JP5725753B2 - Radiation detector - Google Patents

Description

  Embodiments described herein relate generally to a radiation detection apparatus for detecting radiation such as X-rays and gamma rays.

  Radiation detection devices that detect radiation such as X-rays and gamma rays are used in a wide range of fields such as industrial non-destructive inspection, medical diagnosis, and scientific research such as structural analysis.

  In particular, as a planar X-ray detector used in an X-ray diagnostic apparatus, a photodetector comprising a photoelectric conversion element portion in which a plurality of photosensors and TFT (Thin Film Transistor) electrical elements are two-dimensionally arranged. On top of this, there is known a radiation detection device in which a phosphor layer for directly converting radiation into light detectable by a photoelectric conversion element is formed.

  A signal obtained by a photodetector having a photoelectric conversion element is very small and has a level of several tens of nA. Therefore, even a slight increase in leakage current has a large effect, and the acquired data must be corrected.

  FIG. 3 shows the configuration of an X-ray detection panel used in a conventional radiation detection apparatus, and FIG. 4 shows the configuration of a conventional radiation detection apparatus.

  An X-ray detection panel 50 shown in FIG. 3 includes a photoelectric conversion element unit 12 in which a plurality of photosensors and TFTs are two-dimensionally arranged on a glass substrate 11, a wiring unit 13 connected to the photoelectric conversion element unit 12, An electrode pad portion 14 connected to the wiring portion 13 and formed at an end portion of the glass substrate 11, and a phosphor layer 15 formed on the photoelectric conversion element portion 12 are provided.

  On the electrode pad portion 14, the flexible circuit 16 connected to the flexible circuit board 34 (see FIG. 4) on which the detection integrated circuit IC 35 (see FIG. 4) is mounted is interposed via the anisotropic conductive adhesive layer 17. It is connected to the electrode pad portion 14.

  The electrode pad portion 14 of the X-ray detection panel 50 and the anisotropic conductive adhesive layer 17 are bonded together by thermocompression bonding.

  The radiation detection apparatus 60 shown in FIG. 4 is formed by providing a glass plate 62, an adhesive layer 63, and an X-ray detection panel 50 shown in FIG. 3 on a plate-like support member (metal substrate with a cooling mechanism) 61 in order. Yes. An analog circuit board 67 is fixed by a spacer 68 on the opposite surface side of the support member 61.

  In addition, a connector 66 is disposed at the opposite end of the flexible circuit board 34 on which the detection integrated circuit IC 35 is mounted, and is connected to the analog circuit board 67.

  Further, an X-ray incident window 69 that transmits radiation is disposed opposite to the X-ray detection panel 50 and fixed to the external housing 70. The X-ray incident window 69 is made of a material that does not scatter well in order to transmit X-rays, such as carbon fiber reinforced plastic (CFRP).

Japanese Patent No. 3957803

  However, the radiation detection apparatus 60 has the following problems.

  In the radiation detection device 60, since the electric resistance of the X-ray incident window 69 is large, induced charges are generated on the surface of the X-ray detection panel 50. Due to the influence of the generated induced charges, unevenness and noise are generated in the image.

  In the radiation detection apparatus 60, it is difficult to remove the induced charge from the surface of the X-ray detection panel 50, and it is affected by electromagnetic waves from the outside.

  Furthermore, since the internal air in contact with the surface of the X-ray detection panel 50 is greatly affected by the temperature fluctuation / distribution of the surface of the X-ray incident window 69 in contact with the external environment, a temperature distribution is also generated in the X-ray detection panel 50 itself. To do. This temperature distribution partially leads to fluctuations in the values of dark current and leakage current in the X-ray detection panel 50, and causes image unevenness that occurs when fixed noise changes.

  The present invention has been made in view of such a viewpoint, and suppresses the generation of inductive charges in the X-ray detection panel, eliminates the influence of external radio waves, and provides a radiation detection apparatus with less noise and image unevenness. The purpose is to provide.

To achieve the above object, the present radiation detector, a radiation detection panel for detecting radiation, provided on a surface of the radiation detection panel, a small conductive protective layer is release morphism index than glass, the radiation detector A conductive support member that supports the panel; a circuit board that is supported on a surface of the support member opposite to the radiation detection panel support surface and that drives the radiation detection panel; and the radiation detection panel and the circuit board; A flexible circuit member that electrically connects the radiation detection panel, the circuit board, the support member, and a conductive housing that houses the flexible circuit member, and the radiation detection panel facing each other. a radiation entrance window which is the provided on the inner surface of the radiation incident window, low Iritsu and the electrical resistance discharge than the material forming said radiation incident window It includes a layer of material, wherein the support member, the housing, and a layer provided on the inner surface of said radiation incident window is characterized in that as the same potential.

The schematic cross section which shows the X-ray detection panel which concerns on this Embodiment. The schematic cross section which shows the radiation detection apparatus which concerns on this Embodiment. The schematic cross section which shows the conventional X-ray detection panel. The schematic cross section which shows the conventional radiation detection apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows an X-ray detection panel according to this embodiment, and FIG. 2 shows an example of a radiation detection apparatus using the X-ray detection panel.

(X-ray detection panel 10)
The X-ray detection panel 10 includes a photoelectric conversion element unit 12 in which a plurality of photosensors and TFTs are two-dimensionally arranged on a glass substrate 11, a wiring unit 13 connected to the photoelectric conversion element unit 12, and a wiring unit 13 The electrode pad part 14 connected and formed in the edge part of the glass substrate 11, the fluorescent substance layer 15 formed on the photoelectric conversion element part 12, and the electroconductive protective layer 18 formed covering the fluorescent substance layer 15 are provided. ing.

  On the electrode pad portion 14, the flexible circuit 16 connected to the flexible circuit board 34 on which the detection integrated circuit IC 35 is mounted is connected to the electrode pad portion 14 via the anisotropic conductive adhesive layer 17.

  The electrode pad portion 14 and the anisotropic conductive adhesive layer 17 of the X-ray detection panel 10 are bonded together by thermocompression bonding.

(Radiation detection device 20)
In the radiation detection apparatus 20, the X-ray detection panel 10 shown in FIG. 1 as a radiation detection panel is disposed on a plate-like support member 25 supported by a support 23 provided in a housing 21. .

  A connector 22 is disposed on the opposite side of the flexible circuit board 34 on which the detection integrated circuit IC 35 is mounted, and is connected to the analog circuit board 26. The analog circuit board 26 constitutes a circuit board group 24 together with the digital circuit board 27 and is fixed to the support member 25 by a spacer 38. The circuit board group 24 electrically drives the X-ray detection panel 10.

  Further, an X-ray incident window 31 that transmits radiation is disposed to face the X-ray detection panel 10 and is fixed to the casing 21 via an edge-shaped incident window holding member 33.

  Here, the support member 25 and the support | pillar 23 are formed with the material which has electroconductivity. The housing 21 is also formed of a conductive material, and houses the X-ray detection panel 10, the support member 25, the circuit board group 24, the flexible circuit board 34, and the flexible circuit 16.

  An opening 29 is formed in the housing 21 at a position facing the X-ray detection panel 10. Further, the entrance window holding member 33 that connects the opening 29 and the X-ray entrance window 31 is also formed of a conductive material.

  The support 23 electrically connects the support member 25 and the housing 21. Further, a metal foil 28, for example, an aluminum tape is attached to the entire surface of the X-ray incident window 31 on the surface of the X-ray incident window 31 on the X-ray detection panel 10 side.

  The edge-shaped entrance window holding member 33 electrically connects the casing 21 and the metal foil 28 of the X-ray entrance window 31.

  The circuit board group 24 is either fixed to the support member 25, or one of the analog circuit board 26 and the digital circuit board 27 is connected to the support member 25, and the other circuit board is the above-described circuit board. It is fixed to one of the circuit boards. Further, a frame ground is dropped from each circuit board to the support member 25.

  As described above, the X-ray detection panel 10 is surrounded by the support member 25, the casing 21, and the X-ray incident window 31, the metal foil 28 formed on the X-ray incident window 31, and the support member. 25, the column 23, the casing 21, and the edge-shaped entrance window holding member 33 are electrically conductive and therefore have the same potential as the circuit ground.

  Further, the surface of the X-ray detection panel 10 is covered with a conductive protective layer 18. The conductive protective layer 18 and the metal foil 28 may be the same material. The conductive protective layer 18 is electrically connected to the incident window holding member 33 on the edge or the support member 25.

  Further, the space between the X-ray incident window 31 and the X-ray detection panel 10 is thermally insulated by internal air.

  Furthermore, the emissivity of the conductive protective layer 18 that covers the surface of the X-ray detection panel 10 is smaller than that of glass, and the emissivity of the metal foil 28 that covers the inner surface of the X-ray incident window 31 opposed to the X-ray detection panel 10 is X-ray. It is formed so as to be smaller than the material forming the entrance window 31.

(Operation / Effect of Radiation Detection Device 20)
In the radiation detection apparatus 20, a part having high conductivity is disposed so as to surround the X-ray detection panel 10 inside the housing 21, so that electrical conduction can be achieved.

  Therefore, the parts surrounding the X-ray detection panel 10 have the same potential as the X-ray detection panel 10, and the influence of noise such as external static electricity and induction electric field can be reduced, and an X-ray flat panel detector with less image unevenness can be realized. It becomes.

  Further, since the surface of the X-ray detection panel 10 and the X-ray incident window 31 facing the X-ray detection panel 10 has a metal material having excellent electrical conductivity, electromagnetic waves from the outside to the inside of the housing 21 are reduced, Conversely, electromagnetic waves from the inside to the outside can also be reduced.

  Further, a conductive material having excellent thermal conductivity covers the inner surface of the X-ray incident window 31, lowers the heat radiation between the surface of the X-ray incident window 31 and the surface of the X-ray detection panel 10, and heats the X-ray detection panel 10. Therefore, it is possible to reduce the unevenness of the heat factor and to provide the radiation detection apparatus 20 with little image unevenness.

(Other embodiments)
The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

  The present invention is not limited to the X-ray detection panel 10 and the radiation detection apparatus 20 described above, and can be applied to various X-ray detection panels 10 and the radiation detection apparatus 20.

  Specifically, in the radiation detection apparatus 20, the metal foil 28 is attached to the surface of the X-ray incident window 31 on the X-ray detection panel 10 side, but instead of the metal foil 28, a material that forms the incident window is used. A conductive material with low electrical resistance may be formed by vapor deposition, coating, coating, or the like.

  The conductive material such as metal formed on the surface of the X-ray incident window 31 may be formed on both sides as well as on one side.

  Furthermore, in the said radiation detection apparatus 20, although both the electroconductive protective layer 18 and the metal foil 28 were provided, you may abbreviate | omit either depending on the case.

DESCRIPTION OF SYMBOLS 10 X-ray detection panel 11 Glass substrate 12 Photoelectric conversion element part 13 Wiring part 14 Electrode pad part 15 Phosphor layer 16 Flexible circuit 17 Anisotropic conductive adhesive layer 18 Conductive protective layer 20 Radiation detection apparatus 21 Case 22 Connector 23 Post 24 Circuit Board Group 25 Support Member 26 Analog Circuit Board 27 Digital Circuit Board 28 Metal Foil 29 Opening 31 X-Ray Incident Window 33 Incident Window Holding Material 34 Flexible Circuit Board 35 Detection Integrated Circuit IC
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Claims (4)

A radiation detection panel for detecting radiation;
Provided on a surface of the radiation detection panel, a conductive protective layer smaller release morphism rate than glass,
A conductive support member for supporting the radiation detection panel;
A circuit board that is supported on a surface of the support member opposite to the radiation detection panel support surface and drives the radiation detection panel;
A flexible circuit member for electrically connecting the radiation detection panel and the circuit board;
A conductive housing that houses the radiation detection panel, the circuit board, the support member, and the flexible circuit member;
A radiation incident window disposed opposite to the radiation detection panel at an interval;
A layer comprising the said provided on the inner surface of the radiation incident window, Iritsu electrical resistance and low material release than the material forming the said radiation incident window,
Have
The radiation detection apparatus, wherein the support member, the casing, and the layer provided on the inner surface of the radiation incident window have the same potential. The radiation detection apparatus according to claim 1, wherein a layer provided on an inner surface of the radiation incident window is connected to the casing.   The radiation detection apparatus according to claim 1, wherein the radiation detection panel side surface of the radiation incident window is coated with a material having higher thermal conductivity than a material forming the radiation incident window.   The radiation detection apparatus according to claim 1, wherein the radiation entrance window and the radiation detection panel are insulated by internal air.

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