JP2010014581A - Manufacturing method for radiographic image conversion panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a radiographic image conversion panel with improved manufacturing efficiency. <P>SOLUTION: The manufacturing method for a radiographic image conversion panel, wherein on a frame having a predetermined width is provided on the surface of a substrate and a phosphor layer is formed in an area enclosed by the frame, includes the steps of: providing the frame on a surface of a substrate; releasably attaching a masking material to at least a top surface of the frame by using an adhesive, and forming a phosphor layer by vapor phase deposition in the area enclosed by the frame. Assuming w as an adhering width of the adhesive and α as a width of the frame, an adhering width w of the adhesive is in the range of 0<w≤α. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a radiation image conversion panel having a phosphor layer, such as a so-called IP (Imaging Plate) or scintillator, and more particularly to a method for manufacturing a radiation image conversion panel with high production efficiency.

  Today, phosphors that exhibit various responses to radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.) are known, and are used for various applications such as medical applications. ing.

  For example, when irradiated with radiation, a part of this radiation energy is accumulated, and then when irradiated with excitation light such as visible light, a phosphor that exhibits stimulated emission according to the accumulated energy is known. ing. This phosphor is called a stimulable phosphor (accumulating phosphor).

A radiation image information recording / reproducing system using a radiation image conversion panel having the photostimulable phosphor layer is known. For example, it has been put into practical use as FCR (Fuji Computed Radiography) manufactured by Fuji Film. Yes.
In this system, a radiation image (radiation image) of a subject is recorded on a radiation image conversion panel (phosphor layer) by irradiating a subject such as a human body with X-rays or the like. After recording, the conversion panel is scanned two-dimensionally with excitation light to generate stimulated emission, and this stimulated emission light is photoelectrically read to obtain an image signal, and an image generated based on this image signal is A radiation image of the subject is output to a display device such as a CRT or a recording material such as a photographic photosensitive material.

As another example, a phosphor that emits light (fluorescence) when irradiated with radiation is also known, and this phosphor is used in a scintillator. This scintillator panel is also one of the radiation image conversion panels.
The radiation transmitted through the subject is converted into visible light by a scintillator panel, the visible light is converted into electric charge by a photoelectric conversion element such as a photodiode, and the electric charge is sequentially read out by a TFT (Thin Film Transistor) etc. An image forming system is used.

A radiation image conversion panel is usually prepared by adjusting a paint in which a phosphor powder is dispersed in a solvent containing a binder, and applying the paint to a glass or resin panel-like support, followed by drying. Created.
In addition to coating in this way, it is known to form a phosphor layer on a substrate in a radiation image conversion panel by a vapor deposition method (vacuum film forming method) such as a vacuum evaporation method or a sputtering method. (See Patent Documents 1 and 2).

In the method for producing a photostimulable phosphor panel (radiation image conversion panel) of Patent Document 1, a frame is bonded to a substrate with a heat-resistant adhesive having a heat resistance of 150 ° C. or higher, and then peelable on the frame. In addition, a mask material having flexibility to follow the thermal expansion of the frame is affixed, and the vapor deposition position of the stimulable phosphor layer on the substrate is determined by this mask material, and the vapor deposition method (vacuum film forming method) To form a photostimulable phosphor layer. In Patent Document 1, the difference in thermal expansion coefficient between the substrate and the frame is 1 × 10 ⁻⁶ / ° C. or less, and Kapton tape with a heat-resistant adhesive is suitable as a mask material (Kapton is a registered trademark of DuPont). It is described that.

  Patent Document 2 discloses a photostimulable layer (stimulable phosphor layer) made of a photostimulable phosphor on a crystallized glass support by a vapor deposition method (vacuum film-forming method) by an electron beam method (EB method). ) Is formed. The radiation image conversion panel is described. In this patent document 2, the vapor deposition region of the photostimulable layer is determined using a stainless plate mask.

  As described in Patent Documents 1 and 2, the phosphor layer formed by the vacuum film formation method is formed in a vacuum, so there are few impurities, and components such as a binder other than the stimulable phosphor are almost included. Therefore, it has excellent characteristics such as little variation in performance and very good luminous efficiency.

JP 2005-315797 A Japanese Patent No. 2884356

However, in Patent Document 1, if the component of the heat-resistant adhesive of the mask material is released during vapor deposition or the like and adheres to the vapor deposition region, the formed phosphor cannot obtain sufficient adhesion with the substrate. For this reason, there is a problem that the yield is lowered, such as peeling off of the phosphor layer, and high productivity cannot be obtained.
Further, in Patent Document 2 using a stainless steel plate as a mask, even when a stainless steel plate is provided on the frame as a mask, when the substrate is heated when the phosphor layer is deposited, the mask is heated by thermal expansion. The positions of the substrate and the frame are relatively displaced. For this reason, there exists a possibility that it cannot suppress that the fluorescent substance used as a fluorescent substance layer accumulates on a frame. When the phosphor is deposited on the frame, it is necessary to remove the phosphor, and the radiation image conversion panel cannot be efficiently produced.

  An object of the present invention is to provide a method for manufacturing a radiation image conversion panel that solves the problems based on the conventional technology and has high production efficiency.

  In order to achieve the above object, the present invention provides a radiation image conversion panel in which a frame having a predetermined width is provided on the surface of a substrate, and a phosphor layer is formed in a region surrounded by the frame. A step of providing the frame on the surface of the substrate, a step of detachably attaching a mask material to the upper surface of the frame using an adhesive, and a region surrounded by the frame And the step of forming the phosphor layer by vapor deposition, and when the adhesive width of the adhesive is w and the width of the frame is α, the adhesive width w of the adhesive is 0 < The present invention provides a method for producing a radiation image conversion panel, wherein w ≦ α.

In the present invention, the adhesive width w of the adhesive is preferably 0.1α <w ≦ 0.5α.
In the present invention, the adhesive contains, for example, siloxane.

According to the present invention, in the method for manufacturing a radiation image conversion panel in which a frame surrounding the phosphor layer is provided on the substrate, the phosphor layer is formed on the surface of the substrate by a vapor deposition method in a region surrounded by the frame. Before forming, a mask material is attached to at least the upper surface of the frame in an detachable manner using an adhesive. In this case, when the adhesive width of the adhesive is w and the width of the frame is α, by setting the adhesive width w of the adhesive to 0 <w ≦ α, the component is released from the adhesive and the phosphor Even if it adheres to the formation region of the layer, the phosphor layer can be formed without lowering the adhesion to the substrate, and peeling of the phosphor layer can be suppressed. For this reason, a phosphor layer can be manufactured with a high yield, and a radiation image conversion panel can be manufactured with high productivity.
Furthermore, since peeling of the phosphor layer can be suppressed, image defects resulting from this peeling can also be suppressed, and a radiation image conversion panel with good image quality can be obtained.

Below, based on the preferred embodiment shown in an accompanying drawing, the manufacturing method of the radiation image conversion panel of the present invention is explained in detail.
FIG. 1 is a schematic cross-sectional view showing a radiation image conversion panel obtained by a method for manufacturing a radiation image conversion panel according to an embodiment of the present invention.

A radiation image conversion panel 10 (hereinafter referred to as a conversion panel 10) shown in FIG. 1 is basically formed in a substrate 12, a frame 14 provided on the substrate 12, and a region surrounded by the frame 14. A stimulable phosphor layer (hereinafter referred to as a phosphor layer) 16 and a moisture-proof protective layer 20 bonded by an adhesive layer 18.
The conversion panel 10 includes, for example, a phosphor layer 16 made of a stimulable phosphor, and captures radiation images by accumulating (recording) radiation that has passed through the subject, and radiation captured by incidence of excitation light. This is a so-called IP (Imaging Plate) that emits stimulated emission light according to an image.

  In addition, this invention is not limited to the conversion panel 10 which has the fluorescent substance layer 16 which consists of a stimulable fluorescent substance, The flat which has the fluorescent substance layer comprised by CsI which light-emits (fluoresces) by incidence | injection of a radiation. It may be a radiation image conversion panel (scintillator panel) such as a panel detector.

  Note that the conversion panel 10 of the present embodiment may have a film formed before the phosphor layer 16 is formed as long as the above configuration is satisfied. In this case, for example, the surface 12a of the substrate 12 may have a reflection film for reflecting the stimulated emission light, and further may have a barrier film or the like for protecting the reflection film on the reflection film. Good. Further, the phosphor layer 16 may be formed on the surface 12a of the substrate 12 on which these films are formed.

In the conversion panel 10 of the present embodiment, the substrate 12 is a plate-like member or a sheet member, and may be polished so as to have a predetermined flatness. Further, before the phosphor layer 16 is formed, it may be polished to have a predetermined flatness.
The substrate 12 is not particularly limited, and various substrates used in known phosphor panels can be used.
Examples include plastic films such as cellulose acetate film, polyester film, polyethylene terephthalate film, polyamide film, polyimide film, triacetate film, polycarbonate film; quartz glass, alkali-free glass, soda glass, heat-resistant glass (Pyrex (registered trademark), etc.) Examples thereof include a glass sheet formed from a metal sheet such as an aluminum sheet, an iron sheet, a copper sheet, and a chromium sheet, a metal sheet having a metal oxide coating layer, or an alloy sheet such as an aluminum alloy sheet.

In the conversion panel 10, the surface 12 a of the substrate 12 is also required to have a function as a reflecting surface for the stimulated emission light emitted from the phosphor layer 16. It is preferable to have.
As a preferable example of the substrate 12, the substrate 12 made of aluminum or aluminum alloy is preferably exemplified in that the light weight and good light reflectivity are obtained, and the effect of the present invention can be suitably expressed. . In addition to this, a substrate 12 in which a metal layer such as an aluminum layer or an alloy layer such as an aluminum alloy is formed on the surface of a substrate such as a glass plate can also be suitably used. In addition, the alloy which comprises the board | substrate 12, and the alloy layer formed in a base-material surface may contain magnesium etc. for corrosion prevention.

The frame 14 defines the formation area A of the phosphor layer 16 on the surface 12a of the substrate 12, that is, the imaging area of the conversion panel 10. In this embodiment, the formation area A of the phosphor layer 16 is rectangular. Since it is a shape, the frame 14 is provided so as to surround its outer edge, and exhibits the outer shape of the frame 14 (see FIG. 2). The frame 14 is composed of a member having a predetermined thickness and width.
For example, the frame 14 is inserted into a groove 12 b formed on the surface 12 a of the substrate 12 and fixed to the substrate 12.

As will be described later, in the method for manufacturing the conversion panel 10, before forming the phosphor layer 16, a frame that surrounds the formation region A of the phosphor layer 16 on the surface 12 a of the substrate 12, that is, the imaging region of the conversion panel 10. 14 is provided.
The outer shape of the frame 14 is not limited to a rectangular shape, and is appropriately determined according to the outer shape of the formation region A of the phosphor layer 16 (the imaging region of the conversion panel 10).

The method of fixing the frame 14 is not particularly limited to the method of forming the groove 12b in the substrate 12, and the frame 14 is fixed to the substrate using a heat-resistant adhesive having a heat resistance of 150 ° C. or higher, or a molten metal. A method of fixing to the 12 surfaces 12a can also be used. By fixing the frame 14 by such a method, it is possible to prevent the frame 14 from being peeled from the substrate 12 even when the substrate 12 is heated during the deposition of the phosphor layer 16 or during the heat treatment after the deposition. Furthermore, regarding the fixation of the frame 14 with molten metal, in addition to the above-described advantages, moisture permeability from the bonding portion between the substrate 12 and the frame 14 can be reduced.
In addition, a heat resistant adhesive agent is not specifically limited, As an example, an epoxy adhesive agent is illustrated suitably. Similarly, the molten metal is not particularly limited, and aluminum solder is preferably exemplified as an example.

The frame 14 is fixed to the surface 12a of the substrate 12 by performing alignment using an appropriate jig, for example. The groove 12b can be formed with very high positional accuracy by machining or the like. Therefore, by forming such a groove 12b, inserting the frame 14 into the groove 12b, and positioning the frame 14, the positional accuracy of the frame 14 and the substrate 12 and the deposition of the phosphor layer 16 on the substrate 12 are performed. The positional accuracy is improved, and the imaging surface of the phosphor panel can be appropriately set within a predetermined range. Further, by adopting a configuration in which the frame 14 is inserted into the groove 12b, the thickness of the frame 14 can be made thicker by the amount of the portion to be inserted into the groove 12b than when it is fixed on the surface 12a of the substrate 12. In addition to improving the strength, it is easy to handle in manufacturing, and the dimensional accuracy of the frame 14 is easily secured.
The depth of the groove 12b from the surface 12a of the substrate 12 is the thickness of the substrate 12 and the phosphor layer 16 as long as the frame 14 is properly fixed to the substrate 12 and the frame 14 is sufficiently strong. The depth of the groove 12b is preferably 0.2 mm to 5 mm.
In order to increase the positional accuracy between the frame 14 and the substrate 12, the workability when the frame 14 is attached, and the like, it is particularly preferable that the frame 14 is inserted into the groove 12b.

As described above, when the phosphor layer 16 of the conversion panel 10 of the present invention is irradiated with radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet rays, etc.), a part of the radiation energy is obtained. When it is accumulated and then irradiated with excitation light such as visible light, it exhibits stimulated emission according to the accumulated energy. The phosphor layer 16 has, for example, a columnar crystal structure.
The phosphor layer 16 is made of, for example, an alkali halide phosphor, and is formed by a vacuum deposition method.
In the conversion panel 10 of the present invention, various phosphors can be used as the phosphor forming the phosphor layer 16, and the phosphor to be the phosphor layer 16 is not particularly limited, but various known phosphors can be used. Are available.

In particular, the general formula M ^I X · aM ^II X ′ disclosed in Japanese Patent Application Laid-Open No. 61-72087 is disclosed in that the effect of the present invention is easily exhibited and good photostimulated luminescence characteristics are obtained. An alkali halide photostimulable phosphor represented by ₂ · bM ^III X ″ ₃ : cA is preferably used.
(In the above formula, M ^I is at least one selected from the group consisting of Li, Na, K, Pb and Cs, and M ^II is Be, Mg, Ca, Sr, Ba, Zn, Cd, Cu and at least one trivalent metal selected from the group consisting of Ni, M ^III is, Sc, Y, La, Ce , Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, At least one trivalent metal selected from the group consisting of Tm, Yb, Lu, Al, Ga and In, and X, X ′ and X ″ are selected from the group consisting of F, Cl, Br and I A is from Eu, Tb, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er, Gd, Lu, Sm, Y, Tl, Na, Ag, Cu, Bi, and Mg. At least one selected from the group consisting of Also, 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 <c ≦ 0.2.)
Among them, have excellent photostimulated luminescence characteristics, and in terms of such the effect of the present invention is obtained particularly well, M ^I contains at least Cs, X contains at least Br, further, A However, an alkali halide photostimulable phosphor that is Eu or Bi is preferred, and among these, photostimulable phosphors represented by the general formula CsBr: Eu are particularly preferred.

  In addition, U.S. Pat. No. 3,859,527, JP-A-55-12142, 55-12144, 55-12145, 56-116777, 58-69281. 58-206678, 59-38278, 59-75200, and the like, various photostimulable phosphors disclosed in each publication can be suitably used.

Further, the radiation image conversion panel of the present invention is not limited to the conversion panel 10 having the phosphor layer 16 made of a stimulable phosphor, and emits light (fluoresces) by the incidence of radiation as described above. It may be a radiation image conversion panel having a phosphor layer made of a phosphor.
As such phosphors, all known ones can be used. Similarly, the following general formulas are used in that the effects of the present invention are easily manifested and good photostimulated luminescence properties are obtained. :
M ^I X · aM ^II X ′ ₂ · bM ^III X ″ ₃ : zA
An alkali metal halide phosphor represented by the formula is preferably exemplified.
(In the above formula, M ^I represents at least one alkali metal selected from the group consisting of Li, Na, K, Rb and Cs, and M ^II represents Be, Mg, Ca, Sr, Ba, Ni, Cu, Represents at least one alkaline earth metal or divalent metal selected from the group consisting of Zn and Cd, and M ^III represents Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy , Ho, Er, Tm, Yb, Lu, Al, Ga, and In represent at least one rare earth element or trivalent metal. X, X ′, and X ″ are F, Represents at least one halogen selected from the group consisting of Cl, Br, and I, and A represents Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu , Na, Mg, Cu, A and at least one rare earth element or metal selected from the group consisting of g, Tl, and Bi, and a, b, and z are 0 ≦ a <0.5, 0 ≦ b <0.5, and 0 <, respectively. (Represents a numerical value within the range of z <1.0.)
In particular, it is preferred that Cs is contained as M ^{I in the} general formula, ^I is preferably contained as X, T1 or Na is preferably contained as A, and z is 1 × 10 ^It is preferable that the numerical value is within a range of ⁻⁴ ≦ z ≦ 0.1. Among these, alkali metal halide phosphors represented by the formula CsI: Tl are preferably used.

In the present invention, the method for forming the phosphor layer 16 is not particularly limited, but any of various vapor deposition methods such as sputtering and CVD can be used. However, the vacuum deposition method is preferably used as the method for forming the phosphor layer 16 in terms of the film formation speed and the crystal structure of the phosphor layer to be formed.
In particular, when the phosphor layer 16 made of a stimulable phosphor is formed, the film forming material of the phosphor component and the activator (activator) component is heated / separated with another crucible (evaporation source). Preferably, the phosphor layer is formed by a binary vacuum evaporation method that evaporates.

  There are no particular restrictions on the film forming conditions and heating means when performing vacuum vapor deposition, but once the system is evacuated to a high degree of vacuum, argon gas or nitrogen gas is introduced into the system. It is preferable that the degree of vacuum is about 0.01 to 3 Pa (hereinafter referred to as medium vacuum for convenience), and vacuum deposition is performed by heating the film forming material by resistance heating or the like under vacuum. The phosphor layer 16 formed by vapor deposition is formed of columnar crystals independent of each other. The phosphor layer 16 obtained by forming a film under such a medium vacuum, in particular, an alkali halide such as CsBr: Eu. The phosphor layer 16 of the system has a particularly good columnar crystal structure, and is preferable in terms of photostimulable luminescence characteristics and image sharpness.

The moisture-proof protective layer 20 is provided to cover and seal the phosphor layer 16 in order to seal the phosphor layer 16 and prevent moisture absorption.
As long as the moisture-proof protective layer 20 has sufficient moisture-proof properties, various types can be used and are not particularly limited.
The moisture-proof protective film constituting the moisture-proof protective layer 20, for example, a PET (polyethylene terephthalate) film, forming a three-layer between the hybrid layer and the SiO ₂ film and the SiO ₂ film and the SiO ₂ and PVA (polyvinyl alcohol) The moisture-proof protective layer 20 having a total four-layer structure is exemplified. In addition to this, a glass plate (film), a resin film such as polyethylene terephthalate or polycarbonate, a film in which an inorganic substance such as SiO ₂ , Al ₂ O ₃ , or SiC is deposited on the resin film are also preferably exemplified. Incidentally, on the PET film, the SiO ₂ film / SiO ₂ and the hybrid layer / SiO ₂ film a total of four-layer structure proof protective layer 20 of the three layers was formed of the PVA, for example, SiO ₂ film, a sputtering method The SiO ₂ and PVA hybrid films may be formed using a sol-gel method so that the ratio of PVA to SiO ₂ is 1: 1. The moisture-proof protective layer 20 preferably has a moisture permeability of 0.2 to 0.6 (g / (m ² · day)) in an environment where the relative humidity is 90% at a temperature of 40 ° C.
Also, on the PET film, the moisture-proof protective layer 20 of a total of four-layer structure having a three-layer structure of the hybrid layer / SiO ₂ film and the SiO ₂ film / SiO ₂ and PVA, the phosphor layer 16 side of the SiO ₂ film It is preferable to form.

The adhesive layer 18 is for attaching the moisture-proof protective film constituting the moisture-proof protective layer 20 to the upper surface 14 a of the frame 14 and the surface 16 a of the phosphor layer 16.
The adhesive layer 18 is formed, for example, by applying an adhesive to the upper surface 14a of the frame 14 and the surface 16a of the phosphor layer 16.

In the present embodiment, for example, after the adhesive layer 18 is provided, the moisture-proof protective layer 20 is covered so as to cover the surface 16a of the phosphor layer 16, and the moisture-proof protective layer 20, the frame 14, and the phosphor layer 16 are sealed. Glue. The sealing and bonding method is not particularly limited, and for example, a thermal lamination method is used.
Prior to sealing of the phosphor layer 16 by the moisture-proof protective layer 20 so as to improve the adhesive strength when the moisture-proof protective layer 20 and the upper surface 14a of the frame 14 are bonded by the adhesive layer 18, and to obtain a good adhesive strength. The heating of the sealing part (adhered part between the moisture-proof protective layer 20 and the frame 14) and the phosphor layer 16 may be performed by heating the substrate 12, for example.

  The adhesive used for the adhesive layer 18 is not particularly limited as long as it has excellent moisture resistance. For example, a polyester-based adhesive can be suitably used. Furthermore, when the surface 16a of the phosphor layer 16 is also bonded to the moisture-proof protective layer 20, it is preferable that the adhesive also has optical characteristics that do not hinder the incidence of radiation and emission of stimulated emission light.

Next, the manufacturing method of the conversion panel 10 of this embodiment is demonstrated.
FIG. 2 is a schematic plan view showing an arrangement state of frames in the method for manufacturing a radiation image conversion panel according to the embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view showing a mask arrangement state in the method for manufacturing a radiation image conversion panel according to the embodiment of the present invention.
FIG. 4A is an enlarged partial cross-sectional view showing the main part of FIG. 3, and FIG. 4B is a modification of the mask arrangement state in the manufacturing method of the radiation image conversion panel of the embodiment of the present invention. It is a fragmentary sectional view shown, and (c) is a fragmentary sectional view which shows the other modification of the arrangement state of the mask in the manufacturing method of the radiation image conversion panel of the embodiment of the present invention.
FIG. 5 is a schematic cross-sectional view showing the formation state of the phosphor layer in the method for manufacturing the radiation image conversion panel of the present embodiment.

In the method for manufacturing the conversion panel 10 of the present embodiment, first, for example, a substrate 12 (see FIG. 1) having a square shape in plan view is prepared. The substrate 12 is made of, for example, an aluminum alloy.
Grooves 12b (see FIG. 3) surrounding the rectangular formation region A on which the phosphor layer 16 is formed are formed on the surface 12a of the substrate 12 to partition the formation region A.

Next, for example, a frame 14 made of a member having a rectangular cross-sectional shape is inserted into the groove 12b with an adhesive.
Thereby, as shown in FIG. 2, the frame 14 is formed so as to surround the rectangular formation region A. The frame 14 is made of a member having a width α, for example.
The frame 14 is arranged at a position where the distance from the inner edge 15 of the frame 14 to the edge 12c of the substrate 12 is β in the X direction of the two directions orthogonal to the X direction and the Y direction on the surface 12a of the substrate 12. In the Y direction, the distance from the inner edge 15 of the frame 14 to the edge 12c of the substrate 12 is arranged at a position γ.

Next, as shown in FIG. 3, the mask material 30 is detachably attached to the upper surface 14 a of the frame 14 using an adhesive 32.
The mask material 30 is made of, for example, an aluminum tape or a Kapton tape (Kapton is a registered trademark).
The adhesive 32 is not particularly limited as long as the mask material 30 can be detachably attached to the upper surface 14a of the frame 14. As the adhesive 32, for example, a silicone-based adhesive, a latex-based adhesive, an acrylic resin-based adhesive, an olefin-based adhesive, a urethane resin-based adhesive, or an epoxy resin-based adhesive is used. In view of the above, a silicone-based tape using a silicone-based adhesive is most useful.

In the present embodiment, the mask material 30 is provided so as to cover the surface 12a of the substrate 12 other than the formation region A. In this case, the width T of the mask material 30 is equal to the distance γ in the X direction of the substrate 12 and is equal to the distance β in the Y direction of the substrate 12. In this manner, the surface 12 region of the substrate 12 other than the formation region A of the phosphor layer 16 is regulated (masked) by the mask material 30.
The mask material 30 only needs to prevent the phosphor that becomes the phosphor layer 16 from adhering to the upper surface 14a of the frame 14 as a deposit. Therefore, the mask material 30 is not limited to a size that covers the surface 12a of the substrate 12 other than the formation region A. The mask material 30 is provided so as to cover at least the upper surface 14a of the frame 14. Just do it.

In the present invention, as shown in FIG. 4A, when the adhesive width of the adhesive 32 of the mask material 30 is w, the adhesive width w of the adhesive 32 is 0 < Let w ≦ α. More preferably, the adhesive width w of the adhesive is 0.1α <w ≦ 0.5α.
The bonding width w of the adhesive 32 is a length in a direction parallel to the width α direction of the frame 14.

Next, the reason why the adhesive width w of the adhesive 32 is 0 <w ≦ α with respect to the width α of the frame 14 in the present invention will be described.
Regarding the adhesive width w of the adhesive 32 being 0 <w ≦ α, the inventors of the present application are based on the following knowledge obtained through earnest experimental research. When forming the phosphor layer 16 of the conversion panel 10, an aluminum tape was attached to the upper surface 14 a of the frame 14 using an adhesive 32 containing siloxane. Then, when the phosphor layer 16 was formed and the formed phosphor layer 16 was examined, in the region Ca in the vicinity of the inner edge 15 of the frame 14, the adhesion between the phosphor layer 16 and the substrate 12 was insufficient, and the phosphor It was found that the phosphor layer 16 was partially peeled in the region Ca in the layer 16. The peeling occurred even though the film formation conditions of the phosphor layer 16 were appropriate.

Then, when the cause of the peeling was further investigated, it was found that siloxane, which is one of the components of the adhesive 32, was attached to the surface 12a of the substrate 12. And when the relationship between peeling and the amount of siloxane that is a component of the adhesive 32 that adheres to the surface 12a of the substrate 12 was examined, when the amount of attached siloxane exceeds a certain amount, the frequency of occurrence of peeling increases. I found.
Further, when the relationship between the peeling of the phosphor layer 16 and the amount of the adhesive 32 for fixing the mask material 30 was examined, peeling occurs when the bonding width w of the adhesive 32 exceeds the frame width α. We found that the frequency is high. As described above, when the frequency of occurrence of peeling of the phosphor layer 16 increases, the yield for manufacturing the phosphor panel 10 deteriorates, and the productivity decreases. Therefore, the bonding width w of the adhesive 32 is set to w ≦ α. Thereby, in this invention, the phosphor panel 10 can be manufactured with high yield and high production efficiency.

Further, as shown in FIG. 4B, when the end portion 33 of the mask material 30 is fixed to the edge 12c of the substrate 12 using the adhesive 34, the adhesive on the upper surface 14a of the frame 14 was examined. If the adhesive width w of 32 satisfies w ≦ α, the amount of siloxane in the region Ca in the vicinity of the inner edge 15 of the frame 14 is reduced, and the phosphor panel 10 can be manufactured with high yield and high productivity. The inventor is aware.
Further, as shown in FIG. 4C, even if the adhesive 32 protrudes toward the inner edge 15 of the frame 14, the adhesive width w of the adhesive 32 on the upper surface 14a of the frame 14 satisfies w ≦ α. If satisfied, the amount of siloxane in the region Ca (see FIG. 4B) in the vicinity of the inner edge 15 of the frame 14 is reduced, and the phosphor panel 10 can be manufactured with high yield and high productivity. Knows.

  When the mask material is not fixed, the phosphor constituting the phosphor layer 16 is deposited on the upper surface 14a of the frame 14. In this case, in order to manufacture the conversion panel 10, it is necessary to remove deposits on the upper surface 14 a of the frame 14. Thereby, the production efficiency of the conversion panel 10 falls. For this reason, in the present invention, the bonding width w of the adhesive 32 is set to 0 <w. From the above, in the present invention, the bonding width w of the adhesive 32 is set to 0 <w ≦ α.

In the present embodiment, the frame 14 has four sides. In this case, it is preferable that the bonding width w of the adhesive 32 satisfies 0 <w ≦ α in all four sides of the four sides of the frame 14, that is, in all of the frames 14. However, the effect of the present invention can be obtained if the adhesive width w of the adhesive 32 satisfies 0 <w ≦ α for at least one of the four sides of the frame 14.
In the present embodiment, the bonding width w of the adhesive 32 is the same as the width α of the frame 14.

Next, as shown in FIG. 5, with the mask material 30 attached, the formation region A on the surface 12a of the substrate 12 partitioned by the frame 14 has the above-described composition by, for example, vacuum deposition. The phosphor layer 16 (see FIG. 1) is formed. Then, after forming the phosphor layer 16, the mask material 30 is peeled off. In the present embodiment, the upper surface 14 a of the frame 14 is free from deposits such as phosphors that become the phosphor layer 16.
Next, heat treatment (annealing) is performed in order to cause the phosphor layer 16 to exhibit photostimulable light emission characteristics and improve the photostimulated light emission characteristics.

Next, an adhesive is applied to the upper surface 14a of the frame 14 and the surface 16a of the phosphor layer 16 using, for example, a dispenser to form the adhesive layer 18 (see FIG. 1).
Next, for example, the above-described four-layer moisture-proof protective film (not shown) wound in a roll shape is pulled out, and moisture-proof protection is applied to the upper surface 14a of the frame 14 and the surface 16a of the phosphor layer 16 by a thermal lamination method. A film is affixed to form the moisture-proof protective layer 20 (see FIG. 1) having the four-layer structure. Thus, the conversion panel 10 as shown in FIG. 1 is manufactured.
In addition, the moisture-proof protective layer 20 can also be formed using the protective film with which the adhesive agent was apply | coated previously.

In the manufacturing method of the conversion panel 10 of this embodiment, when forming the phosphor layer 16, the mask material 30 is detachably attached to the upper surface 14 a of the frame 14 using an adhesive 32. The width w is set to 0 <w ≦ α. Thereby, when the phosphor layer 16 is formed by, for example, a vacuum deposition method, the substrate 12 is heated to release the components of the adhesive 32, and the inner edge of the frame 14 in the formation region A of the phosphor layer 16. Even if it adheres to the area Ca in the vicinity of 15, the amount is small. For this reason, the phosphor layer 16 can be formed without reducing the adhesion to the substrate 12, and the peeling of the phosphor layer 16 can be suppressed. For this reason, the phosphor layer 16 can be manufactured with a high yield, and the conversion panel 10 can be manufactured with high productivity.
Furthermore, since peeling of the phosphor layer 16 can be suppressed, an image defect due to this peeling can be suppressed, and the conversion panel 10 with good image quality can be obtained. In the present embodiment, the frame 14 Since the mask material 30 is affixed to the upper surface 14a, the phosphor constituting the phosphor layer 16 is suppressed from being deposited on the upper surface 14a of the frame 14. Thereby, when manufacturing the conversion panel 10, since it is not necessary to remove the deposit on the upper surface 14a of the frame 14, the conversion panel 10 can be manufactured with high production efficiency.

In the present invention, when the total area of the adhesive 32 for fixing the mask material 30 and S, the area of the formation region A of the phosphor layer 16 and the S _A, and the total area S of the adhesive 32, When the ratio (S / S _A ) with the area S _A of the formation region A of the phosphor layer 16 is R, this ratio R is preferably 0 <R ≦ 0.13. The ratio R is more preferably 0 <R ≦ 0.047, and further preferably 0.05 <R ≦ 0.025.
In this invention, the effect of this invention can be acquired by making this ratio R into the said range.

  Further, the method for manufacturing the conversion panel 10 is not limited to the method in which the phosphor layer 16 is directly formed in the formation region A (see FIG. 2) of the surface 12a of the substrate 12, but before the phosphor layer 16 is formed. In addition, a reflective film, a barrier film made of polyparaxylene, or the like may be formed in the formation region A (see FIG. 2) of the surface 12a of the substrate 12. Moreover, you may use as a board | substrate what formed these reflective films or barrier films on the surface.

  Further, the moisture-proof protective layer 20 is used so that the adhesive strength when the moisture-proof protective layer 20 and the substrate 12 are bonded by the adhesive layer 18 can be improved and good adhesive strength can be obtained by only one thermal lamination. Prior to sealing the phosphor layer 16, the phosphor layer 16 is preferably heated to a temperature ranging from 30 ° C. to 150 ° C. lower than the softening temperature of the adhesive constituting the adhesive layer 18. For example, the substrate 12 can be heated to a temperature in this range.

  As mentioned above, although the manufacturing method of the radiation image conversion panel of this invention was demonstrated, this invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the summary of this invention, various improvement or change is carried out. Of course, you may go.

  Hereinafter, the present invention will be described in more detail with reference to specific examples of the method for producing a radiation image conversion panel of the present invention.

In this example, an aluminum alloy substrate (JIS A5083) in which a parylene thin film / SiO ₂ thin film was vapor deposited on the substrate was used. As for the size of the substrate, the length in the X direction is 474 mm, the length in the Y direction is 460.5 mm, and the thickness is 10 mm.

In this embodiment, the frame 14 is arranged as shown in FIG. In this case, the width α of the frame 14 was 5.1 mm, the distance β was 20 mm, and the distance γ was 8.25 mm.
In the formation region A, the distance a in the X direction was 434 mm, and the distance b in the Y direction was 444 mm.

As shown in Table 1 below, the adhesive width w of the adhesive is changed variously, the mask material 30 is attached to the upper surface 14a of the frame 14, and the radiation image conversion panel is changed as follows for each radiation image conversion panel. 20 sheets were produced. In addition, the manufacturing method of the radiation image conversion panel of a present Example is fundamentally the same as the manufacturing method of this embodiment.
In addition, the following Table 1, Examples 1 to 4, depending on the bonding width of the radiation image storage panel of Comparative Example 1-3, the area S _A of the total area S and formed regions of the adhesive in the radiation image conversion panel The ratio R is shown in the column “bonded area / formation region”.

In this example, each of the manufactured radiation image conversion panels of Examples 1 to 4 and each of the radiation image conversion panels of Comparative Examples 1 to 3 were evaluated using peeling, frame deposits, and synthesis as evaluation items.
In addition, as the mask material 30, a heat-resistant aluminum tape (Sliontec Co., Ltd .: Slion Tape No. 8063) was used. This heat-resistant aluminum tape has a silicone adhesive. In this example, the width of the mask material 30 (heat-resistant aluminum tape) is the same in Examples 1 to 4 and Comparative Examples 1 to 3, and the adhesive width of the mask material 30 (heat-resistant aluminum tape) is used. It changed according to Examples 1-4 and Comparative Examples 1-3.

Hereinafter, a method for manufacturing each radiation image conversion panel will be described.
First, a groove 12b having a width of 5.1 mm and a depth of 1.3 mm was formed in a square shape (444.2 mm × 454.2 mm) in plan view on the surface 12a (see FIG. 2) of the substrate 12 described above.
Next, an aluminum alloy (JIS A5052) member having a thickness of 2 mm, a width α of 5.1 mm, and an outer dimension of 444.2 mm × 454.2 mm is used, and a heat-resistant epoxy adhesive (manufactured by Alemco Products Co., Ltd .: Alemcobond) 526N (trade name)). In this way, the frame 14 (see FIG. 3) was arranged.

Next, a heat-resistant aluminum tape was attached as the mask material 30 according to the adhesive width of the adhesives of Examples 1 to 4 and Comparative Examples 1 to 3 shown in Table 1 below.
Next, europium bromide is used as the activator component material (activator component film forming material) in the formation region A of the surface 12a of the substrate 12, and the phosphor component material (phosphor component film forming material). The phosphor layer 16 made of CsBr: Eu was formed on the surface of the substrate by binary vacuum deposition using cesium bromide as
In addition, both film-forming materials were heated with a resistance heating apparatus using a tantalum crucible and a 6 kW DC power source.

While setting the board | substrate 12 to the substrate holder of a vacuum evaporation system and setting each film-forming material in the predetermined position of a vacuum evaporation system, the vacuum chamber was obstruct | occluded and evacuation was started. For the exhaust, a diffusion pump and a cryocoil were used.
When the degree of vacuum reached 8 × 10 ⁻⁴ Pa, argon gas was introduced into the vacuum chamber to set the degree of vacuum to 0.8 Pa. Next, the DC power source was driven to energize the crucible, and the formation of the phosphor layer 16 on the surface 12a of the substrate 12 was started. Note that the outputs of the DC power sources of both crucibles were adjusted so that the Eu / Cs molar concentration ratio in the phosphor layer 16 was 0.001: 1 and the film formation rate was 8 μm / min. Note that the film forming conditions are examined in advance and the outputs of the DC power sources of both crucibles are examined. Moreover, it heated so that the temperature of the surface 12a of the board | substrate 12 before the vapor deposition start of the fluorescent substance layer 16 might be set to 160 degreeC with a heating means.

When it is assumed that the thickness of the phosphor layer 16 becomes about 700 μm based on the film formation conditions set in advance, the DC power supply is stopped to energize both crucibles and to the heater that heats the substrate. The energization was stopped and the formation of the phosphor layer was completed.
When the temperature of the substrate 12 reached 100 ° C., the substrate 12 was removed from the substrate holder and taken out from the vacuum chamber. Thereafter, the substrate 12 was subjected to heat treatment at a temperature of 200 ° C. for 1 hour in a nitrogen atmosphere.

On the other hand, on a PET film having a thickness of 6 μm, a SiO ₂ film is formed to a thickness of 100 nm using a sputtering method, and a ratio of PVA to SiO ₂ is 1: 1 on the SiO ₂ film. A hybrid layer of PVA and SiO ₂ is formed to a thickness of 600 nm using a sol-gel method, and a SiO ₂ film is formed to a thickness of 100 nm using a sputtering method on the hybrid layer to form a moisture-proof protective layer 20 was produced.
A polyester resin (Toyobo: Byron 300 (registered trademark)) was applied to the entire surface of the moisture-proof protective layer 20 (SiO ₂ layer surface) to form an adhesive layer 18 having a thickness of 1.2 μm.

The substrate 12 on which the phosphor layer 16 is formed is preheated to 100 ° C., and the moisture-proof protective layer 20 cut into the outer dimensions of the frame 14 (444.2 mm × 454.2 mm) is formed. The conversion panel 10 shown in FIG. 1 is sealed and adhered to the moisture-proof protective layer 20 and the upper surface 14a of the frame 14 and the surface 16a of the phosphor layer 16 by thermal lamination. Got.
In this example, 20 conversion panels 10 each formed by fixing the mask material 30 with each adhesive width shown in Table 1 below were manufactured and evaluated. That is, 20 conversion panels were produced for Examples 1 to 4 and Comparative Examples 1 to 3, respectively.

Next, each evaluation item of “peeling” and “frame deposit” will be described.
About peeling, the solid image of each produced conversion panel was acquired, and it evaluated using this solid image.
Hereinafter, a peeling evaluation method using a solid image will be described.
First, an entire surface of the conversion panel 10 is irradiated with X-rays having a tube voltage of 80 kV and a dose of 10 mR (2.58 × 10 ⁻⁶ C / kg) using a tungsten tube, and then a line scanner type image reading apparatus. (Semiconductor laser light having a wavelength of 660 nm is irradiated, and the stimulated emission light emitted from the surface of the radiation image conversion panel is received by a CCD in which light receiving elements are arranged in a line) and read light (light reception) The solid image was obtained as a radiation image. This radiation image (solid image) was output as a visible image on a film by a laser printer.

Next, the solid images obtained for the respective conversion panels were visually observed using a shaucus ten. If a solid image has white spots, it is assumed that peeling has occurred.
In the evaluation of “peeling”, among 20 sheets, 10 or more peelings occurred as “x”, and 20 sheets where 1 peeling or less occurred as “◯”. Of the 20 sheets, those where no peeling occurred were marked with “◎”.
A bad evaluation of “peeling” indicates that the yield of the phosphor layer 16 is low and the productivity is low.

Regarding the frame deposit, when the phosphor layer was formed and then the mask material was peeled off during the production of the conversion panel, the presence or absence of deposition on the upper surface of the phosphor frame serving as the phosphor layer was visually confirmed. .
In addition, in the evaluation of “frame deposit”, among the 20 sheets, 10 or more sheets deposited on the upper surface of the frame were evaluated as “x”, and among the 20 sheets, 1 sheet was deposited on the upper surface of the frame. In the following, “◯” was given for what occurred, and “◎” for 20 sheets that did not accumulate on the upper surface of the frame.
A bad evaluation of the “frame deposit” indicates that when the conversion panel 10 is manufactured, the deposit needs to be removed, and the production efficiency is low.

  For overall evaluation, if “exfoliation” and “frame deposit” in the evaluation items have “x” in either of them, “x” is indicated, and “exfoliation” and “frame deposit” in the evaluation items are either If there was “◯”, it was “○”, and if “exfoliation” and “frame deposit” of the evaluation items were both “◎”, it was “◎”.

In this example, for each conversion panel, the amount of siloxane on the upper surface 14a of the frame 14 after the mask material 30 was peeled off after the phosphor layer 16 was formed was measured using TOF-SIMS (time-of-flight type 2 manufactured by ION-TOF). Secondary ion mass spectrometer). In TOF-SIMS, Bi ₃ ⁺ was used as the primary ion, and the primary ion was irradiated under conditions of 0.2 pA and 10 kHz.
The amount of siloxane is represented by the relative intensity of the signal indicating Si ₂ C ₅ H ₁₅ O.
The “siloxane amount” shown in the following Table 1 represents an average value of relative intensities of signals indicating Si ₂ C ₅ H ₁₅ O in Examples 1 to 4 and Comparative Examples 1 to 3.

  In addition, “−” in the “adhesion width” column of Comparative Example 1 shown in Table 1 below indicates that the mask material 30 is not fixed with an adhesive. Further, “−” in the column “bonded area / formation region” in Comparative Example 1 indicates that the ratio R cannot be obtained in Comparative Example 1 because no adhesive is used. “-” In the “siloxane amount” column of Comparative Example 1 indicates that no siloxane was detected because no adhesive was used.

  As shown in Table 1 above, in all of Examples 1 to 4, the evaluation of peeling and frame deposits was good. Further, in Example 2 (adhesion width is 1/2 of the width of the frame) and Example 3 (adhesion width is 1/3 of the width of the frame) which falls within the preferable range of the present invention, peeling and evaluation of the frame deposits are performed. Both were particularly good.

On the other hand, the conversion panel of Comparative Example 1 is one in which a mask material is disposed without bonding, and the bonding width is less than the lower limit of the present invention. In Comparative Example 1, although there was no peeling in the phosphor layer, there was a frame deposit, the production efficiency was low, and the overall evaluation was inferior.
In Comparative Example 2, the adhesion width exceeds the upper limit of the present invention and there is no frame deposit, but the evaluation of peeling is poor, the yield of the phosphor layer is low, and the productivity is low. inferior.
In Comparative Example 3, although the adhesion width exceeds the upper limit of the present invention and there is no frame deposit, the evaluation of peeling is poor, the yield of the phosphor layer is low, the productivity is low, and the overall evaluation is inferior.
From the above results, the effects of the present invention are clear.

It is typical sectional drawing which shows the radiographic image conversion panel obtained by the manufacturing method of the radiographic image conversion panel which concerns on embodiment of this invention. It is a typical top view which shows the arrangement | positioning state of the frame in the manufacturing method of the radiographic image conversion panel which concerns on embodiment of this invention. It is typical sectional drawing which shows the arrangement | positioning state of the mask in the manufacturing method of the radiation image conversion panel which concerns on embodiment of this invention. (A) is a fragmentary sectional view showing an enlarged main part of FIG. 3, (b) is a part showing a modification of the arrangement state of the mask in the manufacturing method of the radiation image conversion panel of the embodiment of the present invention. It is sectional drawing, (c) is a fragmentary sectional view which shows the other modification of the arrangement | positioning state of the mask in the manufacturing method of the radiation image conversion panel of embodiment of this invention. It is typical sectional drawing which shows the formation state of the fluorescent substance layer in the manufacturing method of the radiation image conversion panel of this embodiment.

Explanation of symbols

10 Radiation image conversion panel (conversion panel)
12 Substrate 14 Frame 16 Phosphor layer 18 Adhesive layer 20 Moisture-proof protective layer 30 Mask 32 Adhesive

Claims (3)

A method for producing a radiation image conversion panel, wherein a frame having a predetermined width is provided on a surface of a substrate, and a phosphor layer is formed in a region surrounded by the frame,
Providing the frame on the surface of the substrate;
At least on the upper surface of the frame, a step of attaching the mask material in an detachable manner using an adhesive; and
Forming the phosphor layer by a vapor deposition method in a region surrounded by the frame,
When the adhesive width of the adhesive is w and the width of the frame is α,
The method for producing a radiation image conversion panel, wherein an adhesive width w of the adhesive is 0 <w ≦ α.   The method for manufacturing a radiation image conversion panel according to claim 1, wherein the adhesive width w of the adhesive is 0.1α <w ≦ 0.5α.   The method for manufacturing a radiation image conversion panel according to claim 1, wherein the adhesive contains siloxane.

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