Radiation detector, method for manufacturing the same, and radiation imaging device

Abstract

Provided are a radiation detector, a method for manufacturing the same, and a radiation imaging device. The radiation detector includes: a flexible substrate; a plurality of pixels disposed on the substrate and each including a photoelectric conversion element; a scintillator stacked on the substrate; and a deflection suppressing member for suppressing deflection of the substrate. Assuming the size of the pixel is X and the limit deformation of the pixel due to deflection of the substrate is Z, L When the curvature radius of the deflection caused by the weight of the scintillator on the substrate is set to R, the deflection suppression member has a condition satisfying R ≥ X 2 / 2Z L rigidity.

Description

Technical Field

[0001] The disclosed technology relates to a radiation detector, a method for manufacturing the same, and a radiation imaging device. Background Art

[0002] As a technology related to radiographic imaging devices, the following is known, for example. Japanese Patent Application Laid-Open No. 2012-173275 (Patent Document 1) describes a radiographic imaging device comprising: a radiographic imaging device body having a scintillator that converts radiation into fluorescence, and a light detection unit disposed on the radiation incident side of the scintillator; and a support member disposed on the radiation incident side of the radiographic imaging device body and supporting a subject. The light detection unit comprises a thin film portion that detects fluorescence as an electrical signal; and a reinforcing member disposed on the side of the thin film portion opposite the scintillator and bonded to the support member.

[0003] Japanese Patent Application Publication No. 2017-532540 (Patent Document 2) describes a detection unit comprising a first modular detector and a second modular detector connected to each other. The first and second modular detectors are flexible. Reinforcement material is attached to the sides of the first and second modular detectors opposite to their light-receiving surfaces. The reinforcement material is configured to prevent bending of the modular detectors near the attachment point of the reinforcement material. Summary of the Invention

[0004] Problems to be solved by the invention

[0005] As a radiation detector used in a radiographic imaging device, there is known a radiation detector comprising: a substrate; a plurality of pixels disposed on the substrate and each including a photoelectric conversion element; and a scintillator stacked on the substrate. In recent years, flexible materials such as resin films have been used as materials for the substrates constituting the radiation detectors. When the substrate is flexible, for example, during the manufacturing process of the radiation detector, the weight of the scintillator stacked on the substrate may cause the substrate to undergo relatively large local deflections when the substrate is handled. The photoelectric conversion elements constituting the pixels are made of a material that is fragile to bending stress, such as amorphous silicon, and therefore, when the substrate undergoes significant deflection, the pixels may be damaged.

[0006] One aspect of the disclosed technology is to reduce the risk of pixel damage caused by deflection of the substrate due to the weight of the scintillator, compared to a case where a deflection suppressing member having a rigidity determined according to the size of the pixel is not used.

[0007] Means for solving problems

[0008] A radiation detector according to a first embodiment of the disclosed technology includes: a substrate having flexibility; a plurality of pixels provided on the substrate and each including a photoelectric conversion element; a scintillator stacked on the substrate; and a deflection suppressing member for suppressing deflection of the substrate, wherein the pixel size is set to X and the maximum deformation amount of the pixel due to deflection of the substrate is set to Z. L When the curvature radius of the deflection caused by the weight of the scintillator on the substrate is set to R, the deflection suppression member has a rigidity that satisfies the following formula: R ≥ X 2 / 2Z L .

[0009] In a radiation detector of a second embodiment of the disclosed technology, a scintillator is stacked on a first surface side of a substrate, and a deflection suppression member is stacked on at least one of a second surface side of the substrate opposite to the first surface side and a surface side of the scintillator opposite to the surface side in contact with the substrate.

[0010] In the third type of radiation detector of the disclosed technology, the deflection suppression member is laminated on both the second surface side of the substrate and the surface side of the scintillator opposite to the surface side in contact with the substrate.

[0011] In the radiation detector of the fourth aspect of the disclosed technology, the deflection suppression member has higher rigidity than the substrate.

[0012] In the radiation detector of the fifth aspect of the disclosed technology, the deflection suppression member extends over a range larger than the range over which the scintillator extends.

[0013] In the radiation detector of the sixth aspect of the disclosed technology, the substrate has a connection region connected to the flexible wiring, and the deflection suppression member is provided in a region covering at least a portion of the connection region and the scintillator.

[0014] In the radiation detector according to the seventh aspect of the disclosed technology, the bending modulus of the deflection suppression member is 1000 MPa or more and 3500 MPa or less.

[0015] In the radiation detector according to the eighth aspect of the disclosed technology, the ratio of the thermal expansion coefficient of the deflection suppression member to the thermal expansion coefficient of the scintillator is 0.5 or more and 2 or less.

[0016] In the radiation detector according to a ninth aspect of the disclosed technology, the thermal expansion coefficient of the deflection suppression member is 30 ppm / K or more and 80 ppm / K or less.

[0017] In the radiation detector according to a tenth aspect of the disclosed technology, the deflection suppression member is configured to include at least one of acrylic, polycarbonate, and polyethylene terephthalate.

[0018] The radiation detector according to the eleventh aspect of the disclosed technology further includes a reinforcing member provided in a region spanning over the end portion of the scintillator, and reinforcing the deflection suppressing effect of the deflection suppressing member.

[0019] In the radiation detector according to the twelfth aspect of the disclosed technology, the reinforcing member has higher rigidity than the substrate.

[0020] In the radiation detector of the thirteenth aspect of the disclosed technology, the reinforcing member is made of the same material as the deflection suppressing member.

[0021] In the radiation detector according to the fourteenth aspect of the disclosed technology, the substrate is configured to include a resin film.

[0022] In the fifteenth embodiment of the radiation detector of the disclosed technology, the substrate is constructed to include a base material composed of a resin material having a microparticle layer, the microparticle layer including microparticles composed of an inorganic material having an average particle size of greater than 0.05 μm and less than 2.5 μm, and the microparticle layer is arranged on the second surface side of the substrate opposite to the first surface on which the multiple pixels are provided.

[0023] In the radiation detector according to the sixteenth aspect of the disclosed technology, the microparticles contain an element having an atomic number greater than that of an element constituting the resin material and having an atomic number of 30 or less.

[0024] In the radiation detector according to the seventeenth aspect of the disclosed technology, the thermal expansion coefficient of the substrate at a temperature of 300° C. to 400° C. is 20 ppm / K or less.

[0025] In the radiation detector of the eighteenth aspect of the disclosed technology, the substrate satisfies at least one of the following two conditions: a heat shrinkage rate in the longitudinal direction at 400°C of 0.5% or less when the substrate thickness is 25 μm, and an elastic modulus at 500°C of 1 GPa or more.

[0026] The radiation detector according to the nineteenth aspect of the disclosed technology further includes a buffer layer provided between the substrate and the scintillator and having a thermal expansion coefficient between the thermal expansion coefficient of the substrate and the thermal expansion coefficient of the scintillator.

[0027] In the radiation detector according to the twentieth aspect of the disclosed technology, the deflection suppression member extends in regions corresponding to the central portion and the peripheral portion of the scintillator.

[0028] In the radiation detector according to the twenty-first aspect of the disclosed technology, the deflection suppression member is bent along the inclination of the peripheral edge portion of the scintillator.

[0029] In the radiation detector of the twenty-second aspect of the disclosed technology, a space corresponding to the inclination of the peripheral portion of the scintillator is formed between the deflection suppression member and the scintillator.

[0030] In the radiation detector according to the twenty-third aspect of the disclosed technology, the space formed between the deflection suppressing member and the scintillator is filled with a filling material.

[0031] In the radiation detector according to the twenty-fourth aspect of the disclosed technology, the end portions of the deflection suppression member are supported by the spacers.

[0032] In the radiation detector of the twenty-fifth aspect of the disclosed technology, the deflection suppression member is bent along the inclination of the peripheral edge portion of the scintillator, and the end portion of the deflection suppression member is sealed by the sealing member.

[0033] In the radiation detector of the twenty-sixth aspect of the disclosed technology, the reinforcing member is provided in a region that does not overlap with the pixel region.

[0034] A radiation imaging device according to a twenty-seventh aspect of the disclosed technology includes: a radiation detector according to any one of the first to twenty-sixth aspects; a readout unit that reads out charges accumulated in pixels; and a generation unit that generates image data based on the charges read out from the pixels.

[0035] The radiation imaging device according to the twenty-eighth aspect of the disclosed technology further includes a housing having a radiation incident surface for incident radiation and accommodating the radiation detector, wherein the substrate and the scintillator are arranged on the radiation incident surface side.

[0036] The manufacturing method of the radiation detector of the twenty-ninth embodiment of the disclosed technology includes the following steps: a step of forming a plurality of pixels each including a photoelectric conversion element on a flexible substrate; a step of forming a scintillator on the substrate; and a step of configuring a deflection suppression member for suppressing the deflection of the substrate, wherein the larger the size of the pixel, the greater the rigidity of the deflection suppression member.

[0037] In the manufacturing method of the 30th aspect of the disclosed technology, the size of the pixel is X, the limit deformation amount of the pixel due to the deflection of the substrate is Z, L When the curvature radius of the deflection caused by the weight of the scintillator on the substrate is set to R, the deflection suppression member has a rigidity that satisfies the following formula: R ≥ X 2 / 2Z L .

[0038] Effects of the Invention

[0039] According to the first aspect of the disclosed technology, the risk of pixel damage caused by deflection of the substrate due to the weight of the scintillator can be reduced compared to a case where a deflection suppressing member having a rigidity determined according to the size of the pixel is not used.

[0040] According to the second aspect of the disclosed technology, the deflection suppressing effect of the deflection suppressing member can be effectively exhibited.

[0041] According to the third aspect of the disclosed technology, the risk of pixel damage due to substrate deflection can be further reduced.

[0042] According to the fourth aspect of the disclosed technology, the deflection suppressing effect of the deflection suppressing member can be effectively exhibited.

[0043] According to the fifth aspect of the disclosed technology, the deflection suppressing effect of the deflection suppressing member can be effectively exhibited.

[0044] According to the sixth aspect of the disclosed technology, the deflection suppressing effect of the deflection suppressing member can be effectively exhibited.

[0045] According to the seventh aspect of the disclosed technology, it is possible to obtain rigidity suitable for a deflection suppression member.

[0046] According to the eighth aspect of the disclosed technology, the risk of separation between the substrate and the scintillator can be suppressed compared to a case where the ratio of the thermal expansion coefficient of the deflection prevention member to the thermal expansion coefficient of the scintillator is not within the above range.

[0047] According to the ninth aspect of the disclosed technology, the risk of separation between the substrate and the scintillator can be suppressed compared to a case where the thermal expansion coefficient of the deflection suppression member is not within the above range.

[0048] According to the tenth aspect of the disclosed technology, the deflection suppressing member can effectively exert its deflection suppressing effect compared to a case where the deflection suppressing member is composed of other materials, and the risk of separation between the substrate and the scintillator can be suppressed.

[0049] According to the eleventh aspect of the disclosed technology, compared with a case where no reinforcing member is included, deflection of the portion of the substrate corresponding to the end portion of the scintillator can be suppressed.

[0050] According to the twelfth aspect of the disclosed technology, the effect of reinforcing the deflection suppressing effect of the deflection suppressing member is effectively exhibited.

[0051] According to the thirteenth aspect of the disclosed technology, the effect of reinforcing the deflection suppressing effect of the deflection suppressing member is effectively exhibited.

[0052] According to the fourteenth aspect of the disclosed technology, compared with the case where a glass substrate is used as the substrate material, the radiation detector can be made lighter and cheaper, and the risk of substrate breakage due to impact can be reduced.

[0053] According to the fifteenth aspect of the disclosed technology, compared with a case where the substrate does not include a microparticle layer, backscattered rays generated in the substrate can be suppressed.

[0054] According to the sixteenth aspect of the disclosed technology, backscattered radiation can be suppressed more effectively than when the atomic number of the microparticles is not within the above range, and absorption of radiation in the microparticle layer can be suppressed.

[0055] According to the seventeenth aspect of the disclosed technology, pixels can be appropriately formed on the substrate, compared to a case where the thermal expansion coefficient of the substrate is not within the above range.

[0056] According to the eighteenth aspect of the disclosed technology, pixels can be appropriately formed on the substrate, compared to a case where the thermal shrinkage rate and elastic modulus of the substrate are not within the above ranges.

[0057] According to the nineteenth aspect of the disclosed technology, the thermal stress acting on the interface between the substrate and the scintillator can be suppressed compared to a case where no buffer layer is included.

[0058] According to the twenty-seventh aspect of the disclosed technology, the risk of pixel damage due to deflection of the substrate caused by the weight of the scintillator can be reduced compared to a case where a deflection suppressing member having a rigidity determined according to the size of the pixel is not used.

[0059] According to the twenty-eighth aspect of the disclosed technology, the resolution of the radiographic image can be improved compared to a case where the scintillator is arranged on the radiation incident surface side among the substrate and the scintillator.

[0060] According to the twenty-ninth aspect of the disclosed technology, the risk of pixel damage due to deflection of the substrate caused by the weight of the scintillator can be reduced compared to a case where a deflection suppressing member having a rigidity determined according to the size of the pixel is not used.

[0061] According to the thirtieth aspect of the disclosed technology, it is possible to ensure reduction in the risk of damage to pixels caused by deflection of the substrate due to the weight of the scintillator. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a perspective view showing an example of the structure of a radiation imaging device according to an embodiment of the disclosed technology.

[0063] Figure 2 This is a cross-sectional view showing an example of the structure of a radiation imaging device according to an embodiment of the disclosed technology.

[0064] Figure 3 This is a diagram showing an example of the electrical configuration of a radiation imaging device according to an embodiment of the disclosed technology.

[0065] Figure 4 This is a diagram showing an example of a state in which a substrate according to an embodiment of the disclosed technology is bent in an arc shape.

[0066] Figure 5A This is a diagram showing an example of the outer shape of a pixel according to an embodiment of the disclosed technology.

[0067] Figure 5B This is a diagram showing an example of the outer shape of a pixel according to an embodiment of the disclosed technology.

[0068] Figure 5C This is a diagram showing an example of the outer shape of a pixel according to an embodiment of the disclosed technology.

[0069] Figure 6A This is a cross-sectional view illustrating an example of a method for manufacturing a radiation detector according to an embodiment of the disclosed technology.

[0070] Figure 6B This is a cross-sectional view illustrating an example of a method for manufacturing a radiation detector according to an embodiment of the disclosed technology.

[0071] Figure 6C This is a cross-sectional view illustrating an example of a method for manufacturing a radiation detector according to an embodiment of the disclosed technology.

[0072] Figure 6D This is a cross-sectional view illustrating an example of a method for manufacturing a radiation detector according to an embodiment of the disclosed technology.

[0073] Figure 7A This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0074] Figure 7B This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0075] Figure 8A This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0076] Figure 8B This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0077] Figure 8C This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0078] Figure 9 This is a cross-sectional view showing an example of a state in which a substrate is bent due to the weight of the scintillator.

[0079] Figure 10 This is a cross-sectional view showing an example of the structure of a substrate according to an embodiment of the disclosed technology.

[0080] Figure 11A It is a cross-sectional view showing backscattered rays generated in a substrate having a microparticle layer.

[0081] Figure 11B 4 is a cross-sectional view showing backscattered rays generated in a substrate having no fine particle layer.

[0082] Figure 12 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0083] Figure 13 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0084] Figure 14 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0085] Figure 15 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0086] Figure 16 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0087] Figure 17 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0088] Figure 18 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0089] Figure 19 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0090] Figure 20 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0091] Figure 21 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0092] Figure 22 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0093] Figure 23 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0094] Figure 24 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0095] Figure 25This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0096] Figure 26 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0097] Figure 27 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0098] Figure 28 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0099] Figure 29 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0100] Figure 30 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0101] Figure 31 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0102] Figure 32 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0103] Figure 33 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0104] Figure 34 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0105] Figure 35 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0106] Figure 36 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0107] Figure 37 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0108] Figure 38 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0109] Figure 39 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0110] Figure 40 This is a plan view showing an example of the structure of a deflection suppression member according to an embodiment of the disclosed technology.

[0111] Figure 41 This is a perspective view showing an example of the structure of a deflection suppression member according to an embodiment of the disclosed technology.

[0112] Figure 42 This is a cross-sectional view showing an example of the structure of a radiation detector according to an embodiment of the disclosed technology.

[0113] Figure 43 This is a plan view showing an example of the structure of a deflection suppression member according to an embodiment of the disclosed technology.

[0114] Figure 44 This is a plan view showing an example of the structure of a deflection suppression member according to an embodiment of the disclosed technology.

[0115] Figure 45 This is a cross-sectional view showing an example of the structure of a radiation imaging device according to an embodiment of the disclosed technology.

[0116] Figure 46 This is a cross-sectional view showing an example of the structure of a radiation imaging device according to an embodiment of the disclosed technology.

[0117] Figure 47 This is a cross-sectional view showing an example of the structure of a radiation imaging device according to an embodiment of the disclosed technology.

[0118] Description of reference numerals:

[0119] 10. Radiographic imaging devices;

[0120] 12 control unit;

[0121] 14 housing;

[0122] 14A inclined portion;

[0123] 15 Radiation incident surface;

[0124] 16 supporting plate;

[0125] 18 adhesive layer;

[0126] 19 circuit substrate;

[0127] 20 cables;

[0128] 22 gate line driving unit;

[0129] 24 charge amplifiers;

[0130] 26 Signal Processing Unit;

[0131] 28 image memory;

[0132] 29 Control Department;

[0133] 30, 30A, 30B radiation detectors;

[0134] 32 scintillator;

[0135] 32E end;

[0136] 33A Central Department;

[0137] 33B peripheral part;

[0138] 34 substrate;

[0139] 34P particles;

[0140] 34L microparticle layer;

[0141] 35 terminal;

[0142] 36 photoelectric conversion element;

[0143] 37 abutment;

[0144] 39 spacers;

[0145] 41 pixels;

[0146] 41A pixel area;

[0147] 42 TFT;

[0148] 43 gate lines;

[0149] 44 signal lines;

[0150] 50 reflective film;

[0151] 51 adhesive layer;

[0152] 52, 54, 54A, 56 adhesive layer;

[0153] 53 protective layer;

[0154] 55 filling material;

[0155] 57 sealing member;

[0156] 60, 60A deflection restraining member;

[0157] 61 opening;

[0158] 62 through holes;

[0159] 63 slots;

[0160] 64 fragments;

[0161] 70 reinforcement members;

[0162] 80 connection area;

[0163] 81 control substrate;

[0164] 82 Power Supply Department;

[0165] 83 power lines;

[0166] 90 buffer layer;

[0167] L tangent;

[0168] R is the radius of curvature;

[0169] S1 side 1;

[0170] S2 side 2;

[0171] S3, S4, S5, S6 surfaces;

[0172] X size in pixels;

[0173] Z deformation;

[0174] Z L Limit deformation. DETAILED DESCRIPTION

[0175] Hereinafter, an example of an embodiment of the disclosed technology will be described with reference to the accompanying drawings. It should be noted that in each of the drawings, the same or equivalent components and parts are denoted by the same reference numerals.

[0176] [First embodiment]

[0177] Figure 1 This is a perspective view showing an example of the structure of a radiographic imaging device 10 according to an embodiment of the disclosed technology. The radiographic imaging device 10 utilizes a portable electronic cassette. The radiographic imaging device 10 includes a radiation detector 30 (FPD: Flat Panel Detector), a control unit 12, a support plate 16, and a housing 14 that houses the radiation detector 30, the control unit 12, and the support plate 16.

[0178] The housing 14 has a monocoque structure made of, for example, carbon fiber reinforced resin (carbon fiber), which is highly transmissive to radiation such as X-rays, lightweight, and highly durable. The upper surface of the housing 14 serves as a radiation incident surface 15, into which radiation emitted from a radiation source (not shown) and transmitted through a subject (not shown) is incident. Within the housing 14, a radiation detector 30 and a support plate 16 are arranged in order from the radiation incident surface 15 side.

[0179] The support plate 16 supports a circuit board 19 (see FIG. Figure 2 ) is supported and fixed to the housing 14. The control unit 12 is arranged at the end portion of the housing 14. The control unit 12 is configured to include a battery (not shown) and a control unit 29 (see Figure 3 ).

[0180] Figure 2 1 is a cross-sectional view showing an example of the structure of the radiographic imaging device 10. The radiation detector 30 includes a flexible substrate 34; a plurality of photoelectric conversion elements 36 (see FIG. 1 ) provided on the surface of the substrate 34; and Figure 3 ) a plurality of pixels 41; a scintillator 32 stacked on a substrate 34; and a deflection suppressing member 60 for suppressing deflection of the substrate 34.

[0181] The substrate 34 is a flexible substrate having flexibility. In this specification, the flexibility of the substrate 34 means that when one of the four sides of the rectangular substrate 34 is fixed, due to the weight of the substrate 34, the height of the portion separated by 10 cm from the fixed side of the substrate 34 is more than 2 mm lower than the height of the fixed side. For example, as the material of the substrate 34, a resin substrate, a metal foil substrate, or a thin glass with a thickness of about 0.1 mm can be used. In particular, a resin film such as Xenomax (registered trademark), which is a highly heat-resistant polyimide film, can be used. By using a resin film as the material of the substrate 34, the radiation detector 30 can be made lighter and less expensive than when a glass substrate is used as the material of the substrate 34. In addition, the risk of damage to the substrate 34 due to impact can be reduced. A plurality of pixels 41 are respectively arranged on the first surface S1 of the substrate 34.

[0182] The thickness of substrate 34 may be a thickness that provides desired flexibility depending on the hardness and size of substrate 34. When substrate 34 is formed of a base material made of a resin material, the thickness of substrate 34 is preferably, for example, not less than 5 μm and not more than 125 μm, and more preferably not less than 20 μm and not more than 50 μm.

[0183] It should be noted that the coefficient of thermal expansion (CTE) of the substrate 34 at a temperature of 300°C to 400°C is preferably about the same as the coefficient of thermal expansion (approximately ±5ppm / K) of the material (e.g., amorphous silicon) constituting the photoelectric conversion element 36, specifically, preferably 20ppm / K or less. In addition, the thermal shrinkage rate in the MD (Machine Direction) direction of the substrate 34 at 400°C when the thickness is 25μm is preferably 0.5% or less. In addition, the substrate 34 preferably does not have a transition point that is possessed by ordinary polyimide in the temperature range of 300°C to 400°C, and the elastic modulus at 500°C is preferably 1GPa or more. Since the substrate 34 has the above-mentioned characteristics, it can withstand the heat treatment associated with the formation of the pixels 41 on the substrate 34, and the pixels 41 can be properly formed on the substrate 34.

[0184] In addition, when the substrate 34 is formed of a base material composed of a resin material such as polyimide, Figure 10 As shown, the base material made of a resin material preferably has a particle layer 34L containing a plurality of particles 34P made of an inorganic material having an average particle size of 0.05 μm or more and 2.5 μm or less. Furthermore, the particle layer 34L is preferably provided on the second surface S2 side of the substrate 34, which is opposite to the first surface S1 on which the pixels 41 are provided. In other words, the particles 34P are preferably biased toward the second surface S2 side of the substrate 34. The particles 34P may cause unevenness on the surface of the substrate 34, making it difficult to form the pixels 41 on the surface of the particle layer 34L. By placing the particle layer 34L on the second surface S2 side of the substrate 34, the flatness of the first surface S1 can be ensured, making it easier to form the pixels 41.

[0185] The material of the microparticles 34P is preferably an inorganic material containing an element having an atomic number greater than that of the elements constituting the base material of the substrate 34 and being 30 or less. For example, when the base material of the substrate 34 is composed of a resin material such as polyimide containing C, H, O, and N, the microparticles 34P are preferably an inorganic material containing an element having an atomic number greater than that of the elements constituting the resin material (C, H, O, and N) and being 30 or less. Specific examples of such microparticles 34P include SiO2, an oxide of silicon with an atomic number of 14; MgO, an oxide of Mg with an atomic number of 12; Al2O3, an oxide of Al with an atomic number of 13; and TiO2, an oxide of Ti with an atomic number of 22. Furthermore, a specific example of a resin sheet having the aforementioned properties and including the microparticle layer 34L is XENOMAX (registered trademark).

[0186] It should be noted that the above-mentioned thickness in the present embodiment was measured using a micrometer. The thermal expansion coefficient was measured in accordance with JIS K7197:1991. It should be noted that the measurement was carried out as follows: a test piece was cut out from the main surface of the substrate 34 at an angle of 15 degrees each time, the thermal expansion coefficient of each cut test piece was measured, and the highest value was set as the thermal expansion coefficient of the substrate 34. In the measurement of the thermal expansion coefficient, the MD (Machine Direction) direction and the TD (Transverse Direction) direction were measured at intervals of 10°C from -50°C to 450°C, respectively, and (ppm / °C) was converted into (ppm / K). In the measurement of the thermal expansion coefficient, a TMA4000S device manufactured by MAC science was used, the sample length was set to 10 mm, the sample width was set to 2 mm, and the initial load was set to 34.5 g / mm 2 The temperature was raised at a rate of 5°C / min, and the atmosphere was argon. The elastic modulus was measured in accordance with K 7171:2016. The measurement was performed by cutting test pieces from the main surface of substrate 34 at an angle of 15 degrees. Tensile tests were performed on each test piece, and the highest value was defined as the elastic modulus of substrate 34.

[0187] The scintillator 32 is stacked on the first surface S1 side of the substrate 34. The scintillator 32 includes a phosphor that converts the irradiated radiation into light. As an example, the scintillator 32 is composed of an aggregate of columnar crystals including CsI:Tl (cesium iodide with thallium added). The columnar crystals of CsI:Tl can be directly formed on the substrate 34 by, for example, a vapor phase growth method. It should be noted that the columnar crystals of CsI:Tl formed on a substrate different from the substrate 34 can also be attached to the substrate 34. In addition, as the material of the scintillator 32, Gd2O2S:Tb (gadolinium oxysulfide with terbium added) can be used. The photoelectric conversion element 36 (see Figure 3 ) generate electric charges based on the light emitted from the scintillator 32, respectively.

[0188] The surface S3 of the scintillator 32 opposite the surface S6 that contacts the substrate 34, and the surface S4 that intersects the surface S3, are covered with a reflective film 50. The reflective film 50 reflects light emitted from the scintillator 32 toward the substrate 34. Al2O3 can be used as a material for the reflective film 50, for example. The reflective film 50 covers the surfaces S3 and S4 of the scintillator 32 and also covers the substrate 34 around the periphery of the scintillator 32. It should be noted that if the radiation imaging device 10 can obtain a radiographic image of desired quality without the reflective film 50, the reflective film 50 can be omitted.

[0189] In this embodiment, the radiation imaging device 10 employs a surface-sampling (ISS) imaging method, in which the substrate 34 is positioned on the radiation incident side. This method reduces the distance between the strong emission points in the scintillator 32 and the pixels 41, compared to a back-side sampling (PSS) method in which the scintillator 32 is positioned on the radiation incident side. Consequently, the resolution of the radiation image can be improved. It should be noted that the radiation imaging device 10 may also employ a back-side sampling method.

[0190] The support plate 16 is disposed on the side of the scintillator 32 opposite to the radiation incident side. A gap is provided between the support plate 16 and the scintillator 32. The support plate 16 is fixed to a side portion of the housing 14. A circuit board 19 is provided on the surface of the support plate 16 opposite to the scintillator 32. The circuit board 19 is equipped with a signal processing unit 26 that generates image data, an image memory 28 that stores the image data generated by the signal processing unit 26, and other components.

[0191] The circuit board 19 and the substrate 34 are electrically connected via a flexible cable 20 printed on a flexible printed circuit (FPC), TCP (Tape Carrier Package), or COF (Chip On Film). The cable 20 is equipped with a charge amplifier 24 that converts the charge read from the pixel 41 into an electrical signal. Figure 2 The gate line driving unit 22 (see FIG. Figure 3 ).

[0192] The deflection suppression member 60 is laminated on the second surface S2 of the substrate 34, opposite the first surface S1. The deflection suppression member 60 is responsible for imparting the rigidity required to support the scintillator 32. Specifically, the provision of the deflection suppression member 60 suppresses deflection of the substrate 34 due to the weight of the scintillator 32 compared to a case where the deflection suppression member 60 is not provided. The deflection suppression member 60 extends over a wider range than the scintillator 32. In other words, the area of the deflection suppression member 60, when viewed from above, is larger than the area of the scintillator 32, and the scintillator 32 is positioned within the extension of the deflection suppression member 60. Therefore, the planar ends of the deflection suppression member 60 are positioned outward of the planar ends of the scintillator 32. This further enhances the effect of suppressing deflection of the substrate 34 due to the weight of the scintillator 32. Furthermore, the substrate 34 has a connection region 80 on its outer periphery for connection to the cable 20. The deflection suppression member 60 is provided in an area covering at least a portion of the connection region 80 and the scintillator 32. Although the substrate 34 is susceptible to deflection in the connection region 80 connected to the flexible cable 20, providing the deflection suppression member 60 in an area covering at least a portion of the connection region 80 can suppress deflection of the substrate 34 in the connection region 80.

[0193] From the perspective of suppressing the deflection of the substrate 34, the deflection suppression member 60 preferably has a higher rigidity than the substrate 34. The deflection suppression member 60 is preferably a member using a raw material having a bending modulus of 1000 MPa or more and 3500 MPa or less. By setting the bending modulus of the raw material constituting the deflection suppression member 60 to 1000 MPa or more, the function of suppressing the deflection of the substrate 34 in the deflection suppression member 60 can be effectively exerted. By setting the bending modulus of the raw material constituting the deflection suppression member 60 to 3500 MPa or less, for example, in the manufacturing process of the radiation detector 30, when the deflection suppression member 60 is attached to the substrate 34 and a support body (not shown) supporting the substrate 34 is peeled off from the substrate, the substrate 34 deflects moderately, and thus the peeling of the support body from the substrate 34 becomes easier. It should be noted that the measurement method of the bending modulus can be applied to the measurement method specified in JIS K 7171:2016. In addition, the bending rigidity of the deflection suppression member 60 is preferably 3600 Pa·cm 4 Above and 196000Pa·em 4 In addition, the thickness of the deflection suppression member 60 is preferably about 0.1 mm.

[0194] The thermal expansion coefficient of the deflection-reducing member 60 is preferably 30 ppm / K or higher and 80 ppm / K or lower. Furthermore, the thermal expansion coefficient of the deflection-reducing member 60 is preferably close to that of the scintillator 32. Specifically, the ratio of the thermal expansion coefficient C2 of the deflection-reducing member 60 to the thermal expansion coefficient C1 of the scintillator 32 (C2 / C1) is preferably 0.5 or higher and 2 or lower. By satisfying the above-mentioned thermal expansion coefficient of the deflection-reducing member 60, the risk of separation between the substrate 34 and the scintillator 32 during heating or heat generation can be reduced. For example, when the scintillator 32 is primarily composed of CsI:Tl, the thermal expansion coefficient of the scintillator 32 is 50 ppm / K. In this case, materials that can be used for the deflection-reducing member 60 include polyvinyl chloride (PVC) with a thermal expansion coefficient of 60 to 80 ppm / K, acrylic with a thermal expansion coefficient of 70 to 80 ppm / K, polyethylene terephthalate (PET) with a thermal expansion coefficient of 65 to 70 ppm / K, polycarbonate (PC) with a thermal expansion coefficient of 65 ppm / K, and Teflon (registered trademark) with a thermal expansion coefficient of 45 to 70 ppm / K. Considering the aforementioned flexural modulus, the deflection-reducing member 60 is preferably made of at least one of acrylic, PET, and PC.

[0195] Other candidate materials for the deflection suppressing member 60 include, for example, resins such as polyphenylene sulfide (PPS), polyarylate (PAR), polysulfone (PSF), polyethersulfone (PES), polyetherimide (PEI), polyamideimide (PAI), polyetheretherketone (PEEK), phenolic resin, polytetrafluoroethylene, polychlorotrifluoroethylene, silicone resin, and polyethylene naphthalate (PEN). Furthermore, metals such as aluminum, iron, or alloys thereof can be used as the material for the deflection suppressing member 60. Furthermore, a laminate formed by laminating resins and metals can be used as the material for the deflection suppressing member 60. The surface S5 of the deflection suppressing member 60 opposite to the surface in contact with the substrate 34 is adhered to the inner wall of the housing 14 via an adhesive layer 18.

[0196] Figure 3 This diagram shows an example of the electrical structure of the radiographic imaging device 10. A plurality of pixels 41 are arranged in a matrix on the first surface S1 of the substrate 34. Each pixel 41 includes a photoelectric conversion element 36 that generates charge based on light emitted from the scintillator 32, and a TFT (Thin Film Transistor) 42, a switching element that turns on when reading the charge generated in the photoelectric conversion element 36. The photoelectric conversion element 36 may be, for example, a photodiode made of amorphous silicon.

[0197] On the first surface S1 of the substrate 34, gate lines 43 extending in one direction (row direction) along the arrangement of pixels 41, and signal lines 44 extending in a direction (column direction) intersecting the direction in which the gate lines 43 extend, are provided. Pixels 41 are provided corresponding to the intersections of the gate lines 43 and the signal lines 44.

[0198] The gate lines 43 are respectively connected to the gate line driving unit 22. The gate line driving unit 22 reads out the charge accumulated in the pixel 41 based on the control signal supplied from the control unit 29. The signal lines 44 are respectively connected to the charge amplifier 24. The charge amplifier 24 is provided corresponding to the plurality of signal lines 44. The charge amplifier 24 generates an electrical signal based on the charge read from the pixel 41. The output terminal of the charge amplifier 24 is connected to the signal processing unit 26. The signal processing unit 26 performs predetermined processing on the electrical signal supplied from the charge amplifier 24 based on the control signal supplied from the control unit 29, thereby generating image data. The signal processing unit 26 is connected to the image memory 28. The image memory 28 stores the image data generated by the signal processing unit 26 based on the control signal supplied from the control unit 29.

[0199] The control unit 29 communicates with a control console (not shown) connected to the radiation source via a wired or wireless communication unit (not shown) to control the gate line drive unit 22, the signal processing unit 26, and the image memory 28, thereby controlling the operation of the radiation imaging device 10. The control unit 29 may also be configured to include a microcomputer, for example. It should be noted that the gate line drive unit 22 is an example of a readout unit in the disclosed technology. The signal processing unit 26 is an example of a generator in the disclosed technology.

[0200] The following describes an example of the operation of the radiographic imaging device 10. When radiation emitted from a radiation source (not shown) and transmitted through a subject enters the radiation incident surface 15 of the radiographic imaging device 10, the scintillator 32 absorbs the radiation and emits visible light. The photoelectric conversion element 36 constituting the pixel 41 converts the light emitted from the scintillator 32 into electric charge. The charge generated by the photoelectric conversion element 36 is accumulated in the corresponding pixel 41. The amount of charge generated by the photoelectric conversion element 36 is reflected in the pixel value of the corresponding pixel 41.

[0201] When generating a radiographic image, the gate line driver 22 supplies a gate signal to the TFTs 42 via the gate lines 43 based on a control signal supplied by the controller 29. This gate signal turns the TFTs 42 on per row basis. When the TFTs 42 are turned on, the charge accumulated in the pixels 41 is read from the signal lines 44 and supplied to the charge amplifiers 24. The charge amplifiers 24 generate electrical signals based on the charge read from the signal lines 44 and supply these signals to the signal processing unit 26.

[0202] The signal processing unit 26 includes multiple sample-and-hold circuits, a multiplexer, and an analog-to-digital converter (none of which are shown). The multiple sample-and-hold circuits are provided corresponding to the multiple signal lines 44. The electrical signals supplied from the charge amplifier 24 are held by the sample-and-hold circuits. The electrical signals held by each sample-and-hold circuit are input to the analog-to-digital converter via the multiplexer and converted into digital signals. The signal processing unit 26 generates data as image data by associating the digital signals generated by the analog-to-digital converter with the position information of the pixels 41, and supplies the image data to the image memory 28. The image memory 28 stores the image data generated by the signal processing unit 26.

[0203] Since the substrate 34 is flexible, for example, when the substrate 34 is handled during the manufacturing process of the radiation detector 30, the weight of the scintillator 32 may cause the substrate 34 to be locally bent to a relatively large extent. If the substrate 34 is significantly bent, the pixels 41 provided on the surface of the substrate 34 may be damaged.

[0204] Figure 4 34 is a diagram showing a state where the substrate 34 is bent in an arc shape. Figure 4 In the figure, R is the radius of curvature of the deflection generated on the substrate 34, and X is the size of the pixel 41 formed on the substrate 34. That is, the distance between point A, which is one end of the pixel 41, and point B, which is the other end of the pixel 41 (the length of the line segment AB) is the size X of the pixel 41.

[0205] It should be noted that the size of the pixel 41 may also be the size of the photoelectric conversion element 36. In addition, the length of the longest part of the pixel 41 (photoelectric conversion element 36) may also be used as the size of the pixel 41. For example, Figure 5A 、 Figure 5B 、 Figure 5C As shown, when the outer shape of the pixel 41 (photoelectric conversion element 36) is a polygon such as a square, a rectangle, or a regular hexagon, the length of the diagonal of the pixel 41 may be used as the size X of the pixel 41. Alternatively, the length of one side of the pixel 41 may be used as the size X of the pixel 41 (photoelectric conversion element 36). In this case, when the outer shape of the pixel 41 is a rectangle, or when the pixel 41 includes a long side and a short side, it is preferable to use the length of the long side as the size of the pixel 41 (photoelectric conversion element 36).

[0206] exist Figure 4 In , Z is the deformation amount of the pixel 41 caused by the bending of the substrate 34. That is, the deformation amount Z is equivalent to the distance (the length of the line segment BC) between the tangent line L at one end (point A) of the pixel 41 and the other end (point B) of the pixel 41. Figure 4In this example, θ corresponds to the central angle of the sector containing arc AB.

[0207] The size X of the pixel 41 corresponds to the length of the substrate 34 bent in an arc shape on the chord AB of the arc. Therefore, the size X of the pixel 41 can be expressed by the following formula (1).

[0208] X=2Rsin(θ / 2)···(1)

[0209] On the other hand, since ∠BAC is θ / 2, the following formula (2) can be derived.

[0210] sin(θ / 2)=Z / X···(2)

[0211] When equation (2) is substituted into equation (1), the following equations (3) and (4) can be derived.

[0212] X=2R×Z / X···(3)

[0213] R=X 2 / 2Z···(4)

[0214] Here, the maximum value of the deformation amount Z that does not damage the pixel 41 (hereinafter referred to as the limit deformation amount) is set as Z L In the case of , the risk of damage to the pixel 41 can be reduced by limiting the curvature radius R of the bending of the substrate 34 to the range of the following formula (5).

[0215] R≥X 2 / 2Z L ···(5)

[0216] For example, when the size X of the pixel 41 is 150 μm and the limit deformation ZL of the pixel 41 is 0.05 μm, the risk of damage to the pixel 41 can be reduced by setting the curvature radius R of the deflection of the substrate 34 to 225 mm or more.

[0217] It should be noted that the parts that are easily damaged are those with thicker film thickness and higher brittleness. For example, when the photoelectric conversion element 36 includes a photodiode formed in an amorphous silicon layer, the amorphous silicon layer is easily damaged. In this case, the thickness of the amorphous silicon layer is about 0.5 to 2.5 μm, and the thickness is particularly thick in the pixel 41. The limit deformation Z L Small.

[0218] In the radiation detector 30 of this embodiment, the deflection suppression member 60 has a rigidity such that the radius of curvature R of the deflection caused by the weight of the scintillator 32 when the end of the substrate 34 is fixed satisfies Equation (5). In other words, the rigidity of the deflection suppression member 60 is adjusted so that the radius of curvature R of the deflection caused by the weight of the scintillator 32 when the end of the substrate 34 is fixed satisfies Equation (5). That is, the rigidity of the deflection suppression member 60 is determined according to the size of the pixel 41. Therefore, for example, when the substrate 34 is handled during the manufacturing process of the radiation detector 30, the risk of damage to the pixel 41 due to deflection caused by the weight of the scintillator 32 can be reduced compared to a case where Equation (5) is not satisfied. For example, the larger the size X of the pixel 41, the larger the allowable radius of curvature R, and therefore, a deflection suppression member 60 with high rigidity is used.

[0219] The rigidity of the deflection suppression member 60 can be adjusted by, for example, the thickness, density, elastic modulus, etc. of the deflection suppression member 60 . The rigidity of the deflection suppression member 60 can also be adjusted by selecting the material constituting the deflection suppression member 60 .

[0220] Next, a method for manufacturing the radiation detector 30 will be described. Figures 6A to 6D It is a cross-sectional view showing an example of a method of manufacturing the radiation detector 30 .

[0221] First, a plurality of pixels 41 ( Figure 6A ). It should be noted that the pixels 41 may be formed while the substrate 34 is supported by a support (not shown) for supporting the substrate 34 .

[0222] Next, the deflection suppression member 60 ( Figure 6B The deflection suppression member 60 has a rigidity such that the curvature radius R of the deflection generated on the substrate 34 by the weight of the scintillator 32 satisfies the equation (5). For example, the larger the size X of the pixel 41, the higher the rigidity of the deflection suppression member 60.

[0223] Next, the scintillator 32 ( Figure 6C The scintillator 32 can be formed by, for example, growing Tl-doped CsI columnar crystals directly on the substrate 34 using a vapor phase growth method. It should be noted that CsI:Tl columnar crystals formed on a substrate different from the substrate 34 may also be attached to the substrate 34. Furthermore, Gd2O2S:Tb (gadolinium oxysulfide doped with terbium) can be used as the material of the scintillator 32.

[0224] Next, a reflective film 50 is formed so as to cover the surface S3 of the scintillator 32 opposite to the surface S6 in contact with the substrate 34 and the surface S4 ( Figure 6D As a material of the reflective film 50 , for example, Al 2 O 3 can be used. The reflective film 50 may be formed so as to cover the substrate 34 also at the periphery of the scintillator 32 .

[0225] According to the radiation detector 30 and the radiation imaging device 10 of the embodiment of the disclosed technology, the deflection suppression member 60 has a rigidity such that the radius of curvature R of the substrate 34 deflected by the weight of the scintillator 32 satisfies equation (5). Therefore, the radius of curvature R of the substrate 34 deflected by the weight of the scintillator 32 is limited to the range shown in equation (5). Therefore, even if the substrate 34 deflects due to the weight of the scintillator 32 during handling during the manufacturing process of the radiation detector 30, the risk of damage to the pixels 41 can be reduced compared to a case where the disclosed technology is not applied.

[0226] here, Figure 11A 、 Figure 11B Each of them is a cross-sectional view showing an example of a partial structure of a radiation imaging device 10 to which the ISS method is applied as a radiation reading method. Figure 11A and Figure 11B The substrate 34 is respectively configured to include a base material made of a resin material such as polyimide, Figure 11A In the case where the substrate 34 includes the particle layer 34L, Figure 11B This is the case where the substrate 34 does not include a particle layer. When the ISS method is employed, the substrate 34 is positioned on the radiation incident surface 15 side of the housing 14. That is, radiation R incident on the radiation incident surface 15 passes through the substrate 34 and then enters the scintillator 32.

[0227] When radiation enters the substrate 34 made of a resin material containing elements such as C, H, O, and N having relatively small atomic numbers, a large amount of backscattered radiation Rb is generated due to the Compton effect, and the backscattered radiation Rb may leak toward the object 200. Figure 11A As shown, by providing a particle layer 34L including particles 34P made of an inorganic material containing an element having an atomic number larger than the atomic number of the constituent elements (C, H, O, and N) of the resin material on the substrate 34, the backscattered rays Rb generated in the substrate 34 can be absorbed in the particle layer 34L. This is different from the case where the substrate 34 does not include a particle layer (see Figure 11B), the amount of backscattered radiation Rb leaking toward the object 200 can be suppressed. It should be noted that as the atomic number of the element constituting the microparticles 34P increases, the effect of absorbing backscattered radiation Rb increases. However, the amount of radiation absorbed also increases, and the amount of radiation reaching the scintillator 32 decreases. Therefore, the atomic number of the element constituting the microparticles 34P is preferably 30 or less.

[0228] It should be noted that, in the above-mentioned embodiment, the case where the deflection suppression member 60 is provided on the second surface S2 side of the substrate 34 is exemplified, but the disclosed technology is not limited to this embodiment. Figure 7A As shown, the deflection suppression member 60 may be stacked on the surface S3 of the scintillator 32 opposite to the surface S6 contacting the substrate 34. This configuration can achieve substantially the same effect as when the deflection suppression member 60 is provided on the second surface S2 of the substrate 34.

[0229] In addition, if Figure 7B As shown, the deflection suppression member 60 may be laminated on both the second surface S2 side of the substrate 34 and the surface S3 side of the scintillator 32 opposite to the surface S6 side in contact with the substrate 34. By laminating the deflection suppression member 60 on at least one of the second surface S2 side of the substrate 34 and the surface S3 side of the scintillator 32 opposite to the surface S6 side in contact with the substrate 34, the deflection suppression effect of the deflection suppression member 60 is enhanced. In addition, as Figure 7B As shown, by laminating the deflection suppression member 60 on both the second surface S2 side of the substrate 34 and the surface S3 side of the scintillator 32, the deflection suppression effect of the deflection suppression member 60 can be further enhanced, and the risk of damage to the pixels 41 due to deflection of the substrate 34 can be further reduced. It should be noted that when the deflection suppression member 60 is laminated on both the second surface S2 side of the substrate 34 and the surface S3 side of the scintillator 32, the amount of radiation absorbed by the deflection suppression member 60 laminated on the radiation incident side, that is, on the second surface S2 side of the substrate 34, is preferably less than the amount of radiation absorbed by the deflection suppression member 60 laminated on the surface S3 side of the scintillator 32.

[0230] [Second embodiment]

[0231] Figure 8A The radiation detector 30A differs from the radiation detector 30 of the first embodiment in that it further includes a reinforcing member 70 that reinforces the deflection suppressing effect of the deflection suppressing member 60 .

[0232] exist Figure 8AIn the illustrated structure, the deflection suppression member 60 is provided on the second surface S2 side of the substrate 34, and the reinforcing member 70 is provided on the surface S5 side of the deflection suppression member 60, which is opposite to the surface side in contact with the substrate 34. The reinforcing member 70 is provided in a region that straddles the end (outer edge, rim) 32E in the planar direction of the scintillator 32. That is, the reinforcing member 70 is provided on the surface S5 side of the deflection suppression member 60, straddling the boundary between the region where the scintillator 32 is present and the region where the scintillator 32 is not present. From the perspective of enhancing the deflection suppression effect of the deflection suppression member 60, the reinforcing member 70 preferably has higher rigidity than the substrate 34. The preferred ranges of the flexural modulus and thermal expansion coefficient of the reinforcing member 70 are the same as those of the deflection suppression member 60. The reinforcing member 70 can be made of the same material as the deflection suppression member 60, or it can be made of a material having higher rigidity than the deflection suppression member 60.

[0233] here, Figure 9 A cross-sectional view showing an example of a state in which the substrate 34 is bent due to the weight of the scintillator 32. Figure 9 As shown, in the region of the substrate 34 where the scintillator 32 extends, the substrate 34 deflects relatively little due to the rigidity of the scintillator 32. On the other hand, in the portion of the substrate 34 corresponding to the end 32E of the scintillator 32, the substrate 34 deflects relatively much. Portions of the substrate 34 with greater deflection pose a higher risk of damage to the pixels 41 than portions with less deflection.

[0234] According to the radiation detector 30A of the second embodiment of the disclosed technology, a reinforcing member 70, which reinforces the deflection suppression effect of the deflection suppression member 60, is provided in a region spanning the end 32E of the scintillator 32. This can suppress deflection in the portion of the substrate 34 corresponding to the end 32E of the scintillator 32, compared to a case where the reinforcing member 70 is not provided. Consequently, the risk of damage to the pixels 41 can be reduced, compared to a case where the reinforcing member 70 is not provided.

[0235] It should be noted that if Figure 8B As shown, when the deflection suppression member 60 is provided on the surface S3 of the scintillator 32 opposite to the surface S6 in contact with the substrate 34, the reinforcing member 70 may be provided on the second surface S2 of the substrate 34. Figure 8C As shown, when the deflection suppression member 60 is provided on both the second surface S2 of the substrate 34 and the surface S3 of the scintillator 32, the reinforcing member 70 may be provided on the surface S5 of the deflection suppression member 60 opposite to the surface in contact with the substrate 34. Figure 8B and Figure 8C In any of the structures shown, the reinforcing member 70 is provided in a region spanning the end portion (outer edge, rim) 32E of the scintillator 32. Figure 8BIn the structure shown, the reinforcing member 70 is provided on the substrate 34 on the second surface S2 side of the substrate 34 so as to straddle the boundary between the region where the scintillator 32 exists and the region where the scintillator 32 does not exist. Figure 8C In the illustrated structure, the reinforcing member 70 is provided on the surface S5 side of the deflection suppressing member 60 so as to straddle the boundary between the region where the scintillator 32 exists and the region where the scintillator 32 does not exist.

[0236] [Third embodiment]

[0237] Figure 12 This is a cross-sectional view showing an example of the structure of a radiation detector 30B according to the third embodiment of the disclosed technology. The radiation detector 30B includes a buffer layer 90 disposed between a substrate 34 and a scintillator 32. The buffer layer 90 has a thermal expansion coefficient between the thermal expansion coefficients of the substrate 34 and the thermal expansion coefficients of the scintillator 32. As the buffer layer 90, for example, a polyimide film or a parylene film can be used. When XENOMAX (registered trademark) is used as the material for the substrate 34, the difference in thermal expansion coefficients between the substrate 34 and the scintillator 32 becomes larger than when a glass substrate is used as the substrate 34, and the thermal stress acting on the interface between the substrate 34 and the scintillator 32 becomes excessive. By providing the buffer layer 90 between the substrate 34 and the scintillator 32, the thermal stress acting on the interface between the substrate 34 and the scintillator 32 can be suppressed.

[0238] [Other embodiments]

[0239] Figures 13 to 33 Each of them is a cross-sectional view showing an example of how the deflection suppression member 60 is disposed when the deflection suppression member 60 is stacked on the surface of the scintillator 32 opposite to the surface in contact with the substrate 34. Figures 13 to 33 , a region on the substrate 34 where a plurality of pixels 41 are provided, that is, a pixel region 41A is shown.

[0240] When the scintillator 32 is formed by vapor deposition, as shown in FIG. Figures 13 to 33 As shown, the scintillator 32 is formed with an inclination where its thickness gradually decreases toward its outer edge. Hereinafter, the central region of the scintillator 32, whose thickness is assumed to be substantially constant when manufacturing and measurement errors are ignored, is referred to as the central portion 33A. Furthermore, the outer peripheral region of the scintillator 32, which has a thickness that is, for example, 90% or less of the average thickness of the central portion 33A, is referred to as the peripheral portion 33B. Specifically, the scintillator 32 has an inclined surface in the peripheral portion 33B that is inclined relative to the substrate 34.

[0241] like Figures 13 to 33As shown, an adhesive layer 51 , a reflective film 50 , an adhesive layer 52 , a protective layer 53 , and an adhesive layer 54 may be provided between the scintillator 32 and the deflection suppression member 60 .

[0242] The adhesive layer 51 covers the entire surface of the scintillator 32, including the central portion 33A and peripheral portion 33B of the scintillator 32. The adhesive layer 51 serves to secure the reflective film 50 to the scintillator 32. The adhesive layer 51 is preferably light-transmissive. Materials for the adhesive layer 51 include, for example, acrylic adhesives, hot-melt adhesives, and silicone adhesives. Examples of acrylic adhesives include urethane acrylates, acrylic resin acrylates, and epoxy acrylates. Examples of hot-melt adhesives include thermoplastics such as EVA (ethylene-vinyl acetate copolymer), EAA (ethylene and acrylic acid copolymer), EEA (ethylene-ethyl acrylate copolymer), and EMMA (ethylene-methyl methacrylate copolymer). The thickness of the adhesive layer 32 is preferably between 2 μm and 7 μm. A thickness of 2 μm or greater ensures that the reflective film 50 is effectively secured to the scintillator 32. Furthermore, the risk of an air layer forming between the scintillator 32 and the reflective film 50 is minimized. When an air layer is formed between the scintillator 32 and the reflective film 50, multiple reflections may occur, where light emitted from the scintillator 32 is repeatedly reflected between the air layer and the scintillator 32, and between the air layer and the reflective film 50. Furthermore, by setting the thickness of the adhesive layer 32 to 7 μm or less, it is possible to suppress a decrease in the MTF (Modulation Transfer Function) and DQE (Detective Quantum Efficiency).

[0243] The reflective film 50 covers the entire surface of the adhesive layer 51. The reflective film 50 has the function of reflecting the light converted by the scintillator 32. The reflective film 50 is preferably made of an organic material. As the material of the reflective film 50, for example, white PET (Polyethylene Terephthalate), TiO2, Al2O3, foamed white PET, polyester-based high-reflective sheet and mirror-reflective aluminum can be used. It should be noted that white PET refers to a material obtained by adding white pigments such as TiO2 or barium sulfate to PET. In addition, the polyester-based high-reflective sheet refers to a sheet (film) with a multi-layer structure formed by overlapping multiple thinner polyester sheets. In addition, foamed white PET refers to white PET with a porous surface. The thickness of the reflective film 50 is preferably greater than 10 μm and less than 40 μm.

[0244] The adhesive layer 52 covers the entire surface of the reflective film 50. The ends of the adhesive layer 52 extend to the surface of the substrate 34. That is, the adhesive layer 52 is bonded to the substrate 34 at its ends. The adhesive layer 52 secures the reflective film 50 and the protective layer 53 to the scintillator 32. The adhesive layer 52 can be made of the same material as the adhesive layer 51. However, the adhesive strength of the adhesive layer 52 is preferably greater than that of the adhesive layer 51.

[0245] The protective layer 53 covers the entire surface of the adhesive layer 52. That is, the protective layer 53 is provided to cover the entire scintillator 32, and its end portion covers a portion of the substrate 34. The protective layer 53 functions as a moisture-proof film that prevents moisture from penetrating into the scintillator 32. As a material for the protective layer 53, for example, an organic film containing organic materials such as PET, PPS (PolyPhenylene Sulfide), OPP (Oriented PolyPropylene: biaxially oriented polypropylene film), PEN (PolyEthyleneNaphthalate: polyethylene naphthalate), and PI can be used. In addition, as the protective layer 53, a sheet of Mylar tape (registered trademark) in which aluminum is laminated on an insulating sheet (film) such as polyethylene terephthalate by bonding aluminum foil or the like can also be used.

[0246] The deflection suppression member 60 is provided on the surface of the protective layer 53 via the adhesive layer 54. As the material of the adhesive layer 54, for example, the same material as that of the adhesive layer 51 and the adhesive layer 54 can be used.

[0247] exist Figure 13 In the example shown, the deflection suppression member 60 extends in the regions corresponding to the central portion 33A and the peripheral portion 33B of the scintillator 32, and the outer periphery of the deflection suppression member 60 is bent to follow the inclination of the peripheral portion 33B of the scintillator 32. The deflection suppression member 60 is bonded to the protective layer 53 via the adhesive layer 54 in both the region corresponding to the central portion 33A and the region corresponding to the peripheral portion 33B of the scintillator 32. Figure 13 In the illustrated example, the end portion of the deflection suppressing member 60 is arranged in a region corresponding to the peripheral edge portion 33B of the scintillator 32 .

[0248] like Figure 14 As shown, the deflection suppression member 60 is provided only in the region corresponding to the central portion 33A of the scintillator 32 . In this case, the deflection suppression member 60 is adhered to the protective layer 53 via the adhesive layer 54 in the region corresponding to the central portion 33A of the scintillator 32 .

[0249] like Figure 15As shown, when the deflection suppression member 60 extends over the regions corresponding to the central portion 33A and the peripheral portion 33B of the scintillator 32, the deflection suppression member 60 does not need to have a bent portion that follows the inclination of the outer periphery of the scintillator 32. In this case, the deflection suppression member 60 is bonded to the protective layer 53 via the adhesive layer 54 in the region corresponding to the central portion 33A of the scintillator 32. In the region corresponding to the peripheral portion 33B of the scintillator 32, a space corresponding to the inclination of the peripheral portion 33B of the scintillator 32 is formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60.

[0250] Here, the cable 20 is connected to the terminal 35 provided in the connection area 80 on the outer periphery of the substrate 34. The substrate 34 is connected to the control substrate (see FIG. 1 ) via the cable 20. Figure 45 ) connection. If the substrate 34 is bent, the cable 20 may be peeled off from the substrate 34 or may be displaced. In this case, it is necessary to reconnect the cable 20 and the substrate 34. The operation of reconnecting the cable 20 and the substrate 34 is called rework. Figures 13 to 15 As shown, by arranging the end of the deflection suppression member 60 inward of the end of the scintillator 32 , rework can be performed more easily than when the deflection suppression member 60 extends to the vicinity of the connection region 80 .

[0251] like Figures 16 to 19 As shown, the deflection suppression member 60 may be provided so that its end portion is located outside the end portion of the scintillator 32 and is aligned with the end portions of the adhesive layer 52 and the protective layer 53 extending onto the substrate 34. It should be noted that the positions of the end portions of the deflection suppression member 60 and the ends of the adhesive layer 52 and the protective layer 53 do not need to be completely aligned.

[0252] exist Figure 16 In the example shown, the deflection suppression member 60 is bonded to the protective layer 53 via the adhesive layer 54 in the area corresponding to the central portion 33A of the scintillator 32, and in the area corresponding to the peripheral portion 33B of the scintillator 32 and the area further to the outside thereof, a space corresponding to the inclination of the peripheral portion 33B of the scintillator 32 is formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60.

[0253] exist Figure 17 In the example shown, a filler 55 is provided in the area corresponding to the peripheral edge portion 33B of the scintillator 32 and in the area further outside thereof, in the space formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60. The material of the filler 55 is not particularly limited, and for example, resin can be used. Figure 17In the illustrated example, in order to fix the deflection suppression member 60 to the filling material 55 , the adhesive layer 54 is provided over the entire region between the deflection suppression member 60 and the filling material 55 .

[0254] The method for forming the filling material 55 is not particularly limited. For example, after the adhesive layer 54 and the deflection suppression member 60 are sequentially formed on the scintillator 32 covered by the adhesive layer 51, the reflective film 50, the adhesive layer 52, and the protective layer 53, the fluid filling material 55 may be injected into the space formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60, and the filling material 55 may be cured. Alternatively, for example, after the scintillator 32, the adhesive layer 51, the reflective film 50, the adhesive layer 52, and the protective layer 53 are sequentially formed on the substrate 34, the filling material 55 may be formed, and the adhesive layer 54 and the deflection suppression member 60 may be sequentially formed to cover the scintillator 32 and the filling material 55 covered by the adhesive layer 51, the reflective film 50, the adhesive layer 52, and the protective layer 53.

[0255] In this way, the space formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 is filled with the filling material 55. Figure 16 Compared to the embodiment shown, the deflection suppression member 60 can be prevented from peeling off from the scintillator 32 (protective layer 53). In addition, the scintillator 32 is fixed to the substrate 34 by both the deflection suppression member 60 and the filler 55, so peeling off of the scintillator 32 from the substrate 34 can be prevented.

[0256] exist Figure 18 In the example shown, the outer periphery of the deflection suppression member 60 is bent to follow the inclination of the peripheral edge portion 33B of the scintillator 32, and also covers the portion of the adhesive layer 52 and the protective layer 53 that covers the substrate 34. Furthermore, the ends of the deflection suppression member 60 are aligned with the ends of the adhesive layer 52 and the protective layer 53. It should be noted that the positions of the ends of the deflection suppression member 60 and the ends of the adhesive layer 52 and the protective layer 53 do not need to be completely aligned.

[0257] The ends of the deflection suppression member 60, the adhesive layer 54, the protective layer 53, and the adhesive layer 52 are sealed by a sealing member 57. The sealing member 57 is preferably provided in the area from the surface of the substrate 34 to the surface of the deflection suppression member 60, and does not cover the area of the pixel area 41A. As the material of the sealing member 57, a resin can be used, and a thermoplastic resin is particularly preferred. Specifically, acrylic paste and polyurethane paste can be used as the sealing member 57. The deflection suppression member 60 has higher rigidity than the protective layer 53. A restoring force to eliminate the bend acts on the bent portion of the deflection suppression member 60, and thus the protective layer 53 may peel off. By sealing the ends of the deflection suppression member 60, the adhesive layer 54, the protective layer 53, and the adhesive layer 52 with the sealing member 57, peeling of the protective layer 53 can be suppressed.

[0258] exist Figure 19 In the example shown, Figure 17 In the same manner as shown, in the area corresponding to the peripheral portion 33B of the scintillator 32 and the area further outside thereof, a filling material 55 is provided in the space formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60. In addition, in the area corresponding to the end portion of the scintillator 32, another deflection suppression member 60A is stacked on the surface of the deflection suppression member 60 via the adhesive layer 54A. More specifically, the deflection suppression member 60A is provided in the area spanning the end portion (outer edge, edge) of the scintillator 32. The deflection suppression member 60A may also be made of the same material as the deflection suppression member 60. As Figure 9 As shown, the substrate 34 deflects relatively significantly at the ends of the scintillator 32. Forming the laminated structure based on the deflection suppressing members 60 and 60A in the regions corresponding to the ends of the scintillator 32 enhances the effect of suppressing deflection of the substrate 34 at the ends of the scintillator 32.

[0259] like Figures 16 to 19 As shown, even in the case where the end of the deflection suppression member 60 is arranged at a position outside the end of the scintillator 32 and aligned with the ends of the adhesive layer 52 and the protective layer 53, rework can be easily performed compared to the case where the deflection suppression member 60 extends to the vicinity of the connection area 80.

[0260] like Figures 20 to 23 As shown, the deflection suppression member 60 may be provided so that its end portion is located outside the ends of the adhesive layer 52 and the protective layer 53 extending onto the substrate 34 and inside the end portion of the substrate 34 .

[0261] exist Figure 20In the example shown, the deflection suppression member 60 is adhered to the protective layer 53 via the adhesive layer 54 in the area corresponding to the central portion 33A of the scintillator 32, and in the area corresponding to the peripheral portion 33B of the scintillator 32 and the area further to the outside thereof, a space corresponding to the inclination of the peripheral portion 33B of the scintillator 32 is formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60, and between the substrate 34 and the deflection suppression member 60.

[0262] exist Figure 21 In the example shown, the end of the deflection suppression member 60 is supported by the spacer 39. That is, one end of the spacer 39 is connected to the first surface S1 of the substrate 34, and the other end of the spacer 39 is connected to the end of the deflection suppression member 60 via the adhesive layer 56. By using the spacer 39 to support the end of the deflection suppression member 60 that extends while forming a space between the spacer 39 and the substrate 34, it is possible to suppress the deflection suppression member 60 from peeling off. In addition, the deflection suppression effect of the deflection suppression member 60 can be applied to the vicinity of the end of the substrate 34. It should be noted that, instead of providing the spacer 39, it is also possible to imitate Figure 17 In the illustrated example, the spaces formed between the scintillator 32 (protective layer 53 ) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 are filled with a filling material.

[0263] exist Figure 22 In the example shown, the outer periphery of the deflection suppression member 60 is bent to be inclined along the peripheral edge portion 33B of the scintillator 32, and also covers the portion of the adhesive layer 52 and the protective layer 53 covering the substrate 34, as well as the substrate 34 outside the adhesive layer 52 and the protective layer 53. That is, the ends of the adhesive layer 52 and the protective layer 53 are sealed by the deflection suppression member 60. The portion of the deflection suppression member 60 extending on the substrate 34 is bonded to the substrate 34 via the adhesive layer 54. Thus, by covering the ends of the adhesive layer 52 and the protective layer 53 with the deflection suppression member 60, peeling of the protective layer 53 can be suppressed. It should be noted that it is also possible to imitate Figure 18 In the described example, the end portion of the deflection suppression member 60 is sealed using a sealing member.

[0264] exist Figure 23 In the example shown, in a manner in which the ends of the deflection suppression member 60 are supported by the spacer 39, another deflection suppression member 60A is further laminated via the adhesive layer 54A in the area of the surface of the deflection suppression member 60 corresponding to the end of the scintillator 32. More specifically, the deflection suppression member 60A is provided in an area spanning the end (outer edge, edge) of the scintillator 32. The deflection suppression member 60A may also be made of the same material as the deflection suppression member 60. Figure 9As shown in FIG. 3 , the substrate 34 is relatively bent at the end of the scintillator 32. By forming a laminated structure based on the bending suppression members 60 and 60A in the region corresponding to the end of the scintillator 32, the effect of suppressing the bending of the substrate 34 at the end of the scintillator 32 can be enhanced. It should be noted that, instead of providing the spacer 39, a Figure 17 In the illustrated example, the spaces formed between the scintillator 32 (protective layer 53 ) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 are filled with a filling material.

[0265] like Figures 24 to 28 As shown, the deflection suppression member 60 may be provided so that its end is aligned with the end of the substrate 34. It should be noted that the position of the end of the deflection suppression member 60 and the position of the end of the substrate 34 do not need to be completely consistent.

[0266] exist Figure 24 In the example shown, the deflection suppression member 60 is bonded to the protective layer 53 via the adhesive layer 54 in the area corresponding to the central portion 33A of the scintillator 32, and in the area corresponding to the peripheral portion 33B of the scintillator 32 and the area further to the outside thereof, a space corresponding to the inclination of the peripheral portion 33B of the scintillator 32 is formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60, and between the substrate 34 and the deflection suppression member 60.

[0267] exist Figure 25 In the illustrated example, the ends of the deflection-reducing member 60 are supported by the spacer 39. Specifically, one end of the spacer 39 is connected to the cable 20 provided at the end of the substrate 34, while the other end of the spacer 39 is connected to the end of the deflection-reducing member 60 via the adhesive layer 56. By supporting the end of the deflection-reducing member 60, which extends while forming a space between the spacer 39 and the substrate 34, the deflection-reducing member 60 can be prevented from peeling off. Furthermore, the deflection-reducing effect of the deflection-reducing member 60 can be exerted near the end of the substrate 34.

[0268] exist Figure 26 In the example shown, the spaces formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 are filled with a filling material 55. In this embodiment, the connection portion between the cable 20 and the terminal 35 is covered with the filling material 55. In this way, by filling the spaces formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 with the filling material 55, the connection portion between the cable 20 and the terminal 35 is covered with the filling material 55. Figure 24Compared to the embodiment shown in FIG. 1 , the deflection suppression member 60 can be prevented from peeling off from the scintillator 32 (protective layer 53). Furthermore, since the scintillator 32 is fixed to the substrate 34 by both the deflection suppression member 60 and the filler 55, peeling off of the scintillator 32 from the substrate 34 can be prevented. Furthermore, by covering the connection between the cable 20 and the terminal 35 with the filler 55, peeling off of the cable 20 can be prevented.

[0269] exist Figure 27 In the example shown, the outer periphery of the deflection suppression member 60 is bent to follow the slope of the peripheral edge 33B of the scintillator 32. The member also covers the portion of the substrate 34 covered by the adhesive layer 52 and protective layer 53, the substrate outside the adhesive layer 52 and protective layer 53, and the connection between the terminal 35 and the cable 20. The portions of the deflection suppression member 60 extending onto the substrate 34 and the cable 20 are bonded to the substrate 34 and cable 20, respectively, via the adhesive layer 54. Covering the connection between the cable 20 and the terminal 35 with the deflection suppression member 60 prevents the cable 20 from peeling off. Furthermore, since a control board equipped with electronic components is presumably connected to the other end of the cable 20, the substrate 34 may experience significant deflection at the connection between the cable 20 and the terminal 35. Covering the connection between the cable 20 and the terminal 35 with the deflection suppression member 60 prevents deflection of the substrate 34 in this portion.

[0270] exist Figure 28 In the example shown, the space formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 is filled with a filling material 55. In addition, in the area corresponding to the end of the scintillator 32, another deflection suppression member 60A is stacked on the surface of the deflection suppression member 60 via the adhesive layer 54A. More specifically, the deflection suppression member 60A is provided in the area spanning the end (outer edge, edge) of the scintillator 32. The deflection suppression member 60A may also be made of the same material as the deflection suppression member 60. As Figure 9 As shown, the substrate 34 deflects relatively significantly at the ends of the scintillator 32. Forming the laminated structure based on the deflection suppressing members 60 and 60A in the regions corresponding to the ends of the scintillator 32 enhances the effect of suppressing deflection of the substrate 34 at the ends of the scintillator 32.

[0271] like Figures 29 to 33 As shown, the deflection suppression member 60 may be provided so that its end portion is located outside the end portion of the base plate 34 .

[0272] exist Figure 29In the example shown, the deflection suppression member 60 is bonded to the protective layer 53 via the adhesive layer 54 in the area corresponding to the central portion 33A of the scintillator 32, and in the area corresponding to the peripheral portion 33B of the scintillator 32 and the area further to the outside thereof, a space corresponding to the inclination of the peripheral portion 33B of the scintillator 32 is formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60, and between the substrate 34 and the deflection suppression member 60.

[0273] exist Figure 30 In the illustrated example, the ends of the deflection-reducing member 60 are supported by the spacer 39. Specifically, one end of the spacer 39 is connected to the cable 20 provided at the end of the substrate 34, while the other end of the spacer 39 is connected to the end of the deflection-reducing member 60 via the adhesive layer 56. By supporting the end of the deflection-reducing member 60, which extends while forming a space between the spacer 39 and the substrate 34, the deflection-reducing member 60 can be prevented from peeling off. Furthermore, the deflection-reducing effect of the deflection-reducing member 60 can be exerted near the end of the substrate 34.

[0274] exist Figure 31 In the example shown, the spaces formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 are filled with a filling material 55. In this embodiment, the connection portion between the cable 20 and the terminal 35 is covered with the filling material 55. In this way, by filling the spaces formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60, the connection portion between the cable 20 and the terminal 35 is covered with the filling material 55. Figure 29 Compared to the embodiment shown in FIG. 1 , the deflection suppression member 60 can be prevented from peeling off from the scintillator 32 (protective layer 53). Furthermore, since the scintillator 32 is fixed to the substrate 34 by both the deflection suppression member 60 and the filler 55, peeling off of the scintillator 32 from the substrate 34 can be prevented. Furthermore, by covering the connection between the cable 20 and the terminal 35 with the filler 55, peeling off of the cable 20 can be prevented.

[0275] exist Figure 32In the example shown, the outer periphery of the deflection suppression member 60 is bent to follow the slope of the peripheral edge 33B of the scintillator 32. The member covers the portion of the substrate 34 covered by the adhesive layer 52 and the protective layer 53, the substrate outside the adhesive layer 52 and protective layer 53, and the connection between the terminal 35 and the cable 20. The portions of the deflection suppression member 60 extending onto the substrate 34 and the cable 20 are bonded to the substrate 34 and cable 20, respectively, via the adhesive layer 54. Covering the connection between the cable 20 and the terminal 35 with the deflection suppression member 60 prevents the cable 20 from peeling off. Furthermore, since a control board equipped with electronic components is presumably connected to the other end of the cable 20, the substrate 34 may experience significant deflection at the connection between the cable 20 and the terminal 35. Covering the connection between the cable 20 and the terminal 35 with the deflection suppression member 60 prevents deflection of the substrate 34 in this portion.

[0276] exist Figure 33 In the example shown, the space formed between the scintillator 32 (protective layer 53) and the deflection suppression member 60 and between the substrate 34 and the deflection suppression member 60 is filled with a filling material 55. In addition, in the area corresponding to the end of the scintillator 32, another deflection suppression member 60A is stacked on the surface of the deflection suppression member 60 via the adhesive layer 54A. More specifically, the deflection suppression member 60A is provided in the area spanning the end (outer edge, edge) of the scintillator 32. The deflection suppression member 60A may also be made of the same material as the deflection suppression member 60. As Figure 9 As shown, the substrate 34 deflects relatively significantly at the ends of the scintillator 32. Forming the laminated structure based on the deflection suppressing members 60 and 60A in the regions corresponding to the ends of the scintillator 32 enhances the effect of suppressing deflection of the substrate 34 at the ends of the scintillator 32.

[0277] Here, in the manufacturing process of the radiation detector 30, a flexible substrate 34 is attached to a support such as a glass substrate, and after the scintillator 32 is laminated on the substrate 34, the support is peeled off from the substrate 34. At this time, the flexible substrate 34 may bend, thereby damaging the pixels 41 formed on the substrate 34. Before peeling the support from the substrate 34, Figures 13 to 33 In the illustrated embodiment, the deflection suppression member 60 is preliminarily laminated on the scintillator 32 , which can suppress deflection of the substrate 34 that occurs when the support body is peeled from the substrate 34 , thereby reducing the risk of damage to the pixels 41 .

[0278] Figures 34 to 39 Each of them is a cross-sectional view showing an example of an arrangement form of the deflection suppressing member when the deflection suppressing member is provided on the second surface S2 side of the substrate 34 opposite to the first surface S1 in contact with the scintillator 32 .

[0279] exist Figures 34 to 39 In the example shown, substantially the entire second surface S2 of the substrate 34 is in contact with the deflection suppression member 60 via the adhesive layer 54. That is, the area of the deflection suppression member 60 is substantially the same as the area of the substrate 34. On the surface of the deflection suppression member 60 opposite to the surface on the substrate 34 side, another deflection suppression member 60A is also stacked via the adhesive layer 54A. The deflection suppression member 60A may also be made of the same material as the deflection suppression portion 60. In the case where a surface reading method (ISS) is applied as the imaging method of the radiation detector 30, in order to minimize the area of the portion where the deflection suppression member 60A overlaps with the pixel area 41A, it is preferred that the deflection suppression member 60A is only provided on the outer periphery of the substrate 34. That is, as Figures 34 to 39 As shown, the deflection suppression member 60A may be annular with an opening 61 in the portion corresponding to the pixel area 41A. By forming a stacked structure based on the deflection suppression members 60 and 60A at the periphery of the substrate 34, the rigidity of the periphery of the substrate 34, which is relatively prone to deflection, can be enhanced.

[0280] exist Figures 34 to 36 In the example shown, the deflection suppression member 60A is provided in a region spanning the end portion (outer edge, rim) of the scintillator 32. Figure 9 As shown, the substrate 34 deflects relatively significantly at the ends of the scintillator 32. Forming the laminated structure based on the deflection suppressing members 60 and 60A in the regions corresponding to the ends of the scintillator 32 enhances the effect of suppressing deflection of the substrate 34 at the ends of the scintillator 32.

[0281] When the surface scanning method (ISS) is applied as the imaging method of the radiation detector 30, Figure 34 As shown, if a portion of the deflection suppression member 60A overlaps the pixel area 41A, the image may be affected depending on the material of the deflection suppression member 60A. Therefore, when a portion of the deflection suppression member 60A overlaps the pixel area 41A, plastic is preferably used as the material of the deflection suppression member 60A.

[0282] like Figure 35 and Figure 36 As shown, the deflection suppression member 60A is most preferably arranged to span the end (outer edge, edge) of the scintillator 32 and not overlap the pixel area 41A (that is, the end of the opening 61 of the deflection suppression member 60A is arranged outside the pixel area 41A). Figure 35 In the example shown, the position of the end of the opening 61 of the deflection suppression member 60A substantially coincides with the position of the end of the pixel region 41A. Figure 36In the illustrated example, the end of the opening 61 of the deflection suppression member 60A is arranged between the end of the pixel region 41A and the end of the scintillator 32 .

[0283] In addition, if Figure 37 As shown, the position of the end of the opening 61 of the deflection suppression member 60A may also be substantially consistent with the position of the end of the scintillator 32. Figure 38 As shown, the end of the opening 61 of the deflection suppression member 60A can also be positioned outside the end of the scintillator 32. In this case, the deflection suppression member 60A does not extend across the end (outer edge, rim) of the scintillator 32, and thus the effect of suppressing deflection of the substrate 34 at the end of the scintillator 32 may be reduced. However, by forming a stacked structure of the deflection suppression members 60 and 60A around the outer periphery of the substrate 34 where the connection between the cable 20 and the terminal 35 exists, the effect of suppressing deflection of the substrate 34 at the connection between the cable 20 and the terminal 35 is maintained.

[0284] exist Figure 39 In the example shown, the area of the deflection prevention member 60 is larger than the area of the substrate 34, and the end of the deflection prevention member 60 is positioned outward of the end of the substrate 34. In this embodiment, the radiation detector 30 can be fixed inside the housing 14 by screwing the portion of the deflection prevention member 60 extending from the substrate 34 to the housing 14, for example.

[0285] It should be noted that in Figures 34 to 39 , the outer end of the deflection suppressing member 60A is substantially aligned with the end of the substrate 34, but the present invention is not limited to this embodiment. The outer end of the deflection suppressing member 60A may be positioned outside or inside the end of the substrate 34.

[0286] In addition, Figures 34 to 39 In the embodiment, a stacked structure based on the deflection suppression members 60 and 60A is formed on the second surface S2 side of the substrate 34, but the present invention is not limited to this structure. Figures 13 to 33 In the illustrated embodiment, when the deflection suppressing member 60 is provided on the scintillator 32 side, only the deflection suppressing member 60A that reinforces the outer periphery of the substrate 34 may be provided on the second surface S2 side of the substrate 34 .

[0287] Figure 40 6 is a plan view showing an example of the structure of the deflection suppression member 60. The deflection suppression member 60 may have a plurality of through-holes 62 on its main surface. The size and pitch of the through-holes 62 are determined so that the desired rigidity is obtained in the deflection suppression member 60.

[0288] Since the deflection suppression member 60 has a plurality of through-holes 62, air introduced into the surface of the deflection suppression member 60 that is bonded to the scintillator 32 or substrate 34 can be exhausted through the through-holes 62. This can suppress the generation of bubbles at the surface of the deflection suppression member 60 that is bonded to the scintillator 32 or substrate 34.

[0289] In the absence of a means for discharging air introduced into the joint surface of the deflection suppression member 60 that is joined to the scintillator 32 side or the substrate 34 side, bubbles may be generated on the above-mentioned joint surface. For example, when the bubbles generated on the above-mentioned joint surface expand due to the heat during the operation of the radiation imaging device 10, the adhesion between the deflection suppression member 60 and the scintillator 32 side or the substrate 34 side decreases. As a result, the deflection suppression effect of the deflection suppression member 60 may not be fully exerted. Figure 40 As shown, by using a deflection suppression member 60 having a plurality of through holes 62, as described above, the generation of bubbles at the joint surface of the deflection suppression member 60 joined to the scintillator 32 side or the substrate 34 side can be suppressed, thereby maintaining the close contact between the deflection suppression member 60 and the scintillator 32 side or the substrate 34 side, and maintaining the deflection suppression effect of the deflection suppression member 60.

[0290] Figure 41 : is a perspective view showing another example of the structure of the deflection suppression member 60. Figure 41 In the example shown, the deflection suppression member 60 has a concavo-convex structure on the bonding surface with the scintillator 32 side or the substrate 34 side. Figure 41 As shown, the concavo-convex structure may also be configured to include a plurality of grooves 63 arranged parallel to each other. Figure 42 As shown, the surface of the deflection suppression member 60 having a concavo-convex structure formed by a plurality of grooves 63 is bonded to the scintillator 32 covered by the reflective film 50. In this way, since the deflection suppression member 60 has a concavo-convex structure on the bonding surface with the scintillator 32 side or the substrate 34 side, air introduced into the bonding portion between the deflection suppression member 60 and the scintillator 32 side or the substrate 34 side can be discharged from the grooves 63. Figure 40 Similarly, the embodiment shown can suppress the generation of bubbles at the interface between the deflection suppression member 60 and the scintillator 32 or substrate 34. This maintains close contact between the deflection suppression member 60 and the scintillator 32 or substrate 34, and maintains the deflection suppression effect of the deflection suppression member 60.

[0291] Figure 43 and Figure 44 1 and 2 are plan views showing other examples of the structure of the deflection suppression member 60. Figure 43 and Figure 44 As shown, the deflection suppression member 60 may also be divided into a plurality of segments 64. Figure 43As shown in FIG. 1 , the deflection suppression member 60 may be divided into a plurality of segments 64 arranged in one direction. Figure 44 As shown, the deflection suppression member 60 may be divided so that a plurality of segments 64 are arranged in the longitudinal and transverse directions.

[0292] The larger the area of the deflection suppression member 60, the more easily bubbles are generated on the bonding surface of the deflection suppression member 60 with the scintillator 32 side or the substrate 34 side. Figure 43 and Figure 44 As shown, by dividing the deflection suppression member 60 into a plurality of fragments 64, the generation of bubbles at the interface between the deflection suppression member 60 and the scintillator 32 or substrate 34 can be suppressed. This maintains close contact between the deflection suppression member 60 and the scintillator 32 or substrate 34, and maintains the deflection suppression effect of the deflection suppression member 60.

[0293] Figures 45 to 47 Each of these diagrams shows another configuration example of the radiation imaging device 10. The radiation imaging device 10 includes a housing 14, a radiation detector 30 housed in the housing 14, a control board 81, and a power supply unit 82.

[0294] The control substrate 81 is equipped with Figure 3 The control substrate 81 is a substrate for some or all of the electronic components of the control unit 29, image memory 28, gate line drive unit 22, charge amplifier 24, and signal processing unit 26 shown. The control substrate 81 may be a rigid substrate having higher rigidity than the flexible substrate 34. The power supply unit 82 supplies power to the electronic components mounted on the control substrate 81 via power lines 83.

[0295] The housing 14 is preferably lightweight, has low X-ray absorption, and is highly rigid. It is preferably constructed of a material having a significantly higher elastic modulus than that of the deflection suppression member 60. A material having a flexural modulus of 10,000 MPa or greater is preferably used for the housing 14. Suitable materials for the housing 14 include carbon or CFRP (Carbon Fiber Reinforced Plastics) having a flexural modulus of approximately 20,000 to 60,000 MPa.

[0296] During radiographic imaging by the radiographic imaging device 10, a load from the subject is applied to the radiation incident surface 15 of the housing 14. If the deflection suppression member 60 is made of a material with a relatively low elastic modulus, such as soft plastic, and the rigidity of the housing 14 is insufficient, the load from the subject may cause the substrate 34 to deflect, potentially leading to problems such as damage to the pixels 41. By housing the radiation detector 30 equipped with the deflection suppression member 60 within the housing 14, which is made of a material with a flexural modulus of 10,000 MPa or greater, deflection of the substrate 34 caused by the subject's load can be suppressed, even when the deflection suppression member 60 is made of a material with a relatively low elastic modulus, such as soft plastic. By ensuring that the deflection suppression member 60 is in close contact with the inner wall of the housing 14, the effect of suppressing deflection of the substrate 34 caused by the subject's load can be further enhanced. In this case, the deflection suppression member 60 and the inner wall surface of the housing 14 may be bonded via an adhesive layer, or may simply be in contact without an adhesive layer.

[0297] exist Figure 45 and Figure 46 In the example shown, the radiation detector 30, the control substrate 81 and the power supply unit 82 are arranged side by side in the horizontal direction of the figure. Figure 46 As shown, the thickness of the area within the housing 14 housing the radiation detector 30 can be made thinner than the area housing the control board 81 and power supply unit 82. This allows for an extremely thin portable electronic cassette that matches the thickness of the radiation detector 30. To mitigate the step difference between the area housing the radiation detector 30 and the area housing the control board 81 and power supply unit 82, the housing 14 preferably includes an inclined portion 14A connecting these two areas. The presence of the inclined portion 14A in the housing 14 reduces discomfort for the patient when the radiation imaging device 10 is inserted below the patient.

[0298] exist Figure 47 In the example shown, a base 37 having approximately the same size as the substrate 34 of the radiation detector 30 is disposed within the interior space of the housing 14, overlapping the substrate 34. A control substrate 81 and a power supply unit 82 are disposed on the base 37. This configuration allows the size of the radiation imaging device 10, as viewed from above, to be reduced compared to a case where the radiation detector 30, the control substrate 81, and the power supply unit 82 are arranged side by side in the horizontal direction as shown in the figure.

[0299] The disclosures of Japanese Patent Application Nos. 2018-051691, 2018-219697, and 2019-022081 are incorporated herein by reference in their entirety.

[0300] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A radiation detector comprising: a substrate having flexibility; a plurality of pixels disposed on the substrate and each comprising a photoelectric conversion element; a scintillator stacked on the first surface side of the substrate; and a deflection suppressing member that suppresses deflection of the substrate, The deflection suppression member is laminated on both the second surface side of the substrate opposite to the first surface side and the surface side of the scintillator opposite to the surface side in contact with the substrate. The deflection suppression member is formed of at least one of acrylic, polycarbonate, and polyethylene terephthalate.

2. The radiation detector according to claim 1, wherein The deflection suppression member has a bending elastic modulus of 1000 MPa or more and 3500 MPa or less.

3. The radiation detector according to claim 1, wherein The deflection suppression member has higher rigidity than the base plate. The radiation detector according to claim 1 , wherein: The deflection suppression member extends over a range larger than that of the scintillator. The radiation detector according to claim 1 , wherein: The substrate has a connection area connected to a flexible wiring. The deflection suppression member is provided in a region covering at least a portion of the connection region and the scintillator. The radiation detector according to claim 1 , wherein: A ratio of a thermal expansion coefficient of the deflection suppression member to a thermal expansion coefficient of the scintillator is 0.5 or more and 2 or less.

7. The radiation detector according to claim 1, wherein The deflection suppression member has a thermal expansion coefficient of 30 ppm / K or more and 80 ppm / K or less. The radiation detector according to claim 1 , wherein: The radiation detector further includes a reinforcing member provided in a region spanning an end portion of the scintillator and reinforcing a deflection suppressing effect of the deflection suppressing member.

9. The radiation detector according to claim 8, wherein The reinforcing member has higher rigidity than the base plate.

10. The radiation detector according to claim 8 or 9, wherein The reinforcing member is composed of the same material as the deflection suppressing member.

11. The radiation detector according to claim 1, wherein The substrate is configured to include a resin film.

12. The radiation detector according to claim 1, wherein The substrate is composed of a base material made of a resin material having a fine particle layer, wherein the fine particle layer includes fine particles made of an inorganic material having an average particle diameter of 0.05 μm or more and 2.5 μm or less. The particle layer is provided on a second surface of the substrate opposite to the first surface on which the plurality of pixels are provided.

13. The radiation detector according to claim 12, wherein: The fine particles contain an element having an atomic number greater than that of an element constituting the resin material and having an atomic number of 30 or less.

14. The radiation detector according to claim 1, wherein The thermal expansion coefficient of the substrate at a temperature of 300° C. to 400° C. is 20 ppm / K or less.

15. The radiation detector according to claim 1, wherein The substrate satisfies at least one of a heat shrinkage rate in a longitudinal direction of 0.5% or less at 400° C. when the substrate has a thickness of 25 μm and an elastic modulus of 1 GPa or more at 500° C.

16. The radiation detector according to claim 1, wherein The radiation detector further includes a buffer layer provided between the substrate and the scintillator and having a thermal expansion coefficient between a thermal expansion coefficient of the substrate and a thermal expansion coefficient of the scintillator.

17. The radiation detector according to claim 1, wherein The deflection suppression member extends in regions corresponding to a central portion and a peripheral portion of the scintillator.

18. The radiation detector according to claim 4 or 17, wherein: The deflection suppression member is bent along an inclination at a peripheral edge portion of the scintillator.

19. The radiation detector according to claim 4, wherein A space corresponding to the inclination of the peripheral portion of the scintillator is formed between the deflection suppression member and the scintillator.

20. The radiation detector according to claim 4, wherein A filling material is filled in a space formed between the deflection suppression member and the scintillator.

21. The radiation detector according to claim 4, wherein Ends of the deflection suppressing member are supported by spacers.

22. The radiation detector according to claim 4, wherein The deflection prevention member is bent along an inclination at a peripheral edge portion of the scintillator, and an end portion of the deflection prevention member is sealed by a sealing member.

23. The radiation detector according to claim 8, wherein The reinforcing member is provided in a region that does not overlap with the pixel region.

24. A radiographic imaging device comprising: The radiation detector according to any one of claims 1 to 23; a readout section that reads out the charge accumulated in the pixel; as well as A generating unit generates image data based on the charges read out from the pixels.

25. The radiographic imaging device according to claim 24, wherein: The radiation imaging device further includes a housing having a radiation incident surface for incident radiation and accommodating the radiation detector. Of the substrate and the scintillator, the substrate is arranged on the radiation incident surface side.

26. A method for manufacturing a radiation detector, comprising the following steps: forming a plurality of pixels each including a photoelectric conversion element on a flexible substrate; forming a scintillator on the first surface of the substrate; and a step of configuring a deflection suppressing member for suppressing deflection of the substrate so as to be laminated on both the second surface side of the substrate opposite to the first surface side and the surface side of the scintillator opposite to the surface side in contact with the substrate; The larger the pixel size, the higher the rigidity of the deflection suppression member. The deflection suppression member is formed of at least one of acrylic, polycarbonate, and polyethylene terephthalate.

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