JP2018004570A - Radiation detection device and radiation detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an electromagnetic shield property in a radiation detection device having an arrangement from a side to be irradiated with radiation in order of a conductive member to which fixed potential is supplied, a pixel array, and a scintillator.SOLUTION: A radiation detection device includes: a scintillator 400; a pixel array 302 in which a plurality of pixels P for converting visible light converted by the scintillator 400 into an electric signal is arranged on a first surface 306 of a substrate 301 in a two-dimensional array; a first conductive member 200 to which constant potential is supplied. The radiation detection device includes a second conductive member 206 which has an arrangement from a side to be irradiated with radiation in order of a first conductive member 200, the pixel array 302, and the scintillator 400, has the scintillator 400 arranged on a first surface 306 side, is arranged on a side to be irradiated with radiation of the first conductive member 200, and to which constant potential is supplied. The second conductive member 206 is greater than orthogonal projection with respect to the second conductive member 206 of the first conductive member 200.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a radiation detection apparatus and a radiation detection system applied to a medical diagnostic imaging apparatus, a nondestructive inspection apparatus, an analysis apparatus using radiation, and the like.

  2. Description of the Related Art In recent years, thin film semiconductor manufacturing technology has been used for detection devices and radiation detection devices in which switch elements such as TFTs (thin film transistors) and conversion elements such as photoelectric conversion elements are combined. As shown in Patent Document 1, a proposal has been made to configure a radiation detection device by arranging a pixel array on the side irradiated with radiation emitted from a radiation source and a scintillator on the side opposite to the side irradiated with radiation. ing. And in patent document 1, it arrange | positions in order of the conductive member to which constant potential is supplied from the radiation irradiation side of a radiation detection apparatus, a pixel array, and a scintillator, and the electromagnetic noise mixed from the radiation incident side of a pixel array A radiation detection apparatus that suitably reduces the influence has been proposed.

JP 2012-112726 A

  However, in Patent Document 1, the conductive member is only approximately the same size as the substrate on which the pixel array is provided, and the surface of the housing that is irradiated with radiation is larger than the substrate. It has been difficult to reduce the influence of noise.

  Therefore, in the present invention, in the radiation detection device arranged in the order of the conductive member to which a fixed potential is supplied, the pixel array, and the scintillator from the radiation irradiation side of the radiation detection device, the electromagnetic shielding property is improved. Objective.

  In the radiation detection apparatus of the present invention, a plurality of scintillators that convert irradiated radiation into visible light and pixels that convert visible light converted by the scintillator into electrical signals are arranged in a two-dimensional array on the first surface of the substrate. A first conductive member fixed to a second surface opposite to the first surface of the substrate and supplied with a constant potential, and from the side irradiated with radiation, the first array A radiation detection device in which a conductive member, the pixel array, and the scintillator are arranged in this order, and the scintillator is arranged on the first surface side, and the side on which the radiation of the first conductive member is irradiated And a second conductive member to which a constant potential is supplied. The second conductive member is larger than an orthogonal projection of the first conductive member with respect to the second conductive member.

  According to the present invention, it is possible to improve electromagnetic shielding performance in a radiation detection device arranged in the order of a conductive member to which a fixed potential is supplied, a pixel array, and a scintillator from the radiation irradiation side of the radiation detection device. Become.

Plane schematic diagram and cross-sectional schematic diagram for explaining the schematic configuration of the radiation detection apparatus Plane schematic diagram for explaining the configuration of the sensor panel of the radiation detection apparatus Plane schematic diagram of the entire radiation detector Cross-sectional schematic diagram of the entire radiation detector Cross-sectional schematic diagram for explaining another example of the radiation detection apparatus Cross-sectional schematic diagram for explaining another example of the radiation detection apparatus Cross-sectional schematic diagram for explaining a scintillator of a radiation detection apparatus Plane schematic diagram for explaining the scintillator of the radiation detection apparatus Schematic diagram showing an example of a schematic configuration of a radiation detection system

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. In this specification, in addition to α-rays, β-rays, γ-rays, etc., which are beams produced by particles (including photons) emitted by radioactive decay, beams having the same or higher energy, such as X-rays, Particle rays and cosmic rays are also included in the radiation.

  First, the schematic configuration of the radiation detection apparatus of the present invention will be described with reference to FIGS. 1 (a), 1 (b), and 2. FIG. 1A is a schematic plan view excluding the housing portion of the radiation detection apparatus, FIG. 1B is a schematic cross-sectional view of the radiation detection apparatus excluding the housing portion, and AA in FIG. It is a cross-sectional schematic diagram of '. FIG. 2 is a schematic plan view for explaining the configuration of the sensor panel of the radiation detection apparatus.

  As shown in FIG. 1A, FIG. 1B, and FIG. 2, the radiation detection apparatus of the present invention includes a scintillator 400, a pixel array 302, a plurality of connection terminal portions 303, and a first conductive member 200. including. The scintillator 400 converts irradiated radiation into visible light. The scintillator 400 can include a scintillator layer 401 that converts radiation into visible light, and a protective member 402 that protects the scintillator layer 401. In the pixel array 302, a plurality of pixels P that convert visible light converted by the scintillator 400 into electrical signals are arranged on the first surface 306 of the substrate 301 in a two-dimensional array. The substrate 301 includes a second surface 307 that faces the first surface 306. Each of the pixels 302 includes a photoelectric conversion element 304 that converts visible light into an electric signal, and a switch element such as a thin film transistor (TFT) for controlling accumulation and output of the electric signal obtained by the photoelectric conversion element 304. obtain. Each of the plurality of connection terminal portions 303 is provided in the periphery of the pixel array 302 on the first surface 306 of the substrate 301, and electrical connection between the pixel array 300 and an external circuit (details will be described later) via the wiring portion 308. It is for making a general connection. The first conductive member 200 is supplied with a constant potential in order to reduce electromagnetic noise mixed from the radiation irradiation side (second surface 307 side) to the pixel array 302. The first conductive member 200, the pixel array 302, and the scintillator 400 are arranged in this order from the radiation irradiation side, and the scintillator 400 is arranged on the first surface side (first surface 306 side) of the substrate 301. ing. Here, the first conductive member 200 is disposed in a region excluding the region 309 facing the plurality of connection terminal portions 303 on the second surface 307 of the substrate 301. The first conductive member 200 can be fixed to the second surface 307 of the substrate 301 in a region excluding the region 309 via an adhesive. Here, the first conductive member 200 has an end portion located between the end of the region where the pixel array 302 of the second surface 307 is disposed and the region 309 facing the plurality of connection terminal portions 303. , Are arranged in the area excluding the area 309. Note that the pixel array 302 and the wiring portion 308 are covered with a passivation film 310, and in this case, the scintillator 400 is provided on the surface of the passivation film 310 on the first surface 306 side of the substrate 301. Further, the protection member 402 covers the surface of the scintillator layer 401 and the passivation film 310 around it, thereby covering the scintillator layer 401 and the first surface 306 of the substrate 301 to protect the scintillator layer 401. . The protective member 402 can include a conductive layer to which a constant potential is supplied. In that case, the pixel array 302 is shielded against electromagnetic noise by the first conductive member 200 and the conductive layer of the protection member 402 from both surface sides.

  The plurality of connection terminal portions 303 are electrically connected to a drive circuit (not shown) for driving the pixel array 302 as shown in FIG. It includes a plurality of first connection terminal portions arranged along one side and the opposite third side. A plurality of first flexible wiring boards 103b are electrically connected to the plurality of connection terminal portions. Further, the plurality of connection terminal portions 303 are electrically connected to a readout circuit (not shown) for reading out an electrical signal from the pixel array 302, and are opposed to a second side adjacent to the first side of the substrate 301. A plurality of second connection terminal portions arranged along the fourth side are included. A plurality of second flexible wiring boards 103b are electrically connected to the plurality of second connection terminal portions. The electrical connection between the set of connection terminal portions 303 and the flexible wiring board is made by a conductive adhesive 108 such as an anisotropic conductive film.

  The connecting portion 201 is for electrically connecting a constant potential member (details will be described later) for supplying a constant potential to the first conductive member 200 and the first conductive member 200. As shown in FIG. 1A, the connecting portion 201 is provided so as to pass between regions 309 facing the plurality of connecting terminal portions 303 on the second surface 307 on the second side and the fourth side of the substrate 301. It has been. Moreover, the connection part 201 is provided so that it may pass between the some 2nd flexible wiring boards 103a. The signal passing through the second flexible wiring board 103a is an electric signal generated by the pixel array 302 and is very weak compared to the signal for driving the pixel array passing through the first flexible wiring board 103b. Since the connection portion 201 to which a constant potential is supplied is located on the second flexible wiring board 103a side, the electromagnetic noise resistance of the second flexible wiring board 103a through which a weak electric signal passes can be improved. Further, as shown in FIGS. 1A and 1B, the connecting portion 201 is such that a part of the first conductive member 200 is stretched using the same material as the first conductive member 200. It can take a configuration. As a material for the first conductive member 200 and the connection portion 201, a sheet-like member having a total thickness of 0.05 to 0.1 mm in which aluminum and PET (polyethylene terephthalate) are stacked may be used. The sheet resistance applicable as the first conductive member 200 is 10000Ω / □ or less. A plurality of connection portions 201 are preferably provided. In the example illustrated in FIG. 1A, the connection portions 201 are provided at a total of 10 locations, 5 locations on the second side and 5 locations on the fourth side.

  Next, the schematic configuration of the entire radiation detection apparatus of the present invention will be described with reference to FIGS. 3, 4 (a), and 4 (b). 3A is a schematic plan view of the entire radiation detection apparatus, FIG. 4A is a schematic cross-sectional view of the entire radiation detection apparatus, and is a schematic cross-sectional view taken along line AA ′ of FIG. b) is a schematic cross-sectional view taken along the line BB ′ of FIG. 3.

  As shown in FIGS. 3, 4 (a), and 4 (b), the radiation detection apparatus 100 includes a sensor panel 300, a scintillator 400, a first conductive member 200, first and second flexible wiring boards. 103a and 103b, and a housing for housing the connecting portion 201 is included. As shown in FIG. 4, the housing includes an outer box 102 including an outer box upper part 102 a and an outer box lower part 102 b, and a cover 101. As the cover 101 on the radiation irradiation side of the radiation detection apparatus 100, CFRP (carbon fiber reinforced plastic) having a thickness of 1 to 1.5 mm can be suitably used. For the outer box upper part 102a and the outer box lower part 102b, SUS (stainless steel) having a thickness of 1.5 to 2.5 mm having both lightness and robustness can be used. Here, SUS is an alloy steel containing iron (Fe) as a main component (50% or more) and 10.5% or more of chromium (Cr). Therefore, the outer box upper part 102a and the outer box lower part 102b function as electromagnetic shields by supplying a constant potential such as ground. The cover 101 can be adhered and fixed to the outer box upper part 102.

  The radiation detection apparatus 100 further includes a first conductive member 200, a substrate 301 including a pixel array 302 from the side of the scintillator 400, and a support member 106 that supports the scintillator 400 in the housing. The support member 106 includes a radiation absorbing plate 106a and a base 106b, which are arranged in order from the side irradiated with radiation (the scintillator 400 side). The base 106b is made of Al having a thickness of 2 to 3.5 mm, the radiation absorbing plate 106a is made of SUS having a thickness of 0.25 to 1 mm, and is higher in radiation than the base 106b. Has absorption performance. The support member 106 is fixed and held by the spacer 104 to the lower portion 102b of the outer box by screwing or the like. The protective member 402 and the support member 106 of the scintillator 400 are fixed by an adhesive sheet 403 having a buffer function. The pressure-sensitive adhesive sheet 403 preferably has a total thickness of 0.5 to 0.75 mm in order to achieve both a buffer function and adhesiveness. Moreover, it is preferable that the adhesive sheet 403 has an area substantially the same as or wider than the surface of the scintillator 400 on the support member 106 side.

  As shown in FIG. 4A, the second flexible wiring board 103a is provided with a second integrated circuit (IC) 112a having a readout circuit for reading out an electrical signal from the pixel array, so-called COF (Chip). On Film) may be used. The second integrated circuit 112a includes an IC having a power supply circuit and a processing circuit provided in the second printed circuit board 105a, an IC having a control circuit provided in the third printed circuit board 105c, and a third flexible wiring board 103c. It is electrically connected via. The second integrated circuit 112a, the second printed circuit board 105a, the third printed circuit board 105c, and the third flexible wiring board 103c may be disposed between the support member 106 and the outer box lower part 102b. Thereby, these members can be arranged on the side opposite to the side irradiated with radiation with respect to the radiation absorbing plate 106a. Here, a first heat transfer member 109 made of Al and a heat dissipating member 111 made of heat dissipating rubber are disposed between the second integrated circuit 112a and the Al base 106b. As a result, the heat generated in the second integrated circuit 112a is transferred and diffused to the base 106b, thereby relaxing the heat concentration. Further, a second heat transfer member 110 made of Al and a heat dissipation member 111 made of heat radiating rubber are arranged between the second integrated circuit 112a and the outer box lower portion 102b. Thereby, the heat generated in the second integrated circuit 112a is transferred to the outer box lower part 102b and radiated to the outside through the outer box lower part 102b. The second printed circuit board 105 a is fixed to the base 106 b through the spacer 104, and the third printed circuit board 105 c is fixed to the base 106 b and the outer box lower part 102 b through the spacer 104. The spacer 104 can have a heat transfer function in addition to the position restriction by using a material having a higher thermal conductivity than air.

  As shown in FIG. 4B, the first flexible wiring substrate 103b has a so-called COF (Chip On Film) provided with a first integrated circuit 112b having a driving circuit for driving the pixel array. Can be used. The first integrated circuit 112b is electrically connected to an IC having a power supply circuit provided on the first printed circuit board 105b. The first integrated circuit 112b and the first printed circuit board 105b may be disposed between the support member 106 and the outer box lower part 102b. Thereby, these members can be arranged on the side opposite to the side irradiated with radiation with respect to the radiation absorbing plate 106a.

  Meanwhile, a spacer 113 and a buffer member 114 are disposed between the substrate 301 and the first conductive member 200 and the outer box upper portion 102a, and the substrate 301 and the first conductive member 200 are positioned with respect to the outer box upper portion 102a. It is regulated. The spacer 113 is made of SUS having a thickness of 1 to 2.5 mm, and has higher radiation absorption performance than the base 106b. The radiation absorbing plate 106a and the spacer 113 ensure the radiation absorbability of the entire radiation detection apparatus.

  Here, the connecting portion 201 is fixed to the support member 106 so as to be electrically connected to the base 106b. The base 106b of the support member 106 is electrically connected to a constant potential portion of the power supply circuit and the casing by a metal such as a screw used for the spacer 104 and is supplied with a fixed potential, and functions as a constant potential member. . As described above, the connection portion 201 is electrically connected to the base 106b, whereby a constant potential can be supplied to the first conductive member 200. Note that the supplied constant potential may be a ground potential due to grounding or a constant potential generated by any one of the power supply circuits.

  Then, the second conductive member to which a constant potential is supplied to the side on which the radiation of the first conductive member 200 in the casing is irradiated, in other words, between the cover 101 of the casing and the first conductive member 200. 206 is arranged. Here, the second conductive member 206 is larger than the orthogonal projection of the first conductive member 200 with respect to the second conductive member 206. In other words, the second conductive member 206 has a larger area than the first conductive member 200 and can cover a wider area. Accordingly, it is possible to reduce the influence of electromagnetic noise that can be mixed from the area of the difference in area between the cover 101 and the second conductive member 206 that is the surface of the housing that is irradiated with radiation. As shown in FIG. 4B, the second conductive member 206 is sandwiched between the outer box upper part 102a and the spacer 113, and is electrically connected to the outer box upper part 102a so as to have a constant potential. Is supplied from the housing. As a material of the second conductive member 206, a sheet-like member having a total thickness of 0.07 to 0.15 mm in which aluminum and PET (polyethylene terephthalate) are laminated may be used. The sheet resistance applicable as the second conductive member 206 is 10000Ω / □ or less. The second conductive member 206 preferably has a higher rigidity than the first conductive member 200 in order to ensure resistance to impact caused by the deformation of the cover 101, and therefore the total thickness is made thicker. It is preferable. The second conductive member 206 may be directly bonded and fixed to the cover 101.

  In the example shown in FIG. 1A, the connecting portion 201 passes between the regions 309 on the second side and the fourth side of the substrate 301 so as to pass between the plurality of second flexible wiring boards 103a. However, the present invention is not limited to this. For example, as shown in FIG. 5A, the connecting portion 201 passes between the regions 309 on the first side and the third side of the substrate 301 and passes between the plurality of first flexible wiring boards 103b. May be provided. Further, as shown in FIG. 1A, the first conductive member 200 has an end portion facing an end of a region where the pixel array 302 of the second surface 307 is disposed and a plurality of connection terminal portions 303. However, the present invention is not limited to this. For example, as shown in FIGS. 5B and 5C, the first conductive member 200 has a part of the end thereof positioned between the plurality of regions 309 of the second surface 307. It may be arranged. By arrange | positioning in this way, the 1st electroconductive member 200 can be arrange | positioned in a wider area | region compared with the example shown to Fig.1 (a).

  Further, as shown in FIG. 6A, the connection portion 201 is arranged so that it can be disposed between the plurality of first flexible wiring boards and between the plurality of second flexible wiring boards. It may be provided in a larger number than the example shown in 1 (a). In the example illustrated in FIG. 1A, the connection unit 201 uses a configuration in which a part of the first conductive member 200 is stretched using the same material as the first conductive member 200. The present invention is not limited to this. As shown in FIG. 6B, the connection portion 201 may be provided separately from the first conductive member 200 and electrically connected to the first conductive member 200 via the conductive adhesive 205. .

  Here, the scintillator 400 provided in the sensor panel 300 will be described in more detail with reference to FIGS. 7A to 7D. As shown in FIG. 7A, the protective member 402 of the scintillator 400 can include a support layer 204, a moisture-proof layer 405, and an adhesive layer 406. The moisture-proof layer 405 is a layer that protects the scintillator layer 401 from external moisture and the like, and a conductive layer such as Al can be used. By supplying a constant potential to the conductive layer, the moisture-proof layer 405 can function as an electromagnetic shield. The support layer 204 is a layer that supports the moisture-proof layer 405. If the moisture-proof layer 405 has sufficient rigidity, the support layer 204 is not necessarily provided as shown in FIG. For the support layer 204, PET (polyethylene terephthalate) or the like can be suitably used. The adhesive layer 406 is a layer for adhering the moisture-proof layer 405 to the scintillator layer 401 and the sensor panel 300, and a hot melt resin or the like can be suitably used. As shown in FIG. 7C, the adhesive layer 406 is used to suppress electrochemical corrosion when an alkali halide material is used for the scintillator layer 401 and a conductive layer is used for the moisture-proof layer. The scintillator layer 401 may be provided so as to cover it. Otherwise, as shown in FIG. 7D, the adhesive layer 406 may be provided so as to adhere only to the sensor panel 300 without adhering to the scintillator layer 401.

  As shown in FIG. 8A, the conductive layer of the protective member 402 passes between the regions 309 on the first side and the third side of the substrate 301 and passes between the plurality of first flexible wiring boards 103b. It is provided to pass. A part of the conductive layer of the protective member 402 that has passed through is electrically connected to the support member 106, whereby a constant potential is supplied to the conductive layer of the protective member 402 and can function as an electromagnetic shield. In order to reinforce this electromagnetic shielding function, as shown in FIG. 8 (b), the conductive layer of the protection member 402 may be electrically connected to the support member 106 from a plurality of paths through a larger area. Good.

  Next, an example in which the radiation detection apparatus 100 is applied to a radiation detection system will be described with reference to FIG. X-rays 6060 generated by an X-ray tube 6050 serving as a radiation source pass through a chest 6062 of a patient or subject 6061 and enter a radiation detection apparatus 6040 typified by the radiation detection apparatus 100 described above. This incident X-ray includes information inside the body of the subject 6061. The scintillator 216 emits light in response to the incidence of X-rays, and this is photoelectrically converted by a photoelectric conversion element to obtain electrical information. This information can be digitally converted and image-processed by an image processor 6070 serving as a signal processing device, and can be observed on a display 6080 serving as display means in a control room. Further, this information can be transferred to a remote place by transmission processing means such as a telephone line 6090, and can be displayed on a display 6081 serving as a display means such as a doctor room in another place or stored in a recording means such as an optical disk. It is also possible for a doctor to make a diagnosis. Moreover, it can also record on the film 6110 used as a recording medium by the film processor 6100 used as a recording means.

  Note that the above-described embodiments of the present invention are merely examples of implementation in practicing the present invention, and the technical scope of the present invention should not be construed as being limited thereto. It is. That is, the present invention can be implemented in various forms without departing from the technical idea or the main features thereof.

P pixel 200 first conductive member 206 second conductive member 301 substrate 302 pixel array 306 first surface 307 second surface 400 scintillator

Claims (12)

A scintillator that converts the irradiated radiation into visible light;
A pixel array in which a plurality of pixels that convert visible light converted by the scintillator into electrical signals are arranged in a two-dimensional array on the first surface of the substrate;
A first conductive member fixed to a second surface opposite to the first surface of the substrate and supplied with a constant potential;
Including
A radiation detection device in which the first conductive member, the pixel array, and the scintillator are arranged in this order from the side irradiated with radiation, and the scintillator is arranged on the first surface side,
A second conductive member that is disposed on the radiation side of the first conductive member and is supplied with a constant potential;
The radiation detecting apparatus according to claim 1, wherein the second conductive member is larger than an orthogonal projection of the first conductive member with respect to the second conductive member. A housing that houses the second conductive member, the first conductive member, the substrate, and the scintillator;
The radiation detection apparatus according to claim 1, wherein a constant potential is supplied to the second conductive member from the housing.   The end portion of the first conductive member is located between an end of a region where the pixel array is disposed on the second surface and a region facing the plurality of connection terminal portions. Item 2. The radiation detection apparatus according to Item 1.   4. The device according to claim 1, wherein a part of the end portion of the first conductive member is located between regions of the second surface facing the plurality of connection terminal portions. 5. The radiation detection apparatus according to 1.   A connection portion for electrically connecting a constant potential member for supplying a constant potential to the first conductive member and the first conductive member is opposed to the plurality of connection terminal portions on the second surface. The radiation detection apparatus according to claim 1, wherein the radiation detection apparatus is provided so as to pass between regions to be operated. The plurality of connection terminal portions include a plurality of first connection terminal portions arranged along the first side of the substrate and a plurality of second connection sides arranged adjacent to the first side of the substrate. A second connection terminal portion,
The plurality of first connection terminal portions are electrically connected to a drive circuit for driving the pixel array,
The plurality of second connection terminal portions are electrically connected to a readout circuit for reading an electrical signal from the pixel array,
The said connection part is provided so that it may pass between the area | regions facing the said several connection terminal part of the said 2nd surface in the said 2nd edge | side of the said board | substrate. Radiation detection equipment. A plurality of first flexible wiring boards electrically connected to the plurality of first connection terminal portions; and a plurality of second flexible wiring boards electrically connected to the plurality of second connection terminal portions. Including
The radiation detection apparatus according to claim 6, wherein the connection portion is provided so as to pass between the plurality of second flexible wiring boards. A support member for supporting the first conductive member, the substrate, and the scintillator from the scintillator side;
The radiation detection apparatus according to claim 5, wherein the constant potential member is the support member. The support member includes a base, and a radiation absorbing plate disposed between the scintillator and the base,
The radiation detecting apparatus according to claim 8, wherein the constant potential member is the base. The scintillator includes a scintillator layer that converts radiation into visible light, and a protection member that covers at least a part of the scintillator layer and the first surface of the substrate to protect the scintillator layer,
The radiation detecting apparatus according to claim 9, wherein the protective member includes a conductive layer to which a constant potential is supplied.   The radiation detection apparatus according to claim 10, wherein a constant potential is supplied to the first conductive member by grounding the base together with the housing. The radiation detection apparatus according to any one of claims 1 to 11,
A signal processing device for processing an electrical signal obtained by the radiation detection device;
A radiation detection system comprising:

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