A method for preparing an X-ray fluorescent screen and an X-ray fluorescent screen thereof

Abstract

The present invention discloses a method for preparing an X-ray fluorescent screen and the X-ray fluorescent screen thereof. The preparation method comprises the following steps: S1, pretreatment: cleaning and drying a microchannel structure; the microchannel structure is provided with a plurality of through microchannels, and the microchannel structure is made of glass; S2, microchannel coating: coating the sidewalls of the microchannels with a reflective film; S3, preparing a suspension: mixing fluorescent material particles, a carrier solvent, and a surfactant, and dispersing them to prepare a suspension; S4, filling the microchannels; S5, repeating the filling; S6, post-treatment: cleaning the surface of the microchannel structure and encapsulating it; the X-ray fluorescent screen is prepared using the above preparation method; the X-ray fluorescent screen comprises a microchannel structure, the microchannel structure is provided with a plurality of through microchannels arranged in an array, and the microchannels are filled with fluorescent material particles. The present invention fills the glass microchannel structure with fluorescent material particles to improve the resolution and fluorescence transmission efficiency of the X-ray fluorescent screen.

Description

Technical Field

[0001] The present invention relates to the technical field of X-ray detection, and in particular to a method for preparing an X-ray fluorescent screen and the X-ray fluorescent screen. Background Art

[0002] With the development and application of various X-ray imaging technologies, such as nondestructive testing, safety inspections, and medical diagnosis, X-ray detectors have become widely used. Among the widely used hard X-ray detectors, indirect X-ray detectors dominate. These detectors first convert X-rays into fluorescent signals through a scintillator, which are then converted into electrical signals and read out through a coupled photodetector. Resolution is one of the core specifications of X-ray detectors, and high-resolution detectors are increasingly used in nondestructive testing of modern devices. The main factors affecting the resolution of indirect X-ray detectors are the fluorescent screen and the photodetector pixel size. The latter can currently reach micron-level dimensions, far lower than the resolution of currently widely used indirect X-ray detectors. Therefore, the characteristics of the fluorescent screen determine the resolution of the X-ray detector.

[0003] Currently, one of the main approaches to achieving high-resolution scintillator screens is to create a structured screen. This involves arranging the scintillator materials in a pixel-like pattern, so that the fluorescence generated within adjacent scintillators does not interfere with each other during transmission to the photodetector, thus avoiding signal crosstalk. In this implementation, for example, by forming the fluorescent materials into a crystalline column shape, signal crosstalk can be avoided to a certain extent. Furthermore, the fluorescent materials can be packed into isolated microchannel structures, which can fundamentally avoid fluorescence signal crosstalk. Currently used microchannel structures are fabricated on silicon substrates using semiconductor dry or wet etching. These techniques make it difficult to control the surface roughness of the microchannel sidewalls when achieving deep or high-aspect-ratio microchannel structures. Since a significant portion of the fluorescence generated by X-rays is reflected by the sidewalls during transmission within the microchannel, high sidewall surface roughness reduces reflectivity, thereby affecting fluorescence emission efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing an X-ray fluorescent screen and the X-ray fluorescent screen.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing an X-ray fluorescent screen, comprising the following steps:

[0006] S1. Pretreatment: Cleaning and drying the microchannel structure; the microchannel structure is provided with a plurality of through-going microchannels, and the microchannel structure is made of glass;

[0007] S2, microchannel coating: coating the sidewalls of the microchannel with a reflective film;

[0008] S3, preparing a suspension: mixing fluorescent material particles, a carrier solvent, and a surfactant, and dispersing them to prepare a suspension;

[0009] S4. Filling the microchannel: Under vacuum, the suspension is covered on the surface of the microchannel structure, and then left to stand or external force is applied, so that the fluorescent material particles settle into the microchannel;

[0010] S5, repeat filling: check whether the fluorescent material particles in the microchannel are filled to the target thickness. If not, repeat step S4; if so, proceed to the next step;

[0011] S6. Post-processing: cleaning the surface of the microchannel structure and encapsulating it to obtain an X-ray fluorescent screen.

[0012] Furthermore, in step S1, an organic solvent and water are used for cleaning, and the organic solvent is anhydrous ethanol or acetone; the microchannel structure is ultrasonically cleaned for 5-15 minutes.

[0013] Furthermore, in step S2, coating is performed by evaporation, sputtering, or atomic layer deposition; the reflective film is made of aluminum or silver.

[0014] Furthermore, in step S2, a protective film is plated on the surface of the reflective film. The protective film is made of silicon dioxide or aluminum oxide, and the thickness of the protective film is 20-150 nm.

[0015] Furthermore, in step S3, the fluorescent material particles are gadolinium oxysulfide or cesium iodide, and the average particle size of the fluorescent material particles is 0.1-10 μm.

[0016] Furthermore, in step S3, the volume ratio between the surfactant and the carrier solvent is 1:(50-200).

[0017] Furthermore, in step S3, the surfactant is DMF, DMSO, or N-methylpyrrolidone; and / or the carrier solvent is anhydrous ethanol, isopropanol, or acetone.

[0018] Furthermore, in step S4, the external force applied is vibration or centrifugation of the microchannel structure; there is a height difference between the liquid surface of the suspension and the surface of the microchannel structure, and the height difference is 2-20 cm.

[0019] Furthermore, in step S6, the fluorescent material particles remaining on the surface of the microchannel structure are removed, and then the surface of the microchannel structure is covered with an organic film layer, which is a polyester film layer, a polyethylene film layer, a polypropylene film layer or a polyether film layer.

[0020] An X-ray fluorescent screen is manufactured using the above-mentioned method for manufacturing an X-ray fluorescent screen. The X-ray fluorescent screen comprises a microchannel structure provided with a plurality of microchannels that are connected and arranged in an array, and the microchannels are filled with X-ray fluorescent material particles.

[0021] Beneficial effects of the present invention:

[0022] The present invention proposes to use a microchannel structure as a structural carrier of an X-ray fluorescent screen, and fill fluorescent material particles into the through microchannels, thereby realizing an X-ray fluorescent screen with both high resolution and higher fluorescence transmission efficiency. Among them, before the fluorescent material particles are filled, a carrier solvent and a surfactant are first mixed with the fluorescent material particles, so that the fluorescent material particles are efficiently deposited in the microchannel. The surface roughness of the inner wall of the glass microchannel of the present invention is much better than the surface roughness of the microchannel formed by etching on the existing silicon substrate, thereby improving the fluorescence transmission efficiency. In addition, the length (or depth) of the microchannel through the microchannel structure can be arbitrarily selected, or the target filling thickness of the fluorescent material particles can be arbitrarily selected. A microchannel structure with a large depth is expected to be used to achieve the detection of higher energy X-rays.

[0023] The X-ray fluorescent screen produced by the present invention has the advantage of higher fluorescence reflection efficiency of the microchannel inner wall compared to the X-ray fluorescent screen based on silicon-based microchannel array while maintaining high resolution capability. When used in a high-resolution X-ray imaging system, it helps to reduce the X-ray radiation dose. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0025] Figure 1 is a surface SEM image of the microchannel structure of Example 1 of the present invention;

[0026] Figure 2 is a SEM image of the X-ray phosphor screen of Example 1 of the present invention;

[0027] Figure 3 This is a resolution test chart of the X-ray fluorescent screen according to Example 1 of the present invention;

[0028] Figure 4 is a SEM image of the X-ray phosphor screen of Comparative Example 1 of the present invention;

[0029] Figure 5 This is a resolution test chart of the X-ray fluorescent screen of Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0030] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the present invention will be further described in detail below with reference to examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0031] The present invention provides a method for preparing an X-ray fluorescent screen, comprising the following steps:

[0032] S1. Pretreatment: Cleaning and drying the microchannel structure; the microchannel structure is provided with a plurality of through microchannels, and the microchannel structure is made of glass.

[0033] Specifically, organic solvents and water are used for cleaning, the organic solvent can be anhydrous ethanol or acetone, and the water can be pure water. Cleaning can be ultrasonic cleaning of the microchannel structure for 5-15 minutes. In some embodiments, the microchannel structure is a glass microchannel plate (a commercially available product), which has a glass microchannel array. The glass microchannel plate is often used to make electron multiplication devices, which have very high requirements for the surface roughness of the inner wall of the microchannel, usually in the nanometer or sub-nanometer level. The surface roughness of the inner wall of the microchannel in the glass microchannel structure used in the present invention is 0.3-50nm, which helps to improve the resolution and fluorescence transmission efficiency of the fluorescent screen. The specific surface roughness can be flexibly selected according to actual needs, and the present invention is not limited. The period of the microchannel (i.e., the central axis spacing of adjacent microchannels) is 6-120μm, the pore size is 5-100μm, and the depth is 100-2000μm.

[0034] S2. Microchannel coating: coating the sidewalls of the microchannel with a reflective film.

[0035] Specifically, the coating is performed by evaporation, sputtering, or atomic layer deposition. It is understood that evaporation, sputtering, and atomic layer deposition are all existing technologies, and the coating process parameters can be selected according to actual needs and are not specifically limited by the present invention. By coating the microchannel sidewalls with a reflective film, the reflection efficiency of visible light converted from X-rays can be effectively improved.

[0036] Preferably, the reflective film is made of aluminum or silver. If the reflective film is made of aluminum, the surface of the aluminum will oxidize in the air to form aluminum oxide, thereby protecting the reflective film. A protective film can also be plated on the surface of the reflective film, and the protective film can be made of silicon dioxide. If the reflective film is made of silver, a protective film is plated on the surface of the reflective film to prevent oxidation of the reflective film. The protective film can be made of silicon dioxide or aluminum oxide. The thickness of the above-mentioned protective film is 20-150nm, for example, it can be 20nm, 50nm, 80nm, 100nm, 120nm, 150nm, etc. Among them, the protective film can choose the same coating method as the reflective film, or other different coating methods, and the specific selection can be flexibly based on actual needs.

[0037] S3. Prepare suspension: mix fluorescent material particles, carrier solvent and surfactant, and disperse them to obtain suspension.

[0038] Specifically, fluorescent material particles are selected as the filling material for converting X-rays into visible light. The fluorescent material particles are gadolinium oxysulfide (GOS) or cesium iodide (CsI(Tl)). The average particle size of the fluorescent material particles is 0.1-10μm, and can specifically be 0.1, 0.5μm, 1μm, 3μm, 5μm, 8μm, 10μm, etc. The volume ratio between the surfactant and the carrier solvent is 1:(50-200), and can specifically be 1:50, 1:75, 1:100, 1:150, 1:200, etc. The surfactant can be DMF (dimethylformamide), DMSO (dimethyl sulfoxide), or N-methylpyrrolidone. One function of the surfactant is to enable the fluorescent material particles entering the microchannel to adhere to the side walls of the microchannel and not easily detach. Another function is to disperse the fluorescent material particles to prevent them from agglomerating before entering the microchannel. The carrier solvent can be anhydrous ethanol, isopropyl alcohol, or acetone, or other solvents with a certain degree of volatility. Furthermore, the mixed solution of fluorescent material particles, carrier solvent and surfactant is ultrasonically dispersed or vibrationally dispersed to obtain a suspension in which the fluorescent material particles are evenly dispersed. The dispersion process parameters can be selected according to actual needs and are not specifically limited in the present invention.

[0039] S4. Filling the microchannel: Under vacuum, the suspension is covered on the surface of the microchannel structure, and then left to stand or external force is applied, so that the fluorescent material particles settle into the microchannel.

[0040] Wherein, vacuum degree is higher than 0.3 standard atmospheric pressure, and vacuum degree refers to the reading of vacuum meter, and vacuum degree is higher than 0.3 standard atmospheric pressure, it is not limited.Specifically, first microchannel structure is placed in container, then the suspension prepared in S3 step is injected into the container, there is height difference between the liquid level of suspension and the surface of microchannel structure, height difference is preferably 2-20cm, specifically can be 2cm, 3cm, 5cm, 8cm, 10cm, 15cm, 20cm etc., so as to ensure that there are enough fluorescent material particles in container, more fluorescent material particles can be once filled in microchannel. After suspension is covered on the surface of microchannel structure, stand 1.5-2.5 hours or apply external force so that the fluorescent material particles in suspension are deposited in microchannel, wherein, applying external force can be for vibrating microchannel structure or centrifuging, and its processing parameter can be selected according to actual demand, and the present invention is not specifically limited.

[0041] S5. Repeat filling: Check whether the microchannel has been filled with fluorescent material particles to a target thickness. If not, repeat step S4. If so, proceed to the next step. The target thickness refers to the thickness of the fluorescent material particles filled in the microchannel. The target thickness can be selected based on actual needs and is not specifically limited in the present invention.

[0042] Specifically, the distribution of the fluorescent material particles in the microchannel of the microchannel structure is observed by scanning electron microscopy. If the filling thickness of the fluorescent material particles in the microchannel does not reach the target thickness, step S4 is repeated and the suspension prepared in step S3 is used to refill the microchannel until the filling thickness of the fluorescent material particles in the microchannel of the microchannel structure reaches the target thickness.

[0043] In some embodiments, the target thickness can be the length (or depth) of the microchannel. That is, the microchannel is completely filled with fluorescent material particles. Step S5 is then: detecting whether the microchannel is completely filled with fluorescent material particles. If not, step S4 is repeated. If so, the next step is performed. Specifically, the distribution of fluorescent material particles within the microchannel of the microchannel structure is observed using a scanning electron microscope. If the microchannel is not completely filled with fluorescent material particles, i.e., the filling is uneven or insufficient, step S4 is repeated and the suspension prepared in step S3 is used to refill the microchannel until the microchannel of the microchannel structure is completely filled with fluorescent material particles.

[0044] S6. Post-processing: cleaning the surface of the microchannel structure and encapsulating it to obtain an X-ray fluorescent screen.

[0045] Specifically, the fluorescent material particles remaining on the surface of the microchannel structure are removed, for example, by scraping off the particles with a tool, and then a high-transmittance organic film layer is covered on the surface of the microchannel structure. The organic film layer can be a polyester film layer (PET film), a polyethylene film layer (PE film), a polypropylene film layer (BOPP film) or a polyether film layer (PEEK film).

[0046] The present invention also provides an X-ray fluorescent screen manufactured using the aforementioned method. The X-ray fluorescent screen comprises a microchannel structure having a plurality of microchannels arranged in an array and extending therethrough. The microchannels are filled with particles of an X-ray fluorescent material. The microchannel structure can be made of glass, such as a glass microchannel plate having an array of glass microchannels. The X-ray fluorescent material particles can be gadolinium oxysulfide or cesium iodide, and are used to convert X-rays into visible light.

[0047] The present invention proposes to use a microchannel structure as a structural carrier of an X-ray fluorescent screen, and fill fluorescent material particles into the through microchannels, thereby realizing an X-ray fluorescent screen with both high resolution and higher fluorescence transmission efficiency. Among them, before the fluorescent material particles are filled, a carrier solvent and a surfactant are first mixed with the fluorescent material particles, so that the fluorescent material particles are efficiently deposited in the microchannel. The surface roughness of the inner wall of the glass microchannel of the present invention can be controlled within a few nanometers, which is much better than the surface roughness of the microchannel array formed by etching on the existing silicon substrate, thereby improving the fluorescence transmission efficiency. In addition, the length (or depth) of the microchannel through the microchannel structure can be arbitrarily selected during cutting and manufacturing, or the target filling thickness of the fluorescent material particles can be arbitrarily selected. A microchannel structure with a large depth is expected to be used to achieve the detection of higher energy X-rays.

[0048] The X-ray fluorescent screen produced by the present invention fully utilizes the advantages of glass microchannel arrays that can be mass-produced and the low surface roughness of the inner wall of the glass microchannel. While maintaining high resolution capabilities, it has higher microchannel inner wall fluorescence reflection efficiency than X-ray fluorescent screens based on silicon-based microchannel arrays. When used in high-resolution X-ray imaging systems, it helps to reduce X-ray radiation dose.

[0049] The following is described by specific examples:

[0050] Example 1

[0051] A method for preparing an X-ray fluorescent screen comprises the following steps:

[0052] S1. Pretreatment: Clean and dry the microchannel structure, which is made of glass and has a plurality of microchannels extending therethrough. Specifically, ultrasonic cleaning is performed for 10 minutes using an organic solvent (anhydrous ethanol) and pure water. The microchannel structure comprises a glass microchannel array, the surface roughness of the microchannel inner wall being 3 nm, the microchannel period being 25 μm, the pore diameter being 21 μm, and the depth being 500 μm.

[0053] S2. Microchannel coating: A reflective film is coated on the sidewall of the microchannel. Specifically, the reflective film is made of aluminum by physical vapor deposition. The surface SEM image of the microchannel structure after coating is as follows: Figure 1 shown.

[0054] S3. Prepare a suspension: Mix and disperse fluorescent material particles, a carrier solvent, and a surfactant to obtain a suspension. Specifically, the fluorescent material particles are GOS, with an average particle size of 2 μm. The volume ratio of the surfactant to the carrier solvent is 1:100, the surfactant is DMF, and the carrier solvent is anhydrous ethanol. Furthermore, the mixed solution of fluorescent material particles, carrier solvent, and surfactant is ultrasonically dispersed to obtain a suspension in which the fluorescent material particles are uniformly dispersed.

[0055] S4. Filling the microchannel: Under vacuum, the suspension is applied to the surface of the microchannel structure. The suspension is then allowed to settle into the microchannel, or external force is applied. Specifically, the vacuum level is greater than 0.3 standard atmospheres. The microchannel structure is first placed in a container, and the suspension prepared in step S3 is then injected into the container. The height difference between the suspension surface and the surface of the microchannel structure is 3 cm. The container is then allowed to stand for 2 hours.

[0056] S5. Repeat filling: Check whether the microchannels are filled with fluorescent material particles to the target thickness. If not, repeat step S4. If so, proceed to the next step. Specifically, the distribution of fluorescent material particles within the microchannels of the microchannel structure is observed using a scanning electron microscope. If it is found that the filling thickness of the fluorescent material particles within the microchannels has not reached the target thickness, repeat step S4 and refill with the suspension prepared in step S3 until the filling thickness of the fluorescent material particles within the microchannels of the microchannel structure reaches the target thickness.

[0057] S6. Post-processing: Clean and encapsulate the surface of the microchannel structure to obtain an X-ray fluorescent screen. Specifically, remove the fluorescent material particles remaining on the surface of the microchannel structure, and then cover the surface of the microchannel structure with an organic film layer (PET film).

[0058] An X-ray fluorescent screen, manufactured using the aforementioned method, comprises a microchannel structure having a plurality of microchannels arranged in an array and extending therethrough, the microchannels being filled with X-ray fluorescent material particles. The microchannel structure is made of glass, comprising a glass microchannel array, and the X-ray fluorescent material particles are GOS.

[0059] Example 2

[0060] A method for preparing an X-ray fluorescent screen comprises the following steps:

[0061] S1. Pretreatment: Clean and dry the microchannel structure, which is made of glass and has a plurality of microchannels extending therethrough. Specifically, ultrasonic cleaning is performed for 5 minutes using an organic solvent (acetone) and pure water. The microchannel structure comprises a glass microchannel array, the surface roughness of the microchannel inner wall being 1 nm, the microchannel period being 15 μm, the pore diameter being 12 μm, and the depth being 400 μm.

[0062] S2. Microchannel Coating: A reflective film is deposited on the sidewalls of the microchannel. Specifically, the reflective film is sputtered and made of silver. A protective film made of aluminum oxide with a thickness of 50 nm is then deposited on the surface of the reflective film.

[0063] S3. Prepare a suspension: Mix and disperse fluorescent material particles, a carrier solvent, and a surfactant to obtain a suspension. Specifically, the fluorescent material particles are cesium iodide with an average particle size of 1 μm. The volume ratio of the surfactant to the carrier solvent is 1:50, the surfactant is DMSO, and the carrier solvent is isopropyl alcohol. Furthermore, the mixed solution of the fluorescent material particles, carrier solvent, and surfactant is centrifuged to obtain a suspension in which the fluorescent material particles are uniformly dispersed.

[0064] S4. Filling the microchannel: Under vacuum, the suspension is applied to the surface of the microchannel structure. The fluorescent material particles are then allowed to settle into the microchannel, either by allowing the suspension to stand or by applying an external force. Specifically, the vacuum level is 0.3 standard atmospheres. The microchannel structure is first placed in a container, and the suspension prepared in step S3 is then injected into the container. The height difference between the liquid surface of the suspension and the surface of the microchannel structure is 5 cm. The microchannel structure is then vibrated.

[0065] S5. Repeat filling: Check whether the microchannels are fully filled with fluorescent material particles. If not, repeat step S4. If so, proceed to the next step. Specifically, the distribution of fluorescent material particles within the microchannels of the microchannel structure is observed using a scanning electron microscope. If it is found that the microchannels are not fully filled with fluorescent material particles, that is, the filling is uneven or insufficient, step S4 is repeated and the suspension prepared in step S3 is used to refill the microchannels until the microchannels of the microchannel structure are fully filled with fluorescent material particles.

[0066] S6. Post-processing: Clean and encapsulate the surface of the microchannel structure to obtain an X-ray fluorescent screen. Specifically, remove the fluorescent material particles remaining on the surface of the microchannel structure, and then cover the surface of the microchannel structure with an organic film layer (PE film).

[0067] An X-ray fluorescent screen, manufactured using the aforementioned method, comprises a microchannel structure having a plurality of microchannels arranged in an array and extending therethrough, the microchannels being filled with particles of an X-ray fluorescent material. The microchannel structure is made of glass, comprising a glass microchannel array, and the X-ray fluorescent material particles are cesium iodide.

[0068] Example 3

[0069] A method for preparing an X-ray fluorescent screen comprises the following steps:

[0070] S1. Pretreatment: Clean and dry the microchannel structure, which is made of glass and has a plurality of microchannels extending therethrough. Specifically, ultrasonic cleaning is performed for 15 minutes using an organic solvent (acetone) and pure water. The microchannel structure comprises a glass microchannel array, the surface roughness of the microchannel inner wall being 3 nm, the microchannel period being 25 μm, the pore diameter being 21 μm, and the depth being 900 μm.

[0071] S2. Microchannel Coating: A reflective film is deposited on the sidewalls of the microchannels. Specifically, the reflective film is made of silver using atomic layer deposition. A protective film made of silicon dioxide with a thickness of 120 nm is then deposited on the surface of the reflective film.

[0072] S3. Prepare a suspension: Mix fluorescent material particles, a carrier solvent, and a surfactant, and disperse them to obtain a suspension. Specifically, the fluorescent material particles are cesium iodide, and their average particle size is 5 μm. The volume ratio between the surfactant and the carrier solvent is 1:200, the surfactant is N-methylpyrrolidone, and the carrier solvent is acetone. Furthermore, the mixed solution of the fluorescent material particles, the carrier solvent, and the surfactant is centrifuged to obtain a suspension in which the fluorescent material particles are evenly dispersed.

[0073] S4. Filling the microchannel: Under vacuum, the suspension is applied to the surface of the microchannel structure. The fluorescent material particles are then allowed to settle into the microchannel, either by allowing the suspension to stand or by applying an external force. Specifically, the vacuum level is 0.5 standard atmospheres. The microchannel structure is first placed in a container, and the suspension prepared in step S3 is then injected into the container. The height difference between the liquid surface of the suspension and the surface of the microchannel structure is 10 cm. The microchannel structure is then centrifuged.

[0074] S5. Repeat filling: Check whether the microchannels are fully filled with fluorescent material particles. If not, repeat step S4. If so, proceed to the next step. Specifically, the distribution of fluorescent material particles within the microchannels of the microchannel structure is observed using a scanning electron microscope. If it is found that the microchannels are not fully filled with fluorescent material particles, that is, the filling is uneven or insufficient, step S4 is repeated and the suspension prepared in step S3 is used to refill the microchannels until the microchannels of the microchannel structure are fully filled with fluorescent material particles.

[0075] S6. Post-processing: Clean and encapsulate the surface of the microchannel structure to obtain an X-ray fluorescent screen. Specifically, remove the fluorescent material particles remaining on the surface of the microchannel structure, and then cover the surface of the microchannel structure with an organic film layer (BOPP film).

[0076] An X-ray fluorescent screen, manufactured using the aforementioned method, comprises a microchannel structure having a plurality of microchannels arranged in an array and extending therethrough, the microchannels being filled with particles of an X-ray fluorescent material. The microchannel structure is made of glass, comprising a glass microchannel array, and the X-ray fluorescent material particles are cesium iodide.

[0077] Comparative Example 1

[0078] The method for preparing the X-ray fluorescent screen of this comparative example differs from that of Example 1 in that in step S3 of this comparative example, the surfactant is oleic acid, and the remaining steps are the same. An X-ray fluorescent screen is prepared according to the method for preparing the X-ray fluorescent screen of this comparative example.

[0079] Comparative test:

[0080] The X-ray fluorescent screens prepared in Example 1 and Comparative Example 1 were subjected to SEM scanning electron microscope observation and resolution test. The test results are as follows: Figures 2 to 5 The resolution test steps are as follows: Place the X-ray fluorescent screen in close proximity to the visible light CCD (charge-coupled device), then place the resolution card for testing in close proximity to the X-ray fluorescent screen. When the X-ray source is turned on, the resolution card projects onto the X-ray fluorescent screen, which then converts the X-rays into visible light, which is then received by the CCD.

[0081] Figure 2 This is a SEM image of the X-ray fluorescent screen of Example 1. It can be seen from the image that when DMF is used as a surfactant, the GOS particles are more densely packed in the microchannel; Figure 3 This is a resolution test chart of the X-ray fluorescent screen of Example 1. It can be seen from the chart that the resolution of the X-ray fluorescent screen reaches 10lp / mm, with good contrast and brightness. Figure 4This is a SEM image of the X-ray fluorescent screen of Comparative Example 1. It can be seen from the figure that GOS particles can also be successfully filled into the microchannel using oleic acid as a surfactant, but the particle filling is uneven and not substantial; Figure 5 This is a resolution test chart of the X-ray fluorescent screen of comparative example 1. It can be seen from the chart that the resolution of the X-ray fluorescent screen of comparative example 1 also reaches 10 lp / mm, but the contrast and brightness are worse than those of the X-ray fluorescent screen of embodiment 1.

[0082] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A method for preparing an X-ray fluorescent screen, characterized in that: The following steps are involved: S1. Pretreatment: Cleaning and drying a microchannel structure; the microchannel structure is provided with a plurality of through-going microchannels, and the microchannel structure is made of glass; S2, microchannel coating: coating a reflective film on the sidewall of the microchannel; S3. Prepare a suspension: mix the fluorescent material particles, a carrier solvent, and a surfactant, and disperse them to prepare a suspension; the surfactant is DMF, DMSO, or N-methylpyrrolidone; S4, filling the microchannel: under vacuum, covering the surface of the microchannel structure with the suspension, and then allowing it to stand or apply external force, so that the fluorescent material particles settle into the microchannel; In the step S4, applying the external force is vibrating or centrifuging the microchannel structure; there is a height difference between the liquid surface of the suspension and the surface of the microchannel structure, and the height difference is 2-20 cm; S5, repeat filling: check whether the fluorescent material particles in the microchannel are filled to the target thickness. If not, repeat step S4; if so, proceed to the next step; S6. Post-processing: cleaning the surface of the microchannel structure and encapsulating it to obtain an X-ray fluorescent screen.

2. The method for preparing an X-ray fluorescent screen according to claim 1, wherein: In the step S1, an organic solvent and water are used for cleaning, wherein the organic solvent is anhydrous ethanol or acetone; and the microchannel structure is ultrasonically cleaned for 5-15 minutes.

3. The method for preparing an X-ray fluorescent screen according to claim 1, wherein: In the step S2, the film is coated by evaporation, sputtering or atomic layer deposition; the reflective film is made of aluminum or silver.

4. The method for preparing an X-ray fluorescent screen according to claim 3, wherein: In the step S2, a protective film is plated on the surface of the reflective film, the protective film is made of silicon dioxide or aluminum oxide, and the thickness of the protective film is 20-150 nm.

5. The method for preparing an X-ray fluorescent screen according to claim 1, wherein: In the step S3, the fluorescent material particles are gadolinium oxysulfide or cesium iodide, and the average particle size of the fluorescent material particles is 0.1-10 μm.

6. The method for preparing an X-ray fluorescent screen according to claim 1, wherein: In the step S3, the volume ratio between the surfactant and the carrier solvent is 1:(50-200).

7. The method for preparing an X-ray fluorescent screen according to claim 1, wherein: In the step S3, the carrier solvent is anhydrous ethanol, isopropyl alcohol or acetone.

8. The method for preparing an X-ray fluorescent screen according to claim 1, wherein: In the step S6, the fluorescent material particles remaining on the surface of the microchannel structure are removed, and then an organic film layer is coated on the surface of the microchannel structure. The organic film layer is a polyester film layer, a polyethylene film layer, a polypropylene film layer or a polyether film layer.

9. An X-ray fluorescent screen, characterized in that: The X-ray fluorescent screen is manufactured by the method for preparing the X-ray fluorescent screen according to any one of claims 1 to 8; the X-ray fluorescent screen comprises a microchannel structure, the microchannel structure is provided with a plurality of microchannels that are connected and arranged in an array, and the microchannels are filled with X-ray fluorescent material particles.

Images