JP2005172511A - Radiation detector, its manufacturing method, and radiation imaging systems - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve X-ray absorption of a fluorescent formation substrate, and to reuse a expensive heat-resistant substrate. <P>SOLUTION: The manufacturing method of the radiation detector at least comprising the fluorescent screen 100 composed of the columnar fluorescent layer 3 and the protective layer 4 protecting the fluorescent layer 3, the light sensor 110 provided with a plurality of the photoelectric conversion elements 6 for photo-electrically transducing the light from the columnar fluorescent layer 3, and the bond layer 5 for bonding the optical sensor 110 with the fluorescent screen 100, comprises processes as follows: a process for forming the fluorescent screen 100 by forming the columnar fluorescent layer 3 on the fluorescent formation substrate 1; a lamination process for laminating the fluorescent screen 100 provided with the columnar fluorescent layer 3 formed on the fluorescent formation substrate 1, on the optical sensor 110 formed with a plurality of photoelectric transducer element 6 via the bond layer 5 and bonded together; and a separation process for separating the fluorescent formation substrate 1 from the columnar fluorescent layer 3 in the fluorescent screen 100 laminated on the optical sensor 110. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a radiation detection apparatus such as an X-ray area sensor, in which a phosphor is laminated on the surface of a photoelectric conversion element via an adhesive, and a manufacturing method thereof. In the present specification, description will be made on the assumption that the category of radiation includes electromagnetic waves such as X-rays and γ-rays.

  FIG. 5 is a schematic cross-sectional view illustrating a method for manufacturing a radiation detection apparatus using an X-ray phosphor as a conventional example. As shown in FIG. 5, an X-ray area sensor (radiation detection device) that is a sensor of a digital X-ray imaging apparatus includes photoelectric conversion elements 212 arranged in a lattice pattern on a glass substrate 210 and a wiring unit 213 that connects them. And a phosphor layer 203 crystallized in a columnar shape and a reflection layer 202 thereof are formed on an optical sensor 211 including an optical sensor protective layer 214 for protecting them.

  Currently, as means for forming the phosphor layer 203 on the optical sensor 211, 1) a method of directly depositing and coating the phosphor layer 203 on the optical sensor 211 (also referred to as “sensor direct deposition type”), and 2) FIG. As shown in FIG. 5, a reflection layer 202 and a phosphor layer 203 are formed on a phosphor substrate 201 different from the optical sensor 211, covered with a protective layer 204, and then light is passed through an adhesive layer 206 using a roller 220. There is known a method of bonding to the sensor 211 (also referred to as “sensor bonding type”) (205 in the figure indicates a cushioning material). Comparing the two, the latter (sensor bonding type) can efficiently form the phosphor 203 on the optical sensor 211 with a high yield. The above conventional example is disclosed in, for example, Patent Document 1.

  FIG. 6 is a schematic cross-sectional view of the sensor-bonded type X-ray area sensor. This X-ray area sensor has a glass substrate 201, a photoelectric conversion element 212 formed thereon, and an optical sensor 211 having a wiring portion 213 thereof. A fluorescent plate 207 is bonded onto the optical sensor 211 via an adhesive layer 206. In addition, an IC circuit 240 for driving and signal processing is disposed around the optical sensor 211 and connected to the photoelectric conversion element 212 via the wiring portion 213.

  The fluorescent plate 207 includes a columnar phosphor layer 203 made of columnar crystallized phosphor, a phosphor substrate 201 and an undercoat layer 208 that support the phosphor layer 203, and light converted by the phosphor layer 203 as an optical sensor 211. A reflective layer 202 made of an aluminum thin film that reflects to the side, a reflective layer protective layer 209 thereof, and a protective layer 204 made of an organic resin that protects the phosphor layer 203 and the like from the outside air. Further, an electromagnetic shield layer 231 is formed on the fluorescent plate 207 with a second adhesive layer 230 interposed therebetween.

  In the X-ray area sensor having the above-described configuration, X-rays that enter the phosphor layer 203 from the phosphor substrate 201 side are wavelength-converted from X-rays to light such as visible light by the phosphor layer 203, and then visible light Is photoelectrically converted by the photoelectric conversion element 212 of the optical sensor 211 and converted into an electrical signal. An X-ray digital image is formed by amplifying the signal and applying image processing.

  Further, alkali halide phosphors having a columnar crystal structure have begun to be used as phosphor materials for highly sensitive X-ray area sensors. Among these, CsI (cesium iodide): Tl whose emission wavelength matches the sensitivity wavelength of the photoelectric conversion element is used. The maximum emission wavelength is 500 nm to 600 nm. A vapor deposition method is used as a method for forming the alkali halide phosphor. For example, CsI: Tl is obtained by co-evaporating CsI (cesium iodide) and TlI (thallium iodide) on a substrate. By using the phosphor having the columnar crystal structure formed by vapor deposition on the substrate, the film thickness of the phosphor having the columnar crystal structure to be formed can be easily controlled. The thickness of the columnar phosphor layer is known to be 200 μm to 450 μm. The alkali halide phosphor obtained by vapor deposition needs to heat-treat the phosphor layer at a temperature of 200 ° C. to 250 ° C. in order to increase the light emission amount after the vapor deposition step.

As a physical property required for the phosphor used in the X-ray area sensor, it is required that the amount of X-ray absorption from the subject to the phosphor layer is as small as possible. Therefore, a material having a high heat resistance and a small X-ray absorber is essential as a phosphor forming substrate material. Conventionally, amorphous carbon substrates and the like have been disclosed as materials satisfying this characteristic (for example, Patent Document 2).
Japanese Patent Laid-Open No. 2003-066196 JP 2002-236181 A

  However, the amorphous carbon substrate has a size of about 45 cm × 45 cm and a thickness of about 1 mm, and costs tens of thousands of yen to several tens of thousands of yen, leading to high cost of the X-ray area sensor.

  Further, since the carbon substrate is conductive, there is an adverse effect of promoting electrochemical corrosion of the fluorescent metal reflective layer formed on the carbon substrate. In order to suppress electrochemical corrosion, as shown in FIG. 6, it is necessary to sequentially laminate an undercoat insulating layer, a reflective layer, a reflective layer protective layer, and a phosphor layer on a carbon substrate, leading to high costs.

  Further, even with a carbon substrate, X-ray absorption exists, and X-ray absorption becomes a problem with carbon having a thickness of 1 mm, particularly under imaging conditions with low X-ray energy.

  The present invention provides a method for manufacturing a radiation detection apparatus that improves X-ray absorption of a phosphor-formed substrate and enables reuse of an expensive heat-resistant substrate.

  The present invention relates to an X-ray area sensor having at least a columnar phosphor layer, a protective layer, an adhesive layer, and a photoelectric conversion element, a step of forming a columnar phosphor layer on a substrate, and laminating the phosphor layer on the photoelectric conversion element The manufacturing method of the radiation detection apparatus which has the process to peel and the process to peel off this board | substrate is characterized.

  Furthermore, the gist of the manufacturing method of the radiation detecting apparatus is characterized in that a peelable layer is provided between the substrate and the columnar phosphor layer.

  The present invention has been completed based on such an idea.

  That is, the method for manufacturing a radiation detection apparatus according to the present invention photoelectrically converts a scintillator having a phosphor layer that converts wavelength of radiation into light that can be sensed by a photoelectric conversion element, and light that has been wavelength-converted by the phosphor layer. A photoelectric conversion panel having a photoelectric conversion part having a plurality of photoelectric conversion elements, and a method for producing a radiation detection device bonded together via an adhesive layer, the phosphor layer on a phosphor-forming substrate Providing a scintillator having the phosphor layer, and attaching the surface of the scintillator on the side having the phosphor layer onto the photoelectric conversion portion of the photoelectric conversion panel via the adhesive layer. And a step of peeling the phosphor-forming substrate from the scintillator bonded to the photoelectric conversion panel.

  In the present invention, the step of preparing the scintillator includes a step of forming a phosphor layer having a columnar crystal structure by vapor deposition on a peelable layer provided on the phosphor layer forming substrate, and the step of peeling It is preferable that the phosphor-forming substrate is peeled from the scintillator using the peelable layer.

  In the present invention, it is preferable that the peeling step is to peel the phosphor-forming substrate from the scintillator by heating the peelable layer.

  In the present invention, it is preferable that the peelable layer is made of a thermoplastic resin, and in the peeling step, the phosphor forming substrate is peeled from the scintillator by heating the peelable layer.

  In this invention, the said peelable layer consists of a 1st peelable layer closely_contact | adhered to the said fluorescent substance formation board | substrate, and a 2nd peelable layer closely_contact | adhered to the said 1st peelable layer, The said peelable layer is heated by heating. It is preferable that the phosphor-forming substrate is peeled from the scintillator.

  In the present invention, it is preferable to further include a step of forming a fluorescent reflection layer and a moisture-proof protective film on at least the phosphor layer from which the phosphor-forming substrate is peeled after the peeling step. is there.

  A method for manufacturing a scintillator according to the present invention is a method for manufacturing a scintillator having a phosphor layer that converts a wavelength of radiation into light that can be sensed by a photoelectric conversion element, on a peelable layer provided on a phosphor-forming substrate. It has the process of forming the said fluorescent substance layer, It is characterized by the above-mentioned.

  The radiation detection apparatus according to the present invention includes a plurality of phosphor layers that convert radiation into light that can be sensed by the photoelectric conversion elements, and a plurality of photoelectric conversion elements that photoelectrically convert light that has been wavelength-converted by the phosphor layers. And a photoelectric conversion panel having a photoelectric conversion part formed through the adhesive layer, the first moisture-proof protection that covers the surface and the side surface of the phosphor layer on the photoelectric conversion panel side And a second moisture-proof protective layer that is in close contact with the radiation incident surface of the phosphor layer and the first moisture-proof protective layer and covers the radiation incident surface of the phosphor layer.

  In the present invention, it is preferable that the phosphor layer has a columnar crystal structure.

  A radiation imaging system according to the present invention includes any of the radiation detection apparatuses described above, a signal processing unit that processes a signal from the radiation imaging apparatus as an image, and a recording unit that records a signal from the signal processing unit. A display means for displaying a signal from the signal processing means, a transmission processing means for transmitting a signal from the signal processing means, and a radiation source for generating the radiation.

  According to the present invention, the phosphor-forming substrate is peeled off, and the phosphor layer is covered with the first moisture-proof protective layer and the second moisture-proof protective layer, thereby forming the phosphor in the sensor-bonded type radiation detection apparatus. Since the substrate does not exist, an inexpensive glass substrate can be used ignoring the X-ray absorption of the substrate material, and the cost of the X-ray area sensor can be reduced.

  In addition, the columnar crystal structure is destroyed with respect to the phosphor layer by peeling the phosphor-forming substrate from the phosphor layer having a columnar crystal structure formed by vapor deposition on the peelable layer. It is possible to peel off the phosphor-formed substrate without giving such an impact.

  Further, according to the present invention, it is possible to further reduce the manufacturing cost of the X-ray area sensor by cleaning and reusing the peeled phosphor-forming substrate.

  Furthermore, compared to conventional sensor-bonded type radiation detectors, the structure is eliminated and the layer structure is simplified, and the absorption of X-rays from the subject to the phosphor is reduced. X-ray imaging with good quality.

  The best mode for carrying out a method for manufacturing a radiation detection apparatus according to the present invention will be described below with reference to the accompanying drawings. In the following embodiments, the radiation detection apparatus of the present invention is applied as an X-ray area sensor.

  1A to 1F are schematic cross-sectional views for explaining an X-ray area sensor of this embodiment and a manufacturing method thereof.

  First, as shown to Fig.1 (a), the peelable layer 2 was formed on the fluorescent substance formation board | substrate 1 which forms fluorescent substance. As the phosphor forming substrate 1, a glass substrate, a carbon substrate, an aluminum substrate or the like excellent in heat resistance can be used, and can be selected neglecting X-ray absorption. As the peelable layer 2, a thermoplastic resin such as a hot melt resin having a melting temperature of 200 ° C. to 250 ° C. can be used. In addition, silicon resin, fluorine resin, and the like can be used. The thickness of the peelable layer 2 is preferably 20 to 50 μm.

  Next, as shown in FIG. 1B, a columnar phosphor layer 3 was laminated on the peelable layer 2 by a vapor deposition method to a thickness of 500 μm. The columnar phosphor layer 3 is made of an alkali metal halide such as CsI: Na, CsI: Tl, CsBrTl, or the like. The material of the columnar phosphor layer 3 is selected according to the wavelength of the light receiving sensitivity of the photoelectric conversion element. In the case of CsI: Tl, the columnar phosphor layer 3 is formed by co-evaporation of CsI (cesium iodide) and TlI (thallium iodide). After the formation, the columnar phosphor layer 5 is heat-treated at 200 ° C., thereby stabilizing the light emission state.

  Next, as shown in FIG. 1C, a moisture-proof protective layer 4 was laminated on the columnar phosphor layer 3. As a material for the moisture-proof protective layer 4, a material that does not dissolve the columnar phosphor layer 3 made of an alkali metal halide is desired. As a material, an organic film obtained by gas phase polymerization such as thermal CVD or plasma CVD is used. As the organic film, a gas phase polymerized film formed by a thermal CVD method of a polyparaxylene resin or a plasma polymerized film of a fluorine-containing unsaturated hydrocarbon monomer is used.

  Through the above steps, a columnar phosphor layer 3 is formed on the phosphor-forming substrate 1 via the peelable layer 2, and the phosphor plate having the columnar phosphor layer 3 that converts the wavelength of the radiation into light that can be sensed by the photoelectric conversion element. 100 (also called “scintillator” or “scintillator panel”) was obtained.

  Next, non-defective products that satisfy the criteria by performing defect inspection on the obtained fluorescent plate 100 are used to form a plurality of photoelectric conversion elements 6 formed in advance on a glass substrate 7 using an adhesive layer 5 as shown in FIG. And laminated on an optical sensor 110 (also referred to as “sensor panel” or “photoelectric conversion panel”). As the adhesive layer 5, a thermosetting or room temperature curing adhesive such as an acrylic resin or a urethane resin was used. For bonding, a laminate method as shown in FIG. 5 was used. The optical sensor 110 having a plurality of photoelectric conversion elements 6 may be, for example, a photo sensor using amorphous silicon (a-Si) and a TFT (thin film transistor) formed in the same layer or a stacked structure. Applicable.

  Next, as shown in FIG. 1 (e), the phosphor-forming substrate 1 is peeled off at the interface between the peelable layer 2 and the columnar phosphor layer 3 in the phosphor plate 100 bonded onto the optical sensor 110 as described above. did. When the peelable layer 2 is a hot-melt resin, the phosphor forming substrate 1 is peeled off by fixing the photoelectric conversion element 6 side with an adsorption plate (not shown) and having a temperature of 200 to 250 ° C. from the phosphor forming substrate 1 side. While melting the peelable layer 2 made of hot-melt resin from one end of the phosphor-forming substrate 1 to the opposite end with a heat roller, one end of the phosphor-forming substrate 1 is attached to the suction plate ( Lift up (not shown). By the above method, the phosphor-forming substrate 1 and the peelable layer 2 have a higher adhesion than the peelable layer 2 and the columnar phosphor layer 3, so that the phosphor-forming substrate 1 and the peelable layer 2 are made columnar fluorescent. It is possible to peel from the body layer 3. Thus, the columnar phosphor layer is formed by melting the peelable layer 2 and peeling the phosphor-forming substrate 1 from the columnar phosphor layer 3 having a columnar crystal structure formed on the peelable layer 2 by vapor deposition. Thus, the phosphor-forming substrate 1 can be peeled off without giving an impact that destroys the columnar crystal structure. Further, the phosphor-formed substrate 1 that has been further peeled can be cleaned and reused, and the manufacturing cost of the X-ray area sensor can be further reduced.

  Finally, as shown in FIG. 1 (f), it is formed of aluminum foil using the second adhesive layer 8 on the columnar phosphor layer 3 from which at least the phosphor forming substrate 1 and the peelable layer 2 have been removed. A multi-functional layer 9 that also serves as a fluorescent reflection layer, a moisture-proof layer, and an electromagnetic shield layer was laminated, and a protective resin layer 10 was formed on the multi-functional layer 9. Here, instead of the multifunctional layer 9, a phosphor reflection layer, a moisture-proof protective layer, and an electromagnetic shield layer may be provided separately.

  The X-ray area sensor was able to be obtained by the above process.

  Therefore, according to the X-ray area sensor of the present embodiment, the phosphor forming substrate 1 is provided by providing the step of peeling the phosphor forming substrate 1 after the step of bonding the columnar phosphor layer 3 to the photoelectric conversion element 6. Since it is possible to select the substrate material while ignoring the absorption of X-rays, for example, a cheaper glass substrate can be used instead of an expensive amorphous carbon substrate, whereby the entire X-ray area sensor can be used. It became possible to reduce the cost.

  Further, the columnar phosphor layer 3 is peeled off from the columnar phosphor layer 3 having a columnar crystal structure formed on the peelable layer 2 by the vapor deposition method using the peelable layer 2. On the other hand, the phosphor-formed substrate 1 can be peeled off without giving an impact that destroys the structure.

  Further, the phosphor-formed substrate 1 that has been further peeled can be cleaned and reused, and the manufacturing cost of the X-ray area sensor can be further reduced.

  Further, in the X-ray area sensor of this example, compared with the conventional bonding type X-ray area sensor shown in FIG. It is no longer necessary to sequentially stack the pulling insulating layer, the reflective layer, the reflective layer protective layer, and the phosphor layer. From this point, the layer configuration can be further simplified, the absorption of X-rays from the subject to the phosphor is reduced, and the efficiency is improved. Good X-ray photography became possible.

  FIGS. 2A to 2E are schematic cross-sectional views for explaining the X-ray area sensor of this embodiment and the manufacturing method thereof.

  First, as shown in FIG. 2A, the columnar phosphor layer of the present invention in which the peelable layer 2 is formed on the surface of the phosphor forming substrate 1 and the heat-resistant resin layer 11 is laminated on the peelable layer 2. When the alkali halide phosphor used for 3 is formed by vapor deposition, the phosphor-forming substrate is used during vapor deposition in order to maintain the adhesion between the columnar phosphor layer 3 and the vapor deposition surface of the phosphor-forming substrate 1. The surface temperature of 1 needs to be 130 ° C. or higher. Therefore, the heat resistant resin layer 11 needs to have a heat resistance of at least 130 ° C. or more. Further, the alkali halide phosphor used in the columnar phosphor layer 3 of the present invention requires that the phosphor be heat-treated at a temperature of 180 ° C. to 250 ° C. in order to improve the amount of light emission, and thus a heat resistant resin. The layer 11 preferably further has heat resistance at 180 ° C. or higher. At this time, plasma treatment and corona treatment were performed so that the phosphor-formed substrate 1 and the peelable layer 2 were sufficiently adhered to the substrate surface. As the peelable layer 2, a silicon-based resin that is a material that does not dissolve in the heat-resistant resin layer 11, such as a material that does not dissolve in the polyimide precursor solvent, and a material that has low adhesion to the peelable layer (Product name: Colcoat 2000) was used. As the heat resistant resin layer 11, a polyimide resin layer obtained by applying a polyimide precursor on the peelable layer 2 and thermosetting at a temperature of 200 ° C. or a thermal CVD film of polyparaxylylene can be used. As for the film thickness of the heat resistant resin layer 11, 10-30 micrometers is preferable. The heat-resistant resin layer 11 is for preventing an influence caused by heating performed when the phosphor-forming substrate 1 is peeled off on an optical sensor to be formed later.

  Next, as shown in FIG. 2B, the columnar phosphor layer 3 and its moisture-proof protective layer 4 were formed on the heat-resistant resin layer 11. The columnar phosphor layer 3 and its moisture-proof protective layer 4 were the same as described above.

  Through the above steps, a phosphor plate 100 in which the columnar phosphor layer 3 was formed on the phosphor forming substrate 1 via the peelable layer 2 and the heat-resistant resin layer 11 was obtained.

  Next, a non-defective product that satisfies the criteria by performing defect inspection on the obtained fluorescent plate 100 is used to form a plurality of photoelectric conversion elements 6 formed in advance on a glass substrate 7 using an adhesive layer 5 as shown in FIG. The optical sensor 110 having the above structure was attached and laminated. The optical sensor 110 having a plurality of photoelectric conversion elements 6 was the same as described above.

  Next, as shown in FIG. 2D, in the fluorescent plate 100 bonded onto the optical sensor 110 as described above, at the interface between the peelable layer 2 and the heat-resistant resin layer 11, the peelable layer 2 and the phosphor are formed. The substrate 1 was peeled off. At this time, while the glass substrate 7 on the photoelectric conversion element 6 side is fixed, while pulling up one end of the phosphor forming substrate 1, one of the phosphor forming substrates 1 on the substrate 1 is heated with a 200 ° C. heating roller. When heated from the end toward the opposite end, the phosphor-forming substrate 1 and the peelable layer 2 are sufficiently adhered by the adhesion treatment, so that the heat between the phosphor-forming substrate 1 and the heat-resistant resin layer 11 is increased. The peelable layer 2 and the heat-resistant resin layer 11 are easily peeled along the interface due to the expansion difference. Here, as the phosphor forming substrate 1, a glass substrate or a carbon substrate can be used. Since the thermal expansion coefficient of these materials is a value of 1/30 to 1/10 of the thermal expansion coefficient of the heat resistant resin layer 11, peeling is possible due to the difference between the two.

  Finally, as shown in FIG. 2 (e), a multi-functional layer 9 that also serves as a fluorescent reflection layer, a moisture-proof protective layer, and an electromagnetic shield layer is laminated on the heat-resistant resin layer 11, and the multi-functional layer 9 is protected. Resin layer 10 was formed. Here, in this embodiment, in order to suppress the intrusion of moisture from the columnar phosphor layer 4 side and improve the moisture resistance of the columnar phosphor layer 3 and the photoelectric conversion element 6, the columnar phosphor layer 3 is heated by a heating press device. The heat-resistant resin layer 11 in the vicinity of is bent to cover the outermost peripheral portion and the side surface of the columnar phosphor layer 3. The columnar phosphor layer 3 of the radiation imaging apparatus using the above configuration has improved moisture resistance as compared with a structure in which the heat resistant resin layer 11 is not bent. Here, instead of the multifunctional layer 9, a fluorescent reflection layer, a moisture-proof protective layer, and an electromagnetic shield layer may be provided separately.

  The X-ray area sensor was able to be obtained by the above process.

  Therefore, according to the present embodiment, in addition to the same effects as in the first embodiment, the thermal effect on the optical sensor side due to heating is suppressed by using a heat-resistant resin layer, and the heat with the phosphor-forming substrate 1 is increased. The peeling process using the expansion difference can be carried out more effectively.

  3A to 3F are schematic cross-sectional views for explaining the X-ray area sensor of this embodiment and the manufacturing method thereof.

  First, as shown in FIG. 3A, the peelable layer 2 was formed on the phosphor-formed substrate 1. A stainless steel substrate was used as the phosphor forming substrate 1. The peelable layer 2 was composed of two layers, that is, a first first peelable layer 2a and a second second peelable layer 2b.

  When a stainless steel substrate that is a metal material is used as the phosphor forming substrate 1 and a metal material is used as the material of the fluorescent reflecting layer 9a, the single peelable layer 2 has high adhesion to the metal surface of the phosphor forming substrate 1, In addition, it is difficult to select a material having poor adhesion to the metal surface of the fluorescent reflecting layer 9a. It is difficult to select materials that have significant differences in adhesion between metal materials.

  Therefore, in this embodiment, the peelable layer 2 has a two-layer structure, the first peelable layer 2a is made of a material having good adhesion to the metal substrate, and the second peelable layer 2b is made of the first peelable layer 2a. A material having good adhesion to the fluorescent reflection layer 9a and relatively poor adhesion to the fluorescent reflecting layer 9a was selected. Among these, as the first peelable layer 2a, a plasma polymerized film of Si (OCH3) 4 having a thickness of 20 nm (200 angstroms) having a methoxy group (OCH3) that improves adhesion when bonded to a metal material. Using. As the second peelable layer 2b, a plasma polymerized film having a thickness of 40 nm (400 angstroms) using C2F4 as a monomer was used.

  Here, since C2F4, which is an organic material, is used as the second peelable layer 2b, a film having good adhesion with the plasma polymerized film of Si (OCH3) is formed. Since the first peelable layer 2a and the second peelable layer 2b are formed by plasma polymerization, it is possible to continuously form the film without interrupting plasma discharge in the same vacuum film forming apparatus. It is possible to improve the adhesion between the first peelable layer 2a and the second peelable layer 2b. Adhesion is improved because a copolymer of tetramethoxysilane and tetrafluoroethylene is formed at the interface between the first release layer and the second release layer.

  Next, as shown in FIG. 3 (a), a fluorescent reflective layer 9a is laminated on the second peelable layer 2b by sputtering, and the reflective layer protective layer 12 and the columnar phosphor are formed on the fluorescent reflective layer 9a. Layer 3 was formed in order.

  Thus, in order to make the light generated from the columnar phosphor layer 3 by X-rays incident on the photoelectric conversion element 6 without waste, the side opposite to the photoelectric conversion element 6 side of the columnar phosphor layer 3 (X-ray incident side) It is preferable to provide a fluorescent reflection layer 9a. When the fluorescent reflection layer 9a is a metal, it is preferable to form the reflection layer protective layer 12 between the columnar phosphor layer 3 and the fluorescent reflection layer 9. The reflective layer protective layer 12 has a function of suppressing corrosion of the fluorescent reflective layer 9a caused by the fluorescent reflective layer 9a and the columnar phosphor layer 3 being in contact with each other. The effect of the reflective layer protective layer 12 is particularly remarkable when the columnar phosphor layer 3 is made of an alkali halide.

  In the above process, an aluminum sputtered film having a thickness of 300 nm (3000 angstroms) was used as the fluorescent reflecting layer 9a. Moreover, as the reflective layer protective layer 12, a polyimide resin having a thickness of 6 μm obtained by forming a polyimide precursor (trade name: Semicofine LP62) on the fluorescent reflective layer 9a and imidizing at a temperature of 220 ° C. was used. . Further, as the columnar phosphor layer 3, as described above, CsI: Tl having a thickness of 500 μm and a columnar diameter of 5 μm obtained by co-evaporation using CsI (cesium iodide) and TlI (thallium iodide) as an evaporation source is used. It was. After vapor deposition of CsI: Tl, the amount of light emitted by CsI: Tl X-rays was improved by performing a heat treatment at a temperature of 200 ° C. for 4 hours.

  Next, as shown in FIG. 3B, a moisture-proof protective layer 4 was formed on the columnar phosphor layer 3 formed as described above. As the moisture-proof protective layer 4, a polyparaxylylene film having a thickness of 20 μm formed by forming a raw material by a thermal CVD method of paraxylylene was used.

  The phosphor plate 100 in which the columnar phosphor layer 3 is formed on the phosphor forming substrate 1 through the first and second peelable layers 2a and 2b, the fluorescence reflecting layer 9a, and the reflecting layer protective layer 12 is obtained by the above-described steps. .

  Next, as shown in FIG. 3C, a plurality of photoelectric conversion elements 6 formed in advance on the glass substrate 7 by using the adhesive layer 5, by performing defect inspection on the obtained phosphor plate 100 and satisfying the standards. The optical sensor 110 having the above structure was attached and laminated. The optical sensor 110 having a plurality of photoelectric conversion elements 6 was the same as described above.

  Next, as shown in FIG. 3D, in the fluorescent plate 100 bonded onto the optical sensor 110 as described above, the second peelable layer 2b is formed at the interface between the second peelable layer 2b and the fluorescent reflecting layer 9a. The first peelable layer 2b and the phosphor forming substrate 1 were peeled off. In this embodiment, since the adhesive force at the interface between the second peelable layer 2b and the fluorescent reflecting layer 9a is designed to be the lowest, when the temperature is raised as a whole, a phosphor made of a stainless steel substrate Stress due to the difference in thermal expansion between the formation substrate 1 and the glass substrate 7 occurs, and peeling occurs between the fluorescent reflective layer 9a having the lowest interlayer adhesion and the second peelable layer 2b. An adsorption plate (not shown) is set on both the surface of the phosphor forming substrate 1 where the columnar phosphor layer 3 is not formed and the surface of the sensor glass where the photoelectric conversion element conversion element is not formed, and the adsorption plate is moved. Thus, the phosphor-formed substrate 1 can be peeled from the corner side. This is because the stainless steel substrate is elastic and can be easily peeled off from the peripheral portion.

  Next, as shown in FIG. 3 (f), after the phosphor-forming substrate 1 is peeled off, an electromagnetic shield layer 9 b is laminated via the second adhesive layer 8, and the photoelectric conversion element 6 is electrically connected to the peripheral portion. An IC circuit 13 used for signal reading or the like was connected via a wiring portion (not shown), and the portion was sealed with a peripheral portion sealing material 14.

  Through the above steps, an X-ray area sensor (digital X-ray imaging apparatus sensor) could be obtained.

Therefore, according to this example, in addition to the same effects as in Example 1, the phosphor-forming substrate 1 is formed of a stainless steel substrate and the peelable layer has a two-layer structure. The peeling process using the thermal expansion difference between the body forming substrate 1 and the glass substrate can be more effectively performed.

  Next, an application example will be described.

  FIG. 5 shows an application example of the radiation detection apparatus according to the present invention to an X-ray diagnosis system (radiation imaging system).

  In FIG. 5, the X-ray 6060 generated by the X-ray tube 6050 passes through the chest 6062 of the patient or subject 6061 and enters the radiation detection device (image sensor) 6040 as shown in FIG. This incident X-ray includes information inside the body of the patient 6061. The phosphor layer of the radiation detection device 6040 emits light in response to the incidence of X-rays, and this is photoelectrically converted by the photoelectric conversion element unit of the radiation detection device 6040 to obtain electrical information. This information can be digitally converted and image-processed by an image processor 6070 serving as a signal processing means and observed on a display 6080 serving as a 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 by the film processor 6100 used as a recording means.

  As described above, the present invention can be applied to a medical X-ray sensor, but is also effective when applied to other uses such as a nondestructive inspection.

  As described above, the present invention can be applied to uses such as a radiographic imaging system such as a medical X-ray diagnostic apparatus and a nondestructive inspection apparatus, a radiation detection apparatus used therefor, and a manufacturing method thereof.

(A)-(f) is a schematic cross section explaining the radiation detection apparatus by Example 1 of this invention, and its manufacturing method. (A)-(e) is a schematic cross section explaining the radiation detection apparatus by Example 2 of this invention, and its manufacturing method. (A)-(e) is a schematic cross section explaining the radiation detection apparatus by Example 3 of this invention, and its manufacturing method. It is the figure which showed the application example to the radiation imaging system of the radiation detection apparatus by this invention. It is a schematic cross section explaining the manufacturing method of the radiation detection apparatus of a prior art example. It is a schematic cross section explaining the radiation detection apparatus of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Phosphor formation board | substrate 2 Peelable layer 2a 1st peelable layer 2b 2nd peelable layer 3 Columnar fluorescent substance layer 4 Moisture-proof protective layer 5 Adhesive layer 6 Photoelectric conversion element 7 Glass substrate 8 2nd adhesive layer 9 Multifunctional Layer 9a Fluorescent reflective layer 9b Electromagnetic shield layer 10 Protective resin layer 11 Heat resistant resin layer 12 Reflective layer protective layer 13 IC circuit 14 Peripheral sealant 100 Fluorescent plate 110 Optical sensor

Claims (11)

A scintillator having a phosphor layer that converts the wavelength of radiation into light that can be sensed by the photoelectric conversion element; and a photoelectric conversion unit that includes a plurality of photoelectric conversion elements that photoelectrically convert light converted in wavelength by the phosphor layer. A method for producing a radiation detection device, wherein the photoelectric conversion panel is bonded to each other via an adhesive layer,
Providing the phosphor layer on a phosphor-forming substrate and preparing a scintillator having the phosphor layer;
Bonding the surface of the scintillator on the side having the phosphor layer onto the photoelectric conversion part of the photoelectric conversion panel via the adhesive layer;
Peeling the phosphor-forming substrate from the scintillator bonded to the photoelectric conversion panel;
The manufacturing method of the radiation detection apparatus characterized by having. The step of preparing the scintillator has a step of forming a phosphor layer having a columnar crystal structure by vapor deposition on a peelable layer provided on the phosphor layer forming substrate,
The method of manufacturing a radiation detection apparatus according to claim 1, wherein in the peeling step, the phosphor forming substrate is peeled from the scintillator using the peelable layer.   3. The method of manufacturing a radiation detecting apparatus according to claim 2, wherein in the peeling step, the phosphor forming substrate is peeled from the scintillator by heating the peelable layer. The peelable layer is made of a thermoplastic resin,
The method of manufacturing a radiation detecting apparatus according to claim 3, wherein in the peeling step, the phosphor forming substrate is peeled from the scintillator by heating the peelable layer. The peelable layer comprises a first peelable layer that is in close contact with the phosphor-formed substrate, and a second peelable layer that is in close contact with the first peelable layer,
The method of manufacturing a radiation detecting apparatus according to claim 3, wherein in the peeling step, the phosphor forming substrate is peeled from the scintillator by heating the peelable layer.   2. The method according to claim 1, further comprising a step of forming a fluorescent reflection layer and a moisture-proof protective film on at least the phosphor layer from which the phosphor-forming substrate has been peeled after the peeling step. The manufacturing method of the radiation detection apparatus of any one of Claims 5-5. A method of manufacturing a scintillator having a phosphor layer that converts wavelength of radiation into light that can be sensed by a photoelectric conversion element,
A method of manufacturing a scintillator, comprising a step of forming the phosphor layer on a peelable layer provided on a phosphor-forming substrate.   8. The method of manufacturing a scintillator according to claim 7, wherein in the step of forming the phosphor layer, a phosphor layer having a columnar crystal structure is formed on the peelable layer by vapor deposition. A phosphor layer that converts radiation into light that can be sensed by a photoelectric conversion element; and a photoelectric conversion panel that includes a plurality of photoelectric conversion elements that photoelectrically convert light converted in wavelength by the phosphor layer; In the radiation detection apparatus formed by bonding through an adhesive layer,
A first moisture-proof protective layer covering the surface and side surfaces of the phosphor layer on the photoelectric conversion panel side; and a radiation incident surface of the phosphor layer; and the first moisture-proof protective layer; A radiation detection apparatus comprising: a second moisture-proof protective layer covering the radiation incident surface.   The radiation detection apparatus according to claim 9, wherein the phosphor layer has a columnar crystal structure. The radiation detection apparatus according to any one of claims 9 and 10,
Signal processing means for processing a signal from the radiation imaging apparatus as an image;
Recording means for recording a signal from the signal processing means;
Display means for displaying a signal from the signal processing means;
Transmission processing means for transmitting a signal from the signal processing means;
A radiation imaging system comprising: a radiation source that generates the radiation.

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