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

Abstract

This scintillator panel comprises a substrate, a lattice partition formed over the substrate, a fluorescent layer in cells demarcated by the partition, and a reflecting layer surrounding side surface sections and bottom sections of the fluorescent layer, and also having a portion at which the reflecting layer surrounding the side surface sections of the fluorescent layer is a curved surface and a portion at which opposite-facing surfaces of the reflecting layer of the side surface sections of the fluorescent layer are substantially parallel, wherein the ratio, in the width direction, of a portion that is a curved surface of the bottom sections of the reflecting layer and a portion that is flat is 10.0:0 to 1.0:9.0. The invention improves the luminance of the scintillator panel.

Description

[Technical Field]

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

[0002] Conventionally, radiographic images using film have been widely used in medical settings. However, radiographic images using film are analog image information. For this reason, digital radiation detectors such as flat panel detectors (hereinafter referred to as "FPDs") have been developed in recent years. In FPDs, a scintillator panel is used to convert radiation into visible light. The scintillator panel contains a radioactive phosphor that emits visible light in response to 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 radiation information is converted into digital image information. However, scintillator panels have the problem that the light emitted from the radioactive phosphor is scattered within the layer containing the phosphor (phosphor layer), resulting in a decrease in sharpness.

[0003] To reduce the effects of scattering of emitted light, a cell-type scintillator panel has been proposed, in which phosphors are filled into spaces partitioned by partitions with a reflective layer on the surface, i.e., cells. This allows the partitions to suppress scattering of light emitted from the phosphors, thereby enabling the production of highly sharp X-ray images.

[0004] On the other hand, cell-type scintillator panels have a problem in that the amount of phosphor is reduced due to the presence of partition walls, resulting in a decrease in brightness. One known method for improving brightness is to surround the phosphor layer with a reflective surface that has a light-collecting shape, such as a hemispherical shape, in order to reduce the number of times that light emitted within the cell is reflected by the partition walls and suppress light attenuation (Patent Document 1).

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

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-67681 [Patent Document 2] International Publication No. 2014 / 054422 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in Patent Document 1, the partition shape needs to be a shape without parallel surfaces, such as a hemisphere, so the amount of phosphor in the cell is small, resulting in insufficient brightness. Also, Patent Document 2 describes a configuration in which the bottom of the partition has curved portions, but because there are few curved portions, the emitted light is not efficiently directed to the detector due to reflection by the reflective layer on the surface of the partition, resulting in insufficient brightness.

[0008] The present invention has been made in view of the above-mentioned problems in the prior art, and has as its object to improve the brightness of a scintillator panel. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention mainly has the following configuration.

[0010] A scintillator panel comprising: a substrate; lattice-shaped partition walls formed on the substrate; a phosphor layer in cells partitioned by the partition walls; and a reflective layer surrounding the side and bottom portions of the phosphor layer, wherein the reflective layer surrounding the side portions of the phosphor layer has curved portions and portions where opposing surfaces of the reflective layer on the side portions of the phosphor layer are approximately parallel, and the ratio in the width direction of the curved portions of the reflective layer on the bottom of the phosphor layer to the flat portions is 10.0:0 to 1.0:9.0. [Effects of the Invention]

[0011] According to the present invention, the brightness of the scintillator panel can be improved. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view schematically illustrating a radiation detector member including a scintillator panel according to one embodiment of the present invention. [Figure 2] FIG. 1 is a cross-sectional view showing an example of a conventional scintillator panel. [Figure 3] 1 is a cross-sectional view showing an example of a scintillator panel of the present invention. [Figure 4] FIG. 3 is a cross-sectional view showing another example of a scintillator panel of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Scintillator panel) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the scintillator panel according to the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described below.

[0014] FIG. 1 is a cross-sectional view schematically illustrating a radiation detector member 1 including a scintillator panel 2 according to an embodiment of the present invention. The radiation detector member 1 includes a scintillator panel 2 and an output substrate 3. The scintillator panel 2 includes a substrate 4, partition walls 5, and a phosphor layer 6. The phosphor layer 6 is filled in cells defined by the partition walls 5. The phosphor layer 6 contains phosphors 14 and a binder resin 15. A reflective layer 12 is formed on the surface of the partition walls 5. A partition wall auxiliary layer 11 may be provided between the partition walls 5 and the reflective layer 12. A protective layer 13 may 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 barrier layer 7 may be provided on the photoelectric conversion layer 8. The light output surface of the scintillator panel 2 and the photoelectric conversion layer 8 of the output substrate 3 are preferably bonded or adhered to each other via a barrier layer 7. Light emitted from the phosphor layer 6 reaches the photoelectric conversion layer 8, where it is photoelectrically converted and output. Each of these will be described below.

[0015] (substrate) The material constituting the substrate 4 is preferably a material having radiation transparency. For example, the material constituting the substrate 4 may be various types of glass, polymeric materials, metals, etc. Examples of glass include quartz, borosilicate glass, and chemically strengthened glass. Examples of polymeric materials include polyesters such as cellulose acetate and polyethylene terephthalate, polyamides, polyimides, triacetate, polycarbonates, and carbon fiber reinforced resins. Examples of metals include aluminum, iron, and copper. These may be used in combination. Among these, the material constituting the substrate 4 is preferably a polymeric material having high radiation transparency. Furthermore, the material constituting the substrate 4 is preferably a material having excellent flatness and heat resistance.

[0016] From the viewpoint of reducing the weight of the scintillator panel, the thickness of substrate 4 is preferably 2.0 mm or less, more preferably 1.0 mm or less, and even more preferably 0.5 mm or less, when a glass substrate is used. Furthermore, when the substrate is made of a polymeric material, the thickness is preferably 3.0 mm or less, more preferably 1.0 mm or less. The thickness of substrate 4 can be calculated by cutting out a cross section of the substrate using a microtome, observing 10 points on each section using a scanning electron microscope (for example, a field emission scanning electron microscope "S-4800" manufactured by Hitachi, Ltd.), and measuring the average thickness.

[0017] (bulkhead) The partitions 5 are formed on the substrate 4, have a lattice shape, and are provided to form partitioned spaces (cells). Therefore, by matching the size and pitch of the pixels of the photoelectric conversion layer 8 arranged in a lattice pattern on the output substrate 3 with the size and pitch of the cells of the scintillator panel 2, a highly sharp X-ray image can be obtained.

[0018] The material constituting the partition walls 5 is preferably one that can form partition walls with high strength and heat resistance, and is, for example, an inorganic material or a polymer material. Among these, from the viewpoint of flatness of the side surface of the partition walls and processability, it is preferable to use a polymer material as the main component. Here, "mainly composed of a polymer material" means that 50 to 100 mass % of the material constituting the partition walls is a polymer material.

[0019] "Inorganic materials" refer to compounds composed of elements other than carbon, although some simple carbon compounds (such as graphite or diamond, which are allotropes of carbon) are included in the category of inorganic materials.

[0020] When the material constituting the barrier ribs 5 is an inorganic material, it is preferable that the main component is glass. Glass refers to an inorganic amorphous solid containing silicate. When the main component of the barrier ribs 5 is glass, the strength, durability, and heat resistance of the barrier ribs are increased, and deformation and damage are less likely to occur during the process of forming the reflective layer and the process of filling the phosphor. Note that "made of inorganic substances" does not strictly exclude the presence of components other than inorganic substances, but allows the presence of components other than inorganic substances to the extent of impurities contained in the inorganic raw materials themselves or impurities mixed in during the process of manufacturing the barrier ribs 5. Furthermore, "mainly composed of glass" means that 50 to 100 mass % of the material constituting the barrier ribs is glass.

[0021] In particular, the proportion of the low-softening point glass having a softening point of 650°C or less in the partition walls is preferably 95 parts by volume or more, and more preferably 98 parts by volume or more, when the volume of the partition walls is 100 parts by volume.

[0022] Components that can be used as components other than the low-softening point glass include high-softening point glass powder, which is glass with a softening point exceeding 650°C, and ceramic powder. These powders make it easier to adjust the shape of the partition walls in the partition wall formation process. In order 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.

[0023] When the material constituting the partition walls 5 is a polymeric material, the partition walls preferably contain one or more compounds (P) (hereinafter, sometimes simply referred to as "compounds (P)") selected from the group consisting of polyimide, polyamide, polyamideimide, and polybenzoxazole. When the partition walls contain the compound (P), it is possible to form fine partition walls with a high aspect ratio and a smooth surface.

[0024] When the compound (P) has a phenolic hydroxyl group, the resin has suitable solubility in an alkaline developer, which results in a high contrast between exposed and unexposed areas and allows the desired pattern to be formed, which is preferable.

[0025] When the barrier ribs 5 contain the compound (P), the barrier ribs 5 preferably further contain an epoxy compound. The epoxy compound can further improve the processability without impairing the heat resistance and mechanical strength of the compound (P), making it easier to form barrier ribs in a desired shape. This allows for a further increase in the loading amount of the phosphor, thereby further improving the brightness.

[0026] In order not to impair the properties of the compound (P), the content of the epoxy compound in the partition walls 5 preferably does not exceed 2.0 times the content of the compound (P) in terms of mass fraction. When the partition walls contain components other than the compound (P) and the epoxy compound, it is preferable that the total content of those components does not exceed the total amount of the compound (P) and the epoxy compound in terms of mass fraction.

[0027] As the epoxy compound, known compounds can be used, including aromatic epoxy compounds, alicyclic epoxy compounds and aliphatic epoxy compounds.

[0028] (Partition wall auxiliary layer) It is preferable that a barrier rib auxiliary layer 11 is provided between the barrier ribs 5 and a reflective layer 12 (described later). By providing the barrier rib auxiliary layer, when a reflective layer is formed on the surfaces of the barrier ribs and the barrier rib auxiliary layer by the method (described later), curved portions of the reflective layer surrounding the side and bottom portions of the phosphor layer can be easily provided. It is preferable that the barrier rib auxiliary layer 11 be in contact with at least a portion of the barrier ribs and the substrate.

[0029] The material constituting the partition wall auxiliary layer 11 preferably has strength, chemical resistance, heat resistance, and radiation transparency, and is preferably a polymeric material. The polymeric material used for the partition wall auxiliary layer 11 is not particularly limited and includes, for example, thermoplastic resins, thermosetting resins, and photocurable resins. More specifically, examples of the polymeric material include acrylic resins, cellulose-based 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 contained. Among these, thermosetting resins or photocurable resins are preferred from the viewpoints of strength, chemical resistance, and heat resistance. Specifically, resins 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 are preferred. Resins selected from polysiloxane resins, epoxy resins, polyimide resins and polyamide resins are more preferred. The polymer material constituting the partition wall auxiliary layer 11 may be the same material as that of the partition walls.

[0030] The partition wall auxiliary layer 11 may further contain a filler. The material constituting the filler is not particularly limited and may include, for example, glass, a polymeric material, a metal oxide, or a metal nitride. Examples of glass include quartz and borosilicate glass. Examples of polymeric materials include acrylic resin, silicone resin, melamine resin, phenolic resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, triacetate, polycarbonate, polyethylene, polypropylene, polystyrene, and carbon fiber reinforced resin. The polymeric material used as the filler is different from that of the partition wall auxiliary layer. Specifically, the polymeric material is a polymeric material that differs from that of 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.

[0031] (reflective layer) The scintillator panel of the present invention has a reflective layer 12 that surrounds the side and bottom portions of the phosphor layer 6. The presence of the reflective layer 12 allows light emitted in cells partitioned by partition walls in response to radiation to efficiently reach the detector, improving brightness. Here, "the reflective layer 12 surrounds the side and bottom portions of the phosphor layer 6" means that the reflective layer 12 is present on the side and bottom portions of the phosphor layer 6. Note that the reflective layer 12 is not limited to being continuous, and the presence of localized discontinuous portions of the reflective layer 12 due to defects or the like is permitted.

[0032] The material constituting the reflective layer 12 is not particularly limited as long as it has the function of reflecting electromagnetic waves emitted from 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 contained.

[0033] The material constituting the reflective layer 12 is preferably one with high reflectivity even when thin. By making it thin, the reduction in the internal volume of the cell can be suppressed and a larger amount of phosphor can be filled, which tends to improve the brightness of the scintillator panel. For this reason, the reflective layer 12 is preferably made of a metal, and more preferably a material selected from metals selected from silver and aluminum, and alloys containing these metals. From the viewpoint of resistance to discoloration in the atmosphere, a silver alloy containing palladium and copper is preferred.

[0034] The thickness of the reflective layer 12 can be appropriately set depending on the required reflection characteristics and is not particularly limited. For example, the thickness of the reflective layer is preferably 10 nm or more, more preferably 50 nm or more. Furthermore, the thickness of the reflective layer 12 is preferably 500 nm or less, more preferably 300 nm or less. When the thickness of the reflective layer 12 provided on the partition 5 is 10 nm or more, the scintillator panel can suppress light leakage through the partition and obtain sufficient light blocking properties, resulting in improved sharpness. When the thickness of the reflective layer 12 is 500 nm or less, the surface irregularities of the reflective layer 12 are unlikely to increase, and the reflectance is unlikely to decrease.

[0035] The reflective layer 12 preferably has a protective layer 13, which will be 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, a decrease in the reflectance of the reflective layer 12 due to a reaction between the reflective layer 12 and the phosphor layer 6 is suppressed, thereby further improving brightness.

[0036] As shown in FIGS. 3 and 4, the scintillator panel of the present invention has a curved portion S of the reflective layer surrounding the side surface S of the phosphor layer 6. C and a portion S where the opposing surfaces of the reflective layer of the side surface portion 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 has a curved surface. C and the flat part T LThe ratio in the width direction of the portion T C and the flat part T L The "ratio in the width direction of the reflective layer" is the ratio of the curved portion T C and the length of the flat part T L That is, in the scintillator panel of the present invention, in the reflective layer surrounding the side surface portion S of the phosphor layer, the opposing surfaces of the portion S are approximately parallel to each other. P and the surface part S C and a curved portion T in the reflective layer at the bottom T of the phosphor layer. C As shown in Figures 3 and 4, S C and T C are actually the same part, and when viewed as the side part of the phosphor layer 6, S C , and when viewed from the bottom of the phosphor layer 6, T C It is called.

[0037] As shown in FIG. 2, in a conventional scintillator panel having a partition wall shape with a high aspect ratio, the reflective layer surrounding the side surface portion S of the phosphor layer is a portion S where the opposing surfaces of the reflective layer of the side surface portion S of the phosphor layer are approximately parallel to each other. P and the bottom T of the phosphor layer is a flat portion T L In such a conventional scintillator panel, the reflective layer surrounding the side surface S of the phosphor layer has a curved surface S. C and the curved surface of the reflective layer at the bottom T of the phosphor layer. C 3 and 4, the reflective layer 12 surrounding the side surface of the phosphor layer has a curved portion, so that the light emitted by the phosphor layer 6 is more likely to be directed toward the surface of the phosphor layer 6 when reflected by the reflective layer 12, thereby improving the luminance. Also, the reflective layer 12 has a curved portion S surrounding the side surface of the phosphor layer, so that the light emitted by the phosphor layer 6 is more likely to be directed toward the surface of the phosphor layer 6 when reflected by the reflective layer 12, so that the luminance is improved. PBy also having this, the amount of phosphor that can be filled into the barrier ribs increases, and brightness improves.

[0038] Here, the "bottom" of the phosphor layer is the part S from the closest part of the phosphor layer to the substrate to the part S where the surfaces of the reflective layers on the side of the phosphor layer facing each other are approximately parallel to each other. P The "side surface" refers to the area where the phosphor layer contacts with a member other than the phosphor layer, and is the area up to the flat portion T L As mentioned above, S C and T C is both the bottom and the side. "Substantially parallel" means roughly parallel, and whether completely parallel or slightly inclined or curved is included in the category of "substantially parallel." Specifically, it means that the angle between two opposing surfaces is 7° or less. "Curved surface" refers to a surface with continuous changes, and refers to a portion with a curvature other than 0 in a cross-sectional view. "Flat" refers to a portion that does not have the aforementioned curved surface, and also includes a state in which the surface has fine irregularities. "Fine irregularities" here refer to protrusions or recesses with a length of 1 / 100 or less of the thickness of the phosphor layer of the scintillator panel. For the sake of explanation, the reflective layer 12 and phosphor 14 are omitted in Figures 2 to 4.

[0039] The portion T C and the flat part T L The ratio in the width direction of the curved surface of the phosphor layer is 10.0:0 to 1.0:9.0. If the ratio is less than 1.0:9.0 and the curved portion is smaller, the light emitted from the bottom of the phosphor layer, particularly near the edge of the bottom, when reflected by the reflective layer at the bottom, is less likely to travel toward the surface of the phosphor layer 6, which tends to reduce brightness. C and the flat part T LThe ratio in the width direction of the partition wall auxiliary layer is preferably 10.0:0 to 3.0:7.0. There are no particular limitations on the method for adjusting the ratio to 10.0:0 to 1.0:9.0. For example, when a partition wall auxiliary layer is provided, the concentration of the resin solution or the surface tension of the resin constituting the partition wall auxiliary layer may be adjusted in the step of forming the partition wall auxiliary layer, which will be described later. When the cell shape is rectangular, the curved surface of the bottom reflective layer in at least one cross section may be adjusted by adjusting the surface tension of the resin solution or the surface tension of the resin constituting the partition wall auxiliary layer. C and the flat part T L The present invention also includes those in which the ratio in the width direction is within the above range.

[0040] The curved portion S of the reflective layer surrounding the side surface of the phosphor layer C and a portion S where the opposing surfaces of the reflective layer on the side surface of the phosphor layer are substantially parallel to each other. P The ratio in the thickness direction of the reflective layer is preferably 0.5:9.5 to 7.0:3.0. C and a portion S where the opposing surfaces of the reflective layer on the side surface of the phosphor layer are substantially parallel to each other. P The "ratio in the thickness direction of the reflective layer" is the ratio of the curved surface S in the projection image when the reflective layer is projected onto a plane perpendicular to the substrate. C and the length of the portion S where the opposing surfaces are approximately parallel P This refers to the ratio of the lengths of the portions corresponding to the partition walls. If the ratio is greater than 0.5:9.5 and there are more curved portions, the light emitted near the bottom of the phosphor layer 6 will be more likely to head 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 ratio is greater than 7.0:3.0 and there are more approximately parallel portions, the thickness of the phosphor layer near the partition walls increases, and the X-ray absorption coefficient can be improved. The curved portions S of the reflective layer surrounding the side portions of the phosphor layer C and a portion S where the opposing surfaces of the reflective layer on the side surface of the phosphor layer are substantially parallel to each other. PThe ratio in the thickness direction is more preferably 2.0:8.0 to 6.0:4.0. There are no particular limitations on the method for adjusting the ratio to 0.5:9.5 to 7.0:3.0, but examples of the method for adjusting the ratio in the thickness direction include, when a partition wall auxiliary layer is provided, adjusting the concentration of the resin solution or the surface tension of the resin constituting the partition wall auxiliary layer in the step of forming the partition wall auxiliary layer, which will be described later.

[0041] The shape and thickness and width lengths of the reflective layer 12 can be measured by exposing the cross section of the partition wall using an ion milling device (e.g., EMTIC3X, manufactured by LEICA) and then imaging the cross section of the partition wall with a scanning electron microscope (e.g., FE-SEM Merlin, manufactured by Zeiss). The reflective layer 12 formed by the reflective layer forming step described below tends to be thick near the top of the partition wall and thin on the side surface near the bottom. When the thickness varies depending on the location, the thickness of the reflective layer 12 refers to the thickness on the side surface at the center in the height direction of the partition wall.

[0042] (protective layer) Either an inorganic protective layer or 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 also be laminated and used in combination.

[0043] The inorganic protective layer is suitable as a protective layer due to its low water vapor permeability. The inorganic protective layer can be formed by known techniques, such as vacuum film formation methods such as vacuum deposition, sputtering, or CVD, plating, paste coating, or spraying. The material of the inorganic protective layer is not particularly limited. Examples of materials for the inorganic protective layer include oxides such as silicon oxide, indium tin oxide, and gallium zinc oxide, nitrides such as silicon nitride, and fluorides such as magnesium fluoride. Among these, silicon nitride is preferably used as the material for the inorganic protective layer because it has low water vapor permeability and is less likely to reduce the reflectance of silver when forming the inorganic protective layer.

[0044] The thickness of the inorganic protective layer is not particularly limited. The thickness of the inorganic protective layer is, for example, preferably 2 nm or more, more preferably 5 nm or more. The thickness of the inorganic protective layer is preferably 300 nm or less, more preferably 100 nm or less. A thickness of 2 nm or more allows the scintillator panel to have a greater effect of suppressing a decrease in brightness under the usage environment. A thickness of 300 nm or less can suppress coloration due to the inorganic protective layer and further improve brightness. The thickness of the inorganic protective layer can be measured by the same method as that for the thickness of the organic protective layer described below.

[0045] The organic protective layer is preferably a polymeric compound with excellent chemical durability, and preferably contains, for example, polysiloxane or amorphous fluororesin as a main component. Here, "amorphous fluororesin" refers to a fluorine-containing resin in which, when measured by powder X-ray diffraction, no peaks due to a crystalline structure are observed, and only a broad halo is observed. Furthermore, "mainly composed of" means that 50 to 100% by mass of the material constituting the organic protective layer is the polymeric material.

[0046] The organic protective layer can be easily formed by known techniques such as solution coating or spray coating.

[0047] The thickness of the organic protective layer is preferably 0.05 μm or more, more preferably 0.2 μm or more. Furthermore, the thickness of the organic protective layer is preferably 10 μm or less, more preferably 5 μm or less. When the thickness of the organic protective layer is 0.05 μm or more, the scintillator panel 2 can further suppress brightness reduction. Furthermore, when the thickness of the organic protective layer is 10 μm or less, the scintillator panel 2 can further improve brightness by increasing the volume inside the cell and filling a sufficient amount of phosphor 14. The thickness of the organic protective layer can be measured by observation with a scanning electron microscope. The organic protective layer tends to be thinner on the side surface near the top of the partition wall and thicker on the side surface near the bottom. Therefore, when there is such a difference in thickness, the thickness of the organic protective layer refers to the thickness at the side surface at the center in the height direction of the partition wall.

[0048] (phosphor layer) The scintillator panel of the present invention has phosphor layers 6 in cells partitioned by partition walls 5. Phosphors 14 contained in the phosphor layer may be any substance that emits light in a range from ultraviolet light to infrared light, with visible light at the center, when irradiated with radiation, and may be, for example, either inorganic or organic phosphors.

[0049] Examples of inorganic phosphors include sulfide-based phosphors, germanate-based phosphors, halide-based phosphors, barium sulfate-based phosphors, hafnium phosphate-based phosphors, tantalate-based phosphors, tungstate-based phosphors, rare earth silicate-based phosphors, rare earth oxysulfide-based phosphors, rare earth phosphate-based phosphors, rare earth oxyhalide-based phosphors, alkaline earth metal phosphate-based phosphors, and alkaline earth metal fluorohalide-based phosphors.

[0050] 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 oxyhalogen 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 fluorohalide phosphors include europium-activated alkaline earth metal fluorohalide phosphors.

[0051] Examples of organic fluorescent materials include p-terphenyl, p-quaterphenyl, 2,5-diphenyloxazole, 2,5-diphenyl-1,3,4-oxodiazole, naphthalene, diphenylacetylene, and stilbene.

[0052] Two or more of these may be contained. Among these, a phosphor selected from halide phosphors and rare earth oxysulfide phosphors is preferred, and among rare earth oxysulfides, gadolinium oxysulfide is more preferred from the viewpoints of luminous efficiency and chemical stability. The gadolinium oxysulfide is preferably terbium-activated, europium-activated, or praseodymium-activated.

[0053] The phosphor 14 contained in the phosphor layer is preferably in a powder form. There are no particular limitations on the powder form, and more specific examples include granular, columnar, scale, and needle forms. Among these, a particulate phosphor is preferred. By making the phosphor 14 in a particulate form, the phosphor is more uniformly dispersed in the phosphor layer, thereby suppressing bias in the light emission of the phosphor in the phosphor layer and further improving brightness.

[0054] 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 more, the efficiency of converting radiation into visible light is further improved, and brightness can be further improved. Furthermore, aggregation of the phosphor can be suppressed. On the other hand, when the average particle size of the phosphor is 50 μm or less, the smoothness of the surface of the phosphor layer is excellent, and the occurrence of bright spots in the image can be suppressed.

[0055] Here, the average particle size of phosphor 14 in the present invention refers to the particle size that is 50% of the cumulative distribution of particle sizes, and can be measured using a particle size distribution measuring device (for example, MT3300, manufactured by Nikkiso Co., Ltd.). More specifically, the phosphor is placed in a sample chamber filled with water, and after ultrasonic treatment for 300 seconds, the particle size distribution is measured, and the particle size that is 50% of the cumulative distribution is taken as the average particle size.

[0056] In the measurement method described below, the decay time of the luminescence intensity of the scintillator panel is preferably 100 μsec or less, the time required for the luminescence intensity to decrease to 1 / e times the initial luminescence intensity. If the time required for the luminescence intensity to decrease to 1 / e times is 100 μsec or less, it is possible to prevent the X-ray image of each subject from remaining in the image of the subsequent subject in the inspection method described below in which subjects are continuously imaged using a radiological inspection device. As a result, high-speed continuous inspection is possible.

[0057] The decay time of the luminescence intensity can be measured by known methods. Specific examples include a method using ultraviolet light as the excitation light and a fluorescence lifetime measurement device (e.g., Quantaurus-Tau C11367-24; Hamamatsu Photonics K.K.), and a method using radiation as the excitation source and a device composed of an optical fiber, a photodiode, and a photosensor amplifier. For example, a method for shortening the decay time of the luminescence intensity when the phosphor is gadolinium oxysulfide includes using an activator other than terbium. Praseodymium-activated phosphors are particularly preferred because they shorten the decay time.

[0058] (binder resin) The material of the binder resin 15 is not particularly limited. For example, a thermoplastic resin, a thermosetting resin, a photocurable resin, or the like can be used as the binder resin 15. More specifically, the binder resin 15 is preferably an acrylic resin, a cellulose-based resin, an epoxy resin, a melamine resin, a phenolic 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, a polyethylene, a polypropylene, a polycarbonate, a polystyrene, a polyvinyltoluene, a polyvinylpyrrolidone, a polyacrylamide, a polyvinyl acetate, an aromatic hydrocarbon resin, a polyalkylenepolyamine resin, a polybenzimidazole resin, a polypyrrole resin, a polythiophene resin, or the like. Two or more of these may be contained.

[0059] Among these, the binder resin 15 preferably contains at least one selected from polyester resin, polyamide resin, polyimide resin, polyamideimide resin, and polyether-based resin. Here, the polyether-based resin refers to a resin having an ether bond in the main chain, and specific examples include polyether resin, polyetheretherketone resin, and polyetherimide resin. This can suppress light attenuation within the cell of the scintillator panel 2, making it easier to extract sufficient emitted light. Furthermore, the binder resin 15 preferably contains one to three of the above-mentioned resins as main components. This can more easily achieve the effect of suppressing light attenuation within the cell. Note that "main component" means that the total amount of the specific resin among the materials constituting the binder resin 15 is 50 to 100% by mass.

[0060] The resin used as the material for the binder resin 15 preferably has an aromatic hydrocarbon group as a repeating unit in its main chain structure. When the binder resin 15 has an aromatic hydrocarbon group as a repeating unit in its main chain structure, the binder resin is less likely to be discolored by radiation exposure during use of the scintillator panel, resulting in improved brightness. Specific examples of aromatic hydrocarbon groups include a phenylene group, a naphthylene group, an anthracenylene group, and a phenanthrenylene group. Two or more of these may be contained. Among these, from the viewpoints of the solvent solubility, transparency, and color of the resin, a phenylene group or a naphthylene group is preferred, and a phenylene group is particularly preferred.

[0061] The structure of the binder resin can be confirmed by a method of assigning detected peaks using a nuclear magnetic resonance (NMR) spectrometer.

[0062] (Radiation detector) 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 has a photoelectric conversion layer and an output layer on a substrate. The photoelectric conversion layer is generally one in which pixels having photosensors are formed.

[0063] (Radiation inspection equipment) The radiological inspection apparatus of the present invention includes a radiation generating unit that generates radiation and the above-mentioned radiation detector. The radiological inspection apparatus is an apparatus that irradiates a subject with radiation from the radiation generating unit and detects the radiation that has passed through the subject with the radiation detector. By incorporating the radiation detector of the present invention into the radiation detecting unit, a high-brightness radiological inspection apparatus can be obtained.

[0064] (Scintillator Panel Manufacturing Method) A method for manufacturing a scintillator panel according to an embodiment of the present invention includes a partition wall forming step of forming partition walls on a substrate to separate cells, a partition wall auxiliary layer forming step of forming a partition wall auxiliary layer on the surfaces of the partition walls, a reflective layer forming step of forming a reflective layer on the surfaces of the partition walls and the partition wall auxiliary layer, and a phosphor filling step of filling the cells separated by the partition walls with phosphor. Each step will be described below. Note that in the following description, explanations of matters common to those described in the above-described embodiment of the scintillator panel will be omitted as appropriate.

[0065] (Partition formation process) The partition wall forming step is a step of forming partition walls on a substrate to partition cells. More specifically, it is a step of forming partition walls having a lattice shape on a substrate to form spaces (cells) partitioned by the partition walls. As a method for forming partition walls on a substrate, various known methods can be used, and there is no particular limitation. From the viewpoint of easy shape control, the method for forming partition walls is preferably a photolithography method.

[0066] For example, when partition walls containing the compound (P) are formed by photolithography, they can be formed by a coating step of applying a photosensitive resin composition containing the compound (P) to the surface of a substrate to obtain a coating film, and a pattern forming step of exposing and developing the coating film to obtain a partition wall pattern. The "photosensitive resin composition" 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 those mentioned above.

[0067] The coating step is a step of applying the photosensitive resin composition to the entire surface or a portion of the surface of a substrate to obtain a coating film. Examples of methods for applying the photosensitive resin composition include screen printing, bar coating, roll coating, die coating, and blade coating. The thickness of the resulting coating film can be adjusted by the number of coatings, the mesh size of the screen, the viscosity of the photosensitive resin composition, etc.

[0068] Next, the photosensitive resin composition coating film formed by the above method is exposed to actinic rays through a mask having a desired pattern. Actinic rays used for exposure include ultraviolet rays, visible rays, electron beams, and X-rays, but in the present invention, it is preferable to use i-rays (365 nm), h-rays (405 nm), and g-rays (436 nm) from a mercury lamp.

[0069] To form a pattern, after exposure, the unexposed areas are removed with a developer. Examples of the developer 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 hexamethylenediamine. In some cases, these alkaline aqueous solutions may contain, alone or in combination, polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, γ-butyrolactone, and dimethylacrylamide; alcohols such as methanol, ethanol, and isopropanol; esters such as ethyl lactate and propylene glycol monomethyl ether acetate; and ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone.

[0070] Development can be carried out by spraying the developer onto the coating surface, puddling the developer onto the coating surface, immersing the coating in the developer, or immersing the coating in the developer and applying ultrasonic waves, etc. The development conditions, such as the development time and the temperature of the developer in the development step, may be any conditions that allow the exposed area to be removed and a pattern to be formed.

[0071] After development, it is preferable to carry out a rinsing treatment with water. Here, too, the rinsing treatment may be carried out by adding alcohols such as ethanol and isopropyl alcohol, or esters such as ethyl lactate and propylene glycol monomethyl ether acetate to water.

[0072] If necessary, the coating film may be baked before development. This may improve the resolution of the developed pattern and increase the tolerance for development conditions. The baking temperature is preferably in the range of 50 to 180°C, more preferably in the range of 60 to 120°C. The baking time is preferably 5 seconds to several hours.

[0073] After pattern formation, unreacted cationically polymerizable compounds and photocationic polymerization initiators 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 resin composition coating film after pattern formation with the above-mentioned exposure light to generate acid from the photocationic polymerization initiator. By doing so, the reaction of the unreacted cationically polymerizable compounds proceeds during the thermal crosslinking reaction, and the generation of gas resulting from thermal decomposition can be suppressed.

[0074] After development, it is preferable to apply a temperature of 120°C to 300°C to promote a thermal crosslinking reaction. Crosslinking can improve the heat resistance and chemical resistance of the resulting partition walls. This heat treatment method can be selected by selecting a temperature and gradually increasing the temperature, or by selecting a temperature range and continuously increasing the temperature for 5 minutes to 5 hours.

[0075] The substrate used for forming the partition walls may be used as the substrate of the scintillator panel, or the partition walls may be peeled off from the substrate and then placed on the substrate. The partition walls may be peeled off from the substrate by any known method, such as providing a peel-aid layer between the substrate and the partition walls.

[0076] (Partition wall auxiliary layer formation process) The method for producing a scintillator panel according to an embodiment of the present invention includes 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 may be formed on at least a portion of the surface of the partition wall. 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. For example, the partition wall auxiliary layer may be formed by applying a resin solution under vacuum to cells partitioned by the partition walls of a substrate (hereinafter referred to as a partition wall substrate) on which the partition walls have been formed as described above, and then drying the resin solution to remove the solvent.

[0077] (Reflection layer formation process) The method for producing a scintillator panel according to the embodiment of the present invention includes a reflective layer forming step of forming a reflective layer on the surface of the partition walls and / or the partition wall auxiliary layer.

[0078] The method for forming the reflective layer is not particularly limited. For example, the reflective layer can be formed by a vacuum film formation method such as a vacuum deposition method, a sputtering method, or a CVD method, a plating method, a paste coating method, or a spraying method. Among these, a reflective layer formed by a sputtering method is preferred because it has higher uniformity of reflectance and corrosion resistance than reflective layers formed by other methods.

[0079] (Protective layer formation process) (Inorganic protective layer formation process) A method for manufacturing a scintillator panel according to a preferred embodiment may include an inorganic protective layer forming 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. For example, the inorganic protective layer may be formed by a vacuum film-forming method such as vacuum deposition, sputtering, or CVD, a paste coating method, or a spraying method. Among these, an inorganic protective layer formed by sputtering is preferred because it has higher uniformity and corrosion resistance than inorganic protective layers formed by other methods.

[0080] (Organic protective layer formation process) The method for producing a 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. For example, the organic protective layer may be formed by applying a solution of polysiloxane or an amorphous fluorine-containing resin onto the partition wall substrate under vacuum, and then drying the applied solution to remove the solvent.

[0081] When polysiloxane is used, the dried substrate is preferably cured at a temperature higher than the drying temperature. By curing, condensation of the polysiloxane progresses, improving heat resistance and chemical resistance, and making it easier to improve the initial luminance of the scintillator panel.

[0082] When an amorphous fluororesin is used, it has high moisture permeability and chemical resistance, and the initial brightness of the scintillator panel tends to improve.

[0083] (Phosphor filling process) The method for manufacturing a scintillator panel according to an embodiment of the present invention includes a phosphor filling step of filling cells partitioned by partition walls with phosphor. The method for filling the phosphor is not particularly limited. For example, a preferred phosphor filling method is one in which a phosphor paste, in which phosphor powder and a binder resin are mixed in a solvent, is applied to a partition wall substrate under vacuum, followed by drying to remove the solvent, because this method is simple and allows for uniform phosphor filling over a large area.

[0084] As described above, according to the method for manufacturing a scintillator panel according to the embodiment of the present invention, the resulting scintillator provides a high brightness image. [Example]

[0085] The present invention will be described in more detail below with reference to examples and comparative examples. It should be noted that Examples 5, 13, 14 and 22 are currently reference examples, and Examples 1-4, 6-12 and 15-21 are examples of the present invention. The present invention is not limited to these. The compounds used in the examples and comparative examples were synthesized by the following methods.

[0086] (raw material for polyimide A) Amine compound: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (hereinafter referred to as BAHF, manufactured by Tokyo Chemical Industry Co., Ltd.) Acid anhydride: Rikacid (registered trademark) TDA-100 (manufactured by New Japan Chemical Co., Ltd.) Solvent: γ-butyrolactone (hereinafter referred to as GBL, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0087] (Synthesis of Polyimide A) Under a dry nitrogen stream, 29.30 g (0.08 mol) of BAHF was added to 80 g of GBL and dissolved by stirring at 120°C. Next, 30.03 g (0.1 mol) of TDA-100 was added together 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.

[0088] (raw material for photosensitive polyimide varnish) Epoxy compound: "TEPIC" (registered trademark)-VL (manufactured by Nissan Chemical Industries, Ltd.) Photoacid generator "CPI" (registered trademark)-310B (manufactured by San-Apro Co., Ltd.) Silane coupling agent: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0089] (Raw material for partition wall auxiliary layer) The raw materials used to prepare the resin solution for the partition wall auxiliary layer are as follows. Solvent A: Ethyl acetoacetate (manufactured by Yamato Chemical Co., Ltd.) Solvent B: Decane (Fujifilm Wako Pure Chemical Industries, Ltd.) Solvent C: GBL Siloxane resin A: 0.5 parts by mass of phosphoric acid added to 100 parts by mass of polysiloxane A described below Siloxane resin B: TSE-3450 (a mixture of dimethylsiloxane oligomer and curing agent in a mass ratio of 10:1, manufactured by MOMENTIVE) Siloxane resin C: 2 parts by mass of tetrabutyl orthotitanate added to 100 parts by mass of X-40-9250 (manufactured by Shin-Etsu Chemical Co., Ltd.). Epoxy resin A: LE-1421 (a mixture of epoxy compound and acid anhydride in a mass ratio of 10:7, manufactured by Sanyu Rec Co., Ltd.) Polyimide resin A: prepared in the examples described below.

[0090] (Preparation of Resin Solution for Partition Wall Auxiliary Layer) Each resin and solvent were mixed to the concentrations shown in Tables 1 to 3, placed in a stirring vessel, and stirred at room temperature for 30 minutes to obtain each resin solution.

[0091] (Raw material for Polysiloxane A) The organosilanes used in the synthesis of polysiloxane A are as follows: Organosilane S-1: Methyltrimethoxysilane Organosilane S-2: Phenyltrimethoxysilane Organosilane S-3: 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0092] (Synthesis of Polysiloxane A) A 500 ml three-neck flask was charged with 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). A phosphoric acid solution (0.16 g, 0.30 wt. % based on the charged monomers, dissolved in 16.21 g of water) 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. The internal temperature of the solution reached 100 °C one hour after the start of the temperature increase, and the mixture was heated and stirred for 2 hours (internal temperature: 100-110 °C) to obtain a polysiloxane solution. During the temperature increase and heating and stirring, nitrogen was passed through at a flow rate of 0.05 L / min. PGMEA was added to the obtained polysiloxane solution so that the solid content concentration was 40 mass %, to obtain a polysiloxane A solution. 29 Measurement by Si-NMR revealed that the molar ratios of repeating units derived from organosilanes S-1, S-2, and S-3 were 40 mol %, 50 mol %, and 10 mol %, respectively.

[0093] (Evaluation of the reflective layer shape) For each scintillator panel after filling with the phosphor layer, the cross section of the barrier rib was exposed using a triple ion milling device EM TIC 3X (manufactured by LEICA), and the reflective layer-forming portion of the barrier rib cross section was imaged using a field emission scanning electron microscope (FE-SEM) Merlin (manufactured by Zeiss). From the image, the lengths of the curved portion of the reflective layer on the barrier rib side and the portion where the opposing surfaces of the reflective layer were approximately parallel were measured, and the ratio between them was calculated. Similarly, the reflective layer at the bottom of the phosphor layer was observed, and the lengths of the curved portion of the reflective layer and the flat portion in the width direction were measured, and the ratio between them was calculated. To determine the length of the portion where the opposing surfaces of the reflective layer on the barrier rib side were approximately parallel, approximate lines of lengths equivalent to 10 μm were drawn on the opposing reflective layer surfaces in a single cell, and the portions where the angle between the approximate lines was 7° or less were defined as approximately parallel portions.

[0094] (Brightness evaluation) Each scintillator panel after filling with the phosphor layer was aligned with the center of the photosensor surface of an X-ray detector PaxScan 2520V (Varian) so that the cells of the scintillator panel corresponded one-to-one to the pixels of the photosensor, and the edges of the substrate were fixed with adhesive tape to prepare a radiation detector. This detector was irradiated with X-rays from an X-ray emitter L9181-02 (Hamamatsu Photonics) at a tube voltage of 50 kV and a distance of 30 cm between the X-ray tube and the detector, and an image was obtained. The average value of the digital values ​​of 256 × 256 pixels at the center of the light-emitting position of the scintillator panel in the obtained image was used as the brightness value. For each sample, the brightness of Comparative Example 1 was set to 100% for Examples 1 to 14 and Comparative Examples 2 to 4, and the brightness of Comparative Example 5 was set to 100% for Examples 15 to 22 and Comparative Examples 6 to 8.

[0095] (Evaluation of X-ray absorption rate) Each scintillator panel after filling with the phosphor layer was placed on the detector of an EMF123 X-ray spectrometer (EMF Japan Co., Ltd.). The scintillator panel was irradiated with X-rays from an X-ray emitter L9181-02 (Hamamatsu Photonics K.K.) at a tube voltage of 50 kV and a distance of 30 cm between the X-ray tube and the detector, and a photon number spectrum was obtained. The total number of photons in the obtained spectrum was used as the X-ray transmission amount, and the X-ray absorption rate of the scintillator panel was calculated from the difference with the total number of photons when X-rays were irradiated without the scintillator panel. For Examples 1 to 14 and Comparative Examples 2 to 4, relative values ​​were calculated with the value for Comparative Example 1 set to 100. For Examples 15 to 22 and Comparative Examples 6 to 8, relative values ​​were calculated with the value for Comparative Example 5 set to 100. For each relative value, values ​​of 95 or higher were evaluated as A, values ​​of 90 or higher but less than 95 as B, and values ​​less than 90 as C.

[0096] (Evaluation of the decay time of luminescence intensity) For the scintillator panels prepared in each example and comparative example, the luminescence intensity at the wavelength at which the luminescence intensity was maximized (hereinafter referred to as the maximum luminescence wavelength) when excited with light having an excitation wavelength of 297 nm was measured using a Fluorolog 3C-2iHR320 (manufactured by HORIBA Jobin Yvon GmbH). The light source was then turned off, and the time change in the luminescence intensity from the point at which the light source was turned off was measured. The time required for the luminescence intensity to become 1 / e of the luminescence intensity at the point at which the light source was turned off was determined.

[0097] Example 1 (Fabrication of bulkhead substrate) (Preparation of Photosensitive Polyimide Varnish) 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 so that the solids concentration was 60 mass % when the additives other than the solvent were considered as solids. The resulting solution was filtered under pressure using a filter with a retention particle size of 1 μm to obtain photosensitive polyimide varnish A. Hereinafter, the solids equivalent to "photosensitive polyimide varnish A" will be referred to as polyimide resin A.

[0098] (Fabrication of polyimide partition wall) A 125 mm x 125 mm x 0.25 mm PI (polyimide) film was used as the substrate. The photosensitive polyimide varnish A was applied to the surface of the substrate using a die coater so that the dried thickness was 150 μm, and then dried to obtain a coating film of polyimide resin A. Next, the coating film of polyimide resin A was exposed to 2000 mJ / cm using an ultra-high pressure mercury lamp through a photomask (a chrome mask with lattice-shaped openings with a pitch of 127 μm and a line width of 10 μm) having openings corresponding to the desired pattern. 2 The exposed coating film was developed in a 2% by mass aqueous solution of potassium hydroxide to remove the unexposed areas, yielding a grid pattern. The resulting grid pattern was cured by thermal crosslinking in air at 150°C for 60 minutes, yielding a partition wall substrate with grid-shaped partition walls formed on the substrate.

[0099] (Formation of partition wall auxiliary layer) Siloxane resin A was dissolved in solvent A to a solid content of 30% by weight. The obtained resin solution was vacuum-printed into the cells defined 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 partition wall auxiliary layer in the cells as shown in Figure 3.

[0100] (Formation of reflective layer and inorganic protective layer) A reflective layer was formed on the barrier rib substrate with the barrier rib auxiliary layer using a commercially available sputtering device and sputtering target. A glass plate was placed near the barrier rib substrate during sputtering, and sputtering was performed under conditions that resulted in a metal thickness of 300 nm on the glass plate. APC (manufactured by Furuya 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, a protective layer of SiN was formed on the glass substrate in the same vacuum batch to a thickness of 100 nm.

[0101] (Formation of organic protective layer) Fluorine-containing resin solution A resin solution was prepared by mixing 1 part by mass of "CYTOP" (registered trademark) CTL-809M as an amorphous fluorine-containing resin with 1 part by mass of CT-SOLV180 (manufactured by AGC Corporation) as a fluorine-based solvent.

[0102] This resin solution was vacuum-printed onto a partition wall substrate on which a reflective layer and an inorganic protective layer had been formed, then dried at 90°C for 1 hour and further cured at 190°C for 1 hour to form an organic protective layer. The partition wall cross section of the partition wall substrate after the organic protective layer formation was exposed using a triple ion milling system EMTIC3X (manufactured by LEICA), and the partition wall cross section was imaged using a Merlin field emission scanning electron microscope (FE-SEM) (manufactured by Zeiss). The thickness of the organic protective layer on the side surface at the center of the height direction of the partition wall on the partition wall substrate was measured to be 1 μm from the image.

[0103] (phosphor) The phosphors used in the phosphor layer are as follows: Phosphor powder 1: Gd2O2S:Tb (manufactured by Nichia Corporation: average particle size 11 μm) Phosphor powder 2: Gd2O2S:Pr (manufactured by Nichia Corporation: average particle size 5 μm) (Binder resin for phosphor layer) The materials used for the binder resin of the phosphor layer are as follows: Binder resin A: "Ethocel" (registered trademark) 7cp (cellulose-based resin, manufactured by The Dow Chemical Company) Binder resin B: "Vylon" (registered trademark) 270 (polyester resin, manufactured by Toyobo Co., Ltd.) Binder resin C: "Grilamid" (registered trademark) TR55 (polyamide resin, manufactured by EMS-CHEMIE AG) Binder resin D: "Viromax" (registered trademark) HR-15ET (polyamide-imide resin, manufactured by Toyobo Co., Ltd.) Solvent: benzyl alcohol (Fujifilm Wako Pure Chemical Industries, Ltd.) The binder resins shown in Table 1 were dissolved in the above solvents to obtain binder resin solutions.

[0104] (Formation of phosphor layer) A phosphor paste was prepared by mixing 10 parts by mass of phosphor powder 1 with 5 parts by mass of the above-mentioned 10% by mass solution of binder resin A. This phosphor paste was vacuum-printed into cells partitioned by the partition walls of the partition wall substrate on which the reflective layer, inorganic protective layer, and organic protective layer had been formed as described above, and the cells were filled with the phosphor at a volume fraction of 65%. The cells were then dried at 150°C for 15 minutes to form a phosphor layer.

[0105] Examples 2 to 9 In Example 1, (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 shown in Table 1 or Table 2.

[0106] Examples 10 to 12 In Example 2, (Formation of partition wall auxiliary layer) to (Formation of phosphor layer) were carried out in the same manner as in Example 2, except that the binder resin of the phosphor layer was changed to a resin shown in Table 2.

[0107] Example 13 (Fabrication of bulkhead substrate) (Raw material for glass powder-containing paste) Photosensitive monomer M-1: Trimethylolpropane triacrylate Photosensitive monomer M-2: tetrapropylene glycol dimethacrylate Photosensitive polymer: A copolymer of methacrylic acid / methyl methacrylate / styrene in a 40 / 40 / 30 weight ratio, to which 0.4 equivalents of glycidyl methacrylate was added to the carboxyl groups (weight-average molecular weight: 43,000; acid value: 100). Photopolymerization initiator: 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1 (BASF) Polymerization inhibitor: 1,6-hexanediol-bis[(3,5-di-t-butyl-4-hydroxyphenyl)propionate]) UV absorber solution: 0.3% by mass solution of Sudan IV (Tokyo Ohka Kogyo Co., Ltd.) in γ-butyrolactone Viscosity modifier: Flonon EC121 (Kyoeisha Chemical Co., Ltd.) Solvent: γ-butyrolactone (Fujifilm Wako Pure Chemical Industries, Ltd.) Low softening point glass powder: SiO227% by mass, B2O331% by mass, ZnO 6% by mass, Li2O 7% by mass, MgO 2% by mass, CaO 2% by mass, BaO 2% by mass, Al2O323% by mass, refractive index (ng) 1.56, glass softening temperature 588℃, coefficient of thermal expansion 70×10 -7 (K -1 ), average particle size 2.3 μm.

[0108] (Preparation of glass powder-containing paste) 4 parts by mass of photosensitive monomer M-1, 6 parts by mass of photosensitive monomer M-2, 24 parts by mass of photosensitive polymer, 6 parts by mass of photopolymerization initiator, 0.2 parts by mass of polymerization inhibitor, and 12.8 parts by mass of UV absorber solution were heated and dissolved in 38 parts by mass of solvent at a temperature of 80 ° C. After cooling the resulting solution, 9 parts by mass of viscosity modifier was added to obtain organic solution 1. The refractive index (ng) of the organic coating film obtained by applying the obtained organic solution 1 to a glass plate and drying was 1.555. 50 parts by mass of low-softening point glass powder was added to 50 parts by mass of organic solution 1, and the mixture was kneaded using a three-roller kneader to obtain a glass powder-containing paste P.

[0109] (Preparation of glass partition substrate) A soda glass plate measuring 125 mm x 125 mm x 0.7 mm was used as the substrate. The glass powder-containing paste P was applied to the surface of the substrate using a die coater so that the dried thickness would be 150 μm, and then dried to obtain a coating film of the glass powder-containing paste. Next, the coating film of the glass powder-containing paste was coated using a photomask (a chrome mask with a grid-shaped opening with a pitch of 127 μm and a line width of 10 μm) having openings corresponding to the desired pattern, and irradiated with 300 mJ / cm using an ultra-high pressure mercury lamp. 2 The exposed coating film was developed in a 0.5% by mass aqueous solution of ethanolamine to remove the unexposed portions, yielding a lattice-shaped pre-baking pattern. The resulting lattice-shaped pre-baking pattern was baked in air at 580°C for 15 minutes, yielding a partition wall substrate in which lattice-shaped partition walls composed primarily of glass were formed on the substrate.

[0110] Using the obtained partition wall substrate, (Formation of partition wall auxiliary layer) to (Formation of 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 shown in Table 2.

[0111] Example 14 The steps of (Formation of the barrier rib 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 for the barrier rib auxiliary layer was changed to 35% by weight.

[0112] (Comparative Example 1) The steps from (formation of reflective layer and inorganic protective layer) to (formation of phosphor layer) were carried out in the same manner as in Example 1, except that the partition wall auxiliary layer was not formed.

[0113] (Comparative Example 2) The steps of (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 for the barrier rib auxiliary layer was changed to 1 wt %.

[0114] (Comparative Example 3) In Example 13, the exposure dose using an ultra-high pressure mercury lamp in the production of the partition wall was 1000 mJ / cm 2 The steps from (Formation of reflective layer and inorganic protective layer) to (Formation of phosphor layer) were carried out in the same manner as in Example 13, except that the partition wall auxiliary layer was not formed.

[0115] Comparative Example 4 The steps from (formation of reflective layer and inorganic protective layer) to (formation of phosphor layer) were carried out in the same manner as in Example 13, except that the partition wall auxiliary layer was not formed.

[0116] Example 15 In Example 2, except that the phosphors were changed to those shown in Table 4, (Formation of the partition wall auxiliary layer) to (Formation of the phosphor layer) were carried out in the same manner as in Example 2.

[0117] (Examples 16 to 18) In Example 15, (Formation of the partition wall auxiliary layer) to (Formation of the phosphor layer) were carried out in the same manner as in Example 15, except that the resin solution for the partition wall auxiliary layer was changed as shown in Table 4.

[0118] (Examples 19 to 21) In Example 15, (Formation of partition wall auxiliary layer) to (Formation of phosphor layer) were carried out in the same manner as in Example 15, except that the binder resin of the phosphor layer was changed to a resin shown in Table 4.

[0119] Example 22 In Example 14, except that the phosphors were changed to those shown in Table 4, (Formation of the partition wall auxiliary layer) to (Formation of the phosphor layer) were carried out in the same manner as in Example 14.

[0120] (Comparative Example 5) In Comparative Example 1, except that the phosphors were changed to those shown in Table 5, the same procedures as in Comparative Example 1 were followed, from (Formation of reflective layer and inorganic protective layer) to (Formation of phosphor layer).

[0121] (Comparative Example 6) In Comparative Example 2, except that the phosphor was changed to one shown in Table 5, the same procedures as in Comparative Example 2 were followed, from (Formation of reflective layer and inorganic protective layer) to (Formation of phosphor layer).

[0122] (Comparative Example 7) In Comparative Example 3, except that the phosphor was changed to one shown in Table 5, (Formation of reflective layer and inorganic protective layer) to (Formation of phosphor layer) were carried out in the same manner as in Comparative Example 3.

[0123] (Comparative Example 8) In Comparative Example 4, except that the phosphor was changed to one shown in Table 5, the same procedures as in Comparative Example 4 were followed, from (Formation of reflective layer and inorganic protective layer) to (Formation of phosphor layer).

[0124] [Table 1]

[0125] [Table 2]

[0126] [Table 3]

[0127] [Table 4]

[0128] [Table 5] [Explanation of symbols]

[0129] 1 Radiation detector components 2 Scintillator Panel 3 Output Card 4 boards 5 Bulkhead 6. Phosphor layer 7 Diaphragm layer 8 Photoelectric conversion layer 9 Output layer 10 Substrate 11 Partition wall auxiliary layer 12 Reflective layer 13 Protective layer 14 Phosphor 15 Binder resin S: Side of phosphor layer T bottom of phosphor layer S P The portion of the reflective layer on the side of the phosphor layer where the opposing surfaces are approximately parallel to each other S C The curved portion of the reflective layer surrounding the side surface of the phosphor layer T L The flat portion of the reflective layer at the bottom of the phosphor layer T C The curved surface of the reflective layer at the bottom of the phosphor layer

Claims

1. a scintillator panel comprising: a substrate; lattice-shaped partition walls formed on the substrate; a phosphor layer in cells partitioned by the partition walls; a reflective layer surrounding side surfaces and a bottom of the phosphor layer; and a partition wall auxiliary layer provided between the partition walls and the reflective layer, wherein the reflective layer surrounding the side surfaces of the phosphor layer has curved portions and portions in which opposing surfaces of the reflective layer in the side surfaces of the phosphor layer are substantially parallel to each other, wherein a ratio in a width direction of the curved portions of the reflective layer in the bottom of the phosphor layer to a flat portion is 10.0:0 to 1.0:9.0; and a ratio in a thickness direction of the curved portions of the reflective layer surrounding the side surfaces of the phosphor layer to the portions in which opposing surfaces of the reflective layer in the side surfaces of the phosphor layer are substantially parallel to each other is 2.0:8.0 to 7.0:3.

0.

2. A scintillator panel as described in claim 1, wherein the material constituting the reflective layer is selected from metal oxides and metals.

3. 3. The scintillator panel according to claim 1, wherein the partition walls are made of a polymer material.

4. 4. The scintillator panel according to claim 1, wherein the phosphor contained in the phosphor layer is in powder form.

5. 5. The scintillator panel according to claim 1, wherein the time required for the emission intensity to reach 1 / e times the initial emission intensity is 100 μsec or less.

6. A scintillator panel according to any one of claims 1 to 5, wherein the binder resin contained in the phosphor layer is a resin selected from polyester resins, polyamide resins, polyimide resins, polyamideimide resins, and polyether-based resins, and includes at least one resin having an aromatic hydrocarbon group as a repeating unit in the main chain structure.

7. A radiation detector comprising the scintillator panel according to any one of claims 1 to 6 on an output substrate having a photoelectric conversion layer.

8. A radiation inspection device comprising the radiation detector according to claim 7.

9. a partition wall forming step of forming partition walls on the substrate to partition cells; a partition wall auxiliary layer forming step of forming a partition wall auxiliary layer on the surface of the partition wall; a reflective layer forming step of forming a reflective layer on surfaces of the partition walls and the partition wall auxiliary layer; and a phosphor filling step of filling cells defined by the partitions with phosphor, to obtain a scintillator panel having a substrate, lattice-shaped partitions formed on the substrate, a phosphor layer in cells defined by the partitions, and a reflective layer surrounding side and bottom portions of the phosphor layer, wherein the reflective layer surrounding the side portions of the phosphor layer has curved portions and portions where the opposing surfaces of the reflective layer in the side portions of the phosphor layer are approximately parallel, and the ratio in the width direction of the curved portions of the reflective layer at the bottom of the phosphor layer to the flat portions is 10.0:0 to 1.0:9.

0. A method for manufacturing a scintillator panel.

Images