JP2018115955A - Radiation detector and radiation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation detector and a radiation detection device which suppress noise by suppressing incidence of a radiation on a wiring board.SOLUTION: A radiation detector 1 includes: a wavelength conversion member 3 for emitting light when a radiation enters; and a wiring board 21 on which a photoelectric conversion element 4 for photoelectrically converting the light emitted by the wavelength conversion member 3 is mounted. In the wiring board 21, a mounting surface for the photoelectric conversion element 4 is provided in a direction parallel to an incident direction of the radiation, also an end surface on the side that the radiation enters has a shielding member 22 for blocking the incident radiation.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a radiation detector and a radiation detection apparatus. In particular, the present invention relates to a radiation detector having a phosphor that emits fluorescence by incident radiation and a photoelectric conversion element that photoelectrically converts the fluorescence, and a radiation detection apparatus to which the radiation detector is applied.

  Conventionally, a radiation detector is mounted with a phosphor that emits fluorescence (for example, visible light) when excited by incident radiation, and a photoelectric conversion element that converts the fluorescence emitted by the phosphor into an electrical signal (photoelectric conversion). In addition, some have a wiring board on which an electric circuit is formed. In such a radiation detector, noise may be generated when radiation enters the wiring board. For this reason, it is preferable to prevent radiation from entering the wiring board. Patent Documents 1 and 2 disclose a configuration in which a photoelectric conversion element and an electric circuit are covered with a shielding member provided with a slit-shaped opening.

  However, in the configurations described in Patent Document 1 and Patent Document 2, in assembling the radiation detector, the shielding member and the electric circuit must be precisely aligned. For example, if the positioning accuracy is low, radiation that has passed through the opening may enter the electric circuit and generate noise.

JP 2008-51626 A JP 2006-329905 A

  In view of the above situation, the problem to be solved by the present invention is to suppress noise by suppressing the incidence of radiation to a wiring board provided with an electric circuit.

  In order to solve the above-described problems, the present invention provides a radiation detection device including a photoelectric conversion unit that converts light into an electrical signal, a wiring board on which the photoelectric conversion unit is mounted, and a shielding member that blocks incident radiation. The wiring board is provided with a shielding member that shields incident radiation so as to overlap the wiring board when viewed in the incident direction of radiation.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a radiation injects into a wiring board, and can suppress that a noise generate | occur | produces in a wiring board.

FIG. 1 is an exploded perspective view schematically showing a configuration example of a radiation detector. FIG. 2 is an external perspective view schematically showing a configuration example of the radiation detector. FIG. 3 is a diagram schematically illustrating a configuration example of the sensor substrate module. FIG. 4 is a cross-sectional view schematically showing a configuration example of the radiation detector. FIG. 5 is a cross-sectional view schematically illustrating a configuration example of a radiation detector to which a shielding member according to a modification is applied. FIG. 6 is a cross-sectional view schematically illustrating a configuration example of a radiation detector to which a shielding member according to a modification is applied. FIG. 7 is a cross-sectional view schematically showing a configuration example of the radiation detection apparatus.

  Embodiments of the present invention will be described below in detail with reference to the drawings. The radiation detector according to the embodiment of the present invention is used with a predetermined one side directed toward an inspection object and a radiation source. The radiation detector detects radiation that is exposed from the radiation source and enters the predetermined one side from a predetermined direction, and performs photoelectric conversion to generate a radiation image signal (radiation image data). For convenience of explanation, in each drawing, the three-dimensional directions of the radiation detector are indicated by X, Y, and Z arrows. The X direction is the longitudinal direction of the radiation detector, for example, the main scanning direction. The Y direction is the short direction of the radiation detector, for example, the sub-scanning direction. The Z direction is the vertical direction (radiation incidence direction). In addition, regarding the Z direction, one side (one side on which radiation is incident) facing the radiation source or the inspection object in use is an upper side, and the opposite side is a lower side. And the radiation detector which concerns on embodiment of this invention detects the radiation (radiation whose optical axis is parallel to an up-down direction) which injected from the upper side.

<Radiation detector>
First, a configuration example of the radiation detector 1 will be described with reference to FIGS. FIG. 1 is an exploded perspective view schematically showing a configuration example of a radiation detector 1 according to an embodiment of the present invention. FIG. 2 is an external perspective view schematically showing a configuration example of the radiation detector 1 according to the embodiment of the present invention. FIG. 3 is an enlarged view of a part III in FIG. 2, schematically showing a configuration example of the sensor substrate module 2. FIG. 4 is a diagram schematically illustrating a configuration example of the radiation detector 1 according to the embodiment of the present invention, and is a cross-sectional view taken along a plane perpendicular to the main scanning direction. As shown in FIGS. 1 to 4, the radiation detector 1 according to the embodiment of the present invention includes a main body frame 11, a sensor substrate module 2, a wavelength conversion member 3, and a main body cover 12.

  The main body frame 11 is a housing of the radiation detector 1. The main body frame 11 has, for example, a rectangular parallelepiped shape or a rod shape that is long in the main scanning direction as a whole, and is integrally formed of a light-shielding material. As the light-shielding material, for example, various resin materials such as polycarbonate (PC) colored in black can be applied. The main body frame 11 is provided with a sensor board module housing part 111 capable of housing the sensor board module 2 and an opening 112 serving as a radiation path. The sensor board module housing part 111 is, for example, long in the main scanning direction and is on the lower side (one side opposite to the one side on which the radiation is incident, one side facing the inspection object Q and the radiation source 51 (see FIG. 7)). It is a groove-like or concave-shaped part that is open on one side opposite to. The opening 112 communicates the surface (outer peripheral surface) of the upper side of the main body frame 11 (one side on which radiation is incident, one side facing the inspection object Q and the radiation source 51) and the sensor substrate module housing 111. . The opening 112 has, for example, a shape that is long in the main scanning direction when viewed in the vertical direction, and a slit-shaped through hole that passes through the main body frame 11 in the vertical direction is applied.

  The sensor board module 2 includes a wiring board 21 and a predetermined number of photoelectric conversion elements 4 and shielding members 22 provided on the wiring board 21.

  The wiring board 21 of the sensor board module 2 has a long plate shape. The wiring board 21 is provided with a predetermined wiring pattern. The wiring pattern provided on the wiring board 21 includes, for example, pads 211 for electrical connection with a photoelectric conversion element 4 described later. In addition, the kind (material etc.) of the wiring board 21 is not specifically limited, Conventionally well-known various wiring boards, such as conventionally well-known various printed wiring boards, are applicable. Further, the specific configuration (shape, etc.) of the wiring pattern provided on the wiring board 21 is not particularly limited, and is appropriately set according to the configuration of the photoelectric conversion element 4 mounted on the wiring board 21. For convenience of explanation, of the surfaces of the wiring board 21, the surface on which the photoelectric conversion element 4 is mounted is referred to as a first surface, and the opposite surface is referred to as a second surface. In the embodiment of the present invention, the wiring board 21 of the sensor board module 2 has a first surface parallel to the main scanning direction and the vertical direction (radiation incidence direction), and a longitudinal direction parallel to the main scanning direction. It is arranged with. That is, the wiring board 21 is arranged in such a direction that an end surface corresponding to one long side faces upward when viewed in a direction perpendicular to the first surface.

  The photoelectric conversion element 4 is an example of a photoelectric conversion unit, has a light receiving unit 42 that receives fluorescence emitted from a fluorescent layer 32 of the wavelength conversion member 3 described later, and photoelectrically converts the fluorescence incident on the light receiving unit 42 to produce a radiation image. A signal (radiation image data) is generated. In the embodiment of the present invention, an example in which a photodiode array is applied as the photoelectric conversion element 4 (photoelectric conversion unit) is shown. The photodiode array is an electronic component having a plurality of light receiving parts 42 (photodiodes) and a predetermined number of electrodes 43, and generates an electrical signal corresponding to the intensity of light incident on the light receiving part 42. For convenience of explanation, a surface on which the light receiving portion 42 of the photoelectric conversion element 4 is provided is referred to as a “light receiving surface 41”. If the photoelectric conversion element 4 is a photodiode array, the light receiving surface 41 has an elongated shape, and the plurality of light receiving portions 42 are parallel to one long side toward one side of the light receiving surface 41 in the short direction. Are arranged in a straight line (one-dimensional). In addition, the predetermined number of electrodes 43 are provided on the other side in the short direction of the light receiving surface 41 (on one side opposite to the side on which the plurality of light receiving parts 42 are provided). On the first surface of the wiring board 21, a plurality of photoelectric conversion elements 4 (photodiode arrays) are mounted in a straight line (one-dimensional shape) in the longitudinal direction (main scanning direction) of the wiring board 21. ing. Each photoelectric conversion element 4 (photodiode array) is mounted in a direction in which the arrangement direction of the plurality of light receiving portions 42 is parallel to the longitudinal direction of the wiring board 21. Further, in the photoelectric conversion element 4, in a state where the sensor substrate module 2 is accommodated in the sensor substrate module accommodation portion 111 of the main body frame 11, the side on which the light receiving portion 42 is provided is positioned on the upper side, and the side on which the electrode 43 is provided is on the lower side. It is mounted on the wiring board 21 so as to be oriented in the direction.

  In addition, the structure of the photodiode array as the photoelectric conversion element 4 (photoelectric conversion part) is not limited to the said structure. Each photodiode array may be configured to have a plurality of light receiving portions 42 that are arranged in a straight line in a predetermined direction. Furthermore, the photoelectric conversion element 4 is not limited to a photodiode array. The photoelectric conversion element 4 should just be an electronic component which can photoelectrically convert the fluorescence which the fluorescent layer 32 of the wavelength conversion member 3 mentioned later emits into an electrical signal. For example, various known photoelectric conversion elements such as photodiodes and image sensor ICs can be applied to the photoelectric conversion element 4.

  The wavelength conversion member 3 is an example of a wavelength conversion unit that converts radiation into light having a wavelength that can be photoelectrically converted by the photoelectric conversion element 4 (visible light in the embodiment of the present invention). The wavelength conversion member 3 is excited and emits fluorescence (visible light) when radiation enters. The wavelength conversion member 3 includes a base material layer 31, a fluorescent layer 32 provided by being laminated on one surface of the base material layer 31, and a reflective layer 33 provided by being laminated on the fluorescent layer 32, as a whole. It has a long plate shape or sheet shape in the main scanning direction.

  A plate or sheet of a transparent material (more specifically, a material having a high transmittance of fluorescence (visible light) emitted from the fluorescent layer 32) is applied to the base material layer 31. For example, a transparent resin material plate or sheet such as polyethylene terephthalate (PET) can be applied to the base material layer 31. The fluorescent layer 32 is a layer of a material that emits fluorescence (visible light) when excited by radiation. For the fluorescent layer 32, for example, a fluorescent material such as gadolinium oxide sulfur (GOS) can be applied. The reflective layer 33 is a layer made of a material having a high reflectance of fluorescence emitted from the fluorescent layer 32 and a high transmittance of radiation. For the reflective layer 33, for example, a material having high visible light reflectance and high radiation transmittance, such as alumina or calcium carbonate, can be used.

  In addition, the wavelength conversion member 3 is not limited to the said structure. The wavelength conversion member 3 should just have the fluorescence layer 32 which emits the fluorescence of the wavelength which can be excited by the incident radiation and the photoelectric conversion element 4 can photoelectrically convert. For example, in addition to gadolinium oxide sulfur, cesium iodide (CSI), amorphous selenium (A-SE), or the like can be applied to the fluorescent layer 32 of the wavelength conversion member 3. Further, the base material layer 31 is not limited to polyethylene terephthalate, and various resin materials and glass can be applied. The reflective layer 33 may also be made of a material having high visible light reflectance and high radiation transmittance. When the fluorescent layer 32 is made of a material having deliquescence, the wavelength conversion member 3 preferably has a protective layer that covers the fluorescent layer 32 in order to suppress the deliquescence of the fluorescent layer 32. In this case, a material having a high water shielding property and water repellency such as a fluorine resin is applied to the protective layer. Moreover, the dimension and shape of the wavelength conversion member 3 should just be a dimension and shape which can cover all the light-receiving parts 42 of the photoelectric conversion element 4 provided in the wiring board 21. FIG. In other words, it is only necessary to have a size and shape that overlaps all the light receiving portions 42 of all the photoelectric conversion elements 4 when they are arranged so as to overlap the photoelectric conversion elements 4 provided on the wiring board 21.

  The shielding member 22 is made of a material having a low radiation transmittance or includes a material having a low radiation transmittance. Moreover, the shielding member 22 has a long plate shape, a sheet shape, or a rod shape as a whole. For example, the shielding member 22 is a plate-like, sheet-like, or rod-like member containing a material having a low radiation transmittance, such as a tungsten plate, sheet, rod, paper filled with tungsten, rubber, resin, or the like. Is done. The shielding member 22 has a longitudinal direction parallel to the main scanning direction, a width direction parallel to the sub-scanning direction, and a thickness direction on the upper end surface of the wiring board 21 in an orientation parallel to the direction. Be placed.

  The main scanning direction dimension (longitudinal direction dimension) of the shielding member 22 is preferably equal to or larger than the main scanning direction dimension of the wiring board 21. The dimension (width) of the shielding member 22 in the sub-scanning direction is preferably equal to or greater than the dimension (thickness) of the wiring board 21 in the sub-scanning direction. If the wiring pattern is provided on the surface of the wiring board 21, the dimension of the shielding member 22 in the sub-scanning direction is preferably equal to or larger than the dimension of the wiring board 21 including the thickness of the wiring pattern. The vertical dimension (thickness) of the shielding member 22 is not particularly limited, but is preferably larger from the viewpoint of the function of shielding radiation. From the viewpoint of miniaturization of the sensor substrate module 2 and the radiation detector 1. Is preferably smaller. For this reason, the vertical dimension of the shielding member 22 is such that the radiation transmittance in the shielding member 22 and the radiation source 51 are exposed so that the amount of radiation transmitted through the shielding member 22 in the vertical direction is equal to or less than a desired transmission amount. It is appropriately set according to the intensity of the radiation to be emitted.

  The shielding member 22 is provided on the upper end surface of the wiring board 21 (the end surface corresponding to one long side). In addition, when the shielding member 22 is plate-shaped or sheet-shaped, a configuration in which a plurality of shielding members 22 are provided so as to overlap in the vertical direction may be employed. If the dimensions of the shielding member 22 in the main scanning direction and the sub-scanning direction are as described above, the entire upper end surface of the wiring board 21 is covered with the shielding member 22.

  The wiring board 21 of the sensor board module 2 may be provided with a connector 23 for electrical connection with the outside. In this case, the configuration of the connector 23 is not particularly limited, and various known connectors can be applied. Furthermore, other elements, electronic / electrical components, and the like may be mounted on the wiring board 21 of the sensor board module 2. As described above, in the embodiment of the present invention, an electronic / electric circuit that outputs a radiation image is formed by the wiring board 21 and the photoelectric conversion element 4 mounted on the wiring board 21.

  The main body cover 12 has a plate shape that is long in the main scanning direction, and is formed of a material having high radiation transmittance. For the main body cover 12, for example, various resin materials or glass can be applied. In addition, the specific structure of the main body cover 12 is not specifically limited. Further, the radiation detector 1 may not have the main body cover 12.

(Assembly structure of radiation detector)
Here, the assembly structure of the radiation detector 1 will be described.

  A plurality of photoelectric conversion elements 4 are mounted on the first surface of the wiring board 21. The electrode 43 of the photoelectric conversion element 4 mounted on the wiring board 21 and the pad 211 provided on the wiring board 21 are electrically connected by a predetermined wiring such as the bonding wire 24. A connector 23 is mounted on the second surface of the wiring board 21. In addition, elements other than the photoelectric conversion element 4, electronic / electrical components, and the like may be mounted on the first surface and the second surface of the wiring board 21. Furthermore, a shielding member 22 is provided on the upper end surface of the wiring board 21 (end surface on which radiation is incident). The shielding member 22 is joined to the end face on the upper side (upstream side in the radiation incident direction) of the wiring board 21 with, for example, an adhesive or a double-sided adhesive tape. In addition, it is preferable that the shielding member 22 is joined so as to overlap the entire upper end surface (end surface on which radiation is incident) of the wiring board 21 in the vertical direction (radiation incidence direction view). However, the shielding member 22 is provided so as not to overlap with the wavelength conversion member 3 described later in the vertical direction. If the shielding member 22 overlaps only the end face on the upper side of the wiring board 21, the shielding member 22 does not overlap with the wavelength conversion member 3 in the vertical direction. When the wiring pattern is provided on the surface of the wiring board 21, the shielding member 22 is also above the wiring pattern (on the side on which radiation is incident) when viewed in the vertical direction (viewed in the incident direction of radiation). It is preferable to be joined so as to overlap. Thereby, the sensor substrate module 2 is formed.

  The sensor board module 2 is housed and fixed in the sensor board module housing portion 111 of the main body frame 11. As described above, in the sensor board module 2, the first surface (the surface on which the photoelectric conversion element 4 is mounted) of the wiring board 21 is parallel to the main scanning direction and the vertical direction, and the shielding member 22 is bonded. Is accommodated in the sensor board module housing portion 111 of the main body frame 11 with the end face facing upward.

  Note that the sensor substrate module 2 has a position where the wiring board 21 and the photoelectric conversion element 4 mounted on the wiring board 21 do not overlap the opening 112 of the main body frame 11 when viewed in the vertical direction (opening 112 when viewed in the vertical direction). It is preferable that it is disposed at a position where it does not enter the inside. Further, the structure for fixing the sensor board module 2 to the main body frame 11 is not particularly limited. Various structures such as a configuration using an adhesive, a configuration in which a part of the main body frame 11 is crimped, and a configuration in which screws are fixed are used. Fixed structure can be applied.

  The wavelength conversion member 3 has the light receiving surface 41 of the photoelectric conversion element 4 such that the side on which the base material layer 31 is provided faces the light receiving surface 41 of the photoelectric conversion element 4 and the side on which the reflection layer 33 is provided faces the opposite side. Are placed on top of each other. In particular, the wavelength conversion member 3 is disposed so as to overlap all the light receiving portions 42 of all the photoelectric conversion elements 4 when viewed in a direction perpendicular to the light receiving surface 41 of the photoelectric conversion elements 4. However, the wavelength conversion member 3 is positioned so as not to overlap the electrode 43 of the photoelectric conversion element 4 so as not to interfere with the wiring such as the bonding wire 24 that connects the electrode 43 of the photoelectric conversion element 4 and the pad 211 of the wiring board 21. (See FIGS. 3 and 4). Moreover, it is preferable that the wavelength conversion member 3 is disposed at a position overlapping the opening 112 of the main body frame 11 (position entering the inside of the opening 112) when viewed in the vertical direction.

  In addition, the wavelength conversion member 3 and the light receiving surface 41 of the photoelectric conversion element 4 may be in contact or may not be in contact. As a configuration in which the wavelength conversion member 3 and the light receiving surface 41 of the photoelectric conversion element 4 are in contact, for example, a configuration in which the wavelength conversion member 3 is bonded to the light receiving surface 41 of the photoelectric conversion element 4 with an adhesive or the like can be applied. On the other hand, as a configuration in which the wavelength conversion member 3 is not in contact with the light receiving surface 41 of the photoelectric conversion element 4, a configuration in which the wavelength conversion member 3 is bonded to the inner peripheral surface of the sensor substrate module housing portion 111 of the main body frame 11 is applied. it can. In short, the wavelength conversion member 3 only needs to be disposed so as to overlap all the light receiving portions 42 of all the photoelectric conversion elements 4 when viewed in a direction perpendicular to the light receiving surface 41 of the photoelectric conversion elements 4. 4 may be in contact with the light receiving surface 41 or not. However, in order to improve the sensitivity of fluorescence detection by the photoelectric conversion element 4 and improve the resolution, the wavelength conversion member 3 is preferably as close as possible to the light receiving portion 42 of the photoelectric conversion element 4. Is preferably configured such that the wavelength conversion member 3 is in contact with the light receiving surface 41 of the photoelectric conversion element 4.

  The main body cover 12 is provided on the upper side of the main body frame 11. When the main body cover 12 is provided on the upper side of the main body frame 11, foreign matter is prevented from entering the main body frame 11. As described above, the radiation detector 1 may be configured without the main body cover 12.

(Operation of radiation detector)
Next, the operation of the radiation detector 1 will be described. The radiation detector 1 is disposed and used so as to face the radiation source 51 at a predetermined distance so that the radiation exposed from the radiation source 51 (see FIG. 7) is incident thereon. Then, while passing the inspection object Q between the radiation source 51 and the radiation detector 1, the radiation source 51 exposes the radiation to the inspection object Q, and the radiation detector 1 transmits the inspection object Q. Detect radiation.

  As described above, since the shielding member 22 does not overlap the wavelength conversion member 3 when viewed in the vertical direction, the radiation incident on the radiation detector 1 passes through the opening 112 of the main body frame 11 and is not shielded by the shielding member 22. To the wavelength conversion member 3. The fluorescent layer 32 of the wavelength conversion member 3 is excited when radiation enters and emits fluorescence (visible light) according to the intensity of the incident radiation. That is, the incident radiation is converted into light having a wavelength detectable by the photoelectric conversion element 4 by the fluorescent layer 32. And the light-receiving part 42 of the photoelectric conversion element 4 (photodiode array) converts the fluorescence emitted from the fluorescent layer 32 into an electrical signal (photoelectric conversion). At this time, the fluorescence emitted from the fluorescent layer 32 is reflected by the reflective layer 33, thereby increasing the amount of fluorescent light incident on the light receiving unit 42. For this reason, detection sensitivity improves.

  The photoelectric conversion element 4 outputs an electrical signal generated by photoelectric conversion by the light receiving unit 42 at a certain timing as a signal of one line of the radiation image signal (radiation image data). The radiation detector 1 can generate and output a two-dimensional radiation image signal (radiation image data) having internal information of the inspection object Q by continuously executing such an operation. .

(Function)
Here, the operation of the embodiment of the present invention will be described. As shown in FIGS. 3 and 4, the shielding member 22 is joined to the upper end surface (the end surface corresponding to one long side) of the wiring board 21. The shielding member 22 overlaps the wiring board 21 when viewed in the vertical direction. With such a configuration, the radiation incident from above is shielded by the shielding member 22 so as not to be directly incident on the wiring board 21. Here, “radiation is directly incident” means that the radiation that has passed through the opening 112 of the main body frame 11 is incident as it is without being reflected by another member. With such a configuration, noise generated by the incidence of radiation can be suppressed, and the image quality of the radiation image output from the photoelectric conversion element 4 can be improved. In addition, when a wiring pattern is provided on the surface of the wiring board 21, it is preferable that the shielding member 22 also overlaps with this wiring pattern. According to such a configuration, the wiring pattern provided on the surface of the wiring board 21 is also shielded by the shielding member 22 so that the radiation does not directly enter. Therefore, in the wiring pattern provided on the surface, Generation of noise can be suppressed.

  In the embodiment of the present invention, the shielding member 22 is bonded to the wiring board 21. For this reason, even if it is a case where the assembly | attachment precision to the main body frame 11 of the sensor board | substrate module 2 is low, it is suppressed that a radiation injects into the wiring board 21 directly. That is, in a configuration in which a shielding member provided with an opening is used as in the conventional configuration, in order to prevent radiation that has passed through the opening from directly entering the wiring board, the opening and the wiring board Must be strictly positioned. For example, in the conventional configuration, when the wiring board enters the inside of the opening provided in the shielding member as viewed in the vertical direction (direction of the incident radiation), the radiation is directly incident on the entering portion. It will be. For this reason, noise due to incidence of radiation is generated in the wiring board. On the other hand, if the distance in the vertical direction between the wiring board and the opening increases, radiation can be prevented from directly entering the wiring board, but the photoelectric conversion element mounted on the fluorescent layer of the fluorescent member and the wiring board And the distance will increase. For this reason, in this case, the detection sensitivity of the fluorescence by the photoelectric conversion element is lowered, and the resolution of the radiation image to be outputted is lowered.

  On the other hand, in the embodiment of the present invention, the shielding member 22 is joined to the upper end surface of the wiring board 21. With such a configuration, the positional relationship between the wiring board 21 and the shielding member 22 is not affected by the accuracy with which the sensor board module 2 is assembled to the main body frame 11. For this reason, even if it is a case where the assembly precision to the main body frame 11 of the sensor board module 2 is low, it is suppressed that a radiation injects into the wiring board 21 directly. Therefore, it is possible to suppress the generation of noise due to the incidence of radiation in the wiring board 21.

  Further, the wavelength conversion member 3 may be bonded to the light receiving surface 41 of the photoelectric conversion element 4. With such a configuration, the positional relationship among the photoelectric conversion element 4, the wavelength conversion member 3, and the shielding member 22 is constant regardless of the accuracy with which the sensor substrate module 2 is assembled to the main body frame 11. For this reason, since the distance between the portion of the fluorescent layer 32 where the radiation is incident and emits fluorescence and the light receiving portion 42 of the photoelectric conversion element 4 is also constant, a decrease in the fluorescence detection sensitivity by the photoelectric conversion element 4 can be suppressed. At the same time, it is possible to suppress a decrease in the resolution of the output radiographic image. Furthermore, with such a configuration, even if there are individual differences in the assembly accuracy of the sensor substrate module 2, individual differences in detection sensitivity and resolution can be suppressed. Therefore, the quality of the radiation detector 1 can be stabilized.

(Modification of shielding member)
Next, a modified example of the shielding member 22 will be described. 5 and 6 are cross-sectional views schematically illustrating a configuration example of the radiation detector 1 to which the shielding member 22 according to the modification is applied, and are diagrams corresponding to FIG. 4.

  FIG. 5 shows an example in which the shielding member 22 extends from the surface of the wiring board 21 in a substantially perpendicular direction. For convenience of explanation, a portion extending to the first surface side is referred to as a “first extension portion 221”, and a portion extending to the second surface side is referred to as a “second extension portion 222”. ".

The first extending portion 221 overlaps the photoelectric conversion element 4 mounted on the first surface of the wiring board 21 when viewed in the vertical direction. When the first extension part 221 overlaps at least a part of the photoelectric conversion element 4 in the vertical direction, the first extension part 221 of the shielding member 22 directly contacts the photoelectric conversion element 4. The amount of radiation incident on can be reduced. Therefore, generation of noise due to incidence of radiation can be suppressed in the photoelectric conversion element 4. In particular, when the direction perpendicular to the surface on which the photoelectric conversion element 4 of the wiring board 21 is mounted is the thickness direction, the extension dimension B _{1 in} the thickness direction of the first extension portion 221 is the thickness of the photoelectric conversion element 4. It is preferable that the first extending portion 221 overlaps the entire photoelectric conversion element 4 when viewed in the vertical direction. With such a configuration, radiation that directly enters the photoelectric conversion element 4 from above can be eliminated. Therefore, the effect of suppressing the generation of noise in the photoelectric conversion element 4 can be enhanced.

On the other hand, it is preferable that the first extending portion 221 does not overlap the upper side (the side on which the radiation is incident) of the wavelength conversion member 3 when viewed in the vertical direction (viewed in the incident direction of radiation). With such a configuration, since radiation directly incident on the wavelength conversion member 3 is not shielded, a decrease in the amount of radiation incident on the wavelength conversion member 3 can be suppressed, and the radiation detection sensitivity of the radiation detector 1 can be increased. Can be maintained. In this case, the extension dimension B _{1 in} the thickness direction dimension of the first extension part 221 may be the same as the thickness of the photoelectric conversion element 4. When there is a gap between the photoelectric conversion element 4 and the wavelength conversion member 3, the extension dimension B _{1 in} the thickness direction dimension of the first extension part 221 is the thickness of the photoelectric conversion element 4. Above, it should just be below the total value of the thickness of the photoelectric conversion element 4, and the dimension of a clearance gap. With such a configuration, the shielding member 22 does not overlap the wavelength conversion member 3 when viewed in the vertical direction. For this reason, the radiation incident from the opening 112 reaches the wavelength conversion member 3 without being shielded by the shielding member 22. However, the first extension part 221 may overlap a part of the wavelength conversion member 3. Even if the first extension part 221 overlaps with a part of the wavelength conversion member 3, radiation is directly incident on the other part not overlapping from above. Therefore, with such a configuration, radiation can be directly incident on at least a part of the wavelength conversion member 3 from above, so that the radiation detection sensitivity of the radiation detector 1 can be ensured. .

The second extending part 222 overlaps an element or an electronic / electrical component mounted on the second surface of the wiring board 21 when viewed in the vertical direction. In this case, the extension dimension B ₂ in the thickness direction of the second extension part 222 may be equal to or greater than the thickness of elements, electronic / electrical components, etc. mounted on the second surface of the wiring board 21. preferable. According to such a configuration, the second extending portion 222 shields radiation from directly entering the elements, electronic / electrical components, and the like mounted on the second surface of the wiring board 21 from above. Is done. Therefore, it is possible to suppress the occurrence of noise in the elements and electronic / electrical components mounted on the second surface of the wiring board 21. When the shielding member 22 has the second extending portion 222, the shielding member 22 is provided on the wiring board 21 even when elements, electronic / electrical components, and the like are not mounted on the second surface of the wiring board 21. The effect of shielding radiation from entering the wiring pattern can be enhanced. Therefore, the occurrence of noise in the wiring pattern provided on the wiring board 21 is suppressed.

  In addition, in FIG. 5, although the shielding member 22 has shown as an example the structure which has both the 1st extension part 221 and the 2nd extension part 222, it is limited to such a structure. It is not something. For example, the structure in which the shielding member 22 has only any one of the 1st extension part 221 and the 2nd extension part 222 may be sufficient.

  FIG. 6 shows an example of a configuration in which the shielding member 22 is provided not only on the upper end face of the wiring board 21 but also on the first surface and the second surface. According to such a configuration, since the first surface and the second surface of the wiring board 21 are covered with the shielding member 22, the radiation incident from above is shielded so as not to directly enter the wiring board 21. In addition, the incidence of radiation reflected by other members (that is, radiation whose traveling direction is not parallel to the vertical direction) can be suppressed. Therefore, according to such a configuration, the effect of suppressing the incidence of radiation on the wiring board 21 can be enhanced.

Further, in such a configuration, the shielding member 22 is also provided on the upper side of the photoelectric conversion element 4. Accordingly, the portion of the shielding member 22 provided on the first surface of the wiring board 21 overlaps the photoelectric conversion element 4 when viewed in the vertical direction, and therefore radiation directly enters the photoelectric conversion element 4. Is suppressed. Therefore, in the photoelectric conversion element 4, generation | occurrence | production of the noise by incidence | injection of a radiation can be suppressed. In this case, the same dimension as the extension dimension B _{1 of} the first extension part 221 in the sub-scanning direction can be applied to the thickness of the portion of the shielding member 22 provided on the first surface. By setting it as such a dimension, the effect similar to the case where the shielding member 22 has the 1st extension part 221 can be show | played.

Further, when elements and electronic / electrical components are mounted on the second surface of the wiring board 21, if the shielding member 22 is provided on the second surface of the wiring board 21, these elements and It is shielded so that radiation does not enter electronic / electrical components. Therefore, generation of noise due to radiation incidence can be suppressed in the elements and electronic / electrical components mounted on the second surface. In this case, the shielding member 22 may be affixed so as to cover the elements and electronic / electrical components mounted on the second surface of the wiring board 21, and is a configuration overlapping in the vertical direction. Also good. When provided so as to overlap when viewed in the vertical direction, the thickness of the portion of the shielding member 22 provided on the second surface is the extension dimension B in the sub-scanning direction of the second extension part 222 described above. _The same dimensions as ₂ can be applied.

  6 shows a configuration in which the integral shielding member 22 is provided so as to straddle the first surface, the upper end surface, and the second surface of the wiring board 21, but the configuration of the shielding member 22 is as described above. It is not limited to a simple configuration. For example, the separate shielding member 22 may be joined to each of the first surface, the upper end surface, and the second surface of the wiring board 21. Further, the thickness of the shielding member 22 may be different between the first surface of the wiring board 21, the upper end surface, and the portion provided on the second surface. Furthermore, the shielding member 22 does not have to be provided on both the first surface and the second surface of the wiring board 21, and in addition to the upper end surface, any one of the first surface and the second surface is possible. The structure provided only in one side may be sufficient.

<Radiation detection device>
Next, a configuration example of the radiation detection apparatus 5 will be described with reference to FIG. FIG. 7 is a cross-sectional view schematically showing a configuration example of the radiation detection apparatus 5. The radiation detection apparatus 5 includes a radiation source 51 and the radiation detector 1 according to the embodiment of the present invention. The radiation source 51 is a radiation source capable of exposing linear radiation that is long in the main scanning direction. The radiation source 51 only needs to have a configuration capable of exposing linear radiation, and the specific configuration is not limited. The radiation source 51 and the radiation detector 1 are disposed to face each other across the conveyance path P of the inspection object Q. The radiation exposed by the radiation source 51 passes through the inspection object Q transported along the transport path P and enters the radiation detector 1. Then, the radiation detector 1 generates and outputs a two-dimensional radiation image signal (radiation image data) having the internal information of the inspection object Q by the above-described operation.

  As mentioned above, although embodiment of this invention was described in detail, above-mentioned embodiment is only a specific example in implementing this invention. The technical scope of the present invention is not limited to the above-described embodiment. The present invention can be variously modified without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the configuration in which the photodiode array is applied to the photoelectric conversion element is shown, but the photoelectric conversion element is not limited to the photodiode array. The photoelectric conversion element should just be what can photoelectrically convert the fluorescence (visible light) which a fluorescent layer emits.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used for a radiation detector having a fluorescent layer and a photoelectric conversion element that photoelectrically converts fluorescence emitted from the fluorescent layer, and a radiation detection apparatus having this radiation detector. And according to this invention, the noise which originates in incidence | injection of a radiation can be suppressed.

DESCRIPTION OF SYMBOLS 1: Radiation detector, 11: Main body frame, 111: Sensor board module accommodating part, 112: Opening part, 12: Main body cover, 2: Sensor board module, 21: Wiring board, 211: Pad, 22: Shielding member, 221 : First extension part, 222: second extension part, 23: connector, 24: bonding wire, 3: wavelength conversion member, 31: base material layer, 32: fluorescent layer, 33: reflection layer, 4: Photoelectric conversion element, 41: light receiving surface, 42: light receiving unit, 43: electrode, 5: radiation detection device, 51: radiation source, Q: inspection object, P: transport path

Claims (9)

A photoelectric conversion unit that converts light into an electrical signal;
A wiring board on which the photoelectric conversion unit is mounted;
A shielding member for shielding incident radiation;
A radiation detector comprising:
The wiring board is provided along the incident direction of the radiation,
The wiring board is provided with a shielding member that shields incident radiation,
The radiation detector is characterized in that the shielding member is provided so as to overlap the wiring board in a radiation incident direction view. It has a wavelength converter that emits light when radiation is incident,
The radiation detector according to claim 1, wherein the shielding member is disposed so as to overlap the wavelength conversion unit when viewed in the incident direction of radiation.   3. The radiation detector according to claim 1, wherein the shielding member is provided on an end surface of the wiring board on the side on which the radiation is incident. 4.   The said shielding member has a 1st extension part extended to the side by which the said photoelectric conversion part of the said wiring board is mounted, The any one of Claim 1 to 3 characterized by the above-mentioned. The radiation detector described.   The thickness direction dimension of the first extending part when the direction perpendicular to the surface of the wiring board on which the photoelectric conversion part is mounted is the thickness direction dimension of the photoelectric conversion part or more. The radiation detector according to claim 4, wherein   The said shielding member has the 2nd extension part extended to the surface side on the opposite side to the surface where the said photoelectric conversion part of the said wiring board is mounted, The Claim 1 to 5 characterized by the above-mentioned. The radiation detector of any one of Claims.   The shielding member is at least one of a portion laminated on the surface of the wiring board on which the photoelectric conversion unit is mounted and a portion of the wiring board on the opposite side of the surface on which the photoelectric conversion unit is mounted. The radiation detector according to claim 1, further comprising:   The radiation detector according to claim 1, wherein the shielding member is tungsten or contains tungsten. A radiation detection apparatus comprising a radiation source and a radiation detector for detecting radiation exposed to the radiation,
The radiation detector is a radiation detector according to claim 1, wherein the radiation detector is a radiation detector.

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