Scintillator panel, radiation detector, radiation inspection device, and method for manufacturing scintillator panel

Abstract

A scintillator panel comprises a substrate, lattice-shaped partitions formed on the substrate, a phosphor layer within cells partitioned by the partitions, and a reflective layer surrounding the side surfaces and bottom of the phosphor layer. The scintillator panel comprises a curved portion of the reflective layer surrounding the side surfaces of the phosphor layer, and portions of the reflective layer on the side surfaces of the phosphor layer having opposing surfaces that are substantially parallel to each other. The ratio of the curved portion to the flat portion of the reflective layer on the bottom of the phosphor layer in the width direction is 10.0:0 to 1.0:9.0. The scintillator panel improves brightness.

Description

Technical Field

[0001] The present invention relates to a scintillator panel, a radiation detector, a radiation inspection apparatus, and a method for manufacturing a scintillator panel. Background Art

[0002] In the past, radiographic images using films were widely used in medical settings. However, radiographic images using films are analog image information. Therefore, in recent years, digital radiographic detectors such as flat panel radiographic detectors (FPDs) have been developed. In FPDs, a scintillator panel is used to convert radiation into visible light. The scintillator panel contains a radioactive phosphor, and the radioactive phosphor emits visible light in response to the irradiated radiation. The emitted light is converted into an electrical signal by a TFT (thin film transistor) or a CCD (charge-coupled device), and the information about the radiation is converted into digital image information. However, the scintillator panel has a problem in which the light emitted from the radioactive phosphor is scattered in the layer containing the phosphor (phosphor layer), resulting in reduced clarity.

[0003] To minimize the effects of scattering of emitted light, a cell-type scintillator panel has been proposed, in which phosphors are filled within cells, defined by partitions with reflective layers on their surfaces. This suppresses scattering of light emitted from the phosphors by the partitions, enabling the production of high-resolution X-ray images.

[0004] On the other hand, cell-based scintillator panels have the problem of reduced phosphor content and reduced brightness due to the presence of partitions. One method of improving brightness is to reduce the number of times light emitted within the cell is reflected by the partitions. To suppress light attenuation, a method is known in which the phosphor layer is surrounded by a reflective surface with a light-collecting property, such as a hemispherical shape (Patent Document 1).

[0005] Furthermore, in order to increase the amount of phosphor filled in a cell, a cell-type scintillator panel having a partition wall shape with a high aspect ratio has been proposed (Patent Document 2).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-67681

[0009] Patent Document 2: International Publication No. 2014 / 054422 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] However, in Patent Document 1, the partition wall needs to be shaped like a hemisphere without parallel surfaces, resulting in a small amount of phosphor within the cell and insufficient brightness. Furthermore, Patent Document 2 describes a configuration in which the partition wall bottom has a curved portion, but because the curved portion is small, the light emitted by reflection from the reflective layer on the partition wall surface does not efficiently travel toward the detector, resulting in insufficient brightness.

[0012] Therefore, the present invention has been made in view of such conventional problems, and its object is to improve the brightness of a scintillator panel.

[0013] Means for solving problems

[0014] In order to solve the above-mentioned problems, the present invention mainly has the following configurations.

[0015] A scintillator panel comprises a substrate, lattice-shaped partition walls formed on the substrate, a phosphor layer within a unit partitioned by the partition walls, and a reflective layer surrounding the side and bottom portions of the phosphor layer, wherein the scintillator panel comprises a curved portion of the reflective layer surrounding the side portions of the phosphor layer, and portions whose opposing surfaces of the reflective layer on the side portions of the phosphor layer are substantially parallel to each other, and a ratio in the width direction of the curved portion to the flat portion of the reflective layer on the bottom portion of the phosphor layer is 10.0:0 to 1.0:9.0.

[0016] Effects of the Invention

[0017] According to the present invention, the brightness of the scintillator panel can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a cross-sectional view schematically showing a radiation detector member including a scintillator panel according to one embodiment of the present invention.

[0019] Figure 2 This is a cross-sectional view showing an example of a conventional scintillator panel.

[0020] Figure 3 This is a cross-sectional view showing an example of the scintillator panel of the present invention.

[0021] Figure 4 This is a cross-sectional view showing another example of the scintillator panel of the present invention. DETAILED DESCRIPTION

[0022] (Scintillator panel)

[0023] Hereinafter, embodiments of the scintillator panel according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below.

[0024] Figure 1 This is a cross-sectional view schematically showing a radiation detector component 1 including a scintillator panel 2 according to an embodiment of the present invention. The radiation detector component 1 includes a scintillator panel 2 and an output substrate 3. The scintillator panel 2 includes a substrate 4, partitions 5, and a phosphor layer 6. The phosphor layer 6 is filled in cells partitioned by the partitions 5. The phosphor layer 6 includes a phosphor 14 and a binder resin 15. A reflective layer 12 is formed on the surface of the partitions 5. A portion where a partition auxiliary layer 11 is provided may be provided between the partitions 5 and the reflective layer 12. A protective layer 13 may also be provided on the surface of the reflective layer 12. The output substrate 3 includes a substrate 10, an output layer 9 formed on the substrate 10, and a photoelectric conversion layer 8. The photoelectric conversion layer 8 includes a photodiode and is formed on the output layer 9. A diaphragm layer 7 may be provided on the photoelectric conversion layer 8. The light-emitting surface of the scintillator panel 2 and the photoelectric conversion layer 8 of the output substrate 3 are preferably bonded or closely adhered to each other via the diaphragm layer 7. The light emitted from the phosphor layer 6 reaches the photoelectric conversion layer 8, is photoelectrically converted, and is output.

[0025] (Substrate)

[0026] The material constituting the substrate 4 is preferably a material having radiation transmittance. For example, the material constituting the substrate 4 is various glasses, polymer materials, metals, etc. Examples of glass include quartz, borosilicate glass, chemically strengthened glass, etc. Examples of polymer materials include polyesters such as cellulose acetate and polyethylene terephthalate, polyamides, polyimides, triacetate, polycarbonates, carbon fiber reinforced resins, etc. Examples of metals include aluminum, iron, copper, etc. These can be used in combination. Among them, the material constituting the substrate 4 is preferably a polymer material having high radiation transmittance. In addition, the material constituting the substrate 4 is preferably a material having excellent flatness and heat resistance.

[0027] Regarding the thickness of the substrate 4, from the perspective of lightweighting the scintillator panel, for example, in the case of using a glass substrate, it is preferably 2.0 mm or less, more preferably 1.0 mm or less, and further preferably 0.5 mm or less. In addition, in the case of a substrate formed of a polymer material, it is preferably 3.0 mm or less, and more preferably 1.0 mm or less. The thickness of the substrate 4 can be calculated by cutting out a cross section of the substrate using a microtome, observing 10 locations using a scanning electron microscope (e.g., a field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.), and measuring the average thickness.

[0028] (Next door)

[0029] The partition walls 5 are formed on the substrate 4 in a grid-like pattern to define compartmentalized spaces (cells). Therefore, by matching the size and spacing of the pixels of the photoelectric conversion layer 8 arranged in a grid pattern on the output substrate 3 with the size and spacing of the cells of the scintillator panel 2, high-resolution X-ray images are obtained.

[0030] The material constituting the partition wall 5 is preferably a material capable of forming a partition wall having high strength and heat resistance, for example, an inorganic material, a polymer material, etc. Among them, from the viewpoint of the flatness and processability of the side surface of the partition wall, it is preferably a polymer material as the main component. Here, the so-called "polymer material as the main component" means that 50 to 100% by mass of the material constituting the partition wall is a polymer material.

[0031] It should be noted that the term "inorganic material" refers to a compound composed of elements other than carbon. However, a simple portion of carbon compounds (carbon allotropes such as graphite and diamond) is included in the inorganic material.

[0032] When the material constituting the partition wall 5 is composed of an inorganic material, it is preferably composed of glass as the main component. Glass refers to an inorganic amorphous solid containing silicate. If the main component of the partition wall 5 is glass, the strength, durability and heat resistance of the partition wall are improved, and deformation and damage are less likely to occur during the forming process of the reflective layer and the filling process of the phosphor. It should be noted that the so-called "composed of inorganic matter" does not exclude the presence of components other than inorganic matter in a strict sense. The presence of impurities contained in the inorganic matter itself that becomes the raw material and the presence of components other than inorganic matter to the extent of impurities mixed in during the manufacturing process of the partition wall 5 is allowed. In addition, the so-called "glass as the main component" means that 50 to 100% by mass of the material constituting the partition wall is glass.

[0033] In particular, regarding the partition walls, the proportion of the low-softening-point glass having a softening point of 650° C. or lower is preferably 95 parts by volume or more, more preferably 98 parts by volume or more, based on 100 parts by volume of the partition wall portion.

[0034] Components that can be used in addition to the low-softening-point glass include high-softening-point glass powders, such as glass with a softening point exceeding 650°C, and ceramic powders. These powders facilitate adjustment of the partition wall shape during the partition wall formation process. To increase the content of the low-softening-point glass, the content of components other than the low-softening-point glass is preferably less than 5 parts by volume.

[0035] When the material constituting the partition wall 5 is a polymer material, the partition wall preferably comprises a material selected from the group consisting of polyimide, polyamide, polyamideimide and polybenzoic acid. One or more compounds (P) of azole (hereinafter, sometimes simply referred to as "compound (P)"). When the partition wall contains the compound (P), a fine partition wall with a high aspect ratio and a smooth surface can be formed.

[0036] When the compound (P) contains a phenolic hydroxyl group, the resin can have moderate solubility in an alkaline developer, thereby obtaining a high contrast between the exposed area and the unexposed area and enabling formation of a desired pattern, which is preferred.

[0037] When the partition wall 5 comprises the compound (P), the partition wall 5 preferably further comprises an epoxy compound. The epoxy compound can improve the processability without compromising the heat resistance and mechanical strength of the compound (P), making it easy to form a partition wall of a desired shape. This can increase the amount of phosphor filled and further improve the brightness.

[0038] In order not to impair the properties of the compound (P), the content of the epoxy compound in the partition wall 5 is preferably not more than 2.0 times the content of the compound (P) by mass fraction. When the partition wall contains components other than the compound (P) and the epoxy compound, the total content of these components is preferably not more than the total amount of the compound (P) and the epoxy compound by mass fraction.

[0039] As the epoxy compound, known epoxy compounds can be used, and include aromatic epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds.

[0040] (Partition wall auxiliary layer)

[0041] A partition wall auxiliary layer 11 is preferably provided between the partition walls 5 and the reflective layer 12, described later. The presence of the partition wall auxiliary layer allows for the reflective layer to be easily formed on the sides and bottom of the phosphor layer, when a reflective layer is formed on the partition walls and the surface of the partition wall auxiliary layer using the method described later. The partition wall auxiliary layer 11 preferably contacts at least a portion of the partition walls and the substrate.

[0042] The material constituting the partition wall auxiliary layer 11 is preferably a material having strength, chemical resistance, heat resistance, and radiation transmittance, preferably a polymer material. The polymer material used for the partition wall auxiliary layer 11 is not particularly limited, and examples thereof include thermoplastic resins, thermosetting resins, and photocurable resins. More specifically, the polymer material includes acrylic resins, cellulose resins, polysiloxane resins, epoxy resins, melamine resins, phenolic resins, urethane resins, urea resins, vinyl chloride resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyimide resins, polyamide resins, polyethylene, polypropylene, polystyrene, polyvinyl toluene, and polyphenylbenzene. Two or more of these may be included. Among them, from the viewpoints of strength, chemical resistance, and heat resistance, thermosetting resins or photocurable resins are preferred. Specifically, the preferred material is a resin selected from acrylic resins, polysiloxane resins, epoxy resins, melamine resins, phenolic resins, urethane resins, urea resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyimide resins, and polyamide resins. More preferred materials are resins selected from polysiloxane resins, epoxy resins, polyimide resins, and polyamide resins. Furthermore, the polymer material constituting the partition wall auxiliary layer 11 may be the same material as the partition walls.

[0043] The partition wall auxiliary layer 11 may further contain a filler. The material constituting the filler is not particularly limited, and examples thereof include glass, polymer materials, metal oxides, and metal nitrides. Examples of glass include quartz and borosilicate glass. Examples of polymer materials include acrylic resins, silicone resins, melamine resins, phenolic resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, triacetate, polycarbonate, polyethylene, polypropylene, polystyrene, and carbon fiber reinforced resins. It should be noted that the polymer material used as a filler is a material different from that of the partition wall auxiliary layer. Specifically, it is a polymer material that is different from the partition wall auxiliary layer in at least one of the main chain structure, number average molecular weight, weight average molecular weight, and glass transition point. Examples of metal oxides include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, and zinc oxide. Examples of metal nitrides include aluminum nitride, silicon nitride, and titanium nitride. Two or more of these may be used in combination.

[0044] (Reflective layer)

[0045] The scintillator panel of the present invention includes a reflective layer 12 surrounding the side and bottom portions of the phosphor layer 6. The presence of the reflective layer 12 allows light emitted within the cells partitioned by the partition walls upon irradiation with radiation to efficiently reach the detector, thereby improving brightness. Here, the phrase "the reflective layer 12 surrounds the side and bottom portions of the phosphor layer 6" refers to the presence of the reflective layer 12 on the side and bottom portions of the phosphor layer 6. It should be noted that the reflective layer 12 is not limited to being continuous; localized discontinuities in the reflective layer 12 due to defects, etc., are permitted.

[0046] The material constituting the reflective layer 12 is not particularly limited, as long as it reflects electromagnetic waves emitted by the phosphor. Examples include metal oxides such as titanium oxide and aluminum oxide; metals such as silver and aluminum; and alloys containing these. Two or more of these may be included.

[0047] The material constituting the reflective layer 12 is preferably a material with high reflectivity even in a thin film. By making it a thin film, the reduction in the cell's internal volume is suppressed, allowing for a larger amount of phosphor to be filled, thereby easily improving the brightness of the scintillator panel. Therefore, the reflective layer 12 is preferably formed of a metal, more preferably a metal selected from silver and aluminum, and alloys thereof. From the perspective of resistance to atmospheric discoloration, a silver alloy containing palladium and copper is preferred.

[0048] The thickness of the reflective layer 12 can be appropriately set based on the required reflective properties and is not particularly limited. For example, the thickness of the reflective layer is preferably 10 nm or greater, more preferably 50 nm or greater. Furthermore, the thickness of the reflective layer 12 is preferably 500 nm or less, more preferably 300 nm or less. By having a thickness of 10 nm or greater, the reflective layer 12 disposed on the partition wall 5 prevents light from leaking through the partition wall, achieving sufficient light shielding properties, resulting in improved clarity. By having a thickness of 500 nm or less, the surface irregularities of the reflective layer 12 are less likely to increase, and the reflectivity is less likely to decrease.

[0049] The reflective layer 12 preferably has a protective layer 13, described later, on its surface. Even when an alloy or the like that has poor resistance to discoloration in the atmosphere is used as the reflective layer 12, the provision of the protective layer 13 can reduce discoloration of the reflective layer 12. Furthermore, the decrease in reflectivity of the reflective layer 12 caused by the reaction between the reflective layer 12 and the phosphor layer 6 is suppressed, further improving brightness.

[0050] The scintillator panel of the present invention is as follows Figure 3 、 4 As shown in FIG. 1 , the reflective layer having the side surface portion S surrounding the phosphor layer 6 is a curved portion S. C, and the surfaces of the reflecting layer facing each other on the side surface S of the phosphor layer 6 are substantially parallel to each other. P In addition, the reflective layer at the bottom T of the phosphor layer 6 is a curved portion T. C , and the flat part T L The ratio in the width direction is 10.0:0 to 1.0:9.0. Here, the curved portion T of the reflective layer at the bottom of the phosphor layer is referred to as C , and the flat part T L The ratio in the width direction "is the ratio of the reflective layer to the curved surface of the portion T in the projection diagram when the reflective layer is projected onto the plane of the substrate surface. C The length of the part corresponding to the flat part T L That is, the scintillator panel of the present invention has a portion S whose surfaces facing each other are substantially parallel in the reflective layer surrounding the side portion S of the phosphor layer. P and is the surface portion S C Furthermore, in the reflective layer at the bottom T of the phosphor layer, a curved portion T is provided in a certain range in the width direction. C It should be noted that if Figure 3 、 4 As shown, S C With T C In fact, the same portion is referred to as S when it is considered as the side portion of the phosphor layer 6. C , when considered as the bottom of the phosphor layer 6, is referred to as T C .

[0051] like Figure 2 As shown, in a conventional scintillator panel having a high aspect ratio partition wall shape, the reflective layer surrounding the side surface S of the phosphor layer has only a portion S in which the opposing surfaces of the reflective layer of the side surface S of the phosphor layer are substantially parallel to each other. P The bottom T of the phosphor layer has only a flat portion T L Such a conventional scintillator panel does not have a curved portion S of the reflective layer surrounding the side portion S of the phosphor layer. C , the bottom T of the phosphor layer and the curved portion T of the reflective layer C Therefore, the emitted light is not efficiently reflected by the reflective layer on the surface of the partition wall and does not reach the detector, resulting in insufficient brightness. Figure 3 、 4As shown in the figure, the reflective layer 12 having the side surface surrounding the phosphor layer is a curved portion, so that when the light emitted by the phosphor layer 6 is reflected by the reflective layer 12, it is easy to be directed toward the surface of the phosphor layer 6, thereby improving the brightness. In addition, the reflective layer also having the side surface of the phosphor layer has the mutually opposing surfaces substantially parallel portions S. P , thereby increasing the amount of phosphor that can be filled in the partition wall and improving the brightness.

[0052] Here, the "bottom" of the phosphor layer refers to the portion S from the closest portion of the phosphor layer to the substrate to the side surface of the phosphor layer where the opposing surfaces of the reflective layer are substantially parallel to each other. P The so-called "side portion" refers to the portion where the phosphor layer contacts the member other than the phosphor layer, and the portion where the phosphor layer contacts the member other than the phosphor layer, excluding the flat portion at the bottom of the phosphor layer. L As mentioned above, S C and T C It is the bottom and also the side part. The so-called "roughly parallel" means roughly parallel. Even if it is completely parallel, even if it has a certain degree of inclination or curvature, it is also included in the category of roughly parallel. Specifically, it means that the angle formed by two opposing surfaces is 7° or less. The so-called "curved surface" is a surface with continuous changes, and refers to a part with a curvature other than 0 in the cross-sectional view. The so-called "flat" is a part that does not have the above-mentioned curved surface, and also includes the state with fine bumps and unevenness on the surface. The so-called "fine bumps and unevenness" here refers to a protrusion or a concave shape with a length of less than 1 / 100 of the thickness of the phosphor layer of the scintillator panel. It should be noted that for the sake of explanation, in Figures 2-4 The description of the reflective layer 12 and the phosphor 14 is omitted.

[0053] The curved portion T of the reflective layer at the bottom of the phosphor layer C , and the flat part T L The ratio in the width direction is 10.0:0 to 1.0:9.0. If the curved portion is smaller than 1.0:9.0, light emitted from the bottom of the phosphor layer, especially near the end of the bottom, is less likely to be reflected by the bottom reflective layer and thus less likely to be directed toward the surface of the phosphor layer 6, thus facilitating a decrease in brightness. C , and the flat part T LThe ratio in the width direction is preferably 10.0:0 to 3.0:7.0. The method for achieving the above ratio of 10.0:0 to 1.0:9.0 is not particularly limited, and examples thereof include, for example, when providing a partition wall auxiliary layer, adjusting the concentration of the resin solution and the surface tension of the resin constituting the partition wall auxiliary layer in the partition wall auxiliary layer formation step described later. It should be noted that, when the unit shape is rectangular, in at least one cross-sectional shape, the curved portion T of the bottom reflective layer C , and the flat part T L The present invention also encompasses the case where the ratio in the width direction is within the above range.

[0054] The reflective layer surrounding the side surface of the phosphor layer is a curved portion S C , the surface of the reflecting layer facing each other on the side surface of the phosphor layer is substantially parallel to the portion S P The ratio in the thickness direction is preferably 0.5:9.5 to 7.0:3.0. Here, the "reflective layer surrounding the side surface of the phosphor layer is the curved surface portion S C , the surface of the reflecting layer facing each other on the side surface of the phosphor layer is substantially parallel to the portion S P The ratio in the thickness direction "is the ratio of the reflective layer to the curved surface in the projection when the reflective layer is projected onto a plane perpendicular to the substrate. C The length of the portion and the portion S corresponding to the surfaces facing each other are substantially parallel. P If the above ratio is greater than 0.5:9.5 and the curved portion is larger, the light emitted near the bottom of the phosphor layer 6 is easily directed toward the surface of the phosphor layer when reflected by the reflective layer 12, thereby further improving the brightness. On the other hand, if the above ratio is greater than 7.0:3.0 and the substantially parallel portion is larger, the thickness of the phosphor layer near the partition wall increases, thereby improving the X-ray absorption rate. The reflective layer surrounding the side surface of the phosphor layer is a curved portion S C , the surface of the reflecting layer facing each other on the side surface of the phosphor layer is substantially parallel to the portion S P The ratio in the thickness direction is more preferably 2.0:8.0 to 6.0:4.0. The method for achieving the above ratio of 0.5:9.5 to 7.0:3.0 is not particularly limited, and examples thereof include, for example, adjusting the concentration of the resin solution and the surface tension of the resin constituting the partition wall auxiliary layer in the partition wall auxiliary layer formation step described below when providing the partition wall auxiliary layer.

[0055] The shape, thickness, and width of the reflective layer 12 can be measured by exposing the partition wall cross section using an ion cutting device (e.g., EMTIC3X, manufactured by LEICA) and then photographing the partition wall cross section using a scanning electron microscope (e.g., FE-SEMMerlin, manufactured by Zeiss). It should be noted that the reflective layer 12 formed in the reflective layer formation step described below tends to be thicker near the top of the partition wall and thinner on the side surfaces near the bottom. In cases where the thickness varies depending on the location, the thickness of the reflective layer 12 refers to the thickness of the side surfaces at the center of the partition wall in the height direction.

[0056] (Protective layer)

[0057] Both an inorganic protective layer and an organic protective layer can be suitably used as the protective layer 13. As the protective layer 13, an inorganic protective layer and an organic protective layer can be laminated and used in combination.

[0058] The inorganic protective layer is suitable as a protective layer because of its low permeability to water vapor. The inorganic protective layer can be formed by a known method such as a vacuum film forming method such as a vacuum evaporation method, a sputtering method or a CVD method, a plating method, a paste coating method or a spraying method using a sprayer. The material of the inorganic protective layer is not particularly limited. As the material of the inorganic protective layer, for example, oxides such as silicon oxide, indium tin oxide, and gallium zinc oxide, nitrides such as silicon nitride, fluorides such as magnesium fluoride, etc. Among them, as the material of the inorganic protective layer, silicon nitride is preferably used because of its low permeability to water vapor and the fact that the reflectivity of silver is not easily reduced during the formation of the inorganic protective layer.

[0059] The thickness of the inorganic protective layer is not particularly limited. For example, the thickness of the inorganic protective layer is preferably 2 nm or greater, more preferably 5 nm or greater. Furthermore, the thickness of the inorganic protective layer is preferably 300 nm or less, more preferably 100 nm or less. By having a thickness of 2 nm or greater, the scintillator panel can further suppress the reduction in brightness under the operating environment. By having a thickness of 300 nm or less, coloration caused by the inorganic protective layer can be suppressed, further improving brightness. The thickness of the inorganic protective layer can be measured using the same method as the thickness of the organic protective layer described below.

[0060] The organic protective layer preferably contains a polymer compound with excellent chemical durability, for example, polysiloxane or an amorphous fluororesin as its main component. "Amorphous fluororesin" refers to a fluorine-containing resin in which, when measured by powder X-ray diffraction, no peaks attributable to the crystal structure are observed, with only a broad halo observed. Furthermore, "main component" means that the polymer material constitutes 50-100% by mass of the material constituting the organic protective layer.

[0061] The organic protective layer can be easily formed by a known method such as solution coating and spray coating.

[0062] The thickness of the organic protective layer is preferably not less than 0.05 μm, more preferably not less than 0.2 μm. In addition, the thickness of the organic protective layer is preferably not more than 10 μm, more preferably not more than 5 μm. By having the thickness of the organic protective layer be not less than 0.05 μm, the scintillator panel 2 can achieve a greater effect of suppressing the reduction in brightness. In addition, by having the thickness of the organic protective layer be not more than 10 μm, the scintillator panel 2 can increase the volume within the unit, and by filling a sufficient amount of phosphor 14, the brightness can be further improved. The thickness of the organic protective layer can be measured by observation using a scanning electron microscope. It should be noted that the organic protective layer has a tendency to be thin on the side near the top of the partition wall and thick on the side near the bottom. Therefore, in the case where there is such a difference in thickness, the thickness of the above-mentioned organic protective layer refers to the thickness on the side of the central portion in the height direction of the partition wall.

[0063] (Phosphor layer)

[0064] The scintillator panel of the present invention includes a phosphor layer 6 within cells partitioned by partition walls 5. The phosphor 14 included in the phosphor layer may be any substance that emits light in the range of ultraviolet light to infrared light, centered around visible light, when irradiated with radiation, and may be, for example, an inorganic phosphor or an organic phosphor.

[0065] Examples of inorganic phosphors include sulfide phosphors, germanate phosphors, halide phosphors, barium sulfate phosphors, hafnium phosphate phosphors, tantalate phosphors, tungstate phosphors, rare earth silicate phosphors, rare earth oxysulfide phosphors, rare earth phosphate phosphors, rare earth oxyhalide phosphors, alkaline earth metal phosphate phosphors, and alkaline earth metal fluoride halide phosphors.

[0066] Examples of rare earth silicate phosphors include cerium-activated rare earth silicate phosphors. Examples of rare earth oxysulfide phosphors include praseodymium-activated rare earth oxysulfide phosphors, terbium-activated rare earth oxysulfide phosphors, and europium-activated rare earth oxysulfide phosphors. Examples of rare earth phosphate phosphors include terbium-activated rare earth phosphate phosphors. Examples of rare earth oxyhalide phosphors include terbium-activated rare earth oxyhalide phosphors and thulium-activated rare earth oxyhalide phosphors. Examples of alkaline earth metal phosphate phosphors include europium-activated alkaline earth metal phosphate phosphors. Examples of alkaline earth metal fluoride-halide phosphors include europium-activated alkaline earth metal fluoride-halide phosphors.

[0067] Examples of the organic fluorescent substance include p-terphenyl, p-quaterphenyl, 2,5-diphenyl oxazole, 2,5-diphenyl-1,3,4- Oxadiazole, naphthalene, diphenylacetylene, stilbene, etc.

[0068] Two or more of these may be contained. Among these, a phosphor selected from a halide phosphor and a rare earth oxysulfide phosphor is preferred. Among rare earth oxysulfides, gadolinium oxysulfide is more preferred from the viewpoints of luminous efficiency and chemical stability. Gadolinium oxysulfide is preferably terbium-activated, europium-activated, or praseodymium-activated.

[0069] The phosphor 14 contained in the phosphor layer is preferably in a powdered form. There are no particular limitations on the powdered form, and more specifically, it can be in a particulate, columnar, flaky, or needle-shaped form. Among these, particulate phosphors are preferred. By making the phosphor 14 particulate, the phosphor is more evenly dispersed in the phosphor layer, thereby reducing variations in the phosphor's light emission within the phosphor layer and further improving brightness.

[0070] The average particle size of the phosphor 14 is preferably 0.5 to 50 μm, more preferably 3.0 to 40 μm, and even more preferably 4.0 to 30 μm. When the average particle size of the phosphor is 0.5 μm or larger, the efficiency of converting radiation into visible light is further improved, further enhancing brightness. Furthermore, phosphor aggregation can be suppressed. On the other hand, when the average particle size of the phosphor is 50 μm or smaller, the surface smoothness of the phosphor layer is excellent, suppressing the occurrence of bright spots in the image.

[0071] The average particle size of the phosphor 14 in the present invention refers to the particle size at the 50th percentile in the cumulative distribution of particle sizes. This can be measured using a particle size distribution analyzer (e.g., MT3300; manufactured by Nikkiso Co., Ltd.). More specifically, the phosphor is placed in a sample chamber filled with water, ultrasonically treated for 300 seconds, and then the particle size distribution is measured. The particle size at the 50th percentile in the cumulative distribution is defined as the average particle size.

[0072] Regarding the decay time of the scintillator panel's luminous intensity, in the measurement method described below, it is preferable that the time required for the initial luminous intensity to reach 1 / e times the initial luminous intensity be 100 μs or less. If the time required to reach 1 / e times is 100 μs or less, in an inspection method that continuously images subjects using a radiation inspection apparatus described below, it is possible to prevent X-ray images of individual subjects from being retained in subsequent images of subjects. As a result, continuous inspections can be performed at high speed.

[0073] The decay time of luminous intensity can be measured by a known method. Specifically, a method using a fluorescence lifetime measuring device (e.g., Quantaurus-Tau C11367-24; Hamamatsu Photonics (Strain)) with ultraviolet light as the excitation light, a method using a device consisting of an optical fiber, a photodiode, and a light sensor amplifier with radiation as the excitation source, etc. can be cited. As a method for shortening the decay time of luminous intensity, if the phosphor is gadolinium oxysulfide as an example, a method in which the activator of the phosphor uses a substance other than terbium can be cited. In particular, the phosphor is preferably activated by praseodymium, whereby the decay time becomes shorter.

[0074] (Binder resin)

[0075] The material of the binder resin 15 is not particularly limited. For example, thermoplastic resins, thermosetting resins, and photocurable resins can be used as the binder resin 15. More specifically, the binder resin 15 is preferably an acrylic resin, a cellulose resin, an epoxy resin, a melamine resin, a phenol resin, a urea resin, a vinyl chloride resin, a butyral resin, a polyvinyl acetal, a silicone resin, a polyester resin, a polyamide resin, a polyimide resin, a polyetherimide resin, a polyamideimide resin, a polyketone resin, a polyether resin, a polyetheretherketone resin, polyethylene, polypropylene, polycarbonate, polystyrene, polyvinyltoluene, polyvinylpyrrolidone, polyacrylamide, polyvinyl acetate, an aromatic hydrocarbon resin, a polyalkylene polyamine resin, a polybenzimidazole resin, a polypyrrole resin, or a polythiophene resin. Two or more of these may be contained.

[0076] Among them, the binder resin 15 preferably contains at least one selected from polyester resin, polyamide resin, polyimide resin, polyamide-imide resin and polyether resin. Here, the so-called polyether resin is a resin having an ether bond in the main chain, and specifically, polyether resin, polyetheretherketone resin, polyetherimide resin and the like can be cited. In this way, the attenuation of light in the unit of the scintillator panel 2 can be suppressed, and it is easy to fully extract the luminescence. In addition, the binder resin 15 preferably contains 1 to 3 of the above-mentioned resins as main components. In this way, it is easier to obtain the effect of suppressing the attenuation of light in the above-mentioned unit. It should be noted that the so-called main component means that the total amount of the above-mentioned specific resins in the materials constituting the binder resin 15 is 50 to 100% by mass.

[0077] The resin used as the material of the binder resin 15 is preferably a resin having a structure in which an aromatic hydrocarbon group is a main chain in the repeating unit. Since the binder resin 15 has an aromatic hydrocarbon group as a main chain in the repeating unit, the coloring of the binder resin caused by radiation exposure during use of the scintillator panel is less likely to occur, and the brightness is further improved. Specific examples of aromatic hydrocarbon groups include phenylene, naphthylene, anthrylene, and phenanthrenyl. Two or more of these may be contained. Among them, from the perspective of the solvent solubility, transparency, and color tone of the resin, phenylene or naphthylene is preferred, and phenylene is particularly preferred.

[0078] The structure of the binder resin can be confirmed by assigning detected peaks using a nuclear magnetic resonance apparatus (NMR).

[0079] (Radiation Detector)

[0080] The radiation detector of the present invention comprises the scintillator panel described above on an output substrate having a photoelectric conversion layer. The output substrate comprises a photoelectric conversion layer and an output layer on the substrate. The photoelectric conversion layer is generally a layer in which pixels having light sensors are formed.

[0081] (Radiological inspection equipment)

[0082] The radiation inspection apparatus of the present invention comprises a radiation generating unit that generates radiation and the aforementioned radiation detector. The radiation inspection apparatus irradiates a subject with radiation from the radiation generating unit, and the radiation detector detects the radiation transmitted through the subject. By incorporating the radiation detector of the present invention into the radiation detection unit, a high-brightness radiation inspection apparatus can be achieved.

[0083] (Method for Manufacturing Scintillator Panel)

[0084] A method for manufacturing a scintillator panel according to an embodiment of the present invention includes the following steps: a partition wall forming step for forming partition walls on a substrate to demarcate cells; a partition wall auxiliary layer forming step for forming a partition wall auxiliary layer on the surfaces of the partition walls; a reflective layer forming step for forming a reflective layer on the surfaces of the partition walls and the partition wall auxiliary layer; and a phosphor filling step for filling the cells demarcated by the partition walls with phosphor. Each step is described below. It should be noted that in the following description, matters common to those described in the above-described scintillator panel embodiment are omitted as appropriate.

[0085] (Partition Wall Formation Step)

[0086] The partition wall forming process is a process for forming a partition wall on a substrate to demarcate a cell. More specifically, a partition wall having a lattice-like shape is formed on a substrate to form a space (cell) demarcated by the partition wall. As a method for forming a partition wall on a substrate, various known methods can be utilized, without particular limitation. From the perspective of easy shape control, the method for forming a partition wall is preferably a photolithography method.

[0087] For example, when forming the partition wall containing the compound (P) using photolithography, the partition wall can be formed by applying a photosensitive resin composition containing the compound (P) to the surface of the substrate to obtain a coating film, and then exposing and developing the coating film to obtain a partition wall pattern. The "photosensitive resin composition" referred to here refers to a resin composition containing a photocationic polymerization initiator and a cationically polymerizable compound, but may also contain additives such as surfactants, solvents, polymers, etc. other than the above.

[0088] The coating step involves applying the photosensitive resin composition entirely or partially to the surface of the substrate to form a coating film. Examples of methods for applying the photosensitive resin composition include screen printing, a rod coater, a roll coater, a die coater, and a knife coater. The thickness of the resulting coating film can be adjusted by adjusting the number of coating passes, the mesh size of the screen, and the viscosity of the photosensitive resin composition.

[0089] Next, the photosensitive resin composition coating film formed by the above method is exposed to chemical radiation through a mask having a desired pattern. Examples of chemical radiation used for exposure include ultraviolet rays, visible light, electron beams, and X-rays. However, in the present invention, i-rays (365 nm), h-rays (405 nm), and g-rays (436 nm) from a mercury lamp are preferably used.

[0090] To form a pattern, after exposure, the unexposed areas are removed using a developer. Preferred developers include aqueous solutions of tetramethylammonium hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and 1,6-hexanediamine. Depending on the circumstances, these aqueous alkaline solutions may contain polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, and dimethylacrylamide; alcohols such as methanol, ethanol, and isopropyl alcohol; esters such as ethyl lactate and propylene glycol monomethyl ether acetate; and ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone.

[0091] Development can be performed by spraying the developer onto the coating surface, immersing the coating surface in the developer, immersing the coating surface in the developer, or immersing the coating surface in the developer while applying ultrasonic waves. The development conditions, such as the development time and the temperature of the developer during the development step, may be any conditions as long as the exposed areas are removed and pattern formation is possible.

[0092] After development, the film is preferably rinsed with water. Alternatively, alcohols such as ethanol and isopropyl alcohol, or esters such as ethyl lactate and propylene glycol monomethyl ether acetate may be added to the water for rinsing.

[0093] Furthermore, the coating film can be baked before development, if necessary. This can improve the resolution of the pattern after development and increase the tolerance of development conditions. The baking temperature is preferably in the range of 50-180°C, more preferably in the range of 60-120°C, and the baking time is preferably from 5 seconds to several hours.

[0094] After pattern formation, unreacted cationically polymerizable compounds and photocationic polymerization initiators may remain in the coating film of the photosensitive resin composition. Therefore, these may thermally decompose and generate gas during the thermal crosslinking reaction described below. To avoid this, it is preferable to irradiate the entire surface of the patterned resin composition film with the aforementioned exposure light to generate acid from the photocationic polymerization initiator. This allows the reaction of unreacted cationically polymerizable compounds to proceed during the thermal crosslinking reaction, thereby suppressing the generation of gas from thermal decomposition.

[0095] After development, a temperature of 120°C to 300°C is preferably applied to promote thermal crosslinking. Crosslinking can improve the heat resistance and chemical resistance of the resulting partition walls. This heat treatment can be performed by either increasing the temperature in stages or by continuously increasing the temperature within a certain temperature range for 5 minutes to 5 hours.

[0096] The base material when forming the partition wall can be used as a substrate of a scintillator panel, or after peeling the partition wall from the base material, the peeled partition wall can be placed on a substrate for use. The method of peeling the partition wall from the base material can use a known method such as a method of setting a peeling auxiliary layer between the base material and the partition wall.

[0097] (Partition rib auxiliary layer formation step)

[0098] The manufacturing method of the scintillator panel involved in the embodiment of the present invention has a partition wall auxiliary layer forming step of forming a partition wall auxiliary layer on the surface of the partition wall. The partition wall auxiliary layer only needs to be formed on at least a portion of the partition wall surface. The partition wall auxiliary layer is preferably in contact with at least a portion of the partition wall and the substrate. The method for forming the partition wall auxiliary layer is not particularly limited. If an example is given, the partition wall auxiliary layer can be formed by applying a resin solution under vacuum in a cell divided by the partition wall of a substrate (hereinafter referred to as a partition wall substrate) on which the partition wall is formed as described above, and then drying and removing the solvent.

[0099] (Reflective Layer Forming Step)

[0100] The method for manufacturing a scintillator panel according to an embodiment of the present invention includes a reflecting layer forming step of forming a reflecting layer on the surface of the barrier ribs and / or the barrier rib auxiliary layer.

[0101] The method for forming the reflective layer is not particularly limited. For example, the reflective layer can be formed by vacuum film deposition methods such as vacuum evaporation, sputtering, or CVD, plating, paste coating, or spraying using a sprayer. Among these methods, reflective layers formed by sputtering are preferred because they have higher reflectivity uniformity and corrosion resistance than reflective layers formed by other methods.

[0102] (Protective Layer Formation Step)

[0103] (Inorganic protective layer forming step)

[0104] In the manufacturing method of the scintillator panel involved in a preferred embodiment, there may be a step of forming an inorganic protective layer on the surface of the reflective layer. The method for forming the inorganic protective layer is not particularly limited. As an example, the inorganic protective layer can be formed by a vacuum film forming method such as vacuum evaporation, sputtering, or CVD, a paste coating method, or a spraying method using a sprayer. Among these, inorganic protective layers formed by sputtering have higher uniformity and corrosion resistance than inorganic protective layers formed by other methods and are therefore preferred.

[0105] (Organic protective layer forming step)

[0106] The manufacturing method of the scintillator panel according to a preferred embodiment may include an organic protective layer forming step of forming an organic protective layer on the surface of the reflective layer. The method for forming the organic protective layer is not particularly limited. As an example, the organic protective layer can be formed by applying a solution of polysiloxane and an amorphous fluorine-containing resin to the partition wall substrate under vacuum, followed by drying to remove the solvent.

[0107] When polysiloxane is used, the dried substrate is preferably cured at a temperature higher than the drying temperature. Curing promotes condensation of the polysiloxane, improves heat resistance and chemical resistance, and facilitates increasing the initial brightness of the scintillator panel.

[0108] When an amorphous fluororesin is used, the moisture permeability and chemical resistance are high, and the initial brightness of the scintillator panel is likely to be improved.

[0109] (Phosphor Filling Process)

[0110] The manufacturing method of the scintillator panel according to an embodiment of the present invention includes a phosphor filling step of filling the cells partitioned by the partition walls with phosphor. The phosphor filling method is not particularly limited. As an example, a method in which a phosphor paste obtained by mixing phosphor powder and a binder resin in a solvent is applied to a partition wall substrate under vacuum, followed by drying to remove the solvent, is preferred, given its simplicity and the ability to uniformly fill a large area with the phosphor.

[0111] As described above, according to the method for manufacturing a scintillator panel according to the embodiment of the present invention, the obtained scintillator can obtain a high-brightness image.

[0112] Example

[0113] The present invention is further described in detail below with reference to Examples and Comparative Examples. The present invention is not limited thereto. The compounds used in each Example and Comparative Example were synthesized by the following method.

[0114] (Raw material of polyimide A)

[0115] Amine compound: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0116] Acid anhydride: Likaside (registered trademark) TDA-100 (manufactured by Shin Nippon Chemical Co., Ltd.)

[0117] Solvent: γ-butyrolactone (hereinafter referred to as GBL, manufactured by Fujifilm Wako Junyu Co., Ltd.).

[0118] (Synthesis of Polyimide A)

[0119] Under a dry nitrogen stream, 29.30 g (0.08 mol) of BAHF was added to 80 g of GBL and dissolved with stirring at 120°C. Subsequently, 30.03 g (0.1 mol) of TDA-100 was added along with 20 g of GBL, and the mixture was stirred at 120°C for 1 hour, followed by stirring at 200°C for 4 hours to obtain a reaction solution. The reaction solution was then poured into 3 L of water to obtain a white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80°C for 5 hours to obtain polyimide A.

[0120] (Raw material for photosensitive polyimide varnish)

[0121] Epoxy compound: "TEPIC" (registered trademark)-VL (manufactured by Nissan Chemical Co., Ltd.)

[0122] Photoacid generator "CPI" (registered trademark)-310B (manufactured by Sanapro Co., Ltd.)

[0123] Silane coupling agent: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0124] (Raw materials for partition wall auxiliary layer)

[0125] The raw materials used in the preparation of the resin solution for the partition wall auxiliary layer are as follows.

[0126] Solvent A: Ethyl acetoacetate (manufactured by Daiwa Kayaku Co., Ltd.)

[0127] Solvent B: Decane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0128] Solvent C: GBL

[0129] Siloxane resin A: 100 parts by mass of polysiloxane A described below to which 0.5 parts by mass of phosphoric acid was added

[0130] Silicone resin B: TSE-3450 (a mixture of dimethylsiloxane oligomer and curing agent at a mass ratio of 10:1. Produced by Momentive)

[0131] Siloxane resin C: Siloxane resin C obtained by adding 2 parts by mass of tetrabutyl orthotitanate to 100 parts by mass of X-40-9250 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0132] Epoxy resin A: LE-1421 (a mixture of an epoxy compound and an acid anhydride at a mass ratio of 10:7. Manufactured by Sanyu Reckoning Co., Ltd.)

[0133] Polyimide resin A: a resin produced in the examples described below.

[0134] (Preparation of Resin Solution for Partition Rib Auxiliary Layer)

[0135] Each resin and solvent were mixed so as to have the concentrations shown in Tables 1 to 3, added to a stirring container, and stirred at room temperature for 30 minutes to obtain each resin solution.

[0136] (Raw material of polysiloxane A)

[0137] The organosilane used in the synthesis of polysiloxane A is as follows.

[0138] Organosilane S-1: Methyltrimethoxysilane

[0139] Organosilane S-2: Phenyltrimethoxysilane

[0140] Organosilane S-3: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0141] (Synthesis of polysiloxane A)

[0142] In a 500 ml three-necked flask, 16.34 g (0.12 mol) of organosilane S-1, 29.75 g (0.15 mol) of organosilane S-2, 7.39 g (0.03 mol) of organosilane S-3, and 45.00 g of propylene glycol monomethyl ether acetate (PGMEA) were added. A phosphoric acid aqueous solution prepared by dissolving 0.16 g of phosphoric acid in 16.21 g of water (0.30 mass % relative to the added monomers) was added over 30 minutes while stirring at room temperature. The flask was then immersed in a 70°C oil bath and stirred for 90 minutes. The oil bath was then heated to 115°C over 30 minutes. One hour after the heating began, the internal temperature of the solution reached 100°C. From then on, heating and stirring were continued for 2 hours (internal temperature was 100-110°C) to obtain a polysiloxane solution. It should be noted that nitrogen gas was passed through at a flow rate of 0.05 liters / minute during the heating and stirring. PGMEA was added to the obtained polysiloxane solution so that the solid content concentration became 40% by mass to obtain a polysiloxane A solution. The obtained polysiloxane A solution was passed through 29 As a result of Si-NMR measurement, the molar ratios of the repeating units derived from organosilanes S-1, S-2, and S-3 were 40 mol%, 50 mol%, and 10 mol%, respectively.

[0143] (Evaluation of Reflective Layer Shape)

[0144] For each scintillator panel filled with the phosphor layer, a three-ion cutting device, EMTIC 3X (manufactured by LEICA), was used to expose a cross section of the partition wall. The reflective layer-forming portion of the partition wall cross section was photographed using a field emission scanning electron microscope (FE-SEM) Merlin (manufactured by Zeiss). From the captured image, the lengths of the curved portion of the reflective layer on the side of the partition wall and the portion where the opposing surfaces of the reflective layer were substantially parallel were measured, and their ratio was calculated. Similarly, the reflective layer at the bottom of the phosphor layer was observed, and the lengths of the curved portion and the flat portion of the reflective layer in the width direction were measured, and their ratio was calculated. Regarding the lengths of the substantially parallel portions of the opposing surfaces of the reflective layer on the side of the partition wall, an approximate line with a length of 10 μm was drawn on each of the opposing reflective layer surfaces within a single unit. The portions where the angles between these approximate lines were less than 7° were considered to be substantially parallel.

[0145] (Brightness Evaluation)

[0146] Each scintillator panel, after being filled with a phosphor layer, was positioned at the center of the photosensor surface of a PaxScan2520V X-ray detector (Varian), with the scintillator panel cells aligned one-to-one with the photosensor pixels. The substrate ends were secured with adhesive tape to create a radiation detector. Images were acquired by irradiating the detector with X-rays from an L9181-02 X-ray irradiation device (Hamamatsu Photonics) at a tube voltage of 50 kV and a distance of 30 cm between the X-ray tube and the detector. The average value of the digital values ​​of the 256×256 pixels at the center of the scintillator panel's light-emitting position in the resulting image was used as the luminance value. For each sample, a relative comparison was performed, assuming the luminance of Comparative Example 1 was 100% for Examples 1-14 and Comparative Examples 2-4, and assuming the luminance of Comparative Example 5 was 100% for Examples 15-22 and Comparative Examples 6-8.

[0147] (Evaluation of X-ray Absorptivity)

[0148] Each scintillator panel, after being filled with a phosphor layer, was placed on the detector section of an EMF 123 X-ray spectrometer (manufactured by EMF Japan Co., Ltd.). X-rays from an X-ray radiator L9181-02 (manufactured by Hamamatsu Photonics Co., Ltd.) were irradiated onto the scintillator panel at a tube voltage of 50 kV and a distance of 30 cm between the X-ray tube and the detector. A photon count spectrum was obtained. The total number of photons in the obtained spectrum was defined as the X-ray transmission, and the X-ray absorptivity of the scintillator panel was calculated from the difference in total number of photons compared to the total number of photons obtained when irradiated without the scintillator panel. For Examples 1 to 14 and Comparative Examples 2 to 4, relative values ​​were calculated, with the value of Comparative Example 1 being set to 100. For Examples 15 to 22 and Comparative Examples 6 to 8, relative values ​​were calculated, with the value of Comparative Example 5 being set to 100. Regarding each relative value, a value of 95 or more was evaluated as A, a value of 90 or more and less than 95 was evaluated as B, and a value of less than 90 was evaluated as C.

[0149] (Evaluation of Luminous Intensity Decay Time)

[0150] For the scintillator panels produced in each example and comparative example, the luminous intensity at the wavelength (hereinafter referred to as the maximum luminous wavelength) at which the luminous intensity reaches its maximum when excited with light of an excitation wavelength of 297 nm was measured using a Fluorolog3C-2iHR320 (manufactured by HORIBA Jobin Yvon GmbH). The light source was then turned off, and the temporal variation of the luminous intensity from the moment the light source was turned off was measured. The time required for the luminous intensity to reach 1 / e of the luminous intensity at the moment the light source was turned off was calculated.

[0151] (Example 1)

[0152] (Fabrication of partition wall substrate)

[0153] (Preparation of Photosensitive Polyimide Varnish)

[0154] 10 g of polyimide A, 10 g of "TEPIC"-VL, 0.6 g of "CPI"-310B, and 0.8 g of KBM-403 were dissolved in GBL. The amount of solvent (GBL) added was adjusted to achieve a solids concentration of 60% by mass, assuming all additives other than the solvent were solids. The resulting solution was pressure-filtered using a filter with a 1 μm particle retention size to obtain photosensitive polyimide varnish A. Hereinafter, the substance corresponding to the solids content of "photosensitive polyimide varnish A" is referred to as polyimide resin A.

[0155] (Fabrication of Polyimide Partition Walls)

[0156] As a substrate, a PI (polyimide) film of 125 mm × 125 mm × 0.25 mm was used. On the surface of the substrate, the photosensitive polyimide varnish A was applied using a die coater in such a manner that the thickness after drying was 150 μm, and dried to obtain a coating film of polyimide resin A. Next, the coating film of polyimide resin A was coated using an ultra-high pressure mercury lamp at 2000 mJ / cm through a photomask having openings corresponding to the desired pattern (a chrome mask having grid-like openings with a pitch of 127 μm and a line width of 10 μm). 2 The exposed coating film was developed in a 2% by mass potassium hydroxide aqueous solution, and the unexposed portions were removed to obtain a lattice pattern. The resulting lattice pattern was thermally crosslinked and cured in air at 150°C for 60 minutes to obtain a partition wall substrate having lattice-shaped partition walls formed thereon.

[0157] (Formation of Partition Wall Auxiliary Layer)

[0158] Siloxane resin A was dissolved in solvent A so that the solid content was 30 wt%. The obtained resin solution was vacuum printed in the cells divided by the partition walls of the partition wall substrate, dried at 90°C for 1 hour, and further cured at 190°C for 1 hour to form a crystalline silicon film in the cells. Figure 3 The partition wall auxiliary layer shown.

[0159] (Formation of Reflective Layer and Inorganic Protective Layer)

[0160] A reflective layer was formed on a partition wall substrate with a partition wall auxiliary layer formed thereon using a commercially available sputtering apparatus and sputtering target. During sputtering, a glass plate was placed near the partition wall substrate, and sputtering was performed under conditions such that the metal thickness on the glass plate reached 300 nm. APC (manufactured by Fulya Metal Co., Ltd.), a silver alloy containing palladium and copper, was used as the sputtering target for forming the reflective layer. After forming the reflective layer, SiN was applied to the glass substrate in the same vacuum chamber to a thickness of 100 nm as a protective layer.

[0161] (Formation of Organic Protective Layer)

[0162] Fluororesin solution

[0163] 1 part by mass of "CYTOP" (registered trademark) CTL-809M as an amorphous fluorine-containing resin was mixed with 1 part by mass of fluorine-containing solvent CT-SOLV180 (manufactured by AGC Corporation) as a solvent to prepare a resin solution.

[0164] This resin solution was vacuum-printed onto a partition wall substrate formed with a reflective layer and an inorganic protective layer, then dried at 90°C for 1 hour and further cured at 190°C for 1 hour to form an organic protective layer. A cross-section of the partition wall substrate after the organic protective layer was exposed using a triple ion cutting device EMTIC3X (manufactured by LEICA) and photographed using a field emission scanning electron microscope (FE-SEM) Merlin (manufactured by Zeiss). The thickness of the organic protective layer on the side surface of the center portion of the partition wall in the partition wall substrate, as measured from the photographed image, was 1 μm.

[0165] (Phosphor)

[0166] The phosphors used in the phosphor layer are as follows.

[0167] Phosphor powder 1: Gd2O2S:Tb (manufactured by Nichia Chemical Industries, Ltd.: average particle size 11 μm)

[0168] Phosphor powder 2: Gd2O2S:Pr (manufactured by Nichia Chemical Industries, Ltd.: average particle size 5 μm)

[0169] (Binder resin of phosphor layer)

[0170] The materials used for the binder resin of the phosphor layer are as follows.

[0171] Binder resin A: "Etocel" (registered trademark) 7cp (cellulose resin, manufactured by Dawu Kemikal Co., Ltd.)

[0172] Binder resin B: "Bilon" (registered trademark) 270 (polyester resin, manufactured by Toyobo Co., Ltd.)

[0173] Binder resin C: "Grill Amido" (registered trademark) TR55 (polyamide resin, manufactured by EMS-CHEMIE AG)

[0174] Binder resin D: "Biromax" (registered trademark) HR-15ET (polyamide-imide resin, manufactured by Toyobo Co., Ltd.)

[0175] Solvent: Benzyl alcohol (manufactured by Fujifilm and Wako Junyu Co., Ltd.)

[0176] The binder resins shown in Table 1 were dissolved in the above solvent to obtain binder resin solutions.

[0177] (Formation of Phosphor Layer)

[0178] A phosphor paste was prepared by mixing 10 parts by mass of phosphor powder with 5 parts by mass of the 10% concentration binder resin A solution. This phosphor paste was vacuum-printed into cells partitioned by partition walls on the partition wall substrate, where the reflective layer, inorganic protective layer, and organic protective layer had been formed as described above. The cells were filled to a volume fraction of 65% by volume of phosphor, and dried at 150°C for 15 minutes to form a phosphor layer.

[0179] (Examples 2 to 9)

[0180] In Example 1, except that the resin solution for the partition wall auxiliary layer was changed as described in Table 1 or Table 2, the same procedures as in Example 1 were followed to carry out (Formation of the partition wall auxiliary layer) to (Formation of the phosphor layer).

[0181] (Examples 10 to 12)

[0182] In Example 2, except that the binder resin of the phosphor layer was changed to the resin described in Table 2, the same procedures as in Example 2 were carried out from (Formation of Barrier Auxiliary Layer) to (Formation of Phosphor Layer).

[0183] (Example 13)

[0184] (Fabrication of partition wall substrate)

[0185] (Raw materials of paste containing glass powder)

[0186] Photosensitive monomer M-1: trimethylolpropane triacrylate

[0187] Photosensitive monomer M-2: Tetrapropylene glycol dimethacrylate

[0188] Photosensitive polymer: 0.4 equivalent of glycidyl methacrylate was added to the carboxyl groups of a copolymer having a mass ratio of methacrylic acid / methyl methacrylate / styrene = 40 / 40 / 30 (weight average molecular weight 43,000; acid value 100)

[0189] Photopolymerization initiator: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1 (manufactured by BASF)

[0190] Inhibitor: 1,6-Hexanediol-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

[0191] Ultraviolet absorber solution: 0.3% by mass solution of γ-butyrolactone of Stun IV (manufactured by Tokyo Ohka Kogyo Co., Ltd.)

[0192] Viscosity modifier: Fluonon EC121 (manufactured by Kyoeisha Chemical Co., Ltd.)

[0193] Solvent: γ-butyrolactone (manufactured by Fujifilm and Wako Junyu Co., Ltd.)

[0194] Low softening point glass powder: SiO2 27 mass%, B2O3 31 mass%, ZnO 6 mass%, Li2O 7 mass%, MgO 2 mass%, CaO 2 mass%, BaO 2 mass%, Al2O3 23 mass%, refractive index (ng) 1.56, glass softening temperature 588 ° C, thermal expansion coefficient 70×10 -7 (K -1 ), average particle size 2.3μm.

[0195] (Preparation of Paste Containing Glass Powder)

[0196] A solution of 4 parts by mass of photosensitive monomer M-1, 6 parts by mass of photosensitive monomer M-2, 24 parts by mass of a photosensitive polymer, 6 parts by mass of a photopolymerization initiator, 0.2 parts by mass of a polymerization inhibitor, and 12.8 parts by mass of a UV absorber was dissolved in 38 parts by mass of a solvent at 80°C. After the resulting solution was cooled, 9 parts by mass of a viscosity modifier was added to obtain an organic solution 1. The organic coating obtained by applying the resulting organic solution 1 to a glass plate and drying it had a refractive index (ng) of 1.555. After adding 50 parts by mass of low-softening-point glass powder to 50 parts by mass of organic solution 1, the mixture was kneaded using a three-roll mill to obtain a paste P containing glass powder.

[0197] (Production of Glass Partition Wall Substrate)

[0198] As a substrate, a 125 mm × 125 mm × 0.7 mm soda glass plate was used. The above-mentioned paste P containing glass powder was applied to the surface of the substrate using a die coater in such a manner that the thickness after drying was 150 μm, and dried to obtain a coating film of the paste containing glass powder. Next, the coating film of the paste containing glass powder was coated using an ultra-high pressure mercury lamp at 300 mJ / cm through a photomask having openings corresponding to the desired pattern (a chrome mask having grid-like openings with a pitch of 127 μm and a line width of 10 μm). 2 The exposed coating film was developed in a 0.5% by mass aqueous ethanolamine solution to remove the unexposed portions, yielding a lattice-shaped pre-fired pattern. The resulting lattice-shaped pre-fired pattern was fired in air at 580°C for 15 minutes to obtain a partition wall substrate having lattice-shaped partition walls composed primarily of glass formed on the substrate.

[0199] Using the obtained partition wall substrate, (Formation of the partition wall auxiliary layer) to (Formation of the phosphor layer) were carried out in the same manner as in Example 1 except that the resin solution for the partition wall auxiliary layer was changed as described in Table 2.

[0200] (Example 14)

[0201] In Example 13, (Formation of the Barrier Auxiliary Layer) to (Formation of the Phosphor Layer) were carried out in the same manner as in Example 13, except that the solid content of the resin solution of the barrier rib auxiliary layer was 35% by weight.

[0202] (Comparative Example 1)

[0203] In Example 1, except that the barrier rib auxiliary layer was not formed, the same procedures as in Example 1 were followed to carry out (formation of the reflective layer and the inorganic protective layer) to (formation of the phosphor layer).

[0204] (Comparative Example 2)

[0205] (Formation of the barrier rib auxiliary layer) to (Formation of the phosphor layer) were carried out in the same manner as in Example 1 except that the solid content of the resin solution of the barrier rib auxiliary layer was 1% by weight.

[0206] (Comparative Example 3)

[0207] In Example 13, the exposure dose of the ultra-high pressure mercury lamp used in the partition wall formation was set to 1000 mJ / cm 2 Except that the partition wall auxiliary layer was not formed, the same steps as in Example 13 were carried out from (forming the reflective layer and the inorganic protective layer) to (forming the phosphor layer).

[0208] (Comparative Example 4)

[0209] In Example 13, except that the barrier rib auxiliary layer was not formed, the same procedures as in Example 13 were carried out from (forming the reflective layer and the inorganic protective layer) to (forming the phosphor layer).

[0210] (Example 15)

[0211] In Example 2, except that the phosphor was changed to the substance described in Table 4, the same procedures as in Example 2 were carried out from (Formation of Barrier Auxiliary Layer) to (Formation of Phosphor Layer).

[0212] (Examples 16 to 18)

[0213] In Example 15, except that the resin solution for the barrier rib auxiliary layer was changed as described in Table 4, the same procedures as in Example 15 were carried out from (Formation of Barrier Rib Auxiliary Layer) to (Formation of Phosphor Layer).

[0214] (Examples 19 to 21)

[0215] In Example 15, except that the binder resin of the phosphor layer was changed to the resin described in Table 4, the same procedures as in Example 15 were carried out from (Formation of Barrier Auxiliary Layer) to (Formation of Phosphor Layer).

[0216] (Example 22)

[0217] In Example 14, except that the phosphor was changed to the substance described in Table 4, the same procedures as in Example 14 were carried out from (Formation of Barrier Auxiliary Layer) to (Formation of Phosphor Layer).

[0218] (Comparative Example 5)

[0219] In Comparative Example 1, except that the phosphor was changed to the substance described in Table 5, the same procedures as in Comparative Example 1 were carried out from (Formation of Reflective Layer and Inorganic Protective Layer) to (Formation of Phosphor Layer).

[0220] (Comparative Example 6)

[0221] In Comparative Example 2, except that the phosphor was changed to the substance described in Table 5, the same procedures as in Comparative Example 2 were carried out from (Formation of Reflective Layer and Inorganic Protective Layer) to (Formation of Phosphor Layer).

[0222] (Comparative Example 7)

[0223] In Comparative Example 3, except that the phosphor was changed to the substance described in Table 5, the same procedures as in Comparative Example 3 were carried out from (Formation of Reflective Layer and Inorganic Protective Layer) to (Formation of Phosphor Layer).

[0224] (Comparative Example 8)

[0225] In Comparative Example 4, except that the phosphor was changed to the substance described in Table 5, the same procedures as in Comparative Example 4 were carried out from (Formation of Reflective Layer and Inorganic Protective Layer) to (Formation of Phosphor Layer).

[0226] [Table 1]

[0227]

[0228] [Table 2]

[0229]

[0230] [Table 3]

[0231]

[0232] [Table 4]

[0233]

[0234] [Table 5]

[0235]

[0236] Explanation of symbols

[0237] 1 Radiation detector components

[0238] 2 Scintillator panels

[0239] 3 Output substrate

[0240] 4 substrate

[0241] 5. Next door

[0242] 6 Phosphor layer

[0243] 7 Diaphragm layer

[0244] 8 Photoelectric conversion layer

[0245] 9 Output Layer

[0246] 10 substrate

[0247] 11. Spacer auxiliary layer

[0248] 12 Reflection layer

[0249] 13 protective layer

[0250] 14 Phosphor

[0251] 15. Adhesive resin

[0252] S Side surface of phosphor layer

[0253] T Bottom of phosphor layer

[0254] S P The opposing surfaces of the reflective layer on the side surface of the phosphor layer are substantially parallel to each other.

[0255] S C The reflective layer surrounding the side surface of the phosphor layer is a curved portion

[0256] T L The flat portion of the reflective layer at the bottom of the phosphor layer

[0257] TC The reflective layer at the bottom of the phosphor layer is a curved portion.

Claims

1. A scintillator panel comprising a substrate, lattice-shaped partition walls formed on the substrate, a phosphor layer within a unit partitioned by the partition walls, and a reflective layer surrounding the side surfaces and bottom of the phosphor layer, wherein the scintillator panel comprises a portion of the reflective layer surrounding the side surfaces of the phosphor layer having a curved surface, and a portion whose surfaces facing each other are substantially parallel to the side surfaces of the reflective layer of the phosphor layer; a ratio of the curved portion to the flat portion of the reflective layer at the bottom of the phosphor layer in a width direction of 10.0:0 to 1.0:9.0; and a ratio of the curved portion of the reflective layer surrounding the side surfaces of the phosphor layer to the portion whose surfaces facing each other are substantially parallel to the side surfaces of the reflective layer of the phosphor layer in a thickness direction of 0.5:9.5 to 7.0:3.

0. 2 . The scintillator panel according to claim 1 , wherein the partition walls are made of a polymer material. The scintillator panel according to claim 1 or 2, wherein the phosphor contained in the phosphor layer is in powder form. 4 . The scintillator panel according to claim 1 , wherein the time required for the luminous intensity to reach 1 / e times the initial luminous intensity is 100 μs or less. 5 . The scintillator panel according to claim 1 , wherein the binder resin contained in the phosphor layer comprises at least one selected from the group consisting of polyester resin, polyamide resin, polyimide resin, polyamideimide resin, and polyether resin. 6 . A radiation detector comprising the scintillator panel according to claim 1 on an output substrate having a photoelectric conversion layer. 7 . A radiation inspection apparatus comprising the radiation detector according to claim 6 .

8. The method for manufacturing a scintillator panel according to any one of claims 1 to 5, comprising the following steps: A partition wall forming step of forming partition walls on a substrate to partition cells; a step of forming a partition wall auxiliary layer on the surface of the partition wall; a step of forming a reflective layer by forming a reflective layer on the surfaces of the partition walls and the partition wall auxiliary layer; and A phosphor filling step of filling phosphor into cells partitioned by the partition walls.

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