JP2007292635A - Production method of radiation image conversion panel, production device of radiation image conversion panel, radiation image conversion panel, and radiation detector using the panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of a radiation image conversion panel of stable thickness of phosphor film and provide a high-sensitive radiation image conversion panel and a radiation detector using it. <P>SOLUTION: In production methods of the radiation image conversion panel containing a phosphor layer converting radiation into visible light, the production method of the radiation image conversion panel is characterized by implementing deposition on the phosphor layer concerned by using deposition techniques where phosphor basic ingredient particles treated with heat before their filling into an aerosol-generating room are forced to collide to a substrate with carrier gas of high flow rate to be deposited on the substrate (the gas deposition deposition technique (the aerosol deposition film-formation technique or the AD film formation technique)). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a radiation image conversion panel used in medical diagnostic equipment, a device for manufacturing a radiation image conversion panel, a radiation image conversion panel, and a radiation detection apparatus using the radiation image conversion panel.

  Conventionally, a radiation image recording / reproducing method using a stimulable phosphor described in JP-A No. 55-12145, a so-called computed radiography (CR) system is known as an effective diagnostic means in place of radiography. It has been.

  This method uses a radiation image conversion panel containing a stimulable phosphor, and absorbs the radiation transmitted through the subject or emitted from the subject into the stimulable phosphor, visible light, ultraviolet light, etc. The stimulable phosphor is excited in time series with electromagnetic waves (also called excitation light), and the stored radiation energy is emitted as fluorescence (also called stimulated emission light), and this fluorescence is read photoelectrically. The radio image is reproduced as a visible image based on the obtained electrical signal. The conversion panel after reading is subjected to erasure of the remaining image and used for the next photographing.

  According to this method, there is an advantage that a radiographic image with a large amount of information can be obtained with a much smaller exposure dose than the radiographic method using a combination of a radiographic film and an intensifying screen. In contrast, the radiographic method consumes a film every time it is taken, whereas the radiation conversion panel is used repeatedly, which is advantageous in terms of resource protection and economic efficiency.

  The radiation conversion panel is composed only of a support and a photostimulable phosphor layer provided on the surface or a self-supporting photostimulable phosphor layer. The photostimulable phosphor layer is usually a stimulable phosphor layer. There are those composed of a body and a binder that supports and disperses it, and those composed only of aggregates of stimulable phosphors formed by vapor deposition or sintering. Also known is a polymer material impregnated in the gaps between the aggregates. Further, a protective film made of a polymer film or an inorganic vapor deposition film is usually provided on the surface of the photostimulable phosphor layer opposite to the support side.

  Furthermore, recently, a flat panel type digital radiation detection apparatus (hereinafter also referred to as FPD) using an X-ray phosphor layer and a two-dimensional photodetector is becoming widespread. This has advantages such as good image characteristics and high image reading speed, and has been actively researched and developed.

  Stimulable phosphor plates used in conventional CR systems and phosphor layers of FPD are phosphor particles composed of particles having a particle size of about 0.1 to 20 μm, resin binders for bonding the phosphor particles, It consists of the sheet-like form comprised from the space | gap which exists in this clearance gap.

  However, the conventional configuration has a problem in that the amount of light emitted from the phosphor layer is reduced by absorbing a part of the light emitted from the phosphor irradiated with X-rays with the resin binder. In response to this problem, as a radiation image conversion panel using a phosphor film without a resin binder, a stimulable phosphor layer in which elongated columnar crystals are formed on a support by a vapor phase growth method (vapor phase deposition method). (See, for example, Patent Document 1). However, there are many phosphor materials that are difficult to apply such a vapor phase growth method, and there is a problem that the manufacturing apparatus is expensive because it requires a high vacuum.

  On the other hand, as a method for producing a phosphor film having a high filling rate without using a resin binder, a film deposition method by a gas deposition method (aerosol deposition film formation method, AD film formation method) is disclosed (for example, , See Patent Document 2). However, under the manufacturing conditions described in Patent Document 2, since the landing angle when the phosphor particles ejected from the nozzle land on the substrate differs depending on the location of the substrate, the thickness of the resulting phosphor film is not stable and the quality Was not enough.

Under such circumstances, a method for manufacturing a radiation image conversion panel having a quality with a stable phosphor film thickness by an aerosol deposition film forming method (AD film forming method), and a radiation image conversion manufactured by the manufacturing method. It has been desired to develop a panel and a radiation detection apparatus using the radiation image conversion panel.
JP-A-2-58000 JP 2003-215256 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a radiation image conversion panel having a quality with a stable film thickness of a phosphor film, and a highly sensitive radiation image. An object of the present invention is to provide a conversion panel and a radiation detection apparatus using the same.

  1. In a method for manufacturing a radiation image conversion panel having a phosphor layer for converting radiation into visible light, a phosphor material particle that has been subjected to heat treatment before filling the phosphor layer into an aerosol chamber is loaded onto a substrate at a high flow rate. Production of a radiation image conversion panel characterized by being formed using a film deposition method (gas deposition film formation method (aerosol deposition film formation method, AD film formation method)) deposited by collision with gas Method.

  2. 2. The method for producing a radiation image conversion panel according to 1 above, wherein the heat treatment is performed in a gas atmosphere at 300 to 1600 ° C.

  3. 3. The method for producing a radiation image conversion panel as described in 1 or 2 above, wherein the flow rate of the carrier gas is 100 to 400 m / sec.

  4). 4. An aerosol having a heat treatment means for phosphor raw material particles before the radiation image conversion panel manufacturing apparatus used in the method for manufacturing a radiation image conversion panel according to any one of 1 to 3 fills the aerosol generation chamber. An apparatus for manufacturing a radiation image conversion panel, which is a deposition apparatus (aerosol deposition deposition apparatus, AD deposition apparatus) by a deposition method.

  5. A radiation image conversion panel obtained by the method for manufacturing a radiation image conversion panel according to any one of 1 to 3 above.

  6). 5. A radiographic image conversion panel obtained by the apparatus for manufacturing a radiographic image conversion panel as described in 4 above.

  7). 7. A radiation detection apparatus that detects radiation using the radiation image conversion panel according to 5 or 6 above.

  The manufacturing method of the radiation image conversion panel according to the present invention, the radiation image conversion panel, and the radiation detection apparatus using the same can provide the phosphor film having a stable film quality, and have excellent effects with high sensitivity. .

  FIG. 1 is a cross-sectional view showing an example of a radiation image conversion panel manufactured by the method for manufacturing a radiation image conversion panel of the present invention.

  In FIG. 1, 22 is an insulating substrate made of a glass substrate or the like. A plurality of photodiodes and TFTs (thin film transistors) using a semiconductor thin film made of amorphous silicon are two-dimensionally formed on an insulating substrate 22 and a semiconductor protective layer 24 is formed on the surface thereof. As shown in FIG. Next, a phosphor layer 26 is formed on the photodetector to form a scintillator.

  As a method of providing the phosphor layer 26 on the scintillator, the phosphor layer 26 formed on the support substrate 12 (not shown in FIG. 1) may be bonded to the photodetector, and an adhesive is used as necessary. be able to. When the support substrate is opaque, it can be formed so as to contact the phosphor layer 26 and the photodetector, and when the support substrate is optically transparent, the support substrate can be formed so as to contact the photodetector.

  The photodetector may also serve as a support substrate, and the phosphor layer 26 may be formed directly on the semiconductor protective layer 24 of the photodetector. If necessary, a light reflection layer may be disposed on the phosphor layer 26 on the surface not in contact with the photodetector.

  The substrate is not particularly limited to the material, but a general substrate, for example, a resin substrate, ceramics, quartz glass, or a metal substrate such as titanium, stainless steel, or aluminum can be used.

As the phosphor fine particles constituting the phosphor film, conventionally known phosphor materials such as CaWO ₄ , Gd ₂ O ₂ S: Tb, BaSO ₄ : Pb, CsI: Tl can be used. The phosphor particles represented by the general formula of (Gd, M, Eu) ₂ O ₃ are preferable because they have particularly high luminous efficiency. Here, the rare earth element M includes at least one element of yttrium Y, niobium Nd, terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, and ytterbium Yb. Since these elements have a high radiation absorptance, it is possible to obtain a radiographic image with better granularity. Further, by containing 40 to 95% by mass of gadolinium Gd, 5 to 40% by mass of rare earth element M, and 2 to 20% by mass of europium Eu, the radiation absorption rate and the light emission efficiency can be increased. In particular, gadolinium Gd is preferably 70 to 90% by mass, and europium Eu is preferably 5 to 10% by mass.

  As the protective layer, a resin film having high light transmittance, for example, a polyester film, a vinyl chloride film, a polycarbonate film, an inorganic substrate such as glass, or the like can be bonded to the phosphor layer with an adhesive.

  The protective layer may be in close contact with the phosphor layer via an adhesive layer, but has a structure (hereinafter also referred to as a sealing or sealing structure) provided to cover the phosphor surface. More preferred. Any known method may be used for sealing the phosphor surface, but the outermost resin layer on the side in contact with the phosphor surface of the moisture-proof protective film may be a moisture-proof protective film. This is one of the preferred embodiments in that the film can be fused and the sealing operation of the radiation image conversion panel is made efficient.

  The resin film having the heat-fusible property is a resin film that can be fused with a commonly used impulse sealer. For example, ethylene vinyl acetate copolymer (EVA), polypropylene (PP) film, polyethylene ( PE) film and the like can be mentioned, but the present invention is not limited to this.

  Furthermore, a moisture-proof protective film is arranged above and below the photostimulable phosphor plate, and the upper and lower moisture-proof protective films are heated and fused with an impulse sealer or the like in a region where the peripheral edge is outside the peripheral edge of the panel. The sealing structure is preferable because it prevents water from entering from the outer periphery of the plate. In addition, the moisture-proof protective film on the support surface side is a laminated film formed by laminating one or more aluminum films, so that moisture entry can be reduced more reliably, and this sealing method is easy in terms of work. It is preferable. In the method of heat-sealing with the impulse sealer, heat-sealing in a reduced pressure environment is more preferable in terms of preventing displacement of the plate in the moisture-proof protective film and eliminating moisture in the atmosphere.

  The outermost resin layer and the phosphor surface having the heat-sealing property on the side where the phosphor surface of the moisture-proof protective film is in contact may or may not be adhered. Here, the state of non-adhesion means that the phosphor surface and the moisture-proof protective film are optically and mechanically discontinuous even if the phosphor surface and the moisture-proof protective film are in point contact. It is a state that can be treated as a body.

Film Forming Apparatus FIG. 2 is a schematic diagram showing an example of an aerosol deposition film forming apparatus used in the method for manufacturing a radiation image conversion panel of the present invention.

  An embodiment of a film forming apparatus that can be used in the method for manufacturing a radiation image conversion panel of the present invention (hereinafter also referred to as the manufacturing method of the present invention) is illustrated.

  As a film deposition apparatus (aerosol deposition deposition apparatus, AD film deposition apparatus) by the aerosol deposition method, it is disclosed in "Applied Physics" magazine Vol. 68, No. 1, p. 44, JP-A No. 2003-215256, etc. Yes.

  A film forming apparatus 1 of the present invention includes a substrate holder 13 for holding a phosphor film forming substrate 12 (hereinafter also simply referred to as a substrate), an XYZθ stage 14 for operating the holder in three dimensions with XYZθ, and a phosphor material on the substrate. A nozzle having a narrow opening to be ejected, a chamber 16 having a pipe 15 for connecting the nozzle 11 to the aerosol-generating chamber 17, a high-pressure gas cylinder 19 for storing a carrier gas, a phosphor particle material and a carrier gas are agitated and mixed. It comprises an aerosol chamber 17 and a carrier gas pipe 21 connecting them. A temperature control mechanism using a Peltier element is installed on the back surface of the XYZθ stage 14, and the substrate 22 can be maintained at an optimum temperature.

  Furthermore, the phosphor particle raw material in the aerosol chamber 17 is formed on the phosphor and the film forming substrate by the following procedure.

  In the present invention, it is essential that the phosphor particle raw material (hereinafter also referred to as particle raw material) is heat-treated in a gas atmosphere maintained at a predetermined temperature before filling the aerosol forming chamber 17. Preferably, heat treatment is performed at 300 ° C to 1600 ° C. That is, this heat treatment is an important feature of the present invention.

  Thereafter, the phosphor fine particle raw material having an average particle diameter of preferably 0.1 to 2 μm filled in the aerosolization chamber 17 passes through the carrier gas pipe 21 from the high-pressure gas cylinder 19 for storing the carrier gas, and is in the aerosolization chamber. Introduced into 17, it is vibrated and stirred together with the carrier gas to be aerosolized. The aerosolized phosphor fine particle raw material passes through the pipe 15 and is sprayed together with the carrier gas from the nozzle 11 having a narrow opening in the chamber 16 to the phosphor film forming substrate 12 to form a coating film. The chamber 16 is evacuated by a vacuum pump or the like, and the degree of vacuum in the chamber 16 is adjusted as necessary, and is preferably adjusted at a degree of vacuum of 0.1 to 1000 Pa.

  Further, since the substrate holder 13 can be moved three-dimensionally by the XYZθ stage 14, a phosphor layer 26 having a necessary thickness can be formed on a predetermined portion of the substrate. A phosphor protective layer 24 can be provided on the phosphor layer 26 formed on the substrate as necessary.

  The aerosolized phosphor fine particle material can be deposited on the substrate 12 by colliding with a carrier gas preferably having a flow rate of 100 to 400 m / sec. The phosphor fine particles colliding with the carrier gas are bonded to each other by the impact of the collision to form a film.

  Examples of the carrier gas for accelerating and ejecting the fluorescent fine particles 18 include inert gases such as nitrogen gas, carbon dioxide gas, argon gas, and helium gas, and nitrogen gas is preferable.

  Moreover, it is preferable to hold | maintain the temperature of the board | substrate which the fluorescent fine particle 18 collides to -100 degreeC or more and 200 degrees C or less.

The thickness of the phosphor layer for efficiently absorbing radiation varies depending on the type of phosphor, but a thickness in the range of 50 to 500 μm is usually preferable.
In addition, after forming the phosphor layer on the supporting substrate, heat treatment is performed to adjust the film density.

(Flat panel type radiation detector)
A flat panel type radiation detector (FPD) will be described as another example of the radiation detector constituted by the manufacturing method of the present invention.

  A photodiode using a semiconductor thin film made of amorphous silicon and a photoelectric conversion element made of TFT (thin film transistor) are formed two-dimensionally on an insulating substrate made of a glass substrate or the like, and a semiconductor protective layer is formed on the surface. The photodetector is configured as a whole. Next, an FPD is configured by forming a phosphor layer on the photodetector.

  As a method of providing the phosphor layer on the FPD, the phosphor layer formed on the support substrate, that is, the radiation image conversion panel may be bonded to the photodetector, and an adhesive can be used as necessary. When the support substrate is opaque, it can be formed so as to be in contact with the phosphor layer and the photodetector, and when the support substrate is optically transparent, it can be formed so as to be in contact with the photodetector.

  The photodetector may also serve as a support substrate, and the phosphor layer may be formed directly on the semiconductor protective layer of the photodetector. If necessary, a light reflecting layer may be disposed on the phosphor layer on the surface not in contact with the photodetector.

  In the present embodiment, the detailed configuration, material, manufacturing method, and the like of the photodetector are the configurations and materials described in Japanese Patent Application Laid-Open No. 2003-57353, which are preferable because an inexpensive and lightweight FPD can be obtained.

As the above-mentioned phosphor powder, conventionally known phosphor materials such as CaWO ₄ , Gd ₂ O ₂ S: Tb, BaSO ₄ : Pb, CsI: Tl can be used. The phosphor particles represented by the general formula of (Gd, M, Eu) ₂ O ₃ are preferable because they have particularly high luminous efficiency.
Here, the rare earth element M includes at least one element of yttrium Y, niobium Nd, terbium Tb, dysprosium Dy, holmium Ho, erbium Er, thulium Tm, and ytterbium Yb.

Since these elements have high radiation absorptance, it is possible to obtain a radiation image with better granularity. Moreover, a radiation absorption factor and luminous efficiency can be made high by containing 40-95 mass% of gadolinium Gd, 5-40 mass% of rare earth elements M, and 2-20 mass% of europium Eu. In particular, gadolinium Gd is preferably 70 to 90% by mass, and europium Eu is preferably 5 to 10% by mass.
The above-mentioned phosphor support substrate is not particularly limited to materials, but a general substrate such as a resin substrate, ceramics, quartz glass, or a metal substrate such as titanium, stainless steel, or aluminum is used. it can.

  The adhesive layer, the phosphor protective layer, and the semiconductor protective layer are preferably as thin as possible so long as the functions of these layers can be exerted because the brightness and sharpness can be increased, and are usually preferably 20 μm or less.

  As the light reflecting layer, the luminance of the phosphor layer can be improved by forming a general light reflecting material. Examples of these materials include metal films prepared by conventionally known film forming methods such as sputtering and vapor deposition, for example, single metals such as titanium, nickel, platinum, palladium, and aluminum, or alloys thereof.

  In addition, for example, the sharpness of the phosphor layer can be improved by forming the light absorption layer using a carbon powder that is press-molded into a plate shape. The formation of the reflection layer and the absorption layer may be appropriately selected depending on the purpose of X-ray photography.

  Further, if necessary, a highly transparent resin film such as a polyester film, a vinyl chloride film, a polycarbonate film, or an inorganic substrate such as glass is bonded to the phosphor layer with an adhesive as a protective layer for the phosphor. Is also possible. As described above, a radiation detection apparatus can be manufactured by joining a scintillator including a phosphor layer in which phosphor particles are integrated by sintering to a photodetector through an adhesive layer.

(Stimulable phosphor plate)
As another embodiment of the radiation detector constituted by the production method of the present invention, a photostimulable phosphor plate is illustrated.

  This embodiment is composed of a support and a photostimulable phosphor layer provided on the surface of the support, and a surface opposite to the support side of the stimulable phosphor layer is usually a polymer film or an inorganic vapor deposition film. A protective film is provided.

  As the photostimulable phosphor, those that exhibit photostimulated luminescence in the wavelength range of 300 to 500 nm by excitation light in the range of usually 400 to 900 nm are generally used. -160078, 56-74175, 56-116777, 57-23673, 57-23675, 58-206678, 59-27289, 59-27980, 59-56479 Rare earth element activated alkaline earth metal fluoride halide phosphors described in JP-A-59-75200, JP-A-60-84381, JP-A-60-106752, and JP-A-60-166379. , 60-222143, 60-228592, 60-228593, 61-23679, 61-12088 Divalent europium-activated alkaline earth metal fluorohalide-based phosphors described in JP-A Nos. 61-120883, 61-120485, 61-235486, and 61-235487; Rare earth element activated oxyhalide phosphor described in JP-A-12144; cerium-activated trivalent metal oxyhalide phosphor described in JP-A-58-69281; bismuth-activated alkali metal halide described in JP-A-60-70484 Phosphor: divalent europium activated alkaline earth metal halophosphate phosphor described in JP-A-60-141783 and JP-A-60-157100; divalent europium activated alkali described in JP-A-60-157099 Earth metal haloborate phosphor; divalent europium activated alkaline earth described in JP-A-60-217354 Metal hydride halide phosphor; cerium-activated rare earth composite halide phosphor described in JP-A-61-2173 and JP-A-6-21182; cerium-activated rare earth halophosphate fluorescence described in JP-A-61-1390 A divalent europium-activated cerium / rubidium phosphor described in JP-A-60-78151; a divalent europium-activated composite halide phosphor described in JP-A-60-78151; In particular, a divalent europium activated alkaline earth metal fluoride halide phosphor containing iodine, a rare earth element activated oxyhalide phosphor containing iodine, and a bismuth activated alkali metal halide phosphor containing iodine. Indicates high-intensity stimulated luminescence.

As a particularly preferred stimulable phosphor composition,
Formula _{Ba 1-x (M 2)} x FBr y I 1-y: aM 1, bLn, cO
_{Wherein, M 1: Li, Na,} K, of at least one alkali metal atom selected from Rb and _{Cs, M 2: Be, Mg} , at least one alkaline earth metal atom selected from Sr and Ca, Ln: At least one rare earth element selected from Ce, Pr, Sm, Eu, Gd, Tb, Tm, Dy, Ho, Nd, Er, and Yb, x, y, a, b, and c are 0 ≦ x ≦ 0. 3, 0 <y ≦ 0.3, 0 ≦ a ≦ 0.05, 0 <b ≦ 0.2, 0 <c ≦ 0.1. ]
Or
The general formula _{M 1 X · aM 2 X'2 ·} bM 3 X "3: eA
[Wherein, M ₁ is at least one alkali metal atom selected from Li, Na, K, Rb and Cs atoms, and M ₂ is Be, Mg, Ca, Sr, Ba, Zn, Cd, Cu. And at least one divalent metal atom selected from each atom of Ni and M ₃ is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er , Tm, Yb, Lu, Al, Ga, and In, and at least one trivalent metal atom selected from each atom, X, X ′, and X ″ are F, Cl, Br, and I, respectively. At least one selected halogen is an atom, and A is Eu, Tb, In, Cs, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na At least one metal atom selected from Ag, Cu and Mg Ri, also, a, b, e each represent a number between 0 ≦ a <0.5,0 ≦ b <0.5,0 <e ≦ 0.2.]
As the support used for the photostimulable phosphor plate, various polymer materials, glass, metal and the like are used. In particular, a material that can be processed into a flexible sheet or web for handling as an information recording material is suitable. From this point, a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyamide film, a polyimide film, a triacetate film, A plastic film such as a polycarbonate film, a metal sheet such as aluminum, iron, copper, and chromium, or a metal sheet having a coating layer of the metal oxide is preferable. Moreover, although the film thickness of these support bodies changes with materials etc. of the support body to be used, generally it is 80-1000 micrometers, More preferably, it is 80-500 micrometers from the point on handling. The surface of these supports may be a smooth surface, or may be a mat surface for the purpose of improving the adhesion to the photostimulable phosphor layer.

  Further, these supports may be provided with an undercoat layer on the surface on which the photostimulable phosphor layer is provided for the purpose of improving the adhesiveness with the photostimulable phosphor layer.

  As a protective layer provided on the photostimulable phosphor plate, polyester film, polymethacrylate film, nitrocellulose film, cellulose acetate film, etc. can be used, but stretched films such as polyethylene terephthalate film and polyethylene naphthalate film are used. From the viewpoint of transparency and strength, it is preferable as a protective layer. Further, a vapor deposition film obtained by depositing a thin film such as a metal oxide or silicon nitride on the polyethylene terephthalate film or polyethylene terephthalate film is more preferable from the viewpoint of moisture resistance.

The film used for the protective layer can be made optimal moisture-proof by laminating a plurality of vapor-deposited films obtained by vapor-depositing a metal oxide or the like on a resin film or resin film according to the required moisture-proof property, In consideration of preventing moisture absorption deterioration of the phosphor, the moisture permeability is preferably at least 50 g / m ² · day or less. There is no restriction | limiting in particular as a lamination method of a resin film, You may use any well-known method.

  In addition, it is preferable to provide an excitation light absorption layer between the laminated resin films so that the excitation light absorption layer is protected from physical impact and chemical alteration and stable plate performance can be maintained for a long period of time. In addition, the excitation light absorption layer may be provided at a plurality of locations, or a colorant may be contained in the adhesive layer for lamination to form an excitation light absorption layer.

  The protective layer may be in close contact with the phosphor layer via an adhesive layer, but more preferably has a structure (hereinafter also referred to as a sealing or sealing structure) provided to cover the phosphor surface. . Any known method may be used for sealing the phosphor surface, but the outermost resin layer on the side in contact with the phosphor surface of the moisture-proof protective film may be a moisture-proof protective film. This is one of the preferred embodiments in that the film can be fused and the sealing operation of the radiation image conversion panel is made efficient. The resin film having the heat-fusible property is a resin film that can be fused with a commonly used impulse sealer. For example, ethylene vinyl acetate copolymer (EVA), polypropylene (PP) film, polyethylene ( PE) film and the like can be mentioned, but the present invention is not limited to this.

  Furthermore, a moisture-proof protective film is arranged above and below the photostimulable phosphor plate, and the upper and lower moisture-proof protective films are heated and fused with an impulse sealer or the like in a region where the peripheral edge is outside the peripheral edge of the panel. The sealing structure is preferable because it prevents water from entering from the outer periphery of the plate. In addition, the moisture-proof protective film on the support surface side is a laminated film formed by laminating one or more aluminum films, so that moisture entry can be reduced more reliably, and this sealing method is easy in terms of work. It is preferable. In the method of heat-sealing with the impulse sealer, heat-sealing in a reduced pressure environment is more preferable in terms of preventing displacement of the plate in the moisture-proof protective film and eliminating moisture in the atmosphere.

  The outermost resin layer and the phosphor surface having the heat-sealing property on the side where the phosphor surface of the moisture-proof protective film is in contact may or may not be adhered. Here, the state of non-adhesion means that the phosphor surface and the moisture-proof protective film are optically and mechanically discontinuous even if the phosphor surface and the moisture-proof protective film are in point contact. It is a state that can be treated as a body.

  As mentioned above, although the FPD and the photostimulable phosphor plate have been shown as examples of use of the radiation image conversion panel that can be produced by the present invention, the present invention is not limited to these. Another example of use is a fluorescent intensifying screen used in a so-called screen film system in which a conventional fluorescent intensifying screen and a radiographic film are combined.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the embodiment of this invention is not limited to these.

  Hereinafter, an embodiment using a flat panel type digital radiation detector (FPD) will be described.

Example 1
<Production of radiation detection device>
(Preparation of radiation detector 1: the present invention)
A photoelectric conversion element composed of a photodiode and a TFT is formed on a semiconductor thin film composed of amorphous silicon on a non-alkali glass substrate having a thickness of 1.0 mm, and a protective film composed of SiNx is formed on the photoelectric conversion element. A vessel was made.

The particle size was heat treated in a gas atmosphere of 200 ° C. before the formation distribution 0.1 to 1 [mu] m, average particle diameter 0.5μm of (Y, Gd, Eu) phosphor particles ₂ O ₃ was charged into aerosolizing chamber Then, N ₂ gas having a flow rate of 600 m / s was used as a carrier gas, the degree of vacuum in the chamber was 100 Pa, the substrate temperature was 20 ° C., and a film was formed to a thickness of 200 μm by blowing a plate on a 1 mm-thick stainless steel support substrate. . Furthermore, the radiation detection apparatus 1 was produced by joining the phosphor layer and the substrate to the photodetector with an acrylic adhesive (manufactured by Kyoritsu Chemical Co., Ltd .; trade name: Worldlock NO. XSG-5).

Examples 2-5
The radiation detectors 2 to 2 were prepared in the same manner as in Example 1 except that the temperature at which the phosphor particles were heat-treated in the gas atmosphere before film formation was changed to the temperature shown in Table 1, and the flow rate of the carrier gas was changed to the flow rate shown in Table 1. 5 were produced.

Phosphor particles Example 6
(Production of radiation detector 6: comparative example)
A photodetector was produced in the same manner as in the production of the radiation detection apparatus 1.

(Y, Gd, Eu) ₂ O ₃ phosphor particles having a particle size distribution of 0.1 to 1 μm and an average particle size of 0.5 μm are filled in an aerosol chamber, and He gas having a flow rate of 600 m / s is used as a carrier gas. The chamber was vacuumed at 100 Pa and sprayed onto a 1 mm thick stainless steel support substrate to attempt a 200 μm film formation. Furthermore, the radiation detection apparatus 6 was produced by joining a fluorescent substance layer, a board | substrate, and a photodetector with the acrylic adhesive (the Kyoritsu-Chemical company make; brand name Worldlock NO.XSG-5).

<< Evaluation of radiation detector >>
The sharpness was measured for each radiation detection device, and the results obtained are shown in Table 1.
The sensitivity measurement is a value obtained by photographing with an X-ray having a tube voltage of 100 kV through a water phantom having a thickness of 100 mm, and is displayed as a relative sensitivity with the sensitivity of the radiation detection device 6 as a comparative example being set to 1.

  As is apparent from Table 1, the present invention is superior to the comparison.

It is sectional drawing which shows an example of the radiographic image conversion panel manufactured by the manufacturing method of the radiographic image conversion panel of this invention. It is a schematic diagram which shows an example of the aerosol deposition film-forming apparatus used for the manufacturing method of the radiographic image conversion panel of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacture 11 nozzle 12 Substrate for phosphor coating film 13 Substrate holder 14 XYZθ stage 15 Piping 16 Chamber 17 Aerosolization chamber 18 Phosphor fine particles 19 High-pressure gas cylinder 20 Vibrating stirring 21 Carrier gas piping 22 Substrate 23 Pixel 24 Protective layer 25 Detector 26 Phosphor layer

Claims (7)

In a method for manufacturing a radiation image conversion panel having a phosphor layer for converting radiation into visible light, a phosphor material particle that has been subjected to heat treatment before filling the phosphor layer into an aerosol chamber is loaded onto a substrate at a high flow rate. Production of a radiation image conversion panel characterized by being formed using a film deposition method (gas deposition film formation method (aerosol deposition film formation method, AD film formation method)) deposited by collision with gas Method. The method for producing a radiation image conversion panel according to claim 1, wherein the heat treatment is performed in a gas atmosphere at 300 to 1600 ° C. The method for producing a radiation image conversion panel according to claim 1, wherein the flow rate of the carrier gas is 100 to 400 m / sec. The radiation image conversion panel manufacturing apparatus used in the method for manufacturing a radiation image conversion panel according to any one of claims 1 to 3 has a heat treatment means for phosphor raw material particles before filling into the aerosolization chamber. An apparatus for producing a radiation image conversion panel, which is a film deposition apparatus (aerosol deposition deposition apparatus, AD film deposition apparatus) by an aerosol deposition method. A radiation image conversion panel obtained by the method for manufacturing a radiation image conversion panel according to claim 1. A radiation image conversion panel obtained by the apparatus for manufacturing a radiation image conversion panel according to claim 4. A radiation detection apparatus that detects radiation using the radiation image conversion panel according to claim 5.

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