Radiation detector and radiation imaging device

Abstract

The present invention relates to a radiation detector and a radiation imaging device. The radiation detector includes: a sensor substrate comprising a flexible base material; a layer provided on a first surface of the base material and having a plurality of pixels formed thereon for accumulating charges generated in response to light converted from radiation; a conversion layer provided on the first surface of the sensor substrate and converting radiation into the light; and an elastic layer provided on the side of the conversion layer opposite to the side on which the sensor substrate is provided and having a higher restoring force against deflection than the sensor substrate.

Description

Technical Field

[0001] The present invention relates to a radiation detector and a radiation imaging device. Background Art

[0002] Conventionally, radiographic imaging devices that perform radiographic imaging for medical diagnosis are known. Such radiographic imaging devices use a radiation detector that detects radiation transmitted through a subject and generates a radiographic image.

[0003] Radiation detectors include a conversion layer, such as a scintillator, that converts radiation into light, and a sensor substrate with multiple pixels that store charge corresponding to the light converted by the conversion layer. A known example of such a radiation detector is one that uses a flexible substrate in the sensor substrate (see, for example, International Publication No. WO2010 / 070735). Using a flexible substrate can, for example, reduce the weight of a radiation imaging device (radiation detector) and sometimes facilitate imaging of a subject.

[0004] Also, as examples of methods for manufacturing radiation detectors that use a flexible substrate as a sensor substrate, there are known methods known as coating methods and lamination methods. In the coating method, a flexible substrate is formed by coating on a support such as a glass substrate, and the sensor substrate and conversion layer are further formed. The sensor substrate with the conversion layer formed thereon is then peeled from the support by laser stripping. On the other hand, in the lamination method, a sheet that will become the flexible substrate is bonded to a support such as a glass substrate, and the sensor substrate and conversion layer are further formed thereon. The sensor substrate with the conversion layer formed thereon is then peeled from the support by mechanical stripping or laser stripping.

[0005] As described above, both the coating and lamination methods involve peeling the sensor substrate from the support during the manufacturing process. However, peeling the sensor substrate from the support can cause the flexible substrate used in the sensor substrate to warp. This warping can lead to damage to the sensor substrate's pixels or the conversion layer, for example. Summary of the Invention

[0006] The present disclosure provides a radiation detector and a radiation image capturing device. Compared with a structure in which a layer that does not have a higher resilience against bending than the sensor substrate is arranged on the opposite side of the side on which the sensor substrate is arranged in the conversion layer, in the manufacturing process of a radiation detector having a sensor substrate having a flexible base material manufactured using a support body, the influence of bending generated when the sensor substrate is peeled off from the support body can be suppressed.

[0007] The first embodiment of the present disclosure is a radiation detector comprising: a sensor substrate including a flexible substrate and a layer provided on a first surface of the substrate and having a plurality of pixels for accumulating charges corresponding to light converted from radiation; a conversion layer provided on the first surface side of the sensor substrate and converting radiation into light; and an elastic layer provided on the side of the conversion layer opposite to the side on which the sensor substrate is provided and having a higher restoring force against deflection than the sensor substrate.

[0008] Furthermore, in the radiation detector according to a second aspect of the present disclosure, in the radiation detector according to the first aspect, the elastic layer has a bending modulus of elasticity of 150 MPa to 2500 MPa.

[0009] Furthermore, a radiation detector according to a third aspect of the present disclosure is the radiation detector according to the first or second aspect, wherein the elastic layer is made of at least one of polycarbonate, polyethylene terephthalate, and low-density polyethylene.

[0010] Furthermore, a fourth aspect of the present disclosure is the radiation detector of any one of the first to third aspects, wherein a ratio of a thermal expansion coefficient of the elastic layer to a thermal expansion coefficient of the conversion layer is 0.5 to 4.

[0011] Furthermore, a radiation detector according to a fifth aspect of the present disclosure is the radiation detector according to any one of the first to fourth aspects, wherein the thermal expansion coefficient of the elastic layer is 30 ppm / K or more and 200 ppm / K or less.

[0012] In addition, the radiation detector of the sixth embodiment of the present disclosure is based on the radiation detector of any one of the first to fifth embodiments, and the sensor substrate further includes: a terminal portion, which is arranged on the outer periphery of the first surface of the substrate and is connected to a cable for reading out charges from the pixel, and the end of the elastic layer is located at a position further inward than the area where the terminal portion is set.

[0013] Furthermore, a seventh aspect of the present disclosure is the radiation detector of the sixth aspect, wherein the conversion layer includes a peripheral portion having an inclination that decreases in thickness toward the outside and a central portion surrounded by the peripheral portion, and the elastic layer covers at least the central portion.

[0014] In addition, the radiation detector of the eighth embodiment of the present disclosure is based on the radiation detector of the sixth embodiment, wherein the conversion layer has: an inclined peripheral portion whose thickness becomes thinner toward the outside; and a central portion surrounded by the peripheral portion, and the elastic layer covers at least a portion of the peripheral portion and the central portion.

[0015] In addition, the radiation detector of the 9th scheme of the present disclosure is based on the radiation detector of the 6th scheme, and the conversion layer has: an inclined peripheral portion whose thickness becomes thinner as it goes outward; and a central portion surrounded by the peripheral portion, and the end portion of the elastic layer is set at least from the area covering the central portion to the area corresponding to the outer periphery of the peripheral portion.

[0016] In addition, the radiation detector of the tenth embodiment of the present disclosure is based on the radiation detector of any one of the first to fifth embodiments, and the sensor substrate further includes: a terminal portion, which is arranged on the outer periphery of the first surface of the substrate and is connected to a cable for reading out charge from the pixel, and the elastic layer is arranged until it reaches an area opposite to part or all of the area where the terminal portion is set.

[0017] Furthermore, the radiation detector according to an eleventh aspect of the present disclosure is the radiation detector according to any one of the first to fifth aspects, wherein the elastic layer is provided in an area larger than an area of ​​the sensor substrate where the conversion layer is provided.

[0018] Furthermore, a radiation detector according to a twelfth aspect of the present disclosure is the radiation detector according to any one of the first to fifth aspects, wherein an end portion of the elastic layer protrudes outwardly beyond an end portion of the sensor substrate.

[0019] Furthermore, the radiation detector according to a thirteenth aspect of the present disclosure is the radiation detector according to any one of the first to fifth aspects, wherein the elastic layer further includes a support portion provided to extend to a region outside the conversion layer and supporting between an end portion of the elastic layer and the sensor substrate.

[0020] Furthermore, a radiation detector according to a fourteenth aspect of the present disclosure is the radiation detector according to any one of the first to fifth aspects, further comprising a filler that fills a space between the sensor substrate and the elastic layer, excluding the conversion layer.

[0021] Furthermore, a radiation detector according to a fifteenth aspect of the present disclosure is the radiation detector according to the fourteenth aspect, wherein the filler is in contact with the sensor substrate and the elastic layer.

[0022] Furthermore, a radiation detector according to a sixteenth aspect of the present disclosure is the radiation detector according to any one of the first to fifteenth aspects, further comprising: a contact layer provided between the sensor substrate and the conversion layer.

[0023] In addition, the radiation detector of the 17th scheme of the present disclosure is based on the radiation detector of any one of the 1st to 15th schemes, and further includes: a buffer layer, which is arranged between the sensor substrate and the conversion layer, and buffers the difference in thermal expansion coefficient between the conversion layer and the sensor substrate.

[0024] In addition, the radiation detector of the 18th scheme of the present disclosure is based on the radiation detector of any one of the 1st scheme to the 17th scheme, and further includes: an elastic member, which is arranged on the second surface side opposite to the first surface of the substrate and has a higher restoring force against deflection than the sensor substrate.

[0025] Furthermore, a radiation detector according to a nineteenth aspect of the present disclosure is the radiation detector according to the eighteenth aspect, wherein at least a portion of the elastic layer and at least a portion of the elastic member face each other with the sensor substrate and the conversion layer interposed therebetween.

[0026] Furthermore, a radiation detector according to a 20th aspect of the present disclosure is the radiation detector according to the 18th or 19th aspect, wherein the elastic member is made of at least one of polycarbonate, polyethylene terephthalate, and low-density polyethylene.

[0027] Furthermore, a radiation detector according to a twenty-first aspect of the present disclosure is the radiation detector according to any one of the eighteenth to twentieth aspects, wherein a ratio of a thermal expansion coefficient of the elastic member to a thermal expansion coefficient of the conversion layer is 0.5 to 4.

[0028] Furthermore, a radiation detector according to a 22nd aspect of the present disclosure is the radiation detector according to any one of the 18th to 21st aspects, wherein the elastic member has a thermal expansion coefficient of 30 ppm / K or more and 200 ppm / K or less.

[0029] In addition, the radiation detector according to the 23rd aspect of the present disclosure is the radiation detector according to any one of the 1st to 22nd aspects, wherein the substrate is made of resin and has a fine particle layer containing inorganic fine particles having an average particle diameter of 0.05 μm to 2.5 μm.

[0030] Furthermore, a radiation detector according to a 24th aspect of the present disclosure is the radiation detector according to the 23rd aspect, wherein the substrate has a fine particle layer on the second surface side.

[0031] Furthermore, in a radiation detector according to a twenty-fifth aspect of the present disclosure, in addition to the radiation detector according to the twenty-third or twenty-fourth aspect, the fine particles contain an element having an atomic number greater than that of an element constituting the base material and having an atomic number of 30 or less.

[0032] Furthermore, a radiation detector according to a twenty-sixth aspect of the present disclosure is the radiation detector according to any one of the first to twenty-fifth aspects, wherein the thermal expansion coefficient of the substrate at 300° C. to 400° C. is 20 ppm / K or less.

[0033] In addition, the radiation detector of the 27th scheme of the present disclosure is based on the radiation detector of any one of the 1st to 26th schemes, and the substrate satisfies at least one of the following two conditions: the thermal shrinkage rate in the MD (Machine Direction) direction at 400°C is less than 0.5% when the thickness is 25 μm, and the elastic modulus at 500°C is greater than 1 GPa.

[0034] Furthermore, a radiation detector according to a twenty-eighth aspect of the present disclosure is the radiation detector according to any one of the first to twenty-seventh aspects, wherein the elastic layer has a higher rigidity than the base.

[0035] Furthermore, a radiation detector according to a twenty-ninth aspect of the present disclosure is the radiation detector according to any one of the first to twenty-eighth aspects, wherein the conversion layer includes CsI.

[0036] In addition, the radiation image capturing device of the 30th scheme of the present disclosure comprises: a radiation detector recorded in any one of the schemes 1 to 29; a control unit, which outputs a control signal for reading out the charges accumulated in multiple pixels; a driving unit, which outputs a driving signal for reading out the charges from multiple pixels in response to the control signal; and a signal processing unit, which inputs an electrical signal corresponding to the charges read out from the multiple pixels, and generates and outputs image data corresponding to the input electrical signal.

[0037] In addition, the radiation image capturing device of the 31st scheme of the present disclosure is based on the radiation image capturing device of the 30th scheme, and is provided with a control unit and a radiation detector arranged in a direction intersecting with the stacking direction in which the substrate, the layer forming multiple pixels, and the conversion layer in the radiation detector are arranged.

[0038] In addition, the radiation image capturing device of the 32nd scheme of the present disclosure is further provided with: a power supply unit, which provides power to at least one of the control unit, the drive unit and the signal processing unit, based on the radiation image capturing device of the 30th scheme, and the power supply unit, the control unit and the radiation detector are arranged in a direction intersecting with the stacking direction of the sensor substrate, the conversion layer and the elastic layer in the radiation detector.

[0039] In addition, the radiation image capturing device of the 33rd scheme of the present disclosure is further provided with, based on the radiation image capturing device of the 30th scheme: a shell having an irradiation surface to which radiation is irradiated, and accommodating the radiation detector in a state in which the sensor substrate in the radiation detector and the sensor substrate in the conversion layer are opposite to the irradiation surface.

[0040] Effects of the Invention

[0041] According to the first scheme of the present disclosure, compared with a structure in which a layer that does not have a higher restoring force against bending than the sensor substrate is provided on the opposite side of the conversion layer on which the sensor substrate is provided, in the manufacturing process of a radiation detector having a sensor substrate having a flexible base material manufactured using a support body, the influence of the bending generated when the sensor substrate is peeled off from the support body can be suppressed.

[0042] According to the second embodiment, the thickness of the elastic layer for obtaining desired rigidity can be suppressed compared to the case where the flexural modulus is less than 150 MPa or exceeds 2500 MPa.

[0043] According to the third aspect, the peeling between the sensor substrate and the conversion layer can be suppressed compared to the case where at least one of polycarbonate, polyethylene terephthalate, and low-density polyethylene is not included.

[0044] According to the fourth aspect, the peeling between the sensor substrate and the conversion layer can be suppressed compared to the case where the ratio of the thermal expansion coefficients is less than 0.5 or exceeds 4.

[0045] According to the fifth aspect, the peeling between the sensor substrate and the conversion layer can be suppressed compared to the case where the thermal expansion coefficient is less than 30 ppm / K or exceeds 200 ppm / K.

[0046] According to the sixth aspect of the present disclosure, compared with a case where the end portion of the elastic layer is located outside the region where the terminal portion is provided, the terminal can be provided more easily.

[0047] According to the seventh aspect of the present disclosure, the influence of the deflection generated when the sensor substrate is peeled from the support body can be further suppressed compared to a case where the elastic layer does not cover the central portion of the conversion layer.

[0048] According to the eighth aspect of the present disclosure, the influence of deflection generated when the sensor substrate is peeled from the support body can be further suppressed compared to a case where the elastic layer does not cover at least a portion of the peripheral portion and the central portion of the conversion layer.

[0049] According to the ninth aspect of the present disclosure, the influence of deflection generated when the sensor substrate is peeled from the support body can be further suppressed compared to a case where the end portion of the elastic layer is not provided from at least the region covering the central portion of the conversion layer to the region corresponding to the outer periphery of the peripheral portion.

[0050] According to the tenth aspect of the present disclosure, compared with a case where no elastic layer is provided in the region where the terminal portion is provided, a high restoring force against deflection can be applied even to the end portion of the sensor substrate.

[0051] According to the eleventh aspect of the present disclosure, compared to a case where the elastic layer is provided in an area smaller than the area of ​​the sensor substrate where the conversion layer is provided, it is possible to suppress the end portion of the conversion layer from being peeled off from the sensor substrate.

[0052] According to the twelfth aspect of the present disclosure, compared with a case where the end of the elastic layer is located further inward than the end of the sensor substrate, a high restoring force against deflection can be applied even to the further end of the sensor substrate.

[0053] According to the thirteenth aspect of the present disclosure, a high restoring force against deflection can be applied to the further end of the sensor substrate, compared to a case where the space between the end of the elastic layer and the sensor substrate is not supported by the support portion.

[0054] According to the fourteenth aspect of the present disclosure, compared with a case where no filler is filled in the space between the sensor substrate and the elastic layer excluding the conversion layer, a high restoring force against deflection can be applied even to the end portion of the sensor substrate.

[0055] According to the fifteenth aspect of the present disclosure, the elastic layer can be provided more stably than in a case where the filler is not in contact with the sensor substrate and the elastic layer.

[0056] According to the sixteenth aspect of the present disclosure, the conversion layer can be made less likely to peel off from the sensor substrate compared to a case where no adhesion layer is provided.

[0057] According to the seventeenth aspect of the present disclosure, it is possible to suppress separation between the sensor substrate and the conversion layer compared to a case where no buffer layer is provided.

[0058] According to the eighteenth aspect of the present disclosure, the influence of the deflection of the sensor substrate can be suppressed compared to a case where no elastic member having a higher restoring force against deflection than the sensor substrate is provided on the second surface side of the base.

[0059] According to the 19th embodiment of the present disclosure, compared with the case where at least a portion of the elastic layer and at least a portion of the elastic member are not sandwiched between the sensor substrate and the conversion layer, the elastic layer and the elastic member complement each other, thereby further suppressing the influence of the deflection generated by the sensor substrate.

[0060] According to the 20th aspect of the present disclosure, the peeling between the sensor substrate and the conversion layer can be suppressed compared to a case where at least one of polycarbonate, polyethylene terephthalate, and low-density polyethylene is not included.

[0061] According to the twenty-first aspect of the present disclosure, the peeling between the sensor substrate and the conversion layer can be suppressed compared to the case where the ratio of the thermal expansion coefficients is less than 0.5 or exceeds 4.

[0062] According to the twenty-second aspect of the present disclosure, the peeling between the sensor substrate and the conversion layer can be suppressed compared to the case where the thermal expansion coefficient is less than 30 ppm / K or exceeds 200 ppm / K.

[0063] According to the twenty-third aspect of the present disclosure, backscattered radiation generated in the substrate can be suppressed compared to a case where the substrate does not have a fine particle layer containing inorganic fine particles having an average particle diameter of 0.05 μm to 2.5 μm.

[0064] According to the twenty-fourth aspect of the present disclosure, pixels can be formed with higher precision than in the case where the substrate has a fine particle layer on the first surface side.

[0065] According to the twenty-fifth aspect of the present disclosure, backscattered rays can be effectively suppressed and absorption of radiation in the fine particle layer can be suppressed compared to a case where the fine particles do not contain an element having an atomic number greater than that of the element constituting the base material and having an atomic number of 30 or less.

[0066] According to the twenty-sixth aspect of the present disclosure, compared with a case where the thermal expansion coefficient of the substrate at 300° C. to 400° C. exceeds 20 ppm / K, the substrate can be made suitable for manufacturing pixels.

[0067] According to the twenty-seventh aspect of the present disclosure, a substrate suitable for pixel production can be obtained compared to a substrate having a thermal shrinkage in the MD direction at 400° C. exceeding 0.5% and an elastic modulus at 500° C. less than 1 GPa when the substrate has a thickness of 25 μm.

[0068] According to the twenty-eighth aspect of the present disclosure, compared with a case where the rigidity of the elastic layer is equal to or less than the rigidity of the base material, deflection of the base material can be suppressed.

[0069] According to the twenty-ninth aspect of the present disclosure, the conversion efficiency from radiation to visible light can be improved compared to a case where the conversion layer does not contain CsI.

[0070] According to the 30th aspect of the present disclosure, it is possible to suppress separation between the sensor substrate and the conversion layer compared to a case where a radiation detector different from the radiation detector described in any one of the 1st to 29th aspects is provided.

[0071] According to the 31st scheme of the present disclosure, compared to the case of a radiation detector different from the radiation detector described in any one of the 1st to 29th schemes, even if the control unit and the radiation detector are arranged in a direction intersecting with the stacking direction in which the base material, the layer forming a plurality of pixels, and the conversion layer in the radiation detector are arranged, the peeling of the sensor substrate and the conversion layer can be suppressed.

[0072] According to the 32nd scheme of the present disclosure, compared with the case of having a radiation detector different from the radiation detector described in any one of the 1st to 29th schemes, even if the power supply unit, the control unit, and the radiation detector are arranged in a direction intersecting with the stacking direction of the sensor substrate, the conversion layer, and the elastic layer in the radiation detector, the peeling of the sensor substrate and the conversion layer can be suppressed.

[0073] According to the thirty-third aspect of the present disclosure, the quality of radiographic images can be improved compared to a case where the radiation detector is housed in the housing with the irradiation surface and the conversion layer facing each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 This is a block diagram showing an example of a configuration of a main part of an electrical system in the radiation imaging apparatus according to the first exemplary embodiment.

[0075] Figure 2A This is a plan view of an example of the radiation detector according to the first exemplary embodiment as viewed from the first surface side.

[0076] Figure 2B This is a cross-sectional view for explaining an example of a substrate.

[0077] Figure 2C This is an explanatory diagram for explaining backscattered rays generated in a substrate having a fine particle layer by radiation transmitted through a subject.

[0078] Figure 2D This is an explanatory diagram for explaining backscattered rays generated in a substrate having no fine particle layer by radiation transmitted through a subject.

[0079] Figure 3 yes Figure 2A AA line cross-sectional view of the radiation detector shown.

[0080] Figure 4 It is a cross-sectional view for explaining the peripheral portion and the central portion of the conversion layer according to the first exemplary embodiment.

[0081] Figure 5 It is a diagram for explaining an example of a method for manufacturing a radiation detector according to the first exemplary embodiment.

[0082] Figure 6A This is a cross-sectional view showing an example of a state where a radiation detector is installed in a housing when the radiation imaging device according to the embodiment of this example is used in a PSS (Penetration Side Sampling) method.

[0083] Figure 6B This is a cross-sectional view showing an example of a state where a radiation detector is installed in a housing when the radiation imaging apparatus according to the embodiment of this example is used in the ISS (Irradiation Side Sampling) method.

[0084] Figure 6C This is a cross-sectional view showing another example of a state in which a radiation detector is installed in a housing when the radiation imaging device according to the embodiment of this example is used in the PSS method.

[0085] Figure 6D This is a cross-sectional view showing another example of a state in which a radiation detector is installed in a housing when the radiation imaging device according to the embodiment of this example is used in the PSS method.

[0086] Figure 6E This is a cross-sectional view showing another example of a state in which a radiation detector is installed in a housing when the radiation imaging device according to the embodiment of this example is used in the PSS method.

[0087] Figure 7A This is a cross-sectional view showing another example of a state in which a radiation detector is installed in a housing when the radiation imaging device according to the embodiment of this example is used in the PSS method.

[0088] Figure 7B This is a cross-sectional view showing another example of a state in which a radiation detector is installed in a housing when the radiation imaging device according to the embodiment of this example is used in the ISS method.

[0089] Figure 8 It is a cross-sectional view of an example of a radiation detector according to the second exemplary embodiment.

[0090] Figure 9 It is a cross-sectional view of an example of a radiation detector according to the third exemplary embodiment.

[0091] Figure 10 It is a cross-sectional view of another example of the radiation detector according to the third exemplary embodiment.

[0092] Figure 11 It is a cross-sectional view of another example of the radiation detector according to the third exemplary embodiment.

[0093] Figure 12 It is a cross-sectional view of an example of a radiation detector according to the fourth exemplary embodiment.

[0094] Figure 13 It is a cross-sectional view of another example of the radiation detector according to the illustrated embodiment.

[0095] Figure 14 It is a cross-sectional view of another example of the radiation detector according to the illustrated embodiment.

[0096] Figure 15 It is a cross-sectional view of another example of the radiation detector according to the illustrated embodiment.

[0097] Figure 16 It is a cross-sectional view of another example of the radiation detector according to the illustrated embodiment.

[0098] Figure 17 It is a cross-sectional view of another example of the radiation detector according to the illustrated embodiment.

[0099] Figure 18 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0100] Figure 19 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0101] Figure 20 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0102] Figure 21 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0103] Figure 22 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0104] Figure 23 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0105] Figure 24 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0106] Figure 25This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0107] Figure 26 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0108] Figure 27 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0109] Figure 28 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0110] Figure 29 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0111] Figure 30 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0112] Figure 31 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0113] Figure 32 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0114] Figure 33 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0115] Figure 34 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0116] Figure 35 It is a plan view showing an example of the structure of a deflection suppression member according to an exemplary embodiment of the technology disclosed herein.

[0117] Figure 36 It is a perspective view showing an example of the structure of a deflection suppression member according to an exemplary embodiment of the technology disclosed herein.

[0118] Figure 37 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0119] Figure 38It is a plan view showing an example of the structure of a deflection suppression member according to an exemplary embodiment of the technology disclosed herein.

[0120] Figure 39 It is a plan view showing an example of the structure of a deflection suppression member according to an exemplary embodiment of the technology disclosed herein.

[0121] Figure 40 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0122] Figure 41A This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0123] Figure 41B This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0124] Figure 41C This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein.

[0125] Figure 42 This is a cross-sectional view showing an example of the structure of a radiation detector according to an exemplary embodiment of the technology disclosed herein. DETAILED DESCRIPTION

[0126] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the exemplary embodiments do not limit the present invention.

[0127] [First exemplary embodiment]

[0128] The radiation imaging apparatus of the embodiment illustrated in this example has a function of capturing a radiation image of a subject by detecting radiation transmitted through the subject and outputting image information representing the radiation image of the subject.

[0129] First, refer to Figure 1 An overview of an example of the configuration of an electrical system in the radiation imaging apparatus according to the embodiment of this example will be described. Figure 1 This is a block diagram showing an example of a configuration of a main portion of an electrical system in the radiation imaging apparatus according to the embodiment of this example.

[0130] like Figure 1 As shown, the radiation imaging device 1 of the embodiment shown in this example includes a radiation detector 10 , a control unit 100 , a drive unit 102 , a signal processing unit 104 , an image memory 106 , and a power supply unit 108 .

[0131] The radiation detector 10 includes a sensor substrate 12 (see Figure 3 ) and the conversion layer 30 that converts radiation into light (reference Figure 3 The sensor substrate 12 includes a flexible base material 14 and a plurality of pixels 16 provided on a first surface 14A of the base material 14. In the following, the plurality of pixels 16 may be simply referred to as "pixels 16."

[0132] like Figure 1 As shown, each pixel 16 of the embodiment shown in this example includes: a sensor portion 22 that generates and accumulates charges in response to the light converted by the conversion layer; and a switching element 20 that reads the charges accumulated in the sensor portion 22. In the embodiment shown in this example, as an example, a thin film transistor (TFT: Thin Film Transistor) is used as the switching element 20. Therefore, the switching element 20 will be referred to as "TFT20" below. In the embodiment shown in this example, as a layer in which the sensor portion 22 and the TFT20 are formed and further flattened, a layer in which the pixels 16 are formed is provided on the first surface 14A of the substrate 14. In the following, for convenience of explanation, the layer in which the pixels 16 are formed will sometimes be referred to as "pixel 16".

[0133] The pixels 16 are arranged in a direction (with respect to the pixel region 15 of the sensor substrate 12) along a direction Figure 1 The scanning wiring direction corresponding to the horizontal direction of the row is also referred to as the "row direction" below) and the cross direction relative to the row direction (the cross direction with Figure 1 The longitudinal direction of the signal wiring corresponds to the longitudinal direction, hereinafter also referred to as the "column direction") and is arranged in a two-dimensional manner. Figure 1 Although the arrangement of the pixels 16 is simplified in FIG, for example, the pixels 16 are arranged in 1024×1024 pieces in the row direction and the column direction.

[0134] In the radiation detector 10, a plurality of scanning wirings 26 for controlling the switching state (on and off) of the TFTs 20 provided in each row of pixels 16 and a plurality of signal wirings 24 for reading out the charge accumulated in the sensor section 22 provided in each column of pixels 16 are arranged to intersect with each other. Figure 6A The drive unit 102 is connected to the control unit 100 described later. The drive unit 102 outputs a drive signal in accordance with the control signal output from the control unit 100. The plurality of scanning wirings 26 allow the drive signal output from the drive unit 102 to drive the TFT 20 to control the switching state to flow through each of the plurality of scanning wirings. In addition, the plurality of signal wirings 24 are each connected to the pads (see FIG. 130). Figure 6AThe pad 130 (eg, pad 130) is connected to the signal processing unit 104, thereby outputting the charge read from each pixel 16 as an electric signal to the signal processing unit 104. The signal processing unit 104 generates and outputs image data according to the input electric signal.

[0135] The signal processing unit 104 is connected to the control unit 100, which will be described later. The image data output from the signal processing unit 104 is sequentially output to the control unit 100. The control unit 100 is connected to an image memory 106. The image data sequentially output from the signal processing unit 104 is sequentially stored in the image memory 106 under the control of the control unit 100. The image memory 106 has a storage capacity capable of storing a predetermined number of image data. Each time a radiographic image is captured, the image data obtained by the capture is sequentially stored in the image memory 106.

[0136] The control unit 100 includes a CPU (Central Processing Unit) 100A, a memory 100B including ROM (Read Only Memory) and RAM (Random Access Memory), and a nonvolatile storage unit 100C such as a flash memory. An example of the control unit 100 is a microcomputer. The control unit 100 controls the overall operation of the radiographic imaging device 1.

[0137] In addition, in the sensor portion 22 of each pixel 16, a common wiring 28 is provided in the wiring direction of the signal wiring 24 in order to apply a bias voltage to each pixel 16. The common wiring 28 is connected via a pad (see Figure 6A The pads 130 , etc., are connected to a bias power source (not shown) outside the sensor substrate 12 , so that a bias voltage is applied to each pixel 16 from the bias power source.

[0138] The power supply unit 108 supplies power to various components or circuits such as the control unit 100, the driving unit 102, the signal processing unit 104, and the image memory 106. Figure 3 In order to avoid complexity, the wiring connecting the power supply unit 108 and various elements or various circuits is omitted from the illustration.

[0139] Furthermore, the radiation detector 10 according to this exemplary embodiment will be described in detail. Figure 2A This is a plan view of the radiation detector 10 according to the embodiment of this example as viewed from the first surface 14A side. Figure 3 yes Figure 2A AA line cross-sectional view of the radiation detector 10 in FIG.

[0140] The radiation detector 10 of the embodiment shown in this example is as follows Figure 2A as well as Figure 3 As shown in the figure, the sensor substrate 12 including the substrate 14 and the pixels 16, the conversion layer 30, the adhesive layer 32, the reflective layer 34, the bonding layer 36, the protective layer 38, the bonding layer 40, and the elastic layer 42 are provided in the order of the substrate 14, the pixels 16, and the conversion layer 30. In addition, the direction in which the substrate 14, the pixels 16, and the conversion layer 30 are arranged is as follows ( Figure 3 The up-down direction in the image is called the stacking direction (refer to Figure 3 , stacking direction P). For convenience of explanation, the conversion layer 30 side in the stacking direction P of the radiation detector 10 is sometimes referred to as "upper," and the sensor substrate 12 side is sometimes referred to as "lower."

[0141] The substrate 14 is flexible, and is, for example, a resin sheet made of a plastic such as PI (Polyimide). The thickness of the substrate 14 can be such that the desired flexibility is achieved according to the hardness of the material and the size of the sensor substrate 12 (the area of ​​the first surface 14A or the second surface 14B). As an example of flexibility, in the case of a rectangular substrate 14 alone, when one side of the substrate 14 is fixed, the substrate 14 sags by more than 2 mm (lower than the height of the fixed side) due to the gravity caused by the substrate 14's own weight at a distance of 10 cm from the fixed side. As a specific example of the case where the substrate 14 is a resin sheet, a thickness of 5 μm to 125 μm is sufficient, and a thickness of 20 μm to 50 μm is more preferable.

[0142] In addition, the substrate 14 has characteristics that can withstand the manufacture of the pixel 16 described in detail later. In the embodiment shown in this example, it has characteristics that can withstand the manufacture of amorphous silicon TFTs (a-Si TFTs). As characteristics possessed by such a substrate 14, it is preferred that the coefficient of thermal expansion (CTE: Coefficient of Thermal Expansion) at 300°C to 400°C is the same as that of an amorphous silicon (Si) wafer (for example, ±5ppm / K), and specifically preferably is 20ppm / K or less. In addition, as a thermal shrinkage rate of the substrate 14, it is preferred that the thermal shrinkage rate in the MD (Machine Direction) direction at 400°C is 0.5% or less when the thickness is 25μm. In addition, the elastic modulus of the substrate 14 preferably does not have a transition point that is possessed by general PI in the temperature range between 300°C and 400°C, and the elastic modulus at 500°C is 1GPa or more.

[0143] In addition, the substrate 14 of this exemplary embodiment is preferably as follows Figure 2B as well as Figure 2CAs shown, the fine particle layer 14L includes inorganic fine particles 14P having an average particle diameter of 0.05 μm or more and 2.5 μm or less. Figure 2C This is an example of a case where the radiation detector 10 of the embodiment shown in this example is used in an ISS (Irradiation Side Sampling) type radiation detector in which radiation R is irradiated from the sensor substrate 12 side.

[0144] like Figure 2C as well as Figure 2D As shown, backscattered rays Rb are generated in the substrate 14 by the radiation R that has passed through the subject S. When the substrate 14 is made of a resin such as PI, since it is an organic material, the backscattered rays Rb are increased due to the Compton effect for atoms such as C, H, O, and N, which have relatively small atomic numbers and constitute the organic material.

[0145] like Figure 2C As shown in FIG. 1 , when the substrate 14 has a fine particle layer 14L including fine particles 14P that absorb backscattered rays Rb generated in the substrate 14, as shown in FIG. Figure 2D As shown, compared with a case where the substrate 14 does not have the fine particle layer 14L, the backscattered radiation Rb that is scattered backward after passing through the substrate 14 can be suppressed, which is preferable.

[0146] Such microparticles 14P preferably contain inorganic atoms that generate a low amount of backscattered radiation Rb, absorb backscattered radiation Rb, and, on the other hand, absorb little radiation R transmitted through the subject S. Furthermore, from the perspective of suppressing backscattered radiation Rb, which is a trade-off between suppressing backscattered radiation Rb and enhancing the transmittance of radiation R, the microparticles 14P preferably contain elements with atomic numbers greater than those of the resin comprising the substrate 14, such as C, H, O, and N. While a higher atomic number increases the ability to absorb backscattered radiation Rb, an atomic number exceeding 30 increases the amount of radiation R absorbed, significantly reducing the dose of radiation R reaching the conversion layer 30, making it undesirable. Therefore, in the case of a resinous substrate 14, the microparticles 14P preferably use inorganic atoms with atomic numbers greater than those of the organic atoms comprising the substrate 14, but not exceeding 30. Specific examples of such fine particles 14P include SiO2, which is an oxide of Si with an atomic number of 14; MgO, which is an oxide of Mg with an atomic number of 12; Al2O3, which is an oxide of Al with an atomic number of 13; and TiO2, which is an oxide of Ti with an atomic number of 22.

[0147] A specific example of a resin sheet having such characteristics is XENOMAX (registered trademark).

[0148] In addition, for the above-mentioned thickness in the embodiment of this example, a micrometer is used for measurement. For the thermal expansion coefficient, it is measured in accordance with JIS K 7197:1991. In addition, the measurement is carried out as follows: a test piece is cut out by changing the angle by 15 degrees at 15 degrees from the main surface of the substrate 14, and the thermal expansion coefficient of each cut test piece is measured, and the highest value is taken as the thermal expansion coefficient of the substrate 14. The measurement of the thermal expansion coefficient is carried out at intervals of 10°C at -50°C to 450°C for the MD (Machine Direction) direction and the TD (Transverse Direction) direction, and (ppm / °C) is converted into (ppm / K). In the measurement of the thermal expansion coefficient, a TMA4000S device manufactured by MAC Science is used, the sample length is set to 10 mm, the sample width is set to 2 mm, and the initial load is 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 JIS K 7171:2016. The measurement was performed as follows: test pieces were cut out at varying angles of 15° from the main surface of the substrate 14. Tensile tests were performed on each of the test pieces, and the highest value was taken as the elastic modulus of the substrate 14.

[0149] In addition, the fine particles 14P contained in the fine particle layer 14L may cause irregularities on the surface of the base material 14. In such a state where the irregularities are formed on the surface of the base material 14, it may be difficult to form the pixels 16. Figure 2C As shown, the substrate 14 preferably has a fine particle layer 14L on the second surface 14B opposite to the first surface where the pixels 16 are formed, in other words, on the second surface 14 opposite to the first surface where the conversion layer 30 is provided.

[0150] In order to fully absorb the backscattered rays Rb generated in the substrate 14, it is preferable that the substrate 14 has a microparticle layer 14L on the side close to the subject S, such as Figure 2C As shown, in the ISS-type radiation detector 10 , it is preferable that the second surface 14B includes a microparticle layer 14L.

[0151] As described above, in the ISS-type radiation detector 10 , since the base material 14 has the fine particle layer 14L on the second surface 14B, the pixels 16 can be formed with high precision and the backscattered rays Rb can be effectively suppressed.

[0152] Furthermore, the substrate 14 having the desired flexibility is not limited to a resin substrate such as a resin sheet. For example, the substrate 14 may also be a relatively thin glass substrate. As a specific example of a glass substrate, generally, a substrate having a side of approximately 43 cm and a thickness of 0.3 mm or less exhibits flexibility. Therefore, any substrate having a thickness of 0.3 mm or less can be the desired glass substrate.

[0153] like Figure 2A as well as Figure 3 As shown, a plurality of pixels 16 are provided in a portion of the inner area of ​​the first surface 14A of the substrate 14. In other words, in the sensor substrate 12 of this exemplary embodiment, no pixels 16 are provided in the outer periphery of the first surface 14A of the substrate 14. In this exemplary embodiment, the area of ​​the first surface 14A of the substrate 14 where the pixels 16 are provided is referred to as the pixel area 15. Furthermore, in this exemplary embodiment, the term "outer periphery" regarding the sensor substrate 12 refers to a region of a predetermined range extending from the outer edge (the edge of the sensor substrate 12) toward the center of the first surface 14A (or second surface 14B) of the sensor substrate 12. In this exemplary embodiment, this refers to at least the region excluding the region where the conversion layer 30 is provided. Furthermore, the inner periphery of the sensor substrate 12, surrounded by the outer periphery, includes at least the entire pixel area 15.

[0154] In the sensor substrate 12 of the embodiment shown in this example, a region of a predetermined range from the outer edge toward the center is defined as a pad portion 17. The pad portion 17 is a region where pads are provided (see Figure 6A The pads 130 are connected to the plurality of scanning wirings 26, the plurality of signal wirings 24, the common wiring 28, and various flexible cables (see FIG. 6A , etc.) such as the control substrate 110 described later. Figure 6A The pad portion 17 of the illustrated embodiment is an example of a terminal portion of the present disclosure. Furthermore, the circuit substrates such as the driver 102 connected to the scan wiring 26, the signal processing unit connected to the signal wiring 24, and the control substrate 110 are collectively referred to as a "PCB (Printed Circuit Board)."

[0155] As shown in Figure 2 and Figure 3 As shown, the conversion layer 30 of the embodiment shown in this example is provided on a portion of the region including the pixel region 15 of the sensor substrate 12. Thus, the conversion layer 30 of the embodiment shown in this example is not provided on the outer peripheral region of the sensor substrate 12.

[0156] In this exemplary embodiment, a scintillator containing CsI (cesium iodide) is used as an example of the conversion layer 30. Preferred examples of such scintillators include CsI:T1 (thallium-doped cesium iodide) and CsI:Na (sodium-doped cesium iodide), which exhibit an emission spectrum of 400 to 700 nm when irradiated with X-rays. The peak emission wavelength of CsI:T1 in the visible light region is 565 nm.

[0157] In the radiation detector 10 of the illustrated embodiment, as an example, the conversion layer 30 is formed directly on the sensor substrate 12 as long columnar crystals by a vapor deposition method such as vacuum evaporation, sputtering, or CVD (Chemical Vapor Deposition). One example of a method for forming the conversion layer 30 is the following vacuum evaporation method: When using CsI:T1 as the conversion layer 30, the CsI:T1 is vaporized by heating using a heating means such as a resistance-heated crucible in a vacuum environment of 0.01 Pa to 10 Pa. The temperature of the sensor substrate 12 is then set to between room temperature (20°C) and 300°C, and the CsI:T1 is deposited on the sensor substrate 12. The thickness of the conversion layer 30 is preferably between 100 μm and 800 μm.

[0158] In addition, in the embodiment shown in this example, the end on the base point side of the growth direction of the columnar crystals of the conversion layer 30 (in the embodiment shown in this example, the sensor substrate 12 side) is called the "root", and the pointed end on the opposite side of the root in the growth direction is called the "front end".

[0159] In addition, since the conversion layer 30 of the embodiment shown in this example is formed by the vapor deposition method as described above, Figure 3 As shown, the outer peripheral region of the conversion layer 30 has a tendency to become thinner as it moves outward, and thus has a tendency to become thinner as it moves outward. In the embodiment shown in this example, the average value of the thickness of the conversion layer 30 within a given range from the center of the conversion layer 30, ignoring manufacturing errors and measurement errors, is used as a reference. As an example, Figure 4 As shown in FIG, the peripheral region where the relative film thickness to the reference thickness (hereinafter referred to as “relative film thickness”) is 90% or less is referred to as “peripheral portion (peripheral portion 30C)”. Figure 4As shown in FIG. 1 , the area of ​​the conversion layer 30 surrounded by the peripheral portion 30C is referred to as the "central portion (central portion 30B)". In other words, the so-called "central portion" refers to an area that includes at least a portion of the conversion layer 30 where the thickness is approximately constant and also includes a portion that is greater than 90% of the relative film thickness. In the embodiment shown in this example, as a specific example, the area within 5 mm from the outer periphery of the conversion layer 30 and where the relative film thickness is less than 90% of the outer periphery is referred to as the "peripheral portion (peripheral portion 30C)". Therefore, as shown in FIG. Figure 3 as well as Figure 4 As shown in FIG. 1 and FIG. 2 , in the peripheral portion 30C, the thickness of the conversion layer 30 tends to gradually become thinner toward the outer periphery (edge).

[0160] In the embodiment shown in this example, as an example of the conversion layer 30 becoming thinner toward the periphery, a form in which the thickness gradually becomes thinner with a certain slope is shown, but the present invention is not limited to this form, and for example, a form in which the thickness changes in a stepwise manner may also be used.

[0161] As an example, the adhesive layer 32 is shown in FIG. 2 and Figure 3 As shown, in the radiation detector 10 of this exemplary embodiment, the adhesive layer 32 and the reflective layer 34 are provided over the entire region of the conversion layer 30, including the central portion ( 30B) and the peripheral portion ( 30C). In other words, the adhesive layer 32 and the reflective layer 34 of this exemplary embodiment cover the entire upper surface of the conversion layer 30. On the other hand, the adhesive layer 32 and the reflective layer 34 of this exemplary embodiment are not provided directly on the sensor substrate 12.

[0162] The adhesive layer 32 of this exemplary embodiment is a light-transmitting layer. Examples of materials for the adhesive layer 32 include 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).

[0163] As the adhesive layer 32 becomes thicker, that is, the gap between the conversion layer 30 and the reflective layer 34 becomes larger, the light converted by the conversion layer 30 becomes more blurred within the adhesive layer 32. Consequently, the radiographic image obtained by the radiation detector 10 becomes blurred. Therefore, as the adhesive layer 32 becomes thicker, the MTF (Modulation Transfer Function) and DQE (Detective Quantum Efficiency) decrease, and the degree of decrease increases.

[0164] On the other hand, even when the adhesive layer 32 is too thin, including when it is not provided, a tiny air layer (not shown) may form between the conversion layer 30 and the reflective layer 34. In this case, light traveling from the conversion layer 30 to the reflective layer 34 undergoes multiple reflections between the air layer and the conversion layer 30, and between the air layer and the reflective layer 34. If the light is attenuated by the multiple reflections, the sensitivity of the radiation detector 10 decreases. If the thickness of the adhesive layer 32 exceeds 7 μm, the degree of reduction in DQE becomes even greater, even lower than when the adhesive layer 32 is not provided (thickness of 0 μm). Furthermore, if the thickness of the adhesive layer 32 is less than 2 μm, the sensitivity of the radiation detector 10 decreases. Therefore, in the embodiment illustrated, the thickness of the adhesive layer 32 is set to be between 2 μm and 7 μm. The refractive index of the adhesive layer 32 is generally around 1.5, although it varies depending on the material.

[0165] In addition, the adhesive layer 32 has the function of fixing the reflective layer 34 to the conversion layer 30, but if the thickness of the adhesive layer 32 is greater than 2 μm, the effect of fully suppressing the deviation of the reflective layer 34 relative to the conversion layer 30 in the in-plane direction (direction intersecting the thickness direction) can be achieved.

[0166] On the other hand, as an example, the reflective layer 34 is as shown in FIG. 2 and Figure 3 As shown, the reflective layer 34 is provided on the adhesive layer 32 and covers the entire upper surface of the adhesive layer 32. The reflective layer 34 has a function of reflecting the light converted by the conversion layer 30.

[0167] The reflective layer 34 is preferably made of an organic material. For example, at least one of white PET (Polyethylene Terephthalate), TiO2, Al2O3, foamed white PET, a polyester-based high-reflection sheet, and specular reflective aluminum is preferably used. In particular, white PET is preferably used from the perspective of reflectivity.

[0168] White PET is PET made by adding white pigments such as TiO2 or barium sulfate. Highly reflective polyester sheeting is a multilayered sheet (film) made by stacking multiple thin polyester sheets. Foamed white PET is white PET with a porous surface.

[0169] In the illustrated embodiment, the thickness of the reflective layer 34 is set to be between 10 μm and 40 μm. As the thickness of the reflective layer 34 increases, the step between the upper surface of the outer periphery of the reflective layer 34 and the upper surface of the conversion layer 30 increases. In the illustrated embodiment, the radiation detector 10 is manufactured by laminating a sheet (film) of the adhesive layer 36 and the protective layer 38 to the sensor substrate 12, which is already formed up to the reflective layer 34. If the step is large, when the adhesive layer 36 and the protective layer 38 are laminated onto the reflective layer 34, at least one of the adhesive layer 36 and the protective layer 38 may float at the step.

[0170] Furthermore, if the thickness of the reflective layer 34 increases, it becomes in a state that can be described as tough, and therefore it may be difficult to bend it along the inclination of the peripheral edge portion 30C of the conversion layer 30 , making processing difficult.

[0171] Therefore, from these viewpoints, in the radiation detector 10 of the embodiment shown in this example, when white PET is used as the material of the reflective layer 34 , the thickness of the reflective layer 34 is set to 40 μm or less as described above.

[0172] On the other hand, the thinner the reflective layer 34, the lower its reflectivity. Lower reflectivity also tends to reduce the quality of radiographic images obtained by the radiation detector 10. Therefore, from the perspective of the quality of radiographic images obtained by the radiation detector 10, it is preferable to determine the lower limit of the thickness of the reflective layer 34 by considering the desired reflectivity (e.g., 80%). In the radiation detector 10 of the illustrated embodiment, when white PET is used as the material for the reflective layer 34, the thickness of the reflective layer 34 is set to 10 μm or greater, as described above.

[0173] On the other hand, as an example, the adhesive layer 36 is as shown in FIG. 2 and Figure 3As shown, the adhesive layer 36 extends from an area near the outer periphery of the conversion layer 30 on the sensor substrate 12 to an area covering the end of the reflective layer 34. In other words, in the radiation detector 10 of the illustrated embodiment, the adhesive layer 36, which covers the entire conversion layer 30 including the adhesive layer 32 and the reflective layer 34, is directly fixed (bonded) to an area outside the pad portion 17 on the surface of the sensor substrate 12. The adhesive layer 36 has the function of fixing the reflective layer 34 to the sensor substrate 12 and the conversion layer 30. Furthermore, the adhesive layer 36 has the function of fixing the protective layer 38. Examples of materials for the adhesive layer 36 include the same materials as those for the adhesive layer 32. Furthermore, in the illustrated embodiment, the adhesive layer 36 has a stronger adhesive force than the adhesive layer 32.

[0174] Furthermore, as an example, the protective layer 38 is as shown in FIG. 2 and FIG. Figure 3 As shown, the protective layer 38 of this exemplary embodiment is disposed on the adhesive layer 36 and covers the entire upper surface of the adhesive layer 36. The adhesive layer 36 covers the conversion layer 30, whose upper surface is covered by the adhesive layer 32 and the reflective layer 34. The protective layer 38 of this exemplary embodiment protects the conversion layer 30 from moisture, such as humidity. Furthermore, the protective layer 38 of this exemplary embodiment, together with the adhesive layer 36, secures the reflective layer 34 to the sensor substrate 12 and the conversion layer 30. Examples of materials for the protective layer 38 include organic films such as PET, PPS (PolyPhenylene Sulfide), OPP (Oriented PolyPropylene), PEN (PolyEthylene Naphthalate), and PI. As the protective layer 38 , a sheet of ALPET (registered trademark) in which aluminum is laminated by bonding aluminum foil to an insulating sheet (film) such as polyethylene terephthalate can be used.

[0175] In addition, hereinafter, the structure in which the conversion layer 30 , the adhesive layer 32 , the reflective layer 34 , the bonding layer 36 , and the protective layer 38 are stacked is referred to as a stacked body 19 .

[0176] On the other hand, as an example, the elastic layer 42 is shown in FIG. 2 and Figure 3 As shown in FIG. 1 , the conversion layer 30 is provided on the side opposite to the side where the sensor substrate 12 is provided ( Figure 3 Specifically, the elastic layer 42 of the embodiment shown in FIG. 2 and FIG. Figure 3As shown in FIG. 4 , the central portion 30B of the conversion layer 30 is stacked with the adhesive layer 40 interposed therebetween, and protrudes substantially in parallel with the sensor substrate 12 across the conversion layer 30. Figure 3 As shown, the elastic layer 42 is laminated on the laminate 19 via the adhesive layer 40 only in the region corresponding to the central portion 30B of the conversion layer 30 .

[0177] In addition, as shown in Figure 2 and Figure 3 As shown in FIG. 1 , the position of the end of the elastic layer 42 is set to be the same as the position of the end of the adhesive layer 36 and the protective layer 38. The elastic layer 42 does not protrude into the area corresponding to the pad portion 17 and does not directly contact the sensor substrate 12. In the radiation detector 10 of the embodiment shown in this example, by not providing the elastic layer 42 in the area corresponding to the pad portion 17, the cable 112 (see FIG. 1 ) is connected to the pad portion 17. Figure 6A In the case of so-called reprocessing, etc., the elastic layer 42 can be prevented from becoming an obstacle.

[0178] In addition, as an example, the adhesive layer 40 is as shown in FIG. 2 and Figure 3 As shown, it is provided in a region corresponding to the central portion 30B of the conversion layer 30. The adhesive layer 40 has the function of fixing the elastic layer 42 to the laminate 19. Examples of the material of the adhesive layer 40 include the same materials as those of the pressure-sensitive adhesive layer 32 and the adhesive layer 36.

[0179] As will be described in detail later, the elastic layer 42 has a restoring force that restores the sensor substrate 12 (base material 14) to its pre-deflected state if the sensor substrate 12 (base material 14) deflects. Specifically, the elastic layer 42 of this exemplary embodiment has a higher restoring force against deflection than the sensor substrate 12. Furthermore, the elastic layer 42 of this exemplary embodiment has a higher rigidity than the sensor substrate 12 to prevent deflection of the sensor substrate 12 (base material 14).

[0180] The elastic layer 42 having such properties is preferably made of an organic material, such as a sheet made of at least one of PET, white PET, and foamed white PET. Other examples of the elastic layer 42 include organic films such as PC (polycarbonate), LDPE (low-density polyethylene), PPS, OPP, PEN, and PI.

[0181] In the illustrated embodiment, as an example, the thickness of the elastic layer 42 is predetermined based on the material of the elastic layer 42, the desired restoring force, and other factors. The desired restoring force is determined based on the thickness of the substrate 14, the expected deflection of the sensor substrate 12 (substrate 14), and other factors. For example, 1 mm is an example of a thickness. The thinner the elastic layer 42, the smaller the restoring force. Furthermore, the thicker the elastic layer 42, the greater the restoring force, making it more difficult to bend. This makes it difficult to bend the sensor substrate 12 when desired during the manufacturing process of the sensor substrate 12, which will be described later. Furthermore, the dimension of the radiation detector 10 in the stacking direction P increases. Therefore, the thickness of the elastic layer 42 is preferably set to the minimum thickness required to achieve the desired restoring force.

[0182] Specifically, the elastic layer 42 of the embodiment shown in this example preferably uses a material having a bending modulus of 150 MPa or more and 2500 MPa or less. The method for measuring the bending modulus is based on, for example, JIS K 7171:2016. From the perspective of suppressing the deflection of the substrate 14, the elastic layer 42 preferably has a higher bending rigidity than the substrate 14. In addition, if the bending modulus becomes lower, the bending rigidity also becomes lower. In order to obtain the desired bending rigidity, the thickness of the elastic layer 42 must be increased, and the thickness of the entire radiation detector 10 will increase. Considering the material of the elastic layer 42 described above, if you want to obtain a bending rigidity exceeding 140,000 Pacm 4 When the bending rigidity is too high, the thickness of the elastic layer 42 tends to become relatively thick. Therefore, in order to obtain appropriate rigidity and considering the thickness of the entire radiation detector 10, the material used for the elastic layer 42 is more preferably one with a bending elastic modulus of 150 MPa or more and 2500 MPa or less. In addition, the bending rigidity of the elastic layer 42 is preferably 540 Pacm 4 Above and 140000Pacm 4 the following.

[0183] Furthermore, the coefficient of thermal expansion of the elastic layer 42 in this exemplary embodiment is preferably close to that of the material of the conversion layer 30. More preferably, the ratio of the coefficient of thermal expansion of the elastic layer 42 to the coefficient of thermal expansion of the conversion layer 30 (thermal expansion coefficient of the elastic layer 42 / thermal expansion coefficient of the conversion layer 30) is 0.5 to 4. The coefficient of thermal expansion of the elastic layer 42 is preferably 30 ppm / K to 200 ppm / K. For example, when the conversion layer 30 is made of CsI:T1, the coefficient of thermal expansion is 50 ppm / K. In this case, examples of materials for the elastic layer 42 include LDPE with a thermal expansion coefficient of 100ppm / K to 200ppm / K, polyvinyl chloride (PVC) with a thermal expansion coefficient of 60ppm / K to 80ppm / K, acrylic with a thermal expansion coefficient of 70ppm / K to 80ppm / K, PET with a thermal expansion coefficient of 65ppm / K to 70ppm / K, PC with a thermal expansion coefficient of 65ppm / K, and Teflon (registered trademark) with a thermal expansion coefficient of 45ppm / K to 70ppm / K.

[0184] Furthermore, considering the above-mentioned bending modulus, the material of the elastic layer 42 is preferably a material containing at least one of PET, PC, and LDPE.

[0185] Furthermore, from the perspective of elasticity, the elastic layer 42 preferably comprises a material with a yield point. In the illustrated embodiment, the term "yield point" refers to the phenomenon in which stress temporarily and sharply decreases when a material is stretched. On a curve representing the relationship between stress and strain, it refers to the point where strain increases without increasing stress, and is the peak of the stress-strain curve when a material is subjected to a tensile strength test. Examples of resins with a yield point include hard, viscous resins and soft, viscous resins with medium strength. Examples of hard, viscous resins include PC. Examples of soft, viscous resins with medium strength include polypropylene.

[0186] In addition, the radiation detector 10 of the embodiment shown in this example is Figure 5 As shown in the example, the sensor substrate 12 is formed by lamination, for example, on a support 50 such as a glass substrate thicker than the base material 14, with a release layer 51 interposed therebetween. When the sensor substrate 12 is formed by lamination, a sheet forming the base material 14 is bonded to the release layer 51.

[0187] Furthermore, as described above, the conversion layer 30, the adhesive layer 32, the reflective layer 34, the bonding layer 36, and the protective layer 38 are sequentially provided on the substrate 14 to form the laminate 19. Furthermore, the bonding layer 40 and the elastic layer 42 are sequentially provided on the laminate 19. Thereafter, the sensor substrate 12 is peeled off from the support 50 via the release layer 51. The release method is not particularly limited. For example, in mechanical release, any of the four sides of the sensor substrate 12 (substrate 14) is used as the starting point for release, and the sensor substrate 12 is gradually peeled off from the support 50 from the starting side toward the opposite side, thereby releasing the sensor substrate 12. Alternatively, in laser lift-off, for example, a laser is irradiated from the back side of the support 50 (the side opposite to the side on which the sensor substrate 12 is provided). The laser then passes through the support 50, decomposing the release layer 51, thereby releasing the sensor substrate 12 from the support 50.

[0188] Here, when the sensor substrate 12 is peeled off from the support 50, the sensor substrate 12 will bend. Especially in mechanical peeling, in most cases, the sensor substrate 12 is peeled off from the support 50 while being bent. The flexible base material 14 used in the sensor substrate 12 is less rigid than a glass base material and is therefore easy to bend. In addition, when the sensor substrate 12 is bent, it is not the base material 14 that bends as a whole, but it bends or deforms partially or locally, and sometimes the bending manner is different at each position within the surface of the base material 14 (the first surface 14A and the second surface 14B). The deflection or deformation generated in such a situation is referred to as "discontinuous deflection" in the embodiment of this example, as opposed to deflection as a whole. In addition, this discontinuous deflection tends to be more easily caused near the outer periphery of the conversion layer 30.

[0189] In this way, when the sensor substrate 12 (base material 14) is bent, in the radiation detector 10 of the embodiment illustrated in this example, since the elastic layer 42 has a higher restoring force than the base material 14, the bent portion is easy to return to its original state (state before bending), and the base material 14 can be prevented from being bent excessively.

[0190] On the other hand, when the sensor substrate 12 (base material 14) is kept bent, especially when the bending is discontinuous, the conversion layer 30 becomes easy to peel off from the sensor substrate 12, or the conversion layer 30 and the pixels 16 become easy to be damaged.

[0191] In the radiation detector 10 of the illustrated embodiment, as described above, the elastic layer 42 has a higher restoring force than the base 14 , so the deflected portion easily returns to its original state (pre-deflection state), and excessive deflection of the base 14 is suppressed.

[0192] Therefore, according to the radiation detector 10 of the illustrated embodiment, in the manufacturing process of the radiation detector 10 including the sensor substrate 12 having the flexible base material 14 manufactured using the support 50 , the influence of the deflection generated when the sensor substrate 12 is peeled from the support 50 can be suppressed.

[0193] In addition, the radiation detector 10 of the embodiment shown in this example is shown in FIG. 2 and FIG. Figure 3 As shown, even after the sensor substrate 12 is peeled from the support 50, the elastic layer 42 is provided on the laminate 19. Therefore, after the radiation detector 10 is manufactured, especially when the sensor substrate 12 is treated as a single unit rather than as the radiation imaging device 1, even if the sensor substrate 12 (base material 14) is warped, the elastic layer 42 has a high restoring force against the warping, thereby suppressing problems caused by the influence of the warping as described above.

[0194] Next, a radiation imaging device 1 using the radiation detector 10 of the embodiment of this example will be described. In the radiation imaging device 1, the radiation detector 10 is provided in a casing that transmits radiation and has waterproof, antibacterial, and airtight properties.

[0195] exist Figure 6A 2 shows an example of a state where the radiation detector 10 is installed in the housing 120 when the radiation imaging device 1 according to the embodiment of this example is used in the PSS method (Penetration Side Sampling).

[0196] like Figure 6A As shown, the radiation detector 10, the power supply unit 108, and the control board 110 are arranged in a row in a direction intersecting the stacking direction P within the housing 120. The radiation detector 10 is arranged such that the second surface 14B of the base 14 faces the side of the housing 120 opposite to the imaging surface 120A side of the housing 120 irradiated with radiation that has passed through the subject, i.e., the side of the housing 120 from which the radiation is emitted.

[0197] In addition, Figure 6B An example of a state in which the radiation detector 10 is installed in the housing 120 when the radiation imaging apparatus 1 according to the embodiment of this example is used in the ISS method is shown.

[0198] like Figure 6B As shown, within the housing 120, the radiation detector 10, the power supply unit 108, and the control board 110 are arranged side by side in a direction intersecting the stacking direction P. The radiation detector 10 is arranged so that the second surface 14B of the base 14 faces the imaging surface 120A side of the housing 120, which is the irradiation surface of the housing 120 that is irradiated with radiation that has passed through the subject.

[0199] The control substrate 110 is a substrate on which the image memory 106, the control unit 100, and other components are formed. It is electrically connected to the pixels 16 of the sensor substrate 12 via a cable 112 including a plurality of signal traces connected to pads 130 provided on the pad section 17 of the radiation detector 10. While the embodiment illustrated herein utilizes a so-called COF (Chip On Film) in which the driver 102 and the signal processing unit 104 are provided on the cable 112, at least one of the driver 102 and the signal processing unit 104 may be formed on the control substrate 110. Furthermore, the control substrate 110 and the power supply unit 108 are connected via a power line 114.

[0200] The housing 120 is preferably lightweight, has a low absorption rate of radiation R, particularly X-rays, and is highly rigid. It is also preferably made of a material with a sufficiently high elastic modulus. A material having a flexural modulus of 10,000 MPa or greater is preferably used as the material for the housing 120. Suitable materials for the housing 120 include carbon or CFRP (Carbon Fiber Reinforced Plastics) having a flexural modulus of approximately 20,000 to 60,000 MPa.

[0201] When the radiation imaging device 1 captures radiographic images, a load from the subject is applied to the imaging surface 120A of the housing 120. If the housing 120 is not rigid enough, the load from the subject may cause the sensor substrate 12 to bend, potentially leading to problems such as damage to the pixels 16. By housing the radiation detector 10 within the housing 120, which is constructed from a material having a flexural modulus of elasticity of 10,000 MPa or greater, deflection of the sensor substrate 12 caused by the load from the subject can be suppressed.

[0202] Figure 6A as well as Figure 6B The illustrated radiation imaging device 1 can capture radiation images while the radiation detector 10 is bent outward from the second surface 14B of the substrate 14. For example, the radiation detector 10 can be bent in accordance with the imaging portion of the subject and maintained in this state to capture radiation images.

[0203] exist Figure 6A as well as Figure 6B In the radiation imaging device 1 shown, the power supply unit 108 and the control board 110 are provided on the periphery of the relatively rigid housing 120 , thereby suppressing the influence of external forces on the power supply unit 108 and the control board 110 .

[0204] In addition, Figure 6A as well as Figure 6B In the embodiment, the power supply unit 108 and the control board 110 are both provided on one side of the radiation detector 10, specifically, on one side of one side of the rectangular radiation detector 10. However, the positions of the power supply unit 108 and the control board 110 are not limited to the positions of the power supply unit 108 and the control board 110. Figure 6A as well as Figure 6B For example, the power supply unit 108 and the control board 110 may be dispersedly arranged on each of the two opposite sides of the radiation detector 10, or may be dispersedly arranged on each of the two adjacent sides. Figure 6A as well as Figure 6B The power supply unit 108 and the control substrate 110 are shown as one structural unit (substrate), but this is not limited to the above. Figure 6A as well as Figure 6B The embodiment shown may also be an embodiment in which at least one of the power supply unit 108 and the control substrate 110 is provided as a plurality of components (substrates). For example, the power supply unit 108 may be provided as a configuration including a first power supply unit and a second power supply unit (both not shown), and the first power supply unit and the second power supply unit are separately provided on each of two opposing sides of the radiation detector 10.

[0205] Furthermore, when capturing a radiographic image by bending the entire radiation imaging apparatus 1 (radiation detector 10 ), the influence of the bending on the image can be suppressed by performing image correction.

[0206] In addition, if Figure 6A as well as Figure 6B As shown in the example, in many cases, the power supply unit 108 and the control board 110 are each thicker than the radiation detector 10. In such a case, Figure 6CAs shown in the example, the thickness of the portion of the housing 120 where the radiation detector 10 is located is made thinner than the thickness of the portion of the housing 120 where the power supply unit 108 and the control board 110 are located. Furthermore, if the thickness of the portion of the housing 120 where the power supply unit 108 and the control board 110 are located is different from the thickness of the portion of the housing 120 where the radiation detector 10 is located, a step difference may occur at the boundary between the two portions. This may cause a sense of discomfort to the subject who comes into contact with the boundary 120B. Therefore, it is preferable that the boundary 120B be inclined.

[0207] This makes it possible to construct an extremely thin portable electronic cassette that corresponds to the thickness of the radiation detector 10 .

[0208] In this case, for example, the material of the housing 120 may be different between the portion of the housing 120 where the power supply unit 108 and the control board 110 are installed and the portion of the housing 120 where the radiation detector 10 is installed. Furthermore, for example, the portion of the housing 120 where the power supply unit 108 and the control board 110 are installed and the portion of the housing 120 where the radiation detector 10 is installed may be configured as separate bodies.

[0209] In addition, as described above, the housing 120 preferably has a low absorption rate of radiation R, especially X-rays, and high rigidity, and is preferably made of a material with a sufficiently high elastic modulus, but may also be made of a material having a high elastic modulus. Figure 6D As shown in the example, the portion 120C corresponding to the imaging surface 120A of the shell 120 is made of a material having a low absorption rate of radiation R, high rigidity, and a sufficiently high elastic modulus, and the other portions are made of a material different from that of the portion 120C, for example, a material having a lower elastic modulus than that of the portion 120C.

[0210] In addition, you can Figure 6E As shown in the example, the radiation detector 10 and the inner wall of the housing 120 are in contact. In this case, the radiation detector 10 and the inner wall of the housing 120 may be bonded via an adhesive layer or may simply be in contact without an adhesive layer. In this manner, the contact between the radiation detector 10 and the inner wall of the housing 120 further ensures the rigidity of the radiation detector 10.

[0211] In addition, Figure 7A Another example of a state in which the radiation detector 10 is installed in the housing 120 when the radiation imaging apparatus 1 according to the embodiment of this example is used in the PSS method will be described.

[0212] like Figure 7AAs shown, the power supply unit 108 and the control board 110 are arranged side by side in a direction intersecting the stacking direction P in the housing 120 , and the radiation detector 10 , the power supply unit 108 , and the control board 110 are arranged side by side in the stacking direction P.

[0213] In addition, Figure 7B Another example of a state in which the radiation detector 10 is installed in the housing 120 when the radiation imaging apparatus 1 according to the embodiment of this example is used in the ISS method will be described.

[0214] like Figure 7B As shown, the power supply unit 108 and the control board 110 are arranged side by side in a direction intersecting the stacking direction P in the housing 120 , and the radiation detector 10 , the power supply unit 108 , and the control board 110 are arranged side by side in the stacking direction P.

[0215] In addition, Figure 7A as well as Figure 7B In the radiation imaging device 1 shown, a base 118 for supporting the radiation detector 10 and the control board 110 is provided between the control board 110 and the power supply unit 108 and the base 14. The base 118 is made of, for example, carbon.

[0216] Figure 7A as well as Figure 7B The radiation image capturing device 1 shown can capture radiation images in a state where the radiation detector 10 is slightly bent in the outward direction of the second surface 14B of the substrate 14, for example, in a state where the central portion is bent by about 1 mm to 5 mm. However, since the control substrate 110, the power supply unit 108, and the radiation detector 10 are arranged in the stacking direction P and the base 118 is provided, the radiation image will not be bent to the extent that the radiation detector 10 is bent. Figure 7A as well as Figure 7B The degree of the situation of the radiation imaging device 1 shown.

[0217] [Second exemplary embodiment]

[0218] The second exemplary embodiment will now be described. The radiation detector 10 of this exemplary embodiment includes the same configuration as the radiation detector 10 of the first exemplary embodiment (see FIGS. 1 to 3 ), and therefore detailed description of the same configuration will be omitted.

[0219] exist Figure 8 FIG. 1 is a cross-sectional view showing an example of the radiation detector 10 according to the embodiment of this example. Figure 8 As shown, in the radiation detector 10 of the embodiment shown in this example, a filler 70 is filled between the laminate 19 and the elastic layer 42. Figure 8As shown, the radiation detector 10 of the present exemplary embodiment is different from the radiation detector 10 of the first exemplary embodiment in that the space between the laminated body 19 and the elastic layer 42 is filled with a filler 70 .

[0220] The material of the filler 70 is not particularly limited, and a seal made of a general semiconductor material can be used. In addition, the filler 70 can also have elasticity and resilience like the elastic layer 42. In the embodiment shown in this example, the adhesive layer 40 is provided between the elastic layer 42 and the filler 70 in order to fix the elastic layer 42 relative to the filler 70. Figure 8 In the example shown, it is provided on the entire surface of the elastic layer 42 facing the sensor substrate 12 .

[0221] The method for providing the filler 70 is not particularly limited. For example, after sequentially forming the adhesive layer 40 and the elastic layer 42 on the laminate 19, the fluid filler 70 can be injected into the gap between the adhesive layer 40 and the laminate 19 and cured. Alternatively, for example, after the laminate 19 is formed on the sensor substrate 12, the fluid filler 70 can be placed in the area to be filled with the filler 70, and the adhesive layer 40 and the elastic layer 42 can be sequentially formed on the laminate 19 and the filler 70 to provide the filler 70.

[0222] In this manner, the radiation detector 10 of the illustrated embodiment includes a filler 70 between the laminate 19 and the elastic layer 42. The filler 70 supports the elastic layer 42, which protrudes forward (toward the end of the sensor substrate 12) from the central portion 30B. Therefore, the radiation detector 10 of the illustrated embodiment can stably position the elastic layer 42, making it difficult for the elastic layer 42 to peel from the laminate 19. Furthermore, the radiation detector 10 of the illustrated embodiment secures the laminate 19 to the sensor substrate 12 via the elastic layer 42 and the filler 70, making it difficult for the conversion layer 30 to peel from the sensor substrate 12.

[0223] In addition, Figure 8 In the example shown, the filler 70 is filled without a gap between the laminate 19 and the elastic layer 42, but the present invention is not limited thereto. Figure 8 In the illustrated embodiment, for example, a gap (an area not filled with the filler 70 ) may exist partially between the laminate 19 and the elastic layer 42 .

[0224] [Third exemplary embodiment]

[0225] The third exemplary embodiment will now be described. The radiation detector 10 of this exemplary embodiment includes the same configuration as the radiation detector 10 of the first exemplary embodiment (see FIGS. 1 to 3 ), and therefore detailed description of the same configuration will be omitted.

[0226] exist Figure 9 1 is a cross-sectional view of an example of the radiation detector 10 according to the embodiment of this example. Figure 9 FIG. 1 shows a state where the pad 130 is provided on the pad portion 17 and the cable 112 is electrically connected to the pad 130. Figure 9 As shown, the radiation detector 10 of the present exemplary embodiment is different from the radiation detector 10 of the first exemplary embodiment in that the elastic layer 42 is provided up to the region facing the pad portion 17 .

[0227] exist Figure 9 In the example shown, the elastic layer 42 is provided in the entire region facing the pad portion 17, and the end of the elastic layer 42 and the end of the sensor substrate 12 (base material 14) are at the same position. In other words, the side surface of the end of the elastic layer 42 and the side surface of the end of the sensor substrate 12 are so-called flush. Figure 9 In the example shown, the elastic layer 42 may be provided up to a portion of the region facing the pad portion 17. In other words, the end of the elastic layer 42 may be located at a position facing the region within the pad portion 17.

[0228] As described above, the radiation detector 10 of the embodiment shown in this example provides the elastic layer 42 up to the region facing the pad portion 17 , and therefore can provide a high restoring force (elasticity) against deflection up to the end portion of the sensor substrate 12 .

[0229] In addition, when the elastic layer 42 is provided up to the region facing the pad portion 17, it is preferable to Figure 10 As in the example of the radiation detector 10 shown in FIG. 1 , similarly to the second embodiment described above, a filler 70 is filled between the elastic layer 42 and the laminate 19. In particular, it is more preferable to Figure 10 As shown in the example, the filler 70 is also filled between the elastic layer 42 and the sensor substrate 12 in the pad portion 17. In this case, it is preferable to fill the filler 70 after providing the pad 130 and the cable 112 in the pad portion 17.

[0230] like Figure 10As in the radiation detector 10 shown in FIG. 1 , the elastic layer 42 is stably provided by filling with the filler 70. Therefore, the elastic layer 42 is unlikely to be peeled off from the laminate 19, and the conversion layer 30 is unlikely to be peeled off from the sensor substrate 12. Furthermore, in the second exemplary embodiment, as described above, the filler 70 may not be filled in a portion of the region.

[0231] In addition, if Figure 11 As in the example of the radiation detector 10 shown in FIG. 1 , a configuration may be adopted in which a spacer 72 functioning as a support portion for supporting between the end portion of the elastic layer 42 and the sensor substrate 12 is provided on the pad portion 17 .

[0232] There is no particular limitation on the method of setting the isolation member 72. For example, the isolation member 72 can be attached to the end of the elastic layer 42 by means of an adhesive (omitted in the figure), and the elastic layer 42 with the isolation member 72 set thereon is attached to the sensor substrate 12 with the stack 19, the adhesive layer 40, the pad 130 and the cable 112 set thereon, thereby setting the isolation member 72 between the end of the pad portion 17 and the sensor substrate 12.

[0233] In such Figure 11 In the case where an isolation member 72 is provided as in the radiation detector 10 shown, a larger space is provided than in the case where the filler 70 is filled between the stack 19 and the sensor substrate 12 and the elastic layer 42, but since the ends of the elastic layer 42 are supported, the elastic layer 42 is difficult to peel off from the stack 19, and a high restoring force (elasticity) against deflection can be imparted up to the ends of the sensor substrate 12.

[0234] The width of the spacer 72 (in a direction intersecting the stacking direction P) is not limited to the example shown in FIG11 . For example, the width of the spacer 72 may extend to a position closer to the conversion layer 30 than the tip of the cable 112. Furthermore, for example, the spacer 72 may have a width extending across the entire pad portion 17.

[0235] [Fourth exemplary embodiment]

[0236] The radiation detector 10 of this embodiment includes the same configuration as the radiation detector 10 of the first embodiment (see FIGS. 1 to 3 ), and therefore detailed description of the same configuration will be omitted.

[0237] exist Figure 12 FIG. 1 is a cross-sectional view showing an example of the radiation detector 10 according to the embodiment of this example. Figure 12As shown, the radiation detector 10 of the present exemplary embodiment is different from the radiation detector 10 of the first exemplary embodiment in that an elastic member 41 is provided on the second surface 14B of the base material 14 of the sensor substrate 12 .

[0238] like Figure 12 As shown, the elastic member 41 is provided on the second surface 14B of the substrate 14, extending from the outer edge of the substrate 14 to a portion of the region where the conversion layer 30 is provided, with the front end of the elastic member 41 located inside the central portion 30B of the conversion layer 30. Similarly to the elastic layer 42, the elastic member 41 is formed by being bonded to the second surface 14B via an adhesive layer (not shown).

[0239] Like the elastic layer 42, the elastic member 41 has a restoring force that restores the sensor substrate 12 to its pre-deflection state when it is deflected. Specifically, the elastic member 41 of the illustrated embodiment has a higher restoring force against deflection than the sensor substrate 12. Furthermore, the elastic member 41 of the illustrated embodiment has a higher rigidity than the sensor substrate 12 to prevent the sensor substrate 12 (base material 14) from deflecting.

[0240] In addition, the coefficient of thermal expansion of the elastic member 41 in this exemplary embodiment, like the elastic layer 42 described above, is preferably close to that of the material of the conversion layer 30. More preferably, the ratio of the coefficient of thermal expansion of the elastic member 41 to the coefficient of thermal expansion of the conversion layer 30 (coefficient of thermal expansion of the elastic member 41 / coefficient of thermal expansion of the conversion layer 30) is 0.5 or greater and 4 or less. The coefficient of thermal expansion of the elastic member 41 is preferably 30 ppm / K or greater and 200 ppm / K or less. For example, when the conversion layer 30 is made of CsI:Tl, the coefficient of thermal expansion is 50 ppm / K. In this case, examples of materials for the elastic member 41 include LDPE with a thermal expansion coefficient of 100ppm / K to 200ppm / K, polyvinyl chloride (PVC) with a thermal expansion coefficient of 60ppm / K to 80ppm / K, acrylic acid with a thermal expansion coefficient of 70ppm / K to 80ppm / K, PET with a thermal expansion coefficient of 65ppm / K to 70ppm / K, PC with a thermal expansion coefficient of 65ppm / K, and Teflon (registered trademark) with a thermal expansion coefficient of 45ppm / K to 70ppm / K.

[0241] As the elastic member 41 having such characteristics, an organic material is preferably used, similarly to the elastic layer 42 , and for example, a sheet or the like using at least one of PET, white PET, foamed white PET, PC, LDPE, PPS, OPP, PEN, and PI as a material is preferably used.

[0242] As described above, in the radiation detector 10 of the embodiment shown, the elastic member 41 is provided from the outer edge of the base material 14 to a portion of the region where the conversion layer 30 is provided. This allows restoring force and rigidity to be imparted to the outer edge of the sensor substrate 12 .

[0243] In addition, in the radiation detector 10 of the embodiment illustrated in this example, since a portion of the elastic layer 42 and the elastic member 41 are arranged opposite to each other with the sensor substrate 12 and the stacked body 19 (conversion layer 30) sandwiched therebetween, they can complement each other's restoring force and rigidity, and can further suppress the influence of the deflection of the base material 14.

[0244] Furthermore, the region where the elastic member 41 and the elastic layer 42 are disposed facing each other preferably includes a predetermined overlapping region 43 starting from the central portion 30B that is in contact with the boundary of the peripheral portion 30C of the conversion layer 30 .

[0245] The conversion layer 30 has a slope where the thickness decreases toward the outer edge 30C. Therefore, near the boundary between the central portion 30B, where the thickness of the conversion layer 30 varies, and the peripheral portion 30C, discontinuous deflection is likely to occur on the sensor substrate 12. Therefore, it is preferable to include a predetermined region from the central portion 30B, which is adjacent to the boundary with the peripheral portion 30C of the conversion layer 30, where discontinuous deflection is likely to occur, as the overlapping region 43.

[0246] In addition, the area to be set as the overlapping area 43 is not limited to Figure 12 For example, Figure 12 In the figure, only the region corresponding to the central portion 30B is set as the overlapping region 43 , but a region including the boundary between the central portion 30B and the peripheral portion 30C and extending from the central portion 30B to the peripheral portion 30C may be set as the overlapping region 43 .

[0247] In addition, the area where the elastic member 41 is provided can also be provided in the above-mentioned overlapping area 43, and is not limited to Figure 12 For example, the elastic member 41 may be provided over the entire second surface 14B of the base material 14 .

[0248] If the above conditions are satisfied, the specific overlapping region 43 and the region where the elastic member 41 is provided are not particularly limited and may be determined based on the material of the elastic layer 42 , the position of the pixel region 15 , and the reading method.

[0249] As described above, the radiation detector 10 of each of the above-mentioned exemplary embodiments includes: a sensor substrate 12, which includes a flexible base material 14, and a layer provided on the first surface 14A of the base material 14 and forming a plurality of pixels 16 for storing charges corresponding to light converted from radiation; a conversion layer 30, which is provided on the first surface 14A side of the sensor substrate 12 and converts radiation into light; and an elastic layer 42, which is provided on the side of the conversion layer 30 opposite to the side on which the sensor substrate 12 is provided and has a higher restoring force against deflection than the sensor substrate 12.

[0250] As described above, the radiation detector 10 of each of the above-described exemplary embodiments includes the elastic layer 42 disposed on the side of the conversion layer 30 opposite to the side on which the sensor substrate 12 is disposed and having a higher resilience against deflection than the sensor substrate 12. Therefore, compared to a configuration in which a layer having no resilience against deflection is provided, the effects of deflection that occurs when the sensor substrate 12 is peeled off from the support 50 can be suppressed during the manufacturing process of the radiation detector 10 including the sensor substrate 12 having a flexible base material 14 manufactured using the support 50. Furthermore, since the effects of deflection can be suppressed in the radiation detector 10 of each of the above-described exemplary embodiments, peeling of the conversion layer 30 from the sensor substrate 12 and damage to the pixels 16 or the conversion layer 30 can be suppressed.

[0251] The area where the elastic layer 42 is provided is not limited to the above-described exemplary embodiments, and may be at least the area covering the central portion 30B of the conversion layer 30. For example, the end portion of the elastic layer 42 may extend from the area covering the central portion 30B to the area corresponding to the outer periphery of the peripheral portion 30C (the edge of the conversion layer 30 that contacts the first surface 14A). As an example of the area where the elastic layer 42 is provided, Figure 13 As in the example of the radiation detector 10 shown in FIG. 1 , the elastic layer 42 is formed via the adhesive layer 40 so as to cover the surface (upper surface) of the laminate 19, in other words, without providing a space between the elastic layer 42 and the laminate 19. Figure 13 In the example shown, the elastic layer 42 covers the entire central portion 30B and a portion of the peripheral portion 30C of the conversion layer 30 included in the laminate 19, and the end portion of the elastic layer 42 is located in the area corresponding to the peripheral portion 30C. Figure 14 As in the example of the radiation detector 10 shown, the end portion of the elastic layer 42 protrudes outward from the end portion of the sensor substrate 12 .

[0252] In addition, in the above-mentioned exemplary embodiments, the elastic layer 42 is described as a single layer (single layer), but the elastic layer 42 may also be a multi-layered form. Figure 15 As an example of the radiation detector 10 shown in FIG, the elastic layer 42 is a multilayer film in which three layers, namely, a first elastic layer 42A, a second elastic layer 42B, and a third elastic layer 42C, are stacked in this order from the side close to the stack 19. Figure 15 The radiation detector 10 shown is Figure 8 The radiation detector 10 shown is an example of a radiation detector 10 in which the elastic layer 42 is formed into multiple layers. When the elastic layer 42 is formed into multiple layers, the elastic layer 42 as a whole only needs to have a higher restoring force against deflection than the sensor substrate 12 .

[0253] When the elastic layer 42 is formed into multiple layers, it is preferable that each layer included in the elastic layer 42 has a different function. Figure 15 In the example shown, the first elastic layer 42A and the third elastic layer 42C can be non-conductive layers having an antistatic function, while the second elastic layer 42B can be a conductive layer, thereby imparting an electromagnetic shielding function to the elastic layer 42. In this case, the first elastic layer 42A and the third elastic layer 42C can be, for example, an antistatic film such as a film using the antistatic coating "COLCOAT" (trade name: manufactured by COLCOAT Corporation). The second elastic layer 42B can be, for example, a conductive sheet or a conductive mesh sheet made of Cu or the like.

[0254] For example, when the reading method of the radiation detector 10 is the ISS method, a control substrate 110, a power supply unit 108, etc. are sometimes set on the upper side of the sensor substrate 12 (laminate 19). However, in such a case where the elastic layer 42 has an anti-static function, it can shield the electromagnetic noise from the control substrate 110 and the power supply unit 108.

[0255] In addition, in the above-described exemplary embodiments, the conversion layer 30 is directly provided on the sensor substrate 12, but the present invention is not limited to this embodiment, and another layer (film) may be provided between the sensor substrate 12 and the conversion layer 30. For example, Figure 16 As shown in the example, the radiation detector 10 includes an adhesion layer 49 between the sensor substrate 12 and the conversion layer 30. In other words, the sensor substrate 12 can be laminated on the conversion layer 30 via the adhesion layer 49. The adhesion layer 49 improves the adhesion between the sensor substrate 12 and the conversion layer 30, making it more difficult for the conversion layer 30 to peel from the sensor substrate 12 compared to when the adhesion layer 49 is not provided. Therefore, when the adhesion layer 49 is provided, the rigidity of the elastic layer 42 can be reduced compared to when the adhesion layer 49 is not provided. Examples of such adhesion layer 49 include parylene film.

[0256] In addition, for example, Figure 17 As shown in the example, the radiation detector 10 has a buffer layer 47 between the sensor substrate 12 and the conversion layer 30. The buffer layer 47 has a function of buffering the difference between the thermal expansion coefficient of the conversion layer 30 and the thermal expansion coefficient of the base material 14. The thermal expansion coefficient of the buffer layer 47 is the thermal expansion coefficient between the thermal expansion coefficient of the sensor substrate 12 and the thermal expansion coefficient of the conversion layer 30. The greater the difference between the thermal expansion coefficient of the conversion layer 30 and the thermal expansion coefficient of the base material 14, the more preferably the radiation detector 10 has the buffer layer 47. For example, when the above-mentioned XENOMAX (registered trademark) is used in the base material 14, since the difference in thermal expansion coefficient with the conversion layer 30 becomes larger than that of other materials, it is preferable as shown in FIG. Figure 17 A buffer layer 47 is provided as in the radiation detector 10 shown. As the buffer layer 47, a PI film or a parylene film is used.

[0257] Furthermore, in the above-described exemplary embodiments, the radiation detector 10 is manufactured using a lamination method. However, the present invention is not limited to this method, and the radiation detector 10 may also be manufactured using a coating method. Furthermore, although mechanical peeling is described as separating the sensor substrate 12 from the support 50, laser peeling may also be used.

[0258] Furthermore, when using a CsI scintillator as the conversion layer 30, the conversion layer 30 can also be formed on the sensor substrate 12 using a method different from that of the present exemplary embodiment. For example, a member formed by vapor-depositing CsI onto an aluminum plate or the like by vapor deposition can be prepared, and the side of the CsI not in contact with the aluminum plate and the pixels 16 of the sensor substrate 12 can be bonded together using an adhesive sheet or the like, thereby forming the conversion layer 30 on the sensor substrate 12. In this case, it is preferable to bond the member, with the entire conversion layer 30 including the aluminum plate covered with a protective layer 38, to the pixels 16 of the sensor substrate 12. Furthermore, in this case, the side of the conversion layer 30 in contact with the pixels 16 becomes the leading end of the growth direction of the columnar crystals.

[0259] Furthermore, unlike the radiation detector 10 of the embodiment illustrated in this example, GOS (Gd2O2S:Tb) or the like may be used as the conversion layer 30 instead of CsI. In this case, for example, GOS is dispersed in a binder such as a resin, and the resulting sheet is bonded to a support such as white PET via an adhesive layer. The side of the GOS not bonded to the support is bonded to the pixels 16 of the sensor substrate 12 via an adhesive sheet, thereby forming the conversion layer 30 on the sensor substrate 12. Furthermore, using CsI for the conversion layer 30 improves the efficiency of converting radiation into visible light compared to using GOS.

[0260] In addition, in the above-mentioned exemplary embodiments, the following description is given: Figure 1 As shown, pixels 16 are arranged in a two-dimensional matrix, but this is not limiting. For example, a one-dimensional arrangement or a honeycomb arrangement is also possible. Furthermore, the shape of the pixels is not limited and can be rectangular or polygonal, such as a hexagon. Furthermore, the shape of the pixel region 15 is also self-evidently not limited.

[0261] In addition, it is needless to say that the configurations and manufacturing methods of the radiation imaging device 1 and the radiation detector 10 described in the above-described embodiments are merely examples and can be modified according to circumstances without departing from the spirit of the present invention.

[0262] [Other exemplary embodiments]

[0263] First, refer to Figures 18 to 30 Other exemplary embodiments of the elastic layer 42 will be described.

[0264] like Figure 18 As shown, when the elastic layer 42 extends over the regions corresponding to the central portion 30B and the peripheral portion 30C of the conversion layer 30, the elastic layer 42 need not have an inclined bent portion along the outer periphery of the conversion layer 30. In this case, the elastic layer 42 is bonded to the protective layer 38 via the adhesive layer 40 in the region corresponding to the central portion 30B of the conversion layer 30. In the region corresponding to the peripheral portion 30C of the conversion layer 30, a space corresponding to the inclination of the peripheral portion 30C of the conversion layer 30 is formed between the conversion layer 30 (protective layer 38) and the elastic layer 42.

[0265] As described above, the cable 112 is connected to the terminal 130 provided in the connection area of ​​the outer periphery of the sensor substrate 12. The sensor substrate 12 is connected to the control substrate (reference control substrate 110, Figure 6AIf the sensor substrate 12 is bent, the cable 112 may be peeled off from the sensor substrate 12 or may be out of position. In this case, it is necessary to reconnect the cable 112 to the sensor substrate 12. This reconnection of the cable 112 to the sensor substrate 12 is called reworking. Figure 18 As well as the above Figure 13 As shown, by arranging the end of the elastic layer 42 further inward than the end of the conversion layer 30 , reprocessing can be facilitated compared to a case where the elastic layer 42 extends to the vicinity of the connection region.

[0266] like Figure 19 、 Figure 20 As well as the above Figure 3 、 Figure 8 As shown, the elastic layer 42 can be provided so that its ends are positioned outward from the ends of the conversion layer 30 and aligned with the ends of the adhesive layer 36 and the protective layer 38 extending onto the sensor substrate 12. Furthermore, the positions of the ends of the elastic layer 42 and the ends of the adhesive layer 36 and the protective layer 38 do not need to be completely aligned.

[0267] exist Figure 19 In the illustrated example, the outer periphery of the elastic layer 42 is bent along the inclination of the peripheral edge portion 30C of the conversion layer 30, and also covers the portions of the adhesive layer 36 and the protective layer 38 that are covered on the sensor substrate 12. Furthermore, the ends of the elastic layer 42 are aligned with the ends of the adhesive layer 36 and the protective layer 38. Furthermore, the positions of the ends of the elastic layer 42 and the ends of the adhesive layer 36 and the protective layer 38 do not need to be completely aligned.

[0268] The ends of the elastic layer 42, the adhesive layer 40, the protective layer 38, and the adhesive layer 36 are sealed by a sealing member 71. The sealing member 71 is preferably provided in an area extending from the surface of the sensor substrate 12 to the surface of the elastic layer 42 and not covering the pixel area 15. As the material of the sealing member 71, 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 71. The elastic layer 42 has higher rigidity than the protective layer 38, and a restoring force that acts on the bent portion of the elastic layer 42 to eliminate the bending may cause the protective layer 38 to peel off. By sealing the ends of the elastic layer 42, the adhesive layer 40, the protective layer 38, and the adhesive layer 36 with the sealing member 71, peeling of the protective layer 38 can be suppressed.

[0269] exist Figure 20 In the example shown above, Figure 8Similarly to the embodiment shown, fillers 70 are provided in the space formed between the conversion layer 30 (protective layer 38) and the elastic layer 42, in the region corresponding to the peripheral edge 30C of the conversion layer 30 and in the region further outward. Furthermore, in the region corresponding to the end of the conversion layer 30, another elastic layer 42A is laminated on the surface of the elastic layer 42 via an adhesive layer 40A. More specifically, an elastic layer 42D is provided in the region spanning the end (outer edge, margin) of the conversion layer 30. The elastic layer 42D can be made of the same material as the elastic layer 42. In the radiation detector 10, the sensor substrate 12 deflects relatively significantly at the end of the conversion layer 30. Forming the laminated structure of the elastic layers 42 and 42D in the region corresponding to the end of the conversion layer 30 enhances the effect of suppressing deflection of the sensor substrate 12 at the end of the conversion layer 30.

[0270] Even in the Figure 19 、 Figure 20 As well as the above Figure 3 、 Figure 8 As shown, when the ends of the elastic layer 42 are arranged outside the ends of the conversion layer 30 and aligned with the ends of the adhesive layer 36 and the protective layer 38, reprocessing can be facilitated compared to a case where the elastic layer 42 extends to the vicinity of the connection area.

[0271] In addition, you can also Figures 21 to 24 As shown, the elastic layer 42 is provided with its end positioned outside the ends of the adhesive layer 36 and the protective layer 38 extending onto the sensor substrate 12 and inside the end of the sensor substrate 12 .

[0272] exist Figure 20 In the example shown, the elastic layer 42 is bonded to the protective layer 38 via the adhesive layer 40 in the area corresponding to the central portion 30B of the conversion layer 30, and in the area corresponding to the peripheral portion 30C of the conversion layer 30 and the area further outside it, a space corresponding to the inclination in the peripheral portion 30C of the conversion layer 30 is formed between the conversion layer 30 (protective layer 38) and the elastic layer 42, and between the sensor substrate 12 and the elastic layer 42.

[0273] exist Figure 22In the example shown, the end of the elastic layer 42 is supported by the spacer 72. That is, one end of the spacer 72 is connected to the first surface 14A of the base material 14 of the sensor substrate 12, and the other end of the spacer 72 is connected to the end of the elastic layer 42. By supporting the end of the elastic layer 42 that extends while forming a space between the spacer 72 and the sensor substrate 12, it is possible to suppress the peeling of the elastic layer 42. In addition, the deflection suppression effect brought about by the elastic layer 42 can be applied to the vicinity of the end of the sensor substrate 12. In addition, instead of providing the spacer 72, or in addition to providing the spacer 72, it is also possible to imitate Figure 20 In the illustrated example, the spaces formed between the conversion layer 30 (protective layer 38 ) and the elastic layer 42 and between the sensor substrate 12 and the elastic layer 42 are filled with fillers.

[0274] exist Figure 23 In the example shown, the outer periphery of the elastic layer 42 is bent along the inclination of the peripheral portion 30C of the conversion layer 30, and also covers the portion of the adhesive layer 36 and the protective layer 38 covering the sensor substrate 12 and the sensor substrate 12 outside thereof. In other words, the ends of the adhesive layer 36 and the protective layer 38 are sealed by the elastic layer 42. The portion of the elastic layer 42 extending on the sensor substrate 12 is bonded to the sensor substrate 12 via the adhesive layer 40. In this way, by covering the ends of the adhesive layer 36 and the protective layer 38 with the elastic layer 42, peeling of the protective layer 38 can be suppressed. Alternatively, it is also possible to imitate Figure 18 In the described example, the end portion of the elastic layer 42 is sealed using the sealing member 71 .

[0275] exist Figure 24 In the example shown, in a form in which the end of the elastic layer 42 is supported by the spacer 72, another elastic layer 42D is further stacked via the adhesive layer 40A in the area on the surface of the elastic layer 42 corresponding to the end of the conversion layer 30. More specifically, the elastic layer 42D is provided in an area spanning the end (outer edge, rim) of the conversion layer 30. The elastic layer 42D can be made of the same material as the elastic layer 42. In the radiation detector 10, the deflection of the sensor substrate 12 at the end of the conversion layer 30 is relatively large. By forming a stacked structure of the elastic layers 42 and 42D in the area corresponding to the end of the conversion layer 30, the effect of suppressing the deflection of the sensor substrate 12 at the end of the conversion layer 30 can be promoted. In addition, instead of providing the spacer 72, it is also possible to imitate Figure 20 In the illustrated example, the spaces formed between the conversion layer 30 (protective layer 38 ) and the elastic layer 42 and between the sensor substrate 12 and the elastic layer 42 are filled with a filler 70 .

[0276] You can also Figure 25 、 Figure 26 , and the above Figures 9 to 11 As shown, the elastic layer 42 is provided so that its end is aligned with the end of the sensor substrate 12. In addition, the position of the end of the elastic layer 42 and the position of the end of the sensor substrate 12 do not need to be completely consistent.

[0277] exist Figure 25 In the illustrated example, the outer periphery of the elastic layer 42 is bent along the slope of the peripheral edge 30C of the conversion layer 30, and also covers the portion of the sensor substrate 12 covered by the adhesive layer 36 and the protective layer 38, the outer substrate surface, and the connection between the terminal 130 and the cable 112. The portions of the elastic layer 42 extending onto the sensor substrate 12 and the cable 112 are bonded to the sensor substrate 12 and the cable 112, respectively, via the adhesive layer 40. Covering the connection between the cable 112 and the terminal 130 with the flexible elastic layer 42 prevents the cable 112 from peeling off. Furthermore, since the other end of the cable 112 is intended to be connected to a control board equipped with electronic components, the sensor substrate 12 may experience significant deflection at the connection between the cable 112 and the terminal 130. Covering the connection between the cable 112 and the terminal 130 with the elastic layer 42 prevents deflection of the sensor substrate 12 at this location.

[0278] exist Figure 26 In the illustrated example, a filler 70 is filled in the spaces formed between the conversion layer 30 (protective layer 38) and the elastic layer 42, and between the sensor substrate 12 and the elastic layer 42. Furthermore, in regions corresponding to the ends of the conversion layer 30, another flexible elastic layer 42A is laminated on the surface of the elastic layer 42 via an adhesive layer 40A. More specifically, an elastic layer 42D is provided in a region extending across the ends (outer edges, margins) of the conversion layer 30. The elastic layer 42D can be made of the same material as the elastic layer 42. In the radiation detector 10, the sensor substrate 12 deflects relatively significantly at the ends of the conversion layer 30. Forming the laminated structure of the elastic layers 42 and 42D in regions corresponding to the ends of the conversion layer 30 enhances the effect of suppressing deflection of the sensor substrate 12 at the ends of the conversion layer 30.

[0279] In addition, you can also Figures 27 to 30 As well as the above Figure 14 As shown, the elastic layer 42 is provided so that its end portion is located outside the end portion of the sensor substrate 12 .

[0280] exist Figure 27In the illustrated example, the ends of the elastic layer 42 are supported by spacers 72. Specifically, one end of the spacer 72 is connected to the cable 112 provided at the end of the sensor substrate 12, while the other end of the spacer 72 is connected to the end of the elastic layer 42. By supporting the ends of the elastic layer 42, which extend while forming a space between the spacer 72 and the sensor substrate 12, the spacer 72 can suppress peeling of the elastic layer 42. Furthermore, the deflection suppression effect of the elastic layer 42 can be exerted up to the vicinity of the end of the sensor substrate 12.

[0281] exist Figure 28 In the example shown, the spaces formed between the conversion layer 30 (protective layer 38) and the elastic layer 42 and between the sensor substrate 12 and the elastic layer 42 are filled with a filler 70. In this embodiment, the connection between the cable 112 and the terminal 130 is covered by the filler 70. In this way, the spaces formed between the conversion layer 30 (protective layer 38) and the elastic layer 42 and between the sensor substrate 12 and the elastic layer 42 are filled with the filler 70. Figure 29 Compared to the embodiment shown, the elastic layer 42 is prevented from peeling off from the conversion layer 30 (protective layer 38). Furthermore, because the conversion layer 30 is fixed to the sensor substrate 12 by both the elastic layer 42 and the filler 70, peeling off of the conversion layer 30 from the sensor substrate 12 is prevented. Furthermore, because the connection between the cable 112 and the terminal 130 is covered by the filler 70, peeling off of the cable 112 is prevented.

[0282] exist Figure 29 In the illustrated example, the outer periphery of the elastic layer 42 is bent along the slope of the peripheral edge 30C of the conversion layer 30, and also covers the portion of the sensor substrate 12 covered by the adhesive layer 36 and the protective layer 38, the outer substrate surface, and the connection between the terminal 130 and the cable 112. The portions of the elastic layer 42 extending over the sensor substrate 12 and the cable 112 are bonded to the sensor substrate 12 and the cable 112, respectively, via the adhesive layer 40. Covering the connection between the cable 112 and the terminal 130 with the elastic layer 42 prevents the cable 112 from peeling off. Furthermore, since the other end of the cable 112 is intended to be connected to a control board equipped with electronic components, the sensor substrate 12 may experience significant deflection at the connection between the cable 112 and the terminal 130. Covering the connection between the cable 112 and the terminal 130 with the elastic layer 42 prevents deflection of the sensor substrate 12 at this location.

[0283] exist Figure 30In the illustrated example, a filler 70 is filled in the spaces formed between the conversion layer 30 (protective layer 38) and the elastic layer 42, and between the sensor substrate 12 and the elastic layer 42. Furthermore, in regions corresponding to the ends of the conversion layer 30, another elastic layer 42D is laminated on the surface of the elastic layer 42 via an adhesive layer 40A. More specifically, the elastic layer 42D is provided in a region extending across the ends (outer edges, margins) of the conversion layer 30. The elastic layer 42D can be made of the same material as the elastic layer 42. In the radiation detector 10, the sensor substrate 12 deflects relatively significantly at the ends of the conversion layer 30. Forming the laminated structure of the elastic layers 42 and 42D in regions corresponding to the ends of the conversion layer 30 enhances the effect of suppressing deflection of the sensor substrate 12 at the ends of the conversion layer 30.

[0284] As described above, in the manufacturing process of the radiation detector 10, the flexible sensor substrate 12 is attached to the support 50 such as a glass substrate, and after the conversion layer 30 is laminated on the sensor substrate 12, the support 50 is peeled off from the sensor substrate 12. At this time, the flexible sensor substrate 12 is bent, and the pixels 16 formed on the sensor substrate 12 may be damaged. Before peeling the support 50 from the sensor substrate 12, Figures 18 to 30 By laminating the elastic layer 42 on the conversion layer 30 in the illustrated embodiment, the sensor substrate 12 can be prevented from being bent when the support body 50 is peeled off from the sensor substrate 12 , thereby reducing the risk of damaging the pixels 16 .

[0285] in addition, Figure 31 4 is a plan view showing an example of the structure of the elastic layer 42. The elastic layer 42 may have a plurality of through holes 42H on its main surface. The size and pitch of the through holes 42H are determined so as to obtain the desired rigidity in the elastic layer 42.

[0286] The elastic layer 42 has a plurality of through holes 42H, so that air introduced into the interface between the elastic layer 42 and the conversion layer 30 can be discharged through the through holes 42H. This can suppress the generation of bubbles in the interface between the elastic layer 42 and the conversion layer 30.

[0287] If there is no means to discharge the air introduced into the joint surface between the elastic layer 42 and the conversion layer 30, bubbles may be generated on the joint surface. For example, if the bubbles generated on the joint surface expand due to the heat generated during the operation of the radiation imaging device 1, the adhesion between the elastic layer 42 and the conversion layer 30 will be reduced. As a result, the deflection suppression effect of the elastic layer 42 may not be fully exerted. Figure 31By using the elastic layer 42 having a plurality of through holes 42H, the generation of bubbles at the bonding surface between the elastic layer 42 and the conversion layer 30 can be suppressed as described above, thereby maintaining close contact between the elastic layer 42 and the conversion layer 30 and maintaining the deflection suppression effect of the elastic layer 42.

[0288] Figure 32 4 is a perspective view showing another example of the structure of the elastic layer 42. Figure 32 In the example shown, the elastic layer 42 has a concave-convex structure on the interface with the conversion layer 30. The concave-convex structure can be as follows: Figure 32 As shown in FIG. 4 , the elastic layer 42 is formed by including a plurality of grooves 63 arranged in parallel with each other. Figure 33 As shown in FIG. 1 , the surface having the concavo-convex structure formed by the plurality of grooves 63 is bonded to the conversion layer 30 covered by the reflective layer 34. In this way, since the elastic layer 42 has the concavo-convex structure on the bonding surface with the conversion layer 30, the air introduced into the bonding portion between the elastic layer 42 and the conversion layer 30 can be discharged from the grooves 63. Figure 35 Similarly to the embodiment shown, the generation of bubbles can be suppressed at the bonding surface between the elastic layer 42 and the conversion layer 30. This maintains the close contact between the elastic layer 42 and the conversion layer 30 and the deflection suppression effect of the elastic layer 42.

[0289] Figure 34 as well as Figure 35 They are top views showing other examples of the structure of the elastic layer 42. Figure 34 as well as Figure 35 As shown, the elastic layer 42 can be divided into a plurality of segments 54. The elastic layer 42 can be as follows Figure 34 As shown, it is divided into a plurality of fragments 54 (545-54 11 ) are arranged in one direction. In addition, the elastic layer 42 can be as follows Figure 35 As shown, it is divided so that a plurality of fragments 54 (541 to 494) are arranged in the vertical and horizontal directions.

[0290] The larger the area of ​​the elastic layer 42 is, the easier it is to generate bubbles at the joint surface between the elastic layer 42 and the conversion layer 30. Figure 38 as well as Figure 39 As shown, by dividing the elastic layer 42 into a plurality of fragments 54, the generation of bubbles at the interface between the elastic layer 42 and the conversion layer 30 can be suppressed. This maintains close contact between the elastic layer 42 and the conversion layer 30, and maintains the deflection suppression effect of the elastic layer 42d.

[0291] Furthermore, a reinforcing member 55 may be provided on the side of the elastic member 41 opposite to the side in contact with the sensor substrate 12 (the second surface 14B). Figures 36 to 40Each of them is a cross-sectional view showing an example of the installation form of the reinforcing member 55.

[0292] exist Figures 36 to 40 In the example shown, a reinforcing member 55 is laminated on the surface of the elastic member 41 opposite to the surface on the sensor substrate 12 side via an adhesive layer 56. The reinforcing member 55 can be made of the same material as the elastic layer 42. When the radiation detector 10 is used in an ISS mode, in order to minimize the area of ​​the portion where the reinforcing member 55 overlaps with the pixel area 15, it is preferable that the reinforcing member 55 is provided only on the outer periphery of the sensor substrate 12. That is, the reinforcing member 55 can be as follows: Figures 36 to 40 As shown, the ring has an opening 61 in the portion corresponding to the pixel area 15. By forming a laminated structure of the elastic member 41 and the reinforcing member 55 on the outer periphery of the sensor substrate 12, the rigidity of the outer periphery of the sensor substrate 12, which is relatively prone to deflection, can be enhanced.

[0293] exist Figures 36 to 40 In the illustrated example, the reinforcing member 55 is provided in a region extending across the end portions (outer edges, margins) of the conversion layer 30. In the radiation detector 10, the sensor substrate 12 deflects relatively significantly at the end portions of the conversion layer 30. Forming the laminated structure of the elastic member 41 and the reinforcing member 55 in the region corresponding to the end portions of the conversion layer 30 enhances the effect of suppressing deflection of the sensor substrate 12 at the end portions of the conversion layer 30.

[0294] When the radiation detector 10 is used in the ISS mode, Figure 36 If a portion of the reinforcing member 55 overlaps the pixel area 15 as shown, the image may be affected depending on the material of the reinforcing member 55. Therefore, if a portion of the reinforcing member 55 overlaps the pixel area 15, plastic is preferably used as the material of the reinforcing member 55.

[0295] like Figure 37 as well as Figure 38 As shown in FIG41 , it is most preferred that the reinforcing member 55 crosses the end (outer edge, edge) of the conversion layer 30 and does not overlap with the pixel area 15 (i.e., the end of the opening 61 of the reinforcing member 55 is arranged outside the pixel area 15). In the example shown in FIG41 , the position of the end of the opening 61 of the reinforcing member 55 is substantially consistent with the position of the end of the pixel area 15. Figure 42 In the illustrated example, the end of the opening 61 of the reinforcing member 55 is arranged between the end of the pixel region 15 and the end of the conversion layer 30 .

[0296] In addition, the position of the end of the opening 61 of the reinforcing member 55 may be as follows: Figure 39As shown in FIG, the position of the end of the conversion layer 30 is roughly consistent. Alternatively, Figure 40 As shown, the reinforcing member 55 is arranged further outward from the end of the conversion layer 30. In this case, since the reinforcing member 55 straddles the end (outer edge, rim) of the conversion layer 30, the effect of suppressing deflection of the sensor substrate 12 at the end of the conversion layer 30 may be reduced. However, by forming a stacked structure of the elastic member 41 and the reinforcing member 55 on the outer periphery of the sensor substrate 12 at the connection between the cable 112 and the terminal 130, the effect of suppressing deflection of the sensor substrate 12 at the connection between the cable 112 and the terminal 130 can be maintained.

[0297] Furthermore, in the radiation detector 10 of each of the above-described exemplary embodiments, the sensor substrate 12 (base material 14 ) and the elastic member 41 are described as having the same size. However, the sensor substrate 12 and the elastic member 41 may have different sizes.

[0298] For example, when the radiation detector 10 is used in the radiation imaging device 1, the housing 120 (see FIG. Figure 11 In such a case, for example, the radiation detector 10 can be fixed and used. Figure 41A As shown in the example, the elastic member 41 is made larger than the sensor substrate 12, and a baffle is provided, and the radiation detector 10 is fixed using a portion of the baffle. For example, a hole can be provided in the baffle portion of the elastic member 41 and a screw passing through the hole can be used to fix the housing 120 (see FIG. Figure 6A etc.) to fix the shape.

[0299] In addition, the elastic member 41 is not limited to the sensor substrate 12. Figure 41A The elastic member 41 may be formed of a plurality of stacked layers, and a portion of the layers may be formed larger than the sensor substrate 12. For example, Figure 41B As shown in FIG. 1 , the elastic member 41 is formed into a two-layer structure having a first layer 41A having the same size as the sensor substrate 12 (substrate 14) and a second layer 41B larger than the sensor substrate 12. The first layer 41A and the second layer 41B are bonded together by a double-sided tape or an adhesive layer (not shown). The first layer 41A is preferably formed of the same material as the elastic member 41 described above, and has the same properties as the elastic member 41. In addition, the second layer 41B is bonded to the second surface 14B of the substrate 14 by a double-sided tape or an adhesive layer (not shown). As the second layer 41B, for example, ALPET (registered trademark) can be used. In addition, in the case where the elastic member 41 is composed of a plurality of layers, it can be bonded together with the first layer 41A. Figure 41B The opposite of the form shown, such as Figure 41C As shown, the first layer 41A is bonded to the second surface 14B of the base material 14 .

[0300] As described above, when the radiation detector 10 is fixed to the housing 120 (see FIG. Figure 6A In the case of bending the baffle part, the baffle part may be fixed. The thinner the thickness, the easier it is to bend the baffle part of the elastic member 41, and only the baffle part can be bent without affecting the main body of the radiation detector 10. Therefore, when bending the baffle part, it is preferable to fix it as follows. Figure 41B as well as Figure 41C As in the example shown, the elastic member 41 is composed of a plurality of stacked layers, and only a part of the layers is larger than the sensor substrate 12 .

[0301] In addition, you can Figure 42 As shown in the example above, Figures 41A to 41C In contrast to the radiation detector 10, the elastic member 41 is made smaller than the sensor substrate 12. By positioning the end of the sensor substrate 12 at a position further outward than the end of the elastic member 41, the position of the end of the sensor substrate 12 can be easily confirmed when the radiation detector 10 is housed in the housing 120 (see FIG. 7 ) and assembled, thereby improving the positioning accuracy. Figure 42 The embodiment shown is preferable because the same effect can be obtained as long as at least a portion of the end portion of the sensor substrate 12 (base material 14 ) is located outside the elastic member 41 .

[0302] The disclosures of Japanese Patent Applications Nos. 2018-051690, 2018-219696, and 2019-022148 are incorporated herein by reference in their entirety.

[0303] 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, characterized in that have: A sensor substrate including a flexible base material and a layer provided on a first surface of the base material and having a plurality of pixels formed thereon for accumulating charges generated in response to light converted from radiation; a conversion layer provided on the first surface side of the sensor substrate and configured to convert radiation into the light; and an elastic layer provided on the side of the conversion layer opposite to the side on which the sensor substrate is provided and having a higher restoring force against deflection than that of the sensor substrate; The substrate satisfies at least one of a heat shrinkage rate in the machine direction (MD) at 400° C. of 0.5% or less and an elastic modulus of 1 GPa or more at 500° C. when the substrate has a thickness of 25 μm. The elastic layer has a bending modulus of elasticity of 150 MPa or more and 2500 MPa or less.

2. The radiation detector according to claim 1, wherein The elastic layer is made of at least one of polycarbonate, polyethylene terephthalate, and low-density polyethylene.

3. The radiation detector according to claim 1, wherein A ratio of a thermal expansion coefficient of the elastic layer to a thermal expansion coefficient of the conversion layer is greater than or equal to 0.5 and less than or equal to 4.

4. The radiation detector according to claim 1, wherein The thermal expansion coefficient of the elastic layer is greater than or equal to 30 ppm / K and less than or equal to 200 ppm / K.

5. The radiation detector according to claim 1, wherein The sensor substrate further comprises: a terminal portion provided on the outer periphery of the first surface of the substrate and connected to a cable for reading out charge from the pixel; The end portion of the elastic layer is located inside a region where the terminal portion is provided. The radiation detector according to claim 5 , wherein: The transformation layer has: having an inclined peripheral portion that becomes thinner toward the outside; and a central portion surrounded by the peripheral portion, The elastic layer covers at least the central portion.

7. The radiation detector according to claim 5, wherein The transformation layer has: having an inclined peripheral portion that becomes thinner toward the outside; and a central portion surrounded by the peripheral portion, The elastic layer covers at least a portion of the peripheral portion and the central portion.

8. The radiation detector according to claim 5, wherein The transformation layer has: having an inclined peripheral portion that becomes thinner toward the outside; and a central portion surrounded by the peripheral portion, The end portion of the elastic layer is provided at least from a region covering the central portion to a region corresponding to the outer periphery of the peripheral portion.

9. The radiation detector according to claim 1, wherein The sensor substrate further comprises: a terminal portion provided on the outer periphery of the first surface of the substrate and connected to a cable for reading out charge from the pixel; The elastic layer is provided up to a region facing a part or the entire region where the terminal portion is provided.

10. The radiation detector according to claim 1, wherein The elastic layer is provided in an area larger than an area of ​​the sensor substrate where the conversion layer is provided.

11. The radiation detector according to claim 1, wherein An end portion of the elastic layer protrudes outward more than an end portion of the sensor substrate.

12. The radiation detector according to claim 1, wherein The elastic layer further comprises: The support portion is provided up to a region outside the conversion layer and supports between the end portion of the elastic layer and the sensor substrate.

13. The radiation detector according to claim 1, wherein The radiation detector further comprises: A filling member fills the space between the sensor substrate and the elastic layer that does not include the conversion layer.

14. The radiation detector according to claim 13, wherein The filling member is connected to the sensor substrate and the elastic layer.

15. The radiation detector according to claim 1, wherein The radiation detector further comprises: The adhesion layer is provided between the sensor substrate and the conversion layer.

16. The radiation detector according to claim 1, wherein The radiation detector further comprises: A buffer layer is provided between the sensor substrate and the conversion layer to buffer a difference between a thermal expansion coefficient of the conversion layer and a thermal expansion coefficient of the sensor substrate.

17. The radiation detector according to claim 1, wherein The radiation detector further comprises: The elastic member is provided on a second surface side of the base material opposite to the first surface and has a higher restoring force against deflection than the sensor substrate.

18. The radiation detector according to claim 17, wherein At least a portion of the elastic layer and at least a portion of the elastic member face each other with the sensor substrate and the conversion layer interposed therebetween.

19. The radiation detector according to claim 17 or 18, wherein The elastic member is made of at least one of polycarbonate, polyethylene terephthalate and low-density polyethylene.

20. The radiation detector according to claim 17, wherein A ratio of a thermal expansion coefficient of the elastic member to a thermal expansion coefficient of the conversion layer is 0.5 or more and 4 or less.

21. The radiation detector according to claim 17, wherein The elastic member has a thermal expansion coefficient of 30 ppm / K or more and 200 ppm / K or less.

22. The radiation detector according to claim 17, wherein The substrate is made of resin and has a fine particle layer containing inorganic fine particles having an average particle diameter of 0.05 μm to 2.5 μm.

23. The radiation detector according to claim 22, wherein: The substrate has the fine particle layer on the second surface side.

24. The radiation detector according to claim 22 or 23, wherein: The fine particles include an element having an atomic number greater than that of an element constituting the base material and having an atomic number of 30 or less.

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

26. The radiation detector according to claim 1, wherein The elastic layer has higher rigidity than the base material.

27. The radiation detector according to claim 1, wherein The conversion layer contains CsI.

28. The radiation detector according to claim 1, wherein The elastic layer extends in regions corresponding to the central portion and the peripheral portion of the conversion layer.

29. The radiation detector according to claim 10 or claim 28, wherein: The elastic layer is bent along the inclination of the peripheral portion of the conversion layer.

30. The radiation detector according to claim 10, wherein A space corresponding to the inclination of the peripheral portion of the conversion layer is formed between the elastic layer and the conversion layer.

31. The radiation detector according to claim 10, wherein A filling member is filled in the space formed between the elastic layer and the conversion layer.

32. The radiation detector according to claim 10, wherein The ends of the elastic layer are supported by the isolation member.

33. The radiation detector according to claim 10, wherein The elastic layer is bent along the inclination of the peripheral portion of the conversion layer. The ends of the elastic layer are sealed by a sealing member.

34. The radiation detector according to claim 1, wherein A reinforcing member is provided to reinforce the substrate, the reinforcing member being provided on a side of the surface of the base material opposite to the conversion layer. The reinforcing member is provided in a region that straddles an end portion of the conversion layer and is provided in a region that does not overlap with a pixel region.

35. The radiation detector according to claim 17, wherein A reinforcing member is provided on the side of the elastic member opposite to the side in contact with the sensor substrate. The reinforcing member is provided in a region that straddles an end portion of the conversion layer and is provided in a region that does not overlap with a pixel region.

36. A radiographic imaging device, characterized in that: have: The radiation detector according to claim 1; a control unit that outputs a control signal for reading out the charges accumulated in the plurality of pixels; a driving unit configured to output a driving signal for reading out charges from the plurality of pixels in response to the control signal; and The signal processing unit receives an electric signal corresponding to the charge read out from the plurality of pixels, and generates and outputs image data corresponding to the input electric signal.

37. The radiation imaging device according to claim 36, wherein: The control unit and the radiation detector are arranged in a direction intersecting a stacking direction in which a substrate, a layer forming a plurality of pixels, and a conversion layer are arranged in the radiation detector.

38. The radiation imaging device according to claim 36, wherein: The radiation imaging device further comprises: a power supply unit that supplies power to at least one of the control unit, the drive unit, and the signal processing unit, The power supply unit, the control unit, and the radiation detector are arranged in a direction intersecting a stacking direction of a sensor substrate, a conversion layer, and an elastic layer in the radiation detector.

39. The radiation imaging device according to claim 36, wherein The radiation imaging device further comprises: The housing has an irradiation surface to be irradiated with radiation and houses the radiation detector in a state where the sensor substrate and the conversion layer in the radiation detector face the irradiation surface.

Images