JP2008008899A - Radiographic image detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form more easily a moisture-proof structure of a radiographic image detector. <P>SOLUTION: A radiographic image detector, includes: a substrate 10; and a square-shaped radiation detecting section 11 mounted on the substrate 10 and having two opposing sides from which signal lines 12 are drawn out. An insulating rib member 13 is provided on the substrate 10 and the signal lines 12 so as to have insulation along only not more than three outer sides of the radiation detecting section 11, and a moisture-proof film 14 is pasted along the upper surface of the rib member 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a radiation image detector, and more particularly to a moisture-proof structure thereof.

  Conventionally, in the medical field and the like, various types of direct-type radiation image detectors that generate radiation when irradiated with radiation transmitted through the subject and record the radiation image related to the subject by accumulating the charge have been proposed and put into practical use. ing.

  Patent Document 1 proposes an X-ray imaging device that uses amorphous selenium as a photoconductive layer and detects the generation of electric charges by irradiating the selenium with X-rays under application of a bias voltage. Such an image sensor is preferably covered with a sufficient moisture-proof structure because sensitivity of the image sensor gradually deteriorates due to environmental humidity and image defects increase.

As a moisture-proof structure, for example, a structure has been proposed in which a spacer is provided in a frame shape as disclosed in Patent Document 2 and a moisture-proof property is provided by filling a curable synthetic resin with an auxiliary plate installed above. Yes.
JP 2000-284056 A JP 2005-286183 A

  However, as described above, it is difficult to form a spacer in a frame shape depending on the material, and a simpler moisture-proof structure has been desired.

  In addition, for example, in a radiographic image detector for mammography, a layer of amorphous selenium or the like extends as far as possible to the end of the detector because of a request to perform imaging as close to the chest wall as possible. However, at this time, it has been difficult to achieve both the above-described requirement relating to the arrangement of layers such as amorphous selenium and moisture-proof performance.

  An object of this invention is to provide the radiographic image detector which has a moisture-proof structure which can be formed more simply in view of said situation.

  A radiological image detector according to the present invention is a radiological image detector comprising a substrate and a rectangular radiation detector placed on the substrate and having a rectangular radiation line drawn out from two opposite sides. The insulating rib member is provided on the substrate and the signal line only along three or less sides of the outer periphery, and a moisture-proof film is attached along the upper surface of the rib member.

  Moreover, in the radiographic image detector of the said invention, a rib member can be installed on a board | substrate and a signal wire | line only along two sides of the outer periphery of a radiation detection part.

  Further, the rib member can have a thickness substantially equal to the thickness of the radiation image detector.

  According to the radiological image detector of the present invention, the rib member having insulating properties is installed on the substrate and the signal line only along the three or less sides of the outer periphery of the radiation detector, and the moisture-proof along the upper surface of the rib member. Since the adhesive film is pasted, it is not necessary to form a frame-like spacer as in the prior art, and the moisture-proof structure can be formed more easily.

  As the rib material, glass other than synthetic resin can be used. In order to obtain a high degree of moisture resistance, it is preferable to use glass. In this case, the structure according to the present invention is particularly effective.

  In addition, since the moisture-proof film is attached along the upper surface of the rib member as described above, the gap is smaller than when the moisture-proof film is directly attached to the substrate without using the rib member. Can be suppressed, and a high degree of sealing becomes possible.

  Further, the signal line is protected by the rib member, and disconnection of the signal line can be prevented.

  Further, the moisture-proof structure comprising the ribs of three sides or less and the moisture-proof film in the present invention corresponds to the radiation image detector in which the image detection portion extends to the end portion of the substrate, and effectively prevents moisture. It is possible.

  Hereinafter, an embodiment of the radiation image detector of the present invention will be described with reference to the drawings. 1 is a perspective view of the radiation image detector, FIG. 2 is a top view of the radiation image detector shown in FIG. 1, FIG. 3 is a cross-sectional view of the radiation image detector shown in FIG. 4 is a cross-sectional view taken along line 4-4 of the radiation image detector shown in FIG.

  As shown in FIGS. 1 to 4, the radiation image detector according to the present embodiment includes a glass substrate 10, a rectangular radiation detection unit 11 placed on the glass substrate 10, and two radiation detection units 11 facing each other. The signal line 12 drawn from the side, the rib member 13 placed only along two opposing sides of the radiation detection unit 11, and the moisture proof attached to the rib member 13 and the upper surface of the radiation detection unit 11 The film 14 is provided.

  As the glass substrate 10, a glass substrate having an arbitrary thickness can be used, but a glass substrate having a thickness of 0.5 mm to 2.5 mm, preferably 1 mm to 2 mm is usually used.

  The signal line 12 is drawn out from two opposite sides of the lower surface of the radiation detection unit 11 and provided on the glass substrate 10.

  The rib member 13 is formed of an insulating material and is formed in a rectangular parallelepiped shape. And it is formed with the same length as two opposite sides of the radiation detector 11. The thickness of the rib member 13 is preferably such that when the moisture-proof film 14 is attached to the upper surface of the rib member 13 and the radiation detection unit 11, no perforation due to wrinkle occurs. It is desirable to form with a thickness of about ± 30% of the thickness of the detection unit 11. More desirably, the thickness is substantially equal to that of the radiation detection unit 11. Moreover, as a material of the rib member 13, glass or a plastic material can be used, but it is desirable to use glass. And the rib member 13 is adhere | attached with the adhesive agent on the glass substrate 10 with which the signal wire | line 12 was provided.

  The adhesive is preferably an epoxy adhesive, and a two-type reactive epoxy adhesive, a thermosetting epoxy adhesive, or a photocurable epoxy adhesive can be used.

The moisture-proof film 14 is arbitrarily selected from those having a moisture permeability of 0.2 g · 25 μm / m ² · 24 hr or less measured at 40 ° C. and 90% RH. As an example of such a moisture-proof film, a film obtained by depositing silicon oxide or aluminum oxide on a polyethylene terephthalate film, a film obtained by laminating a polymer film on both surfaces of an aluminum foil, or the like can be used. Here, as the polymer film laminated with the aluminum foil, materials such as polyethylene tephthalate, nylon, polyethylene, and polypropylene can be used.

  The moisture-proof film 14 is affixed along the upper surface of the rib member 13, as shown in FIGS. One end of the moisture-proof film 14 is bent along the side surface of the radiation detection unit 11 on one side of the radiation detection unit 11 from which the signal line 12 is not drawn, and is bonded on the glass substrate 10. Yes. Further, the other end of the moisture-proof film is bent along the side surface of the radiation detection unit 11 and the glass substrate 10 on the other side of the radiation detection unit 11 from which the signal line 12 is not drawn, and further the glass substrate 10. It is bent along the lower surface of and bonded.

  It is desirable to attach the moisture-proof film with an epoxy adhesive.

  In order to remove the surplus portion of the moisture-proof film, a cut can be made by running a cutter blade on the bonded rib member, and the surplus portion can be peeled off.

  The feature of this structure is that the rib member is arranged on the upper part of the signal line as in the radiological image detector of the present invention, so that processing can be performed without damaging the signal line when forming a sealing structure thereafter. is there.

  In the radiation image detector of the above embodiment, the rib member 13 is arranged only along two sides of the radiation detection unit 11, but the rib member 13 is arranged only along three sides of the radiation detection unit 11. You may do it. FIG. 5 is a perspective view of a radiation image detector in which the rib members 13 are arranged only along three sides of the radiation detection unit 11, and FIG. 6 is a top view thereof.

  In the radiation image detector shown in FIG. 5, the rib member 13 is provided only along three sides of the four sides of the radiation detection unit 11, while the remaining one side reaches the end of the glass substrate 10. The radiation detection unit 11 is provided. For this reason, also in the radiographic image detector shown in FIG. 5, the radiographic image detector in which the radiation detection unit 11 extends to the end can be effectively moisture-proof without using a frame-shaped spacer that is difficult to form. .

  At this time, the rib member 13 has a U-shaped shape, but for this, one member may be cut and formed as a single piece, but each side is made into an appropriate shape. After creating by cutting, you may make it adhere | attach each other using the adhesive mentioned above. The former can be created more easily than the frame-shaped one, but the latter is preferred because it is easier to produce.

  An example of the radiation detection unit 11 will be described below. FIG. 7 is a perspective view of a part of the radiation detection unit 11, and FIG. 8 is a cross-sectional view taken along line 8-8 of the radiation detection unit 11 shown in FIG.

  As shown in FIG. 7, the radiation detection unit 11 is a first electrode layer 1 that transmits radiation carrying a radiation image, and a recording that generates charges when irradiated with radiation that has passed through the first electrode layer 1. Of the charge generated in the photoconductive layer 2 for recording and the photoconductive layer 2 for recording acts as an insulator for the charge of one polarity and acts as a conductor for the charge of the other polarity The layer 3, the reading photoconductive layer 4 that generates charges when irradiated with reading light, and the second electrode layer 5 are laminated in this order. In the vicinity of the interface between the recording photoconductive layer 2 and the charge transport layer 3, a power storage unit 6 for accumulating charges generated in the recording photoconductive layer 2 is formed. The first electrode layer 1 side is formed on the glass substrate 10 as the upper surface, and the second electrode layer 5 side is formed as the lower surface.

The first electrode layer 1 may be any material that can transmit radiation. For example, Nesa film (SnO ₂ ), ITO (Indium Tin Oxide), IDIXO (Idemitsu Indium X- metal Oxide (Idemitsu Kosan Co., Ltd.) can be used with a thickness of 50 to 200 nm, and Al or Au with a thickness of 100 nm can also be used.

  The second electrode layer 5 includes a plurality of transparent linear electrodes 7 that transmit reading light and a plurality of light-shielding linear electrodes 8 that shield reading light. Further, as shown in FIG. 1, the transparent linear electrodes 7 and the light shielding linear electrodes 8 are alternately arranged in parallel at a predetermined interval.

  The transparent linear electrode 7 transmits the reading light and is made of a conductive material. Any material may be used as long as it is as described above. For example, ITO or IDIXO can be used in the same manner as the first electrode layer 1. Alternatively, a metal such as Al or Cr may be used to form a thickness that allows the reading light to pass (for example, about 10 nm).

  The light shielding linear electrode 8 shields the reading light and is made of a conductive material. Any material may be used as long as it is as described above. For example, metals such as Al and Cr can be used.

  A signal line 12 shown in FIGS. 1 to 4 is obtained by extending the transparent linear electrode 7 and the light-shielding linear electrode 8 to extend.

  The recording photoconductive layer 2 only needs to generate a charge when irradiated with radiation, and is excellent in that the quantum efficiency is relatively high with respect to radiation and the dark resistance is high. A material mainly composed of Se is used. A thickness of about 500 μm is appropriate.

As the charge transport layer 3, for example, the larger the difference between the mobility of charges charged in the first electrode layer 1 at the time of recording a radiographic image and the mobility of charges having the opposite polarity, the better (for example, 10 ^2). or more, preferably 10 ³ or higher) poly N- vinylcarbazole (PVK), N, N'-diphenyl -N, N'-bis (3-methylphenyl) - [1,1'-biphenyl] -4,4 ' -Organic compounds such as diamine (TPD) and discotic liquid crystal, or TPD polymer (polycarbonate, polystyrene, PVK) dispersion, a semiconductor material such as a-Se or As ₂ Se ₃ doped with 10 to 200 ppm of Cl is suitable. It is.

  The reading photoconductive layer 4 may be any material that exhibits conductivity when irradiated with reading light and erasing light. For example, a-Se, Se-Te, Se-As-Te, metal-free phthalocyanine, A photoconductive substance mainly containing at least one of metal phthalocyanine, MgPc (Magnesium phtalocyanine), VoPc (phase II of Vanadyl phthalocyanine), CuPc (Cupper phtalocyanine) and the like is preferable. A thickness of about 0.1 to 1 μm is appropriate.

  In addition, as a manufacturing method of the radiographic image detector of this embodiment, the radiation detection part 11 is formed on the glass substrate 10 with a vacuum film forming method, for example, Then, the rib member 13 is affixed, the rib member 13 and radiation Although the moisture-proof film 14 may be attached to the upper surface of the detection unit 11, the rib member 13 may be attached before the radiation detection unit 11 is formed. Specifically, a rib member is previously bonded with a thermosetting epoxy adhesive on the glass substrate on which the signal line 12 is formed, and then the radiation detection unit 11 is formed by a vacuum film forming method. You may make it stick a moisture-proof film along with an adhesive along.

  The radiation detection unit 11 is not limited to the above-described configuration, and may be a so-called indirect radiation detection unit that converts radiation into visible light using a phosphor layer and photoelectrically converts the visible light.

The perspective view which shows one Embodiment of the radiographic image detector of this invention Top view of the radiation image detector shown in FIG. 3-3 sectional view of the radiation image detector shown in FIG. 4-4 sectional view of the radiation image detector shown in FIG. The perspective view which shows other embodiment of the radiographic image detector of this invention. Top view of the radiation image detector shown in FIG. The perspective view which shows schematic structure of a radiation detection part Sectional view taken along line 8-8 of the radiation detector shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Board | substrate 11 Radiation detection part 12 Signal line 13 Rib member 14 Moisture-proof film

Claims (3)

In a radiation image detector comprising a substrate and a rectangular radiation detection unit placed on the substrate and having a signal line drawn out from two opposite sides,
Only along the three or less sides of the outer periphery of the radiation detection unit, an insulating rib member is installed on the substrate and the signal line, and
A radiation image detector, wherein a moisture-proof film is adhered along the upper surface of the rib member.   The radiation image detector according to claim 1, wherein the rib member is disposed on the substrate and the signal line only along two outer sides of the radiation detection unit.   The radiographic image detector according to claim 1, wherein the rib member has a thickness substantially equal to a thickness of the radiographic image detector.

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