Preparation method of PMMA (polymethyl methacrylate) organic membrane liquid for temporary substrate of micro-channel plate

Abstract

The invention discloses a preparation method of PMMA (polymethyl methacrylate) organic membrane liquid for a temporary substrate of a microchannel plate, and relates to the technical field of PMMA organic membrane liquid preparation, which comprises the following steps: 1) putting PMMA powder into a vacuum drying oven, and drying at 70-80 DEG C for 2-4 hours; (2) preparing a PMMA membrane solution with the mass fraction of 10%-20% from PMMA powder and a xylene solution, stirring at room temperature for 48 hours, and filtering; and 3) mixing the PMMA membrane solution, absolute ethyl alcohol and dibutyl phthalate according to a volume ratio of (40: 3: 1)-(40: 2: 1), and stirring for 4-6 hours. Compared with an organic mask prepared in the current market, the preparation method of the PMMA organic film liquid for the temporary substrate of the micro-channel plate has the advantages that the PMMA organic mask which is stable and uniform in performance and high in viscosity is prepared, the surface of the PMMA organic mask is free of colored stripes, spots and pinholes, the number of tips on the surface of the PMMA organic film is small, almost no pinholes exist, the film layer is relatively flat, and the preparation method of the PMMA organic film liquid for the temporary substrate of the micro-channel plate is suitable for large-scale production. And photoelectron reflection can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of PMMA organic film liquid preparation, in particular to a method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate. Background Art

[0002] The third generation of low-light image intensifiers are mainly characterized by GaAs negative electron affinity photocathode and MCP with anti-ion feedback membrane. The electrons emitted by the photocathode of the low-light image intensifier are multiplied by MCP many times and then gathered at its output end. The gas molecules are ionized under the action of the working voltage to produce positive ions, which bombard the inner wall of MCP and the photocathode, and finally form ion spots on the fluorescent screen, which also seriously reduces the life of the photocathode.

[0003] In order to eliminate and reduce ion feedback, relevant researchers proposed to cover the MCP input surface with a layer of Al2O3 ultra-thin film of appropriate thickness as an anti-ion feedback film. At present, most of them use an organic mask coated on the MCP input surface as a temporary substrate, on which an Al2O3 film is evaporated or sputtered, and an ultra-thin continuous anti-ion feedback film is obtained by decomposing and removing the organic film.

[0004] At present, the yield of temporary organic film substrates is very low, and there are various problems. Organic masks have stripes, wrinkles, unevenness, etc. Soluble organic polymers are usually used as materials for preparing organic membrane liquids, which are divided into oil-soluble materials and water-soluble materials. However, no matter which material is used to prepare the organic membrane, there are more or less problems in the preparation process; the reason is still caused by the inapplicability of the organic membrane formula, mainly including:

[0005] 1) The film-forming material has low plasticity, high brittleness, and insufficient ductility, resulting in large stress changes. During film formation, the microchannel input surface area cannot be completely covered, resulting in large area defects; the film-forming material has low viscosity, and after film formation, it cannot adhere firmly to the MCP, and the adhesion is not strong;

[0006] 2) The solvent evaporation rate is unstable. If the evaporation rate is too fast, the flatness of the film layer will be poor; if the evaporation rate is too slow, the film will be uneven and wrinkles will appear. In addition, the solvent dissolves the film-forming material, and the solubility is too strong, which will reduce the viscosity of the organic membrane liquid.

[0007] 3) The film shrinks after drying, is fragile and prone to cracking.

[0008] Based on this, we propose a method for preparing PMMA organic film liquid for temporary substrate of microchannel plate. Summary of the invention

[0009] 1. Technical issues to be resolved

[0010] In view of the shortcomings of the prior art, the present invention provides a method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate, which has the advantages of a smooth surface, strong adhesion, high mechanical strength, and great flexibility, and solves the problems of uniformity and stability of the organic mask and adhesion between the microchannel plate and the organic mask.

[0011] (II) Technical solution

[0012] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate comprises the following steps:

[0013] 1) Place PMMA powder in a vacuum drying oven and dry at 70-80°C for 2-4 hours;

[0014] 2) Prepare a PMMA film solution with a mass fraction of 10%-20% using PMMA powder and xylene solution, stir at room temperature for 48 hours, and filter;

[0015] 3) Mix the PMMA film solution, anhydrous ethanol and dibutyl phthalate in a volume ratio of 40:3:1-40:2:1, and stir for 4-6 hours;

[0016] 4) After the preparation is completed, take out the finished product for use.

[0017] Preferably, in step 2), the weight ratio of PMMA powder to xylene solution is 1:50.

[0018] Preferably, the stirring in steps 2) and 3) is performed using a magnetic stirrer at a stirring speed of 200-300 rpm.

[0019] (III) Beneficial effects

[0020] Compared with the prior art, the present invention provides a method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate, which has the following beneficial effects:

[0021] 1. Compared with the organic masks currently prepared on the market, the method for preparing the PMMA organic film liquid for the temporary substrate of the microchannel plate prepares a PMMA organic mask with stable performance, uniformity and high viscosity. There are no colored stripes, spots and pinholes on the surface of the film. The number of tips on the surface of the PMMA organic film is small, there are almost no pinholes, the film layer is relatively flat, and the reflection of photoelectrons can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a configuration flow chart of the present invention. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1 The present invention provides a technical solution: a method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate, comprising the following steps:

[0025] 1) First, the ambient temperature for preparing the organic film substrate is 18-26°C, the ambient humidity is 30%-60%, and the environmental cleanliness is above ISO6;

[0026] 2) First, place the PMMA powder in a vacuum drying oven and dry it at 70-80°C for 2-4 hours;

[0027] 3) Weigh 1 part of PMMA powder and 50 parts of xylene solution and put them into a beaker for later use;

[0028] 4) At room temperature, use a magnetic stirrer at a stirring speed of 200-300 rpm for 48 hours to fully dissolve PMMA and open the molecular chains. Then filter to obtain a PMMA solution, and store it in a brown bottle in a sealed container away from light.

[0029] 5) Measure 1000 parts of PMMA solution, 22-25 parts of dibutyl phthalate and 50-75 parts of anhydrous ethanol, mix them together, use a magnetic stirrer at room temperature, and stir at a speed of 200-300 rpm for 4-6 hours to fully mix them before use.

[0030] The specific structure is to carry out organic film coating according to the process of anti-ion feedback membrane microchannel plate, and the prepared PMMA organic film liquid is dropped into water, and a uniform organic film will be formed on the liquid surface. The film surface has no color stripes, spots and pinholes, and is not easy to wrinkle. After coating on the surface of the microchannel plate, the surface morphology is observed by using an atomic force microscope to find that the PMMA organic film has a small number of tips on the surface, almost no pinholes, and a relatively smooth film layer, which can reduce photoelectron reflection.

[0031] In summary, compared with the organic masks currently prepared on the market, the method for preparing PMMA organic film liquid for temporary substrate of microchannel plate prepares a PMMA organic mask with stable performance, uniformity and high viscosity, and there are no colored stripes, spots and pinholes on the surface of the film. The number of tips on the surface of PMMA organic film is small, there are almost no pinholes, the film layer is relatively flat, and the reflection of photoelectrons can be reduced.

[0032] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate, characterized in that: The following steps are involved: 1) Place PMMA powder in a vacuum drying oven and dry at 70-80°C for 2-4 hours; 2) Prepare a PMMA film solution with a mass fraction of 10%-20% using PMMA powder and xylene solution, stir at room temperature for 48 hours, and filter; 3) Mix the PMMA film solution, anhydrous ethanol and dibutyl phthalate in a volume ratio of 40:3:1-40:2:1, and stir for 4-6 hours; 4) After the preparation is completed, take out the finished product for use.

2. The method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate according to claim 1, characterized in that: In the step 2), the weight ratio of PMMA powder to xylene solution is 1:

50.

3. The method for preparing a PMMA organic film liquid for a temporary substrate of a microchannel plate according to claim 2, characterized in that: In the steps 2) and 3), a magnetic stirrer is used for stirring at a speed of 200-300 rpm.

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