Radiation detection module

Abstract

To provide a radiation detection module that can reduce the width of a frame.SOLUTION: A radiation detection module comprises a photoelectric conversion substrate 2, a scintillator layer 5, a wiring board, a moisture-proof cover 7, and a sealing part 8. The sealing part 8 is provided between the photoelectric conversion substrate 2 and moisture-proof cover 7 and between the wiring board and moisture-proof cover 7. The sealing part 8 is provided in a frame shape in a non-detection area NDA, and covers the scintillator layer 5 together with the photoelectric conversion substrate 2 and moisture-proof cover 7.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE The present invention relates to a radiation detection module. [Background technology]

[0002] As a radiation detector, for example, an X-ray detector (X-ray flat panel detector) is known. The X-ray detection module of the X-ray detector includes a scintillator layer that converts X-rays into fluorescence, and a photoelectric conversion substrate that converts the fluorescence into an electrical signal. The scintillator layer includes, for example, cesium iodide (CsI). In order to increase the efficiency of using the fluorescence and improve the sensitivity characteristics, the X-ray detection module may further include a light reflecting layer provided on the scintillator layer.

[0003] Here, it is necessary to isolate the scintillator layer and the light reflecting layer from the external atmosphere in order to suppress deterioration of characteristics caused by water vapor, etc. As a result, a technique has been proposed to cover the scintillator layer and the light reflecting layer with a hat-shaped moisture-proof cover and to bond the peripheral portion of the moisture-proof cover to the photoelectric conversion substrate, as a structure that can obtain high moisture-proof performance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-189101 [Patent Document 2] JP 2021-105591 A Summary of the Invention [Problem to be solved by the invention]

[0005] This embodiment provides a radiation detection module that allows for a narrow frame. [Means for solving the problem]

[0006] The radiation detection module according to one embodiment includes: a photoelectric conversion substrate having a photoelectric conversion element located in a detection region and a pad located in a non-detection region outside the detection region and electrically connected to the photoelectric conversion element; a scintillator layer provided on the photoelectric conversion substrate and positioned in the detection region; a wiring board fixed to the non-detection area of ​​the photoelectric conversion board and electrically connected to the pads; a moisture-proof cover provided above the photoelectric conversion substrate and the scintillator layer and positioned in the detection region and the non-detection region; The device is provided with a sealing portion that is located between the photoelectric conversion substrate and the moisture-proof cover and between the wiring substrate and the moisture-proof cover, is frame-shaped in the non-detection area, and covers the scintillator layer together with the photoelectric conversion substrate and the moisture-proof cover. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing an X-ray detector according to an embodiment. [Diagram 2] FIG. 2 is a perspective view showing a support substrate, an X-ray detection panel, a circuit board, a plurality of FPCs, and an image transmission section of the X-ray detector. [Diagram 3] FIG. 3 is an enlarged cross-sectional view showing a part of the X-ray detection panel. [Figure 4] FIG. 4 is a circuit diagram showing the X-ray detection panel, the circuit board, and a plurality of FPCs. [Diagram 5] FIG. 5 is a plan view showing the X-ray detection panel, illustrating the positional relationship between the pads and the sealing portion, etc. FIG. [Figure 6] FIG. 6 is a cross-sectional view showing the X-ray detection panel shown in FIG. 5 along line VI-VI, and also shows the FPC and the connecting material. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing the detection area and non-detection area of ​​the X-ray detection panel, together with the FPC and the connecting material. [Figure 8] 8 is an enlarged cross-sectional view showing the X-ray detection panel, the FPC, and the connecting material shown in FIG. 7 along line VIII-VIII. [Figure 9] FIG. 9 is a cross-sectional view showing an X-ray detection panel, an FPC, a connecting material, and a moisture-proof portion according to a comparative example. [Figure 10] FIG. 10 is a cross-sectional view showing an X-ray detection panel, an FPC, a connecting material, and a moisture-proof portion according to the first modification of the above embodiment. [Figure 11] FIG. 11 is an enlarged cross-sectional view showing the detection region and the non-detection region of the X-ray detection panel according to the second modification of the embodiment, and also shows the FPC, the connecting material, and the moisture-proof portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present invention, modifications, and comparative examples will be described with reference to the drawings. (One embodiment) First, an X-ray detector according to an embodiment will be described in detail. Fig. 1 is a cross-sectional view showing an X-ray detector 1 according to this embodiment. The X-ray detector 1 is an X-ray image detector, and is a flat panel X-ray detector that uses an X-ray detection panel. The X-ray detector 1 is used, for example, for general medical purposes.

[0009] 1, the X-ray detector 1 includes an X-ray detection module 10, a support substrate 12, spacers 9a, 9b, 9c, and 9d, a housing 51, an entrance window 52, ​​and the like. The X-ray detection module 10 includes an X-ray detection panel PNL, a circuit board 11, an FPC (flexible printed circuit board) 2e1, and the like. The X-ray detection panel PNL is located between the support substrate 12 and the entrance window 52. The X-ray detection panel PNL includes a moisture-proof cover 7 facing the entrance window 52.

[0010] The entrance window 52 is attached to an opening of the housing 51. The entrance window 52 transmits X-rays. Therefore, the X-rays pass through the entrance window 52 and are incident on the X-ray detection panel PNL. The entrance window 52 is formed in a plate shape and has a function of protecting the inside of the housing 51. It is desirable to form the entrance window 52 thinly and using a material with low X-ray absorption rate. This makes it possible to reduce scattering of X-rays and attenuation of the amount of X-rays that occur at the entrance window 52. As a result, a thin and lightweight X-ray detector 1 can be realized. The X-ray detection module 10 , the support substrate 12 , etc. are housed inside a space surrounded by a housing 51 and an entrance window 52 .

[0011] The X-ray detection panel PNL is light and has low mechanical strength because it is constructed by laminating thin members. For this reason, the X-ray detection panel PNL is fixed to one flat surface of the support substrate 12 via an adhesive sheet. The support substrate 12 is formed into a plate shape from, for example, an aluminum alloy, and has the strength required to stably hold the X-ray detection panel PNL. This makes it possible to suppress damage to the X-ray detection panel PNL when vibrations or impacts are applied to the X-ray detector 1 from the outside.

[0012] The circuit board 11 is fixed via spacers 9a and 9b to the other surface of the support board 12. By using the spacers 9a and 9b made of an electrically insulating material, an electrical insulation distance can be maintained between the support board 12, which is mainly made of metal, and the circuit board 11. The circuit board 11 is fixed to the inner surface of the housing 51 via spacers 9c and 9d. By using the spacers 9c and 9d made of an electrically insulating material, it is possible to maintain an electrical insulation distance between the housing 51, which is mainly made of metal, and the circuit board 11. The housing 51 supports the support board 12 and the like via the circuit board 11 and the spacers 9a, 9b, 9c, and 9d.

[0013] A connector corresponding to the FPC2e1 is mounted on the circuit board 11, and the FPC2e1 is electrically connected to the circuit board 11 via the connector. A thermocompression method using ACF (anisotropic conductive film) is used to connect the FPC2e1 and the X-ray detection panel PNL. This method ensures electrical connection between a plurality of fine pads on the X-ray detection panel PNL and a plurality of fine pads on the FPC2e1, and the FPC2e1 is physically fixed to the X-ray detection panel PNL. The pads on the X-ray detection panel PNL and the pads on the FPC2e1 will be described later.

[0014] As described above, the circuit board 11 is electrically connected to the X-ray detection panel PNL via the connector, the FPC 2e1, etc. The circuit board 11 electrically drives the X-ray detection panel PNL and electrically processes the output signal from the X-ray detection panel PNL.

[0015] Fig. 2 is a perspective view showing the support substrate 12, the X-ray detection panel PNL, the circuit board 11, the multiple FPCs 2e1, 2e2, and the image transmission unit 4 of the X-ray detector 1 according to this embodiment. Note that Fig. 2 does not show all components of the X-ray detector 1. Some components of the X-ray detector 1, such as a sealing unit described below, are omitted in Fig. 2. With regard to the photoelectric conversion substrate 2, a detection area (a detection area DA described below) is shown, but a non-detection area (a non-detection area NDA described below) is not shown.

[0016] As shown in Fig. 2, the X-ray detection panel PNL includes a photoelectric conversion substrate 2, a scintillator layer 5, etc. The photoelectric conversion substrate 2 includes a base material 2a, a plurality of photoelectric conversion units 2b, a plurality of gate lines (or control lines) G1, a plurality of data lines (or signal lines) T1, etc. Note that the numbers, arrangements, etc. of the photoelectric conversion units 2b, the gate lines G1, the data lines T1, and the FPCs 2e1 and 2e2 are not limited to the example in Fig. 2. The FPCs 2e1 and 2e2 each function as a wiring substrate.

[0017] The multiple gate lines G1 are provided above the base material 2a, extend in a row direction X as a first direction, and are arranged at predetermined intervals in a column direction Y as a second direction intersecting the first direction. The multiple data lines T1 are provided above the base material 2a, extend in the column direction Y, intersect with the multiple gate lines G1, and are arranged at predetermined intervals in the row direction X.

[0018] The multiple photoelectric conversion units 2b are provided on one surface of the base material 2a. The photoelectric conversion units 2b are provided in a rectangular region defined by the gate lines G1 and the data lines T1. One photoelectric conversion unit 2b corresponds to one pixel of an X-ray image. The multiple photoelectric conversion units 2b are arranged in a matrix in the row direction X and the column direction Y. From the above, the photoelectric conversion substrate 2 is an array substrate.

[0019] Each photoelectric conversion unit 2b has a thin-film photodiode 15a as a photoelectric conversion element and a TFT (thin-film transistor) 13a as a detection switching element. Hereinafter, the thin-film photodiode 15a is referred to as a TFD 15a. The TFT 13a is provided above the base material 2a and is connected to a corresponding one of the gate lines G1 and a corresponding one of the data lines T1. The TFD 15a is provided above the base material 2a and is electrically connected to the TFT 13a.

[0020] The gate line G1 is electrically connected to the circuit board 11 via the FPC 2e1. The circuit board 11 provides a control signal S1 to the gate lines G1 via the FPC 2e1. The data line T1 is electrically connected to the circuit board 11 via the FPC 2e2. The image data signal S2 (charges accumulated in the photoelectric conversion unit 2b) converted by the TFD 15a is transmitted to the circuit board 11 via the TFT 13a, the data line T1, and the FPC 2e2.

[0021] The X-ray detector 1 includes an image transmission unit 4. The image transmission unit 4 is connected to a circuit board 11 via wiring 4a. The image transmission unit 4 may be incorporated into the circuit board 11. The image transmission unit 4 generates an X-ray image based on image data signals converted into digital signals by a plurality of analog-digital converters (not shown). The generated X-ray image data is output from the image transmission unit 4 to an external device.

[0022] FIG. 3 is an enlarged cross-sectional view showing a part of the X-ray detection panel PNL according to this embodiment. As shown in Fig. 3, the photoelectric conversion substrate 2 has a base material 2a, a plurality of photoelectric conversion units 2b, and insulating layers 21, 22, 23, 24, and 25. The plurality of photoelectric conversion units 2b are located in a detection area DA. Each photoelectric conversion unit 2b includes a TFD 15a and a TFT 13a. The TFT 13a includes a gate electrode GE, a semiconductor layer SC, a source electrode SE, and a drain electrode DE. The TFD 15a is composed of a thin-film photodiode.

[0023] The base material 2a has a plate-like shape and is made of an insulating material. Examples of the insulating material include glass such as alkali-free glass. In this embodiment, the base material 2a is made of glass, but may be made of an organic insulating material such as resin. The planar shape of the base material 2a is, for example, a rectangle. The thickness of the base material 2a is, for example, 0.5 to 0.7 mm. The insulating layer 21 is provided on the base material 2a.

[0024] A gate electrode GE is formed on the insulating layer 21. The gate electrode GE is electrically connected to the gate line G1. The insulating layer 22 is provided on the insulating layer 21 and the gate electrode GE. The semiconductor layer SC is provided on the insulating layer 22 and faces the gate electrode GE. The semiconductor layer SC is formed of a semiconductor material such as amorphous silicon as an amorphous semiconductor or polycrystalline silicon as a polycrystalline semiconductor.

[0025] A source electrode SE and a drain electrode DE are provided on the insulating layer 22 and the semiconductor layer SC. The gate electrode GE, the source electrode SE, the drain electrode DE, the gate line G1, and the data line T1 are formed using a low-resistance metal such as aluminum or chromium.

[0026] The source electrode SE is electrically connected to the source region of the semiconductor layer SC. The source electrode SE is also electrically connected to the data line T1. The drain electrode DE is electrically connected to the drain region of the semiconductor layer SC.

[0027] The insulating layer 23 is provided on the insulating layer 22, the semiconductor layer SC, the source electrode SE, and the drain electrode DE. The conductive layer CL is formed above the insulating layer 23 and is electrically connected to the drain electrode DE. The TFD 15a is formed on the conductive layer CL and is electrically connected to the conductive layer CL. The TFD 15a is formed through a film formation process and a patterning process using a dry etching method.

[0028] The insulating layer 24 is provided on the insulating layer 23, the conductive layer CL, and the TFD 15a. The bias line BL1 is provided on the insulating layer 24 and connected to the TFD 15a through a contact hole formed in the insulating layer 24. The insulating layer 25 is provided on the insulating layer 24 and the bias line BL1.

[0029] The insulating layers 21, 22, 23, 24, and 25 are made of insulating materials such as inorganic insulating materials and organic insulating materials. Examples of inorganic insulating materials include oxide insulating materials, nitride insulating materials, and oxynitride insulating materials. Examples of organic insulating materials include resins.

[0030] The scintillator layer 5 is provided on the photoelectric conversion substrate 2 (the multiple photoelectric conversion sections 2b). The scintillator layer 5 is located at least in the detection area DA, and covers the upper parts of the multiple photoelectric conversion sections 2b. The scintillator layer 5 is configured to convert incident X-rays into light (fluorescence).

[0031] The TFD 15a converts the light incident through the scintillator layer 5 into electric charges. The converted electric charges are stored in the TFD 15a. The TFT 13a can switch between storing electric charges in the TFD 15a and discharging electric charges from the TFD 15a. If the self-capacitance of the TFD 15a is insufficient, the photoelectric conversion substrate 2 may further include a capacitor (storage capacitor) to store the electric charges converted by the TFD 15a.

[0032] The scintillator layer 5 is made of thallium-activated cesium iodide (CsI:Tl). When the scintillator layer 5 is formed by using a vacuum deposition method, the scintillator layer 5 is made of an aggregate of a plurality of columnar crystals. The thickness of the scintillator layer 5 is, for example, 600 μm. At the outermost surface of the scintillator layer 5, the thickness of the columnar crystals of the scintillator layer 5 is 8 to 12 μm.

[0033] The material forming the scintillator layer 5 is not limited to CsI:Tl. The scintillator layer 5 may be formed of thallium-activated sodium iodide (NaI:Tl), sodium-activated cesium iodide (CsI:Na), europium-activated cesium bromide (CsBr:Eu), sodium iodide (NaI), or the like.

[0034] When forming the scintillator layer 5 using the vacuum deposition method, a mask having an opening is used. In this case, the scintillator layer 5 is formed in a region facing the opening on the photoelectric conversion substrate 2. The scintillator material deposited by deposition is also deposited on the surface of the mask. The scintillator material is also deposited near the opening of the mask, and crystals grow so as to gradually protrude into the opening. When the crystals protrude from the mask into the opening, deposition of the scintillator material onto the photoelectric conversion substrate 2 in the vicinity of the opening is suppressed. Therefore, as shown in FIG. 2, the thickness of the scintillator layer 5 in the vicinity of the periphery gradually decreases toward the outside.

[0035] Alternatively, the scintillator layer 5 may have a plurality of scintillator sections arranged in a matrix, provided one-to-one with the photoelectric conversion section 2b, each having a rectangular prism shape. When forming such a scintillator layer 5, a scintillator material obtained by mixing gadolinium oxysulfide (Gd2O2S) phosphor particles with a binder material is applied onto the photoelectric conversion substrate 2, and the scintillator material is baked and hardened. After that, dicing is performed with a dicer, etc., to form a lattice-shaped groove portion in the scintillator material. In the above case, air or an inert gas such as nitrogen (N2) for preventing oxidation is sealed between the plurality of scintillator sections. Alternatively, the space between the plurality of scintillator sections may be set to a space reduced in pressure from the atmospheric pressure.

[0036] In this embodiment, the X-ray detection panel PNL further includes a light reflecting layer 6. The light reflecting layer 6 is provided on the scintillator layer 5. In other words, the light reflecting layer 6 is provided on the X-ray incident side of the scintillator layer 5. The light reflecting layer 6 is located at least in the detection area DA, and covers the upper surface of the scintillator layer 5. The light reflecting layer 6 is provided to improve the efficiency of use of light (fluorescence) and to improve the sensitivity characteristics. That is, the light reflecting layer 6 reflects light generated in the scintillator layer 5 toward the side opposite to the side where the photoelectric conversion unit 2b is provided, so that the light is directed toward the photoelectric conversion unit 2b. However, the light reflecting layer 6 is not necessarily required, and may be provided according to the sensitivity characteristics required for the X-ray detection panel PNL.

[0037] For example, a coating material made of a mixture of light-scattering particles such as titanium oxide (TiO2), a resin, and a solvent is applied onto the scintillator layer 5, and the coating material is then dried to form the light-reflecting layer 6.

[0038] The structure of the light reflecting layer 6 and the manufacturing method of the light reflecting layer 6 are not limited to the above examples, and can be modified in various ways. For example, the light reflecting layer 6 may be formed by depositing a layer made of a metal having high light reflectance, such as a silver alloy or aluminum, on the scintillator layer 5. Alternatively, the light reflecting layer 6 may be formed by providing, on the scintillator layer 5, a sheet whose surface includes a metal layer having high light reflectance, such as a silver alloy or aluminum, or a resin sheet including light scattering particles.

[0039] In addition, when a paste-like coating material is applied onto the scintillator layer 5 and the coating material is dried, the coating material shrinks as it dries, so that tensile stress is applied to the scintillator layer 5, and the scintillator layer 5 may peel off from the photoelectric conversion substrate 2. For this reason, it is preferable to provide a sheet-like light reflecting layer 6 on the scintillator layer 5. In this case, the light reflecting layer 6 can be bonded onto the scintillator layer 5 using, for example, double-sided tape, but it is more preferable to place the light reflecting layer 6 on the scintillator layer 5. If the sheet-like light reflecting layer 6 is placed on the scintillator layer 5, peeling of the scintillator layer 5 from the photoelectric conversion substrate 2 due to expansion or contraction of the light reflecting layer 6 can be easily suppressed.

[0040] The moisture-proof cover (moisture-proof sheet) 7 covers the scintillator layer 5 and the light reflecting layer 6. The moisture-proof cover 7 is provided to prevent the properties of the light reflecting layer 6 and the scintillator layer 5 from deteriorating due to moisture contained in the air. The moisture-proof cover 7 completely covers the exposed portion of the scintillator layer 5. There may be a gap between the moisture-proof cover 7 and the light reflecting layer 6 etc., or the moisture-proof cover 7 may be in contact with the light reflecting layer 6 etc.

[0041] The moisture-proof cover 7 is formed of a sheet containing a metal. Examples of the metal include metals containing aluminum, metals containing copper, metals containing magnesium, metals containing tungsten, stainless steel, and Kovar. When the moisture-proof cover 7 contains a metal, the moisture-proof cover 7 can prevent or significantly suppress the permeation of moisture.

[0042] The moisture-proof cover 7 may also be formed of a laminated sheet in which a resin layer and a metal layer are laminated. In this case, the resin layer can be formed of a material such as polyimide resin, epoxy resin, polyethylene terephthalate resin, Teflon (registered trademark), low-density polyethylene, high-density polyethylene, elastic rubber, etc. The metal layer can contain, for example, the above-mentioned metals. The metal layer can be formed by using a sputtering method, a lamination method, etc.

[0043] In this case, it is preferable to provide the metal layer closer to the scintillator layer 5 than the resin layer. Since the metal layer can be covered with the resin layer, damage that the metal layer may sustain due to external forces or the like can be suppressed. Furthermore, if the metal layer is provided closer to the scintillator layer 5 than the resin layer, deterioration of the properties of the scintillator layer 5 due to moisture permeation through the resin layer can be suppressed.

[0044] Examples of the moisture-proof cover 7 include a sheet including a metal layer, a sheet including an inorganic insulating layer, a laminate sheet (first laminate sheet) in which a resin layer and a metal layer are laminated, and a laminate sheet (second laminate sheet) in which a resin layer and an inorganic insulating layer are laminated. In view of the above, the inorganic layer of the moisture-proof cover 7 is not limited to a metal layer, and may be an inorganic insulating layer. Alternatively, the moisture-proof cover 7 may have both a metal layer and an inorganic insulating layer. The inorganic insulating layer may be formed of a layer including silicon oxide, aluminum oxide, or the like. The inorganic insulating layer may be formed using a sputtering method or the like.

[0045] When the moisture-proof cover 7 is formed of a laminated sheet including a metal layer, for example, the thickness of the resin layer can be substantially the same as the thickness of the metal layer. If the moisture-proof cover 7 includes a resin layer having such a thickness, the rigidity of the moisture-proof cover 7 can be increased, and the occurrence of pinholes in the moisture-proof cover 7 during the manufacturing process can be suppressed. In general, the linear expansion coefficient of resin is greater than the linear expansion coefficient of metal, so that if the thickness of the resin layer is made too large, warping of the photoelectric conversion substrate 2 is likely to occur. Therefore, in the moisture-proof cover 7, the thickness of the resin layer is preferably equal to or less than the thickness of the metal layer.

[0046] Furthermore, the thickness of the moisture-proof cover 7 can be determined in consideration of the absorption of X-rays, rigidity, etc. In this case, the thicker the moisture-proof cover 7, the greater the amount of X-rays absorbed by the moisture-proof cover 7. On the other hand, the thinner the moisture-proof cover 7, the lower the rigidity of the moisture-proof cover 7, making it more susceptible to breakage.

[0047] For example, if the thickness of the moisture-proof cover 7 is less than 10 μm, the rigidity of the moisture-proof cover 7 becomes too low, and pinholes may be formed in the moisture-proof cover 7 due to damage from external forces, etc., which may cause leakage. If the thickness of the moisture-proof cover 7 exceeds 50 μm, the rigidity of the moisture-proof cover 7 becomes too high, and the ability to conform to the unevenness of the upper end of the scintillator layer 5 becomes poor. This may make it difficult to check the gaps and leakage paths described above. Furthermore, warping of the photoelectric conversion substrate 2 may occur easily.

[0048] Therefore, the thickness of the moisture-proof cover 7 is preferably 10 μm or more and 50 μm or less. In this case, the moisture-proof cover 7 can be, for example, an aluminum foil having a thickness of 10 to 50 μm. If the aluminum foil has a thickness of 10 to 50 μm, the amount of X-ray transmission can be increased by about 20 to 30% compared to an aluminum foil having a thickness of 100 μm. Furthermore, if the aluminum foil has a thickness of 10 to 50 μm, the occurrence of the above-mentioned leak can be suppressed, and the above-mentioned gap and leak path can be easily confirmed. Furthermore, warping of the photoelectric conversion substrate 2 can be suppressed.

[0049] In order to reduce the thermal expansion and contraction of the metal, it is preferable that the thickness of the metal such as aluminum is 30 μm or less, and therefore it is preferable that the moisture-proof cover 7 includes an aluminum foil having a thickness of 10 to 30 μm.

[0050] Here, since the exposure of the human body to a large amount of X-rays has adverse effects on health, the amount of X-ray exposure to the human body is kept to a minimum. Therefore, in the case of the X-ray detector 1 used in medical treatment, the intensity of the irradiated X-rays is low, and the intensity of the X-rays passing through the moisture-proof cover 7 may become very low. The moisture-proof cover 7 according to this embodiment is a sheet having a thickness of 10 to 50 μm, so that it is possible to capture an X-ray image even when the intensity of the irradiated X-rays is low.

[0051] FIG. 4 is a circuit diagram showing the X-ray detection panel PNL, the circuit board 11, and the plurality of FPCs 2e1 and 2e2 according to the present embodiment. 2 to 4, the circuit board 11 is provided with a readout circuit 11a as a drive circuit and a signal detection circuit 11b as a detection circuit. These circuits can be provided on one board, or can be provided separately on multiple boards. The other ends of the multiple wirings provided on the FPC 2e1 are each electrically connected to the readout circuit 11a. The other ends of the multiple wirings provided on the FPC 2e2 are each electrically connected to the signal detection circuit 11b.

[0052] The readout circuit 11a switches the TFT 13a between an on state and an off state. The readout circuit 11a has a plurality of gate drivers 11aa and a row selection circuit 11ab. A control signal S1 is input to the row selection circuit 11ab from an image processing unit (not shown) provided outside the X-ray detector 1. The row selection circuit 11ab inputs the control signal S1 to the corresponding gate driver 11aa according to the scanning direction of the X-ray image. The gate driver 11aa inputs the control signal S1 to the corresponding gate line G1.

[0053] For example, the readout circuit 11a sequentially inputs a control signal S1 to multiple gate lines G1 via the FPC 2e1. The control signal S1 input to the gate line G1 turns the TFT 13a on or off, and when the TFT 13a is turned on, a charge (image data signal S2) from the TFD 15a is output to the FPC 2e2.

[0054] The signal detection circuit 11b has a plurality of integral amplifiers 11ba, a plurality of selection circuits 11bb, and a plurality of AD converters (Analog-to-digital converters) 11bc. One integral amplifier 11ba is electrically connected to one data line T1. The integral amplifier 11ba sequentially receives image data signals S2 from the plurality of photoelectric conversion units 2b. The integral amplifier 11ba then integrates the current flowing within a certain time and outputs a voltage corresponding to the integral value to the selection circuit 11bb. In this way, it is possible to convert the value of the current (amount of charge) flowing through the data line T1 within a predetermined time into a voltage value. That is, the integral amplifier 11ba converts image data information corresponding to the intensity distribution of the fluorescence generated in the scintillator layer 5 into potential information.

[0055] The selection circuit 11bb selects the integral amplifier 11ba to perform reading, and sequentially reads out the image data signal S2 converted into potential information. The AD converter 11bc sequentially converts the read image data signal S2 into a digital signal. The image data signal S2 converted into a digital signal is input to the image processing unit via wiring. The image data signal S2 converted into a digital signal may be transmitted to the image processing unit wirelessly. The image processing unit composes an X-ray image based on the image data signal S2 converted into a digital signal. The image processing unit may be integrated with the circuit board 11.

[0056] Fig. 5 is a plan view showing the X-ray detection panel PNL according to this embodiment, and is a diagram for explaining the positional relationship between the pads 2d1, 2d2 and the sealing portion 8. In Fig. 5, the scintillator layer 5 is shaded with an upward slanting line to the right, and the sealing portion 8 is shaded with an downward slanting line to the right. Fig. 6 is a cross-sectional view showing the X-ray detection panel PNL shown in Fig. 5 along line VI-VI, and also showing the FPC2e1 and the connecting material AD. Here, the structure of the left end portion of the X-ray detection panel PNL and the FPC2e1 will be explained using Figs. 5 and 6, but the explanation using Figs. 5 and 6 can also be applied to the structure of the lower end portion of the X-ray detection panel PNL and the FPC2e2.

[0057] 5 and 6, the photoelectric conversion substrate 2 has a detection area DA and a non-detection area NDA outside the detection area DA. In this embodiment, the non-detection area NDA has a frame-like shape. The base material 2a is located in the detection area DA and the non-detection area NDA.

[0058] The scintillator layer 5 is located at least in the detection area DA. The photoelectric conversion substrate 2 further has a plurality of pads 2d1 and a plurality of pads 2d2. The pads 2d1 and 2d2 are located in the non-detection area NDA. In this embodiment, the plurality of pads 2d1 are arranged along the left side of the substrate 2a, and the plurality of pads 2d2 are arranged along the lower side of the substrate 2a. Note that FIG. 5 shows the plurality of pads in a schematic manner, and the number, shape, size, position, and pitch of the plurality of pads are not limited to the example shown in FIG. 5.

[0059] One gate line G1 is a metal wiring that extends through the detection area DA and the non-detection area NDA and is electrically connected to the multiple TFDs 15a and one of the multiple pads 2d1 aligned in the row direction X. More specifically, in each photoelectric conversion unit 2b, the gate line G1 is electrically connected to the TFD 15a via the TFT 13a.

[0060] One data line T1 is a metal wiring that extends through the detection area DA and the non-detection area NDA and is electrically connected to one of the pads 2d2 and the multiple TFDs 15a aligned in the column direction Y. More specifically, in each photoelectric conversion unit 2b, the data line T1 is electrically connected to the TFD 15a via the TFT 13a.

[0061] The FPC2e1 is fixed to the non-detection area NDA of the photoelectric conversion substrate 2 and is electrically connected to the pad 2d1. The FPC2e1 is fixed to the photoelectric conversion substrate 2 by a connection material AD. The connection material AD is formed of ACF. The connection material AD is located between the pad 2d1 and the FPC2e1. The connection material AD is bonded to the photoelectric conversion substrate 2 including the pad 2d1 and the FPC2e1, and is electrically connected to the pad 2d1 and the FPC2e1.

[0062] The X-ray detection panel PNL further includes a sealing portion 8. The sealing portion 8 is provided around the scintillator layer 5. The sealing portion 8 has a frame-like shape and extends continuously around the scintillator layer 5. The sealing portion 8 is bonded to the photoelectric conversion substrate 2 (e.g., the insulating layer 25). In this embodiment, the sealing portion 8 overlaps the multiple pads 2d1 and the multiple pads 2d2 in a planar view. In particular, the sealing portion 8 overlaps the entire multiple pads 2d1 and the entire multiple pads 2d2 in a planar view.

[0063] The moisture-proof cover 7 is provided above the photoelectric conversion substrate 2, the scintillator layer 5, and the light reflecting layer 6. The moisture-proof cover 7 is located in the detection area DA and the non-detection area NDA. In the plan view shown in FIG. 5, the moisture-proof cover 7 completely covers the scintillator layer 5. As shown in FIG. 6, the portion of the scintillator layer 5 that is not covered by the photoelectric conversion substrate 2 and the sealing portion 8 is completely covered by the moisture-proof cover 7. The moisture-proof cover 7 is bonded to the sealing portion 8. The moisture-proof cover 7, together with the photoelectric conversion substrate 2 and the sealing portion 8, seals the scintillator layer 5 and the light reflecting layer 6.

[0064] For example, by joining the moisture-proof cover 7 and the sealing portion 8 in an environment where the pressure is reduced below atmospheric pressure, the moisture-proof cover 7 can be brought into contact with the light reflecting layer 6 and the like. Generally, the scintillator layer 5 has voids that account for about 10 to 40% of its volume. By joining the moisture-proof cover 7 and the sealing portion 8 in an environment where the pressure is reduced below atmospheric pressure, damage to the moisture-proof cover 7 can be suppressed even when the X-ray detector 1 is transported by aircraft or the like. For the above reasons, it is preferable that the pressure in the space defined by the sealing portion 8 and the moisture-proof cover 7 be lower than atmospheric pressure.

[0065] The sealing portion 8 is located between the photoelectric conversion substrate 2 and the moisture-proof cover 7 and between the FPC 2e1 and the moisture-proof cover 7. The sealing portion 8 is provided in a frame shape in the non-detection area NDA. The sealing portion 8 covers the photoelectric conversion substrate 2 and the moisture-proof cover 7 as well as the scintillator layer 5 and the light reflecting layer 6.

[0066] The sealing portion 8 is formed of a material containing a thermoplastic resin. The sealing portion 8 is formed of a material containing a thermoplastic resin as a main component. The sealing portion 8 may be formed of 100% thermoplastic resin. Alternatively, the sealing portion 8 may be formed of a material in which an additive is mixed into a thermoplastic resin.

[0067] When forming the sealing portion 8, first, a heated material (thermoplastic resin) is applied onto the non-detection area NDA, FPC 2e1, etc. of the photoelectric conversion substrate 2 using a dispenser. The material then solidifies and is bonded to the photoelectric conversion substrate 2, FPC 2e1, etc. Next, the moisture-proof cover 7 is brought into contact with the outer surface of the material. Next, the material is heated together with the vicinity of the periphery of the moisture-proof cover 7, etc. This melts the material, and the sealing portion 8 joined to the moisture-proof cover 7 is formed.

[0068] Here, for example, if the sealing portion 8 contains an ultraviolet-curable resin as a main component, it is necessary to irradiate ultraviolet rays when joining the sealing portion 8 to the photoelectric conversion substrate 2, the moisture-proof cover 7, etc. However, the moisture-proof cover 7 contains metal and the like and is therefore unable to transmit ultraviolet rays. In addition, if the moisture-proof cover 7 is one that transmits ultraviolet rays, the scintillator layer 5 may be discolored by the ultraviolet rays, and the light (fluorescence) generated in the scintillator layer 5 may be absorbed by the scintillator layer 5.

[0069] In contrast, since the sealing portion 8 contains a thermoplastic resin, it can be easily bonded by heating. In addition, the scintillator layer 5 does not discolor due to ultraviolet light. In addition, the time required for heating and cooling the sealing portion 8 is short, so that the manufacturing time can be shortened, and therefore the manufacturing cost can be reduced.

[0070] Examples of thermoplastic resins that can be used include nylon, PET (Polyethyleneterephthalate), polyurethane, polyester, polyvinyl chloride, ABS (Acrylonitrile Butadiene Styrene), acrylic, polystyrene, polyethylene, and polypropylene. In this case, the water vapor permeability of polyethylene is 0.068 g mm / day m 2 The water vapor transmission rate of polypropylene is 0.04 g mm / day m 2 Polyethylene and polypropylene have low water vapor permeability. Therefore, it is preferable that the sealing portion 8 is formed of a material containing a thermoplastic resin, which is at least one of polyethylene and polypropylene. If the sealing portion 8 contains at least one of polyethylene and polypropylene as a main component, the amount of moisture that penetrates the inside of the sealing portion 8 and reaches the scintillator layer 5 can be significantly reduced.

[0071] FIG. 7 is an enlarged cross-sectional view showing the detection area DA and non-detection area NDA of the X-ray detection panel PNL, and also shows the FPC 2e1 and the connecting material AD. 7, the gate line G1 has a first wiring L1a which is a metal wiring and a second wiring L1b which is a metal wiring. The first wiring L1a is located between the insulating layer 21 and the insulating layer 22, similar to the gate electrode GE. The first wiring L1a extends in the detection area DA, and an end of the first wiring L1a is located in the non-detection area NDA. The first wiring L1a and the gate electrode GE are formed of the same material.

[0072] The second wiring L1b is located between the insulating layer 22 and the insulating layer 23, similar to the source electrode SE. The second wiring L1b is provided in the non-detection area NDA and extends from a region facing the first wiring L1a to a region facing the pad 2d1. The second wiring L1b and the source electrode SE are made of the same material. The second wiring L1b passes through a contact hole formed in the insulating layer 22 and is connected to the first wiring L1a.

[0073] The pad 2d1 is formed on the insulating layer 23 and is connected to the second wiring L1b through a contact hole formed in the insulating layer 23. The pad 2d1 is made of metal. In this embodiment, the insulating layer 24 and the insulating layer 25 are not formed in the region facing the pad 2d1. The pad 2d1 is exposed on the upper surface side of the photoelectric conversion substrate 2. Unlike the present embodiment, the pad 2d1 may be formed of a laminate of a metal layer made of metal and a protective layer made of a transparent conductive material such as ITO (Indium Tin Oxide). In this case, the protective layer has the upper surface of the pad 2d1. The metal layer of the pad 2d1 is covered with a protective layer made of an inorganic material such as ITO. Therefore, compared with the case where the pad 2d1 is made of only a metal material, corrosion of the metal part of the pad 2d1 can be suppressed.

[0074] The gate line G1 may be formed without the second wiring L1b. In that case, the first wiring L1a is formed to extend to a region facing the pad 2d1, and the pad 2d1 is connected to the first wiring L1a through contact holes formed in the insulating layer 22 and the insulating layer 23.

[0075] The scintillator layer 5 has a side surface 5a and an upper surface 5b. The side surface 5a is located in the non-detection area NDA. The side surface 5a is a forward tapered surface. The upper surface 5b of the scintillator layer 5 faces the light reflecting layer 6 and the moisture-proof cover 7. The moisture-proof cover 7 is directly bonded to the outer surface of the sealing portion 8 .

[0076] The FPC 2e1 includes a base material 31, wiring L2, an insulating layer 33, and a pad 34. The base material 31 is made of an electrically insulating material such as resin. The wiring L2 is a metal wiring and is located between the base material 31 and the insulating layer 33. The pad 34 is provided on the surface of the insulating layer 33 on the pad 2d1 side, and is connected to the wiring L2 through a contact hole formed in the insulating layer 33. The pad 34 faces the pad 2d1 in the height direction Z.

[0077] FIG. 8 is an enlarged cross-sectional view showing the X-ray detection panel PNL, the FPC 2e1, and the connecting material AD shown in FIG. 7 along line VIII-VIII. 8, the photoelectric conversion substrate 2 has a plurality of second wirings L1b and a plurality of pads 2d1, and the second wirings L1b and the pads 2d1 are connected in a one-to-one relationship. The FPC 2e1 has a plurality of wirings 32 and a plurality of pads 34, and the wirings 32 and the pads 34 are connected in a one-to-one relationship.

[0078] 7 and 8, the sealing portion 8 is in contact with the insulating layer 23, the insulating layer 24, the insulating layer 25, the side surface 5a of the scintillator layer 5, the FPC 2e1, the connecting material AD, etc. The side surface of the connecting material AD on the scintillator layer 5 side and the side surfaces of the connecting material AD located at both ends in the column direction Y are covered with the sealing portion 8. Here, the structure of the left end portion of the X-ray detection panel PNL and the FPC2e1 has been explained using Figures 7 and 8, but the explanation using Figures 7 and 8 is also applicable to the structure of the lower end portion of the X-ray detection panel PNL and the FPC2e2.

[0079] According to the X-ray detector 1 according to an embodiment configured as described above, the X-ray detection module 10 includes the photoelectric conversion substrate 2, the scintillator layer 5, the FPC 2e1, the moisture-proof cover 7, and the sealing portion 8. The sealing portion 8 is located between the FPC 2e1 and the moisture-proof cover 7. The region overlapping the FPC 2e1 and the pad 2d1 can be used as a region for forming the sealing portion 8. The sealing portion 8 is located between the FPC 2e2 and the moisture-proof cover 7. The region overlapping the FPC 2e2 and the pad 2d2 can be used as a region for forming the sealing portion 8.

[0080] Since the sealing portion 8 overlaps the FPC 2e1 and the FPC 2e2, the width of the non-detection area NDA on the left side and bottom side of the photoelectric conversion substrate 2 can be narrowed compared to a case in which the sealing portion 8 does not overlap the FPC 2e1 and the FPC 2e2. Therefore, an X-ray detection module 10 (X-ray detection panel PNL) that can have a narrow frame can be obtained, and the X-ray detection module 10 (X-ray detection panel PNL) can be made smaller.

[0081] The sealing portion 8 can cover the pads of the photoelectric conversion substrate 2, the pads of the FPCs 2e1 and 2e2, and the connecting material AD. Therefore, compared to a case where the electrical connection portion between the photoelectric conversion substrate 2 and the FPC 2e1 and the electrical connection portion between the photoelectric conversion substrate 2 and the FPC 2e2 are exposed, corrosion of the electrical connection portions can be suppressed, and the reliability of the electrical connection portions can be improved.

[0082] The sealing portion 8 is formed of a material containing a thermoplastic resin. Therefore, the sealing portion 8 can absorb the irregularities of the photoelectric conversion substrate 2, the scintillator layer 5, the FPC 2e1, and the FPC 2e2, and can form the sealing portion 8 with high adhesive strength.

[0083] (Comparative Example) Next, an X-ray detector according to a comparative example will be described in detail. Fig. 9 is a cross-sectional view showing an X-ray detection panel PNL, an FPC 2e1, a connecting material AD, and a moisture-proof part 40 according to this comparative example. The X-ray detector 1 is configured similarly to the above embodiment, except for the configuration described in this comparative example.

[0084] 9, the sealing portion 8 does not overlap the FPC 2e1 and the pads 2d1. The FPC 2e1 and the pads 2d1 are located outside the sealing portion 8 and are provided with a gap therebetween in the sealing portion 8. Therefore, in this comparative example, it is difficult to narrow the frame of the X-ray detection panel PNL.

[0085] The X-ray detection module 10 further includes a moisture-proof part 40. The moisture-proof part 40 is in contact with the photoelectric conversion substrate 2, the FPC 2e1, the connecting material AD, etc. The moisture-proof part 40 covers the side of the connecting material AD on the scintillator layer 5 side, the side of the connecting material AD located at both ends in the column direction Y, etc. In this comparative example, by adding the moisture-proof part 40 to the configuration of the X-ray detection module 10, it is possible to improve the reliability of the electrical connection between the photoelectric conversion substrate 2 and the FPC 2e1.

[0086] (Variation 1) Next, an X-ray detector according to Modification 1 of the above embodiment will be described in detail. Fig. 10 is a cross-sectional view showing the X-ray detection panel PNL, the FPC 2e1, the connecting material AD, and the moisture-proof part 50 according to this Modification 1. The X-ray detector 1 is configured similarly to the above embodiment, except for the configuration described in Modification 1.

[0087] As shown in FIG. 10, the X-ray detection module 10 further includes a moisture-proof part 50. The moisture-proof part 50 is formed of a moisture-proof material, such as silicone resin. The moisture-proof part 50 covers the side of the connecting material AD on the outer periphery side of the photoelectric conversion substrate 2. The moisture-proof part 50 covers the connecting material AD together with the photoelectric conversion substrate 2, the FPC 2e1, and the sealing part 8. The entire electrical connection part can be covered with the moisture-proof part 50 or the like so that the electrical connection part between the photoelectric conversion substrate 2 and the FPC 2e1 is not exposed to the outside air. This can further suppress corrosion of the electrical connection part.

[0088] (Variation 2) Next, an X-ray detector according to Modification 2 of the above embodiment will be described in detail. Fig. 11 is an enlarged cross-sectional view showing the detection area DA and non-detection area NDA of the X-ray detection panel PNL according to Modification 2, and also shows the FPC 2e1, the connecting material AD, and the moisture-proof part 50. The X-ray detector 1 is configured similarly to Modification 1, except for the configuration described in Modification 2.

[0089] 11, the second wiring L1b, which is a metal wiring, includes an upper surface Sa and an end surface Sb. The upper surface Sa is covered with an insulating layer 23. The end surface Sb is located farthest from the detection area DA and is exposed to the outside of the insulating layer 22 and the insulating layer 23. As in the present modified example 2, the second wiring L1b may extend to the end of the photoelectric conversion substrate 2. For example, before the cutting process that determines the outer shape of the photoelectric conversion substrate 2 during manufacturing, the second wiring L1b may be connected to a pad for testing, an electric circuit for static electricity countermeasures, or the like. The pad 2d1 is provided above the insulating layer .

[0090] The moisture-proof section 50 covers not only the electrical connection section between the photoelectric conversion substrate 2 and the FPC 2e but also the end face Sb. Even if the metal wiring (gate line G1, data line T1, etc.) extends to the end of the photoelectric conversion substrate 2 and the end face of the metal wiring is exposed, the moisture-proof section 50 can cover the end face. Therefore, in the present modification 2, corrosion of the metal wiring can be suppressed.

[0091] Although the embodiment of the present invention has been described, the above embodiment is presented as an example and is not intended to limit the scope of the invention. The above novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The above embodiment and its modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0092] For example, the above-mentioned technology is not limited to application to the X-ray detection module 10 and the X-ray detector 1, but can be applied to various radiation detection modules such as other X-ray detection modules, and various radiation detectors such as other X-ray detectors. The radiation detection module may include a radiation detection panel that detects radiation, instead of the X-ray detection panel PNL. [Explanation of symbols]

[0093] 1...X-ray detector, 10...X-ray detection module, PNL...X-ray detection panel, 2...photoelectric conversion board, 2b...photoelectric conversion section, 13a...TFT, 15a...TFD, G1...gate line, T1...data line, L1a...first wiring, L1b...second wiring, Sa...top surface, Sb...end surface, 2d1, 2d2...pads, 21-25...insulating layer, 5...scintillator layer, 6...light reflecting layer, 7...moisture-proof cover, 8...sealing section, 11...circuit board, 2e1, 2e2...FPC, 34...pad, 50...moisture-proof section, AD...connecting material, DA...detection area, NDA...non-detection area, X...row direction, Y...column direction.

Claims

1. a photoelectric conversion substrate having a photoelectric conversion element located in a detection region and a pad located in a non-detection region outside the detection region and electrically connected to the photoelectric conversion element; a scintillator layer provided on the photoelectric conversion substrate and positioned in the detection region; a wiring board fixed to the non-detection area of ​​the photoelectric conversion board and electrically connected to the pads; a moisture-proof cover provided above the photoelectric conversion substrate and the scintillator layer and positioned in the detection region and the non-detection region; a sealing portion that is provided in a frame shape in the non-detection region and is located between the photoelectric conversion substrate and the moisture-proof cover and between the wiring substrate and the moisture-proof cover, and that covers the scintillator layer together with the photoelectric conversion substrate and the moisture-proof cover; Radiation detection module.

2. The sealing portion is formed of a material including a thermoplastic resin which is at least one of polyethylene and polypropylene. The radiation detection module according to claim 1 .

3. The moisture-proof cover is any one of a sheet including a metal layer, a sheet including an inorganic insulating layer, a first laminate sheet in which a resin layer and the metal layer are laminated, and a second laminate sheet in which the resin layer and the inorganic insulating layer are laminated. The radiation detection module according to claim 1 .

4. Further equipped with a moisture-proof section, The photoelectric conversion substrate is a metal wiring extending through the detection region and the non-detection region, electrically connected to the photoelectric conversion element and the pad, and including a top surface and an end surface located farthest from the detection region; an insulating layer covering the upper surface of the metal wiring; The pad is provided above the insulating layer, The end surface is exposed to the outside of the insulating layer, The moisture-proof portion covers the end surface. The radiation detection module according to claim 1 .

5. a connecting member located between the pad and the wiring board, bonded to the photoelectric conversion substrate including the pad and the wiring board, and electrically connected to the pad and the wiring board; the moisture-proof portion covers the photoelectric conversion substrate, the wiring substrate, the sealing portion, and the connecting material; The radiation detection module according to claim 4 .

Images