the preparation of the organic film of the micro-channel plate is completed, the carrier 20 is combined with the upper cover 40, which is convenient to operate and realizes dry and wet separation, thereby realizing safe and clean transfer of the micro-channel plate.

[0054] In the drying step, the drying temperature of the vacuum drying oven is set to 70-80 degrees Celsius, and the drying time is 200-300 minutes.

[0055] Preferably, the drying step further includes the step of:

[0056] The carrier 20 is taken out, the upper cover 40 is opened, and the carrier 20 is placed on the microscope stage under a magnifying glass 5X, the film layer quality of the organic film is checked in a "Z" shape, if there are wrinkles, cracks, watermarks and stripe defects, the organic film layer is removed, and then the above steps S1-S7 are performed again until a qualified organic film is coated. If the film layer quality of the organic film is normal, it is placed in a micro-channel plate packaging box for standby.

[0057] The method for removing the organic film layer includes placing the micro-channel plate under a UV lamp for irradiation for 4 hours to make the organic film layer decompose and fall off.

[0058] Compared with the organic mask prepared in the market, the film prepared by the application has no wrinkle, rupture and watermark, the qualified rate of the micro-channel plate organic film layer is increased from 20% to 90% or more, the quality and qualified rate of the micro-channel plate organic mask are effectively improved, the rapid production of industry is realized, and the production cost of the product is reduced.

[0059] The technical features of the above-mentioned embodiments can be combined arbitrarily, and to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, it should be considered that it is within the scope of the present application.

[0060] The above-mentioned embodiments only express several embodiments of the application, the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are within the protection scope of the application.

Claims

1. A method of coating a microchannel plate for a third-generation image intensifier, characterized by, The method comprises the following steps: configuring a film pasting tool, which comprises a carrier plate for carrying the microchannel plate, and adjusting the inclination angle of the carrier plate to 3-4 degrees; a limiting groove is arranged at the center of the carrier plate, and the microchannel plate is placed in the limiting groove; a flow guide groove is arranged between the limiting groove and the outer side of the carrier plate, and the flow guide groove is suitable for quickly draining the deionized water in the limiting groove; configuring a film pasting environment, placing the debugged film pasting tool in the center of a tank containing deionized water, and slowly controlling the height of the deionized water until the water surface is 1 cm above the supporting surface of the carrier plate; loading the microchannel plate, clamping the side of the microchannel plate and placing it on the film pasting tool, so that the microchannel plate is tightly attached to the carrier plate; pasting the organic film, dropping organic liquid 1 cm above the center area of the microchannel plate, and standing until the organic liquid spreads to form a thin film of non-color rainbow stripes; slowly draining the deionized water in the tank, and the drainage rate of the deionized water is 1-1.5 L / min, so that the thin film gradually pastes on the microchannel plate and the carrier plate from high to low and from top to bottom, until it completely covers the entire microchannel plate and carrier plate; air drying, taking out the film pasting tool together with the microchannel plate, and blowing away the deionized water between the microchannel plate and the organic film using a nitrogen gun; transporting, installing an upper cover and a handle on the carrier plate, and closing the microchannel plate in a sealed space between the upper cover and the film pasting tool; and transferring the carrier plate with the microchannel plate to a vacuum drying oven through the handle; drying, setting the drying temperature and time of the vacuum drying oven, and drying the organic film on the microchannel plate.

2. The film coating method according to claim 1, wherein The film pasting tool comprises a supporting seat and a carrier plate, and the supporting seat has supporting legs that can adjust the inclination angle of the supporting seat, and the carrier plate is placed on the supporting seat.

3. The film coating method according to claim 1, wherein After the step of configuring the film pasting environment, the method further comprises the steps of: After standing for a moment, using a strong light flashlight to irradiate the surface of the deionized water to check whether there are impurities on the water surface and in the water, and if there are, removing the impurities on the water surface and in the water.

4. The film coating method according to claim 1, wherein Before the step of air drying, the method further comprises the steps of: using a sharp forceps to pierce the organic film on the two outer edges of the flow guide grooves on the carrier plate, preventing the stress between the notch and the organic film from causing the film layer to break, and then scraping the excess organic film along the 8mm transition layer outer circle of the carrier plate to avoid the film layer wrinkles extending to the effective area of the microchannel plate.

5. The film forming method according to claim 4, wherein The step of air drying specifically comprises: adjusting the flow rate of the nitrogen gun to 0.01 sccm, using the nitrogen gun to blow dry the deionized water between the microchannel plate and the organic film from top to bottom along the inclination direction of the microchannel plate in a "Z" shape path.

6. The film coating method according to claim 1, wherein In the step of drying, the drying temperature of the vacuum drying oven is set to 70-80 degrees Celsius, and the drying time is 200-300 minutes.

7. The film coating method according to claim 1, wherein After the step of drying, the method further comprises the steps of: taking out the carrier plate, opening the upper cover, and checking the film layer quality of the organic film in a "Z" shape, and if there are wrinkles, breaks, watermarks and stripe defects, removing the organic film layer and re-coating the film.

8. The film forming method according to claim 7, wherein The method for removing the organic film layer comprises placing the microchannel plate under the ultraviolet lamp for irradiation for 4 hours to make the organic film layer decompose and fall off.

Images