JP2003057351A - Manufacturing method of radiation detection assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a highly-sensitive, highly-sharp and inexpensive radiation detection assembly. SOLUTION: In Figure 1 (a), a photodetector formed on a substrate 1 for the photodetector is shown. In Figure (b), a phosphor layer 5 comprising small- size phosphor particles is formed by screen printing in one-time or plural-times on photoelectric conversion element apertures 3 of the photodetector. In Figure (c), a phosphor layer 6 comprising large-size phosphor particles is formed by screen printing in one-time or plural-times on the photoelectric conversion elements 2 of the photodetector. In Figure (d), a phosphor layer 5 comprising the small-size phosphor particles is formed by screen printing again in piles on the small-size phosphor layer of the phosphor layer formed beforehand. In Figure (e), a phosphor layer 6 comprising the large-size phosphor particles is formed by screen printing again in piles on the large-size phosphor layer of the phosphor layer formed beforehand. Small-size phosphor layer printing and large-size phosphor layer printing are performed alternately in plural times, to thereby form the phosphor layer having the prescribed thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a radiation detecting device, and more particularly to a method for manufacturing a radiation detecting device used for X-ray imaging and the like. In this specification,
It is assumed that electromagnetic waves such as X-rays and γ-rays and α-rays and β-rays are included in the radiation.

[0002]

2. Description of the Related Art Conventionally, an X-ray film system having a fluorescent screen having an X-ray phosphor inside and a double-sided coating sensitizer has been generally used for X-ray photography. But,
Recently, a digital radiation detecting apparatus having an X-ray phosphor layer, a plurality of two-dimensionally arranged photoelectric conversion elements, and a two-dimensional photodetector formed in the gap between the photoelectric conversion elements and electric elements such as TFTs for data transfer. Since the image characteristics are good and the data is digital data, there is an advantage that the data can be shared by importing it into a networked computer system. The patent application is also filed.

Among these digital radiation detectors,
A device having high sensitivity and high sharpness is disclosed in Japanese Patent Application Laid-Open No. 9-61.
In Japanese Patent No. 536, a phosphor is formed by forming a phosphor layer on the entire surface of a photodetector of a radiation detector and then removing the phosphor layer between the photoelectric conversion elements of the photodetector in a groove shape by laser light. A method of separating a layer in a columnar shape only on each photoelectric conversion element is disclosed. It is known that the radiation detection device manufactured in this way has high sharpness characteristics.

The radiation incident on the phosphor layer is converted into visible light by the separated phosphor layer, and the visible light generated for each phosphor layer is incident on each photoelectric conversion element of the detector and converted into an electric signal. By being converted, this radiation detection device has high sharpness characteristics.

Further, for the purpose of improving the sensitivity of this radiation detecting apparatus, a structure in which a light reflecting film made of a metal thin film is provided on the surface of a phosphor layer separated in columns is disclosed in Japanese Patent Laid-Open No. 9-6153.
No. 6 publication. Further, as a method of providing a light reflection film on the wall surface of the column structure, a method of providing it by a vapor deposition method is disclosed.

However, since the above-mentioned conventional technique does not emit light between the phosphor layers separated in columns, the sharpness is better than that of a phosphor layer having the same phosphor material and the same thickness and having no void. However, there was a problem of low sensitivity.

Further, it is possible to increase the thickness of the separated phosphor layer in order to increase the sensitivity, but it is difficult to form the groove by making the laser light reach very deep in the phosphor layer. The groove depth cannot be increased beyond a certain height, and the sensitivity cannot be increased beyond a certain level.

Further, since the X-ray absorption is extremely small between the separated phosphor layers produced by the above laser, nearly 100% of the radiation is transmitted, and the sensor circuits and semiconductor elements located thereunder are adversely affected by noise and the like. There was a problem of affecting.

Therefore, the particle size of the phosphor particles of the phosphor layer formed on the gap of the photoelectric conversion element is smaller than the particle size of the phosphor particles of the phosphor layer formed on the photoelectric conversion element. A characteristic radiation detection device has been proposed.

According to this apparatus, the particle size of the phosphor particles formed in the gaps between the photoelectric conversion elements is made smaller than the particle size of the phosphor particles formed on the photoelectric conversion elements. The scattering coefficient of the phosphor layer between the above elements can be made larger than the scattering coefficient of light by the phosphor particles in the phosphor layer on the photoelectric conversion element, and the gap between the phosphor layer on the photoelectric conversion element and the photoelectric conversion element gap can be increased. It is possible to cause light reflection at the interface of the phosphor layer, and the light emitted from the phosphor layer on the photoelectric conversion element is efficiently incident on each photoelectric conversion element to improve the sharpness. Since the phosphor is arranged in the gap between the separated phosphor layers of the conventional example, the sensitivity can be improved as compared with the conventional case. Further, in the above-mentioned conventional technique, since the photoelectric conversion element gap is filled with the fluorescent substance, radiation is absorbed by the fluorescent substance, and the circuit or the TFT of the optical converter arranged in the photoelectric conversion element gap located thereunder. It does not adversely affect the semiconductor device such as.

Further, in the above-mentioned prior art, since the sharpness is good, a large-diameter phosphor particle having a drawback that the sharpness is deteriorated when the amount of emitted light is large is used as the phosphor layer on each photoelectric conversion element. Since it can be used, a highly sensitive radiation detection device can be obtained.

As a method of manufacturing this radiation detecting device, phosphors provided in a one-to-one correspondence on each photoelectric conversion element are formed, and thereafter, a particle size smaller than the particle size of each phosphor is provided between the phosphors. There has been proposed a method of manufacturing by forming a phosphor layer in which the phosphor made of is filled and integrated.

Further, a phosphor layer is formed in a one-to-one correspondence with each photoelectric conversion element, and a phosphor having a particle size smaller than that of each phosphor layer is filled between the formed phosphors so as to be integrated. There is proposed a method in which a converted phosphor layer is formed, and each photoelectric conversion element and each phosphor layer corresponding to each photoelectric conversion element are aligned and connected by an adhesive layer.

[0014]

However, according to the above-mentioned manufacturing method, the phosphor layers provided in a one-to-one correspondence on each photoelectric conversion element are formed, and then the space between the phosphors is very narrow. Since it is required to fill the phosphor with no bubbles, it is necessary to perform this manufacturing process in a vacuum or to specially embed the phosphor while applying ultrasonic vibration.

Furthermore, in order to cause diffuse reflection at the interface between each photoelectric conversion element and the phosphor formed on the gap, the phosphor particles of the phosphor layer of each photoelectric conversion element have a large particle size on the gap. It is necessary to produce the phosphor particles of the phosphor layer formed in step 1 with a small particle size. However, when the screen printing method, which is the cheapest and easiest patterning method for producing the above, is used, the thixotropic property of the printing paste containing the phosphor is inversely proportional to the particle size of the phosphor, and thus the large particle size of high light emission is obtained. When a phosphor layer is formed in a columnar shape in a one-to-one correspondence with each photoelectric conversion element by multi-layer printing using a printing paste containing phosphor particles, the thixotropic property is insufficient. The phosphor layer to be formed spreads due to its own weight (hereinafter, referred to as a print sag), and in an extreme case, it may come into contact with the phosphor layer on the adjacent photoelectric conversion element, which reduces the sharpness of the radiation detection apparatus. Therefore, it has been impossible to use phosphor particles having a sufficiently large particle size.

Further, a phosphor layer is formed in advance on the gaps between the photoelectric conversion elements by using a printing paste containing a phosphor having a small particle diameter, and then a printing paste containing a phosphor having a large particle diameter is applied on each photoelectric conversion element. Although a method of forming the same is conceivable, the gap between the photoelectric conversion elements is several tens of μm, while the thickness of the phosphor is several hundreds of μm, and therefore the width of several tens of microns is several hundred μm.
It was impossible in the screen printing process because it was necessary to carry out m-height laminated printing.

Therefore, according to the present invention, in the method of forming the phosphor layer having the above-mentioned structure, when the phosphor layer is formed by using the screen printing method which is inexpensive and easy to manufacture, the bubble is generated without any special device. It is an object of the present invention to provide a method for forming a phosphor layer in which a large amount of phosphor particles having high emission and having a very small printing sag and high emission can be used.

[0018]

In order to solve the above-mentioned problems, the present invention compares the particle diameters of a plurality of photoelectric conversion elements and the phosphor particles of a phosphor layer formed on each of the photoelectric conversion elements. In a method of manufacturing a radiation detecting device including a phosphor layer having a small particle size of phosphor particles of a phosphor layer formed on a gap between photoelectric conversion elements, a mesh screen is used once or a plurality of times on a photodetector. First step of performing screen printing and drying once to form corresponding phosphor layers on the photoelectric conversion element gaps one-to-one, and performing screen printing and drying one or more times using a metal screen to perform photoelectric conversion The method is characterized by including a step of repeatedly performing a plurality of times the second step of forming one-to-one corresponding phosphor layers on the element.

Furthermore, the average particle diameter of the phosphor particles in the phosphor layer formed on the photoelectric conversion element is 5 μm or more and 50 μm or more.
It is desirable that the average particle diameter of the phosphor particles in the phosphor layer formed on the gap between the photoelectric conversion elements is 1 μm or more and less than 5 μm.

According to the above method, at the beginning of the phosphor layer forming step, screen printing and drying are performed once or plural times using a mesh screen having high printing accuracy, and grids of low height are formed on the gaps between the photoelectric conversion elements. Forming a phosphor layer made of a small particle size phosphor. Next, screen printing and drying are performed once or multiple times using a metal screen in the openings of the lattice-shaped phosphor layer having a low height to form the phosphor layer on the photoelectric conversion element in a one-to-one correspondence. Even when the phosphor layer formed in a grid shape having a low height prints a phosphor paste having a large particle size, the function of preventing print sagging is fulfilled and print sagging does not occur.

Further, since the height of the lattice is low, even if few bubbles are generated, the structure is easily removed immediately.
By repeating this a plurality of times as one cycle, the phosphor layer can be formed to a desired height without limitation in manufacturing.

Further, when printing a phosphor printing paste having a large particle size, if a mesh screen having a good printing position accuracy, that is, a fine mesh, is used, the mesh is clogged and the print pattern becomes faint to form a predetermined pattern. Can not. However, according to the present invention, when printing a large-diameter phosphor printing paste, the printing position accuracy is inferior due to the presence of the small-diameter phosphor layer walls, but is printed with a metal screen consisting of a punched pattern without mesh. Therefore, it is possible to print a phosphor having a sufficiently large particle diameter in a desired printing pattern without causing clogging.

A positive correlation is recognized in the relationship between the phosphor particle size and the amount of emitted light. In particular, when the particle size is reduced to 1 μm or less, the amount of emitted light sharply decreases, so that it cannot be used as a phosphor layer. However, in the range of more than that, the luminescence amount increases with the particle size, and when the particle size is 5 μm or more, the luminescence amount tends to slightly increase, reaches saturation at a particle size of about 50 μm, and thereafter the luminescence amount is almost increased. Absent. Further, if the particles become too large, the variation in the amount of light emission between photoelectric conversion elements becomes large, so it is not preferable to use a phosphor having a very large particle size. Therefore, in order to obtain high light emission, the average particle size of the phosphor particles in the phosphor layer having a large particle size is preferably in the range of 5 μm or more and 50 μm.

In order to obtain diffuse reflection, it is necessary that the average particle size of the phosphor particles of the small particle size phosphor layer is smaller than the average particle size of the large particle size phosphor layer, and the range where light emission is also obtained. Therefore, it is necessary to have a particle size of 1 μm or more. Furthermore, when the average particle size of the small particle size phosphor layer is 1 to 5 μm, light emission is obtained in the fluorescent material layer, and the diffuse reflectance at the interface between the large particle size and small particle size phosphor layer is increased. It is more preferable because it becomes large.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic view of a method of manufacturing a radiation detecting apparatus according to Embodiment 1 of the present invention, in which (a)
The radiation detecting apparatus of the present invention can be formed through the step (e) in this order.

In FIG. 1A, 1 is a substrate for a photodetector having an insulating property such as a glass substrate, 2 is a photoelectric conversion element using a semiconductor thin film made of amorphous silicon or the like, and 3 is this photoelectric conversion element. The photoelectric conversion element gap in which the TFT and the like for controlling the reading of the electric charges of 4 are arranged is a semiconductor protective layer for protecting the semiconductors 2 and 3, and these constitute a photodetector.

FIG. 1 (b) is a diagram in which a phosphor layer 5 made of phosphor particles of small particle size is formed on the photoelectric conversion element gap 3 of the photodetector by screen printing one or more times. FIG. 1 (c) shows the photoelectric conversion element 2 of the photodetector,
It is the figure which formed the fluorescent substance layer 6 which consists of a large diameter fluorescent substance particle by the screen printing of once or multiple times. Figure 1
(D) is a diagram in which the phosphor layer 5 made of small-diameter phosphor particles is formed by screen printing on the small-diameter phosphor layer of the phosphor layer formed in (b) and (c). Is.
FIG. 1 (e) shows a phosphor layer 6 made of large-diameter phosphor particles formed by screen printing on the large-diameter phosphor layer of the phosphor layers formed in (b) and (c). FIG. In this way, by printing the small particle size phosphor layer and the large particle size phosphor layer alternately a plurality of times, a phosphor layer having a predetermined thickness can be formed.

Fluorescence is screen-printed on the gaps between the photoelectric conversion elements of the photodetector shown in FIG. 1 (a) by using a printing paste and a mesh screen made of the small particle size phosphor shown in FIG. 1 (b). Form body layers. The thickness of the small particle size phosphor layer formed by printing is the viscosity of the printing paste,
Depending on the particle size of the phosphor material, it is generally 20-100μ
It is preferable for it to be m because the amount of bubbles is small and the productivity is good. Since the film thickness of the small particle size phosphor layer obtained by printing and drying once is about 10 to 30 μm, in the step of FIG. 1B, a small particle size phosphor layer having a required film thickness is formed. In order to
It is necessary to perform overprinting about 1 to 5 times.
FIG. 1 (c) is a diagram in which a printing paste made of a large particle size phosphor is printed on it using a metal screen between the small particle size phosphor layers. It is necessary that the film thickness formed by printing is approximately the same as that of the small particle size phosphor layer in order to print the small particle size phosphor layer next. Next, in FIG. 1D, a phosphor layer is formed again by screen printing using a printing paste made of small-diameter phosphor particles and a mesh screen. The printing thickness and the number of times are the same as those in the step of FIG. Further, as in FIG. 1C, a printing paste composed of large-diameter phosphor particles is printed between the small-diameter phosphor layers in FIG. 1E using a metal screen. Thus, FIG.
The steps (b) and (c) are repeated a plurality of times to form a desired phosphor layer thickness.

The final required thickness of the phosphor layer varies depending on the required sensitivity and sharpness of the radiation detector and the phosphor material, but it is generally in the range of 100 to 500 μm, and it depends on the thickness. The number of prints is determined by

The screen printing of the present invention can utilize a conventional screen printing technique, and FIGS. 2 and 3 are views for explaining a method of forming a phosphor layer by screen printing.

FIG. 2 is a plan view of a metal screen plate for forming a large particle size phosphor layer used in the present invention. The screen plate has a screen frame 7 that gives tension to the screen on the outside, and a screen 9 made of a metal foil such as nickel on the inside and a mesh 8 made of polyester or stainless steel for evenly applying the tension to the screen. , And an opening 10 corresponding to the photoelectric conversion element 2 of the photodetector is formed as a print on the screen.

Further, instead of the metal foil screen 9, a mesh screen made of polyester or stainless steel,
If a mask portion 10 made of an emulsion is arranged in place of the opening 10, the mesh screen plate for forming the small particle size phosphor layer used in the present invention is constructed. These screen versions are
You can use the screen printing plate you normally use,
The accuracy of the printed pattern is determined by the photoelectric conversion element size and the photoelectric conversion element pitch.
In the case of less than μm, an accuracy of about ± 10 μm is required, and it is necessary to manage with a stricter value than the accuracy of an ordinary screen printing plate. Therefore, as a master for printing a pattern on the screen plate, a film master is not accurate, and therefore it is preferable to use a glass master for baking.

FIG. 3 is a diagram for explaining a screen printing method for forming a phosphor layer on the photoelectric conversion element of the photodetector using the screen plate of FIG. A screen plate composed of a plate frame 7 and a screen 9 was arranged on the photodetector 11 with a constant gap. A phosphor paste 12 consisting of phosphor powder, a resin binder, a solvent, etc. is placed on the screen, and a squeegee 13 is brought into contact with the screen in the direction of the arrow and slid with a constant printing pressure, whereby a fixed amount of paste is released from the opening 10 of the screen. It is possible to form a phosphor paste pattern composed of phosphor particles having the same pattern as the screen pattern on the discharged photoelectric conversion element of the photodetector. A phosphor pattern can be obtained by drying the printed phosphor paste.

Since the phosphor layers 5 and 6 are produced by screen printing, the printing paste can be produced as follows.

CaWO ₄ , Gd ₂ O ₂ S: Tb, BaS
A transparent resin, a solvent and, if necessary, an additive such as a dispersant and an antifoaming agent are added to and mixed with phosphor particles made of a phosphor material such as O ₄ : Pb to prepare a phosphor paste. Here, as the organic material mixed in the printing paste, organic materials used in conventional screen printing can be used, and as the binder resin, nitrocellulose, cellulose acetate, ethyl cellulose, polyvinyl alcohol, polyvinyl butyral, polyester. Resins such as vinyl chloride, vinyl acetate, vinyl acetate, acrylic resin and polyurethane, or monomers of these resins can be used.

Further, examples of the organic solvent include alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone,
Esters such as butyl acetate and ethyl acetate, cyclic hydrocarbons such as toluene and xylene, organic solvents such as butyl carbitol and terpineol, and water can be used.

Furthermore, a plasticizer made of phthalic acid ester such as dibutyl phthalate or dioctyl phthalate may be added. Further, an additive for imparting a phosphor powder dispersibility improving effect, a defoaming effect, and a thixotropic effect may be added.

When the phosphor, binder and solvent are mixed in the following proportions in the printing paste, a printing paste having good screen printing suitability can be obtained. In addition, in the following description, a mass part represents the mass ratio of each component.

100 parts by mass of phosphor Binder 2 to 20 parts by mass Solvent 20-100 parts by mass

The printing paste for forming the large particle size phosphor layer 5 and the small particle size phosphor layer 6 may be the same material or different, but the printing paste for the large particle size phosphor layer is small. It is necessary to select a material having good wettability when printed between the particle size phosphor layers.

A light reflecting layer and a protective layer are formed on the phosphor layer formed as described above. The light reflection layer is a metal thin film,
For example, sputter single metals such as aluminum, gold, titanium, nickel, platinum, palladium or alloys thereof,
It is formed by a film forming method such as vapor deposition. Alternatively, a resin containing reflective fine particles made of titanium oxide, aluminum oxide, silicon oxide or the like may be formed by a method such as laminating or coating. Further, the small particle size phosphor layer material used as the scattering reflection layer used in the present invention may be formed by a method such as coating.

Further, as a protective layer material for the phosphor on the reflective layer, a resin film, for example, a polyester film,
Bonding a vinyl chloride film, a polycarbonate film or the like or an inorganic substrate such as glass or the like is preferable because the properties such as abrasion resistance, mechanical strength, chemical resistance and moisture resistance can be improved.

The protective layer 4 of the photodetector can be made of any material such as polyimide and parylene that has a barrier property against the above printing paste and has a high transmittance of the light emitted from the phosphor. It can be formed by a vacuum film forming method such as CVD. The film thickness may be any thickness that does not interfere with light transmission.
Since it is preferable because the sharpness can be increased, it is set to about 20 μm or less here.

FIG. 4 is a diagram of the radiation detecting apparatus manufactured by the manufacturing method of the present invention described above. A substrate 1, a photoelectric conversion element 2 formed thereon, a photoelectric conversion element gap 3 composed of a TFT or an electric element, and a photodetector composed of these protective layers 4, and a pair of photoelectric conversion elements 2 formed thereon. The large-particle-diameter phosphor layer 6 formed integrally and the small-particle-size phosphor layer 5 formed on the photoelectric conversion element gap 3 are manufactured by the above-described manufacturing method to form a radiation detector. ing. Further, in FIG. 4, the light reflection layer 14 for efficiently transmitting the light converted by the phosphor layers 5 and 6 to the photoelectric conversion element 2 and the protective layer 15 of the phosphor layer and the reflection layer are arranged on the above. ing.

(Embodiment 2) FIG. 5 is a schematic view of a method of manufacturing a radiation detecting apparatus according to Embodiment 2 of the present invention.
The radiation detecting apparatus of the present invention can be formed through the step (e) in this order. The same parts as those in FIG. 1 are designated by the same reference numerals.

In FIG. 5 (a), a small particle phosphor layer 5 having the same size as the photoelectric conversion element gap is screen-printed on the protective layer 15 on which a reflection layer 14 is formed, if necessary. Form. FIG. 5B is a diagram in which the phosphor layer 6 made of large-diameter phosphor particles is formed in the same size as the photoelectric conversion element by screen printing, similarly to the embodiment 1. FIG. 5C shows a small particle size phosphor formed by screen printing on the small particle size phosphor layer 5 and the large particle size phosphor layer 6 of the phosphor layers formed in FIGS. 5A and 5B. It is the figure which formed the fluorescent substance layer 5 which consists of particles. FIG. 5 (d) shows
It is the figure which further overlapped on the large particle size fluorescent substance layer of the fluorescent substance layer formed by (a), (b), and formed the fluorescent substance layer 6 which consists of large particle size fluorescent substance particles by screen printing.

As shown in FIGS. 5 (a) to 5 (d), by printing the small particle size phosphor layer and the large particle size phosphor layer alternately a plurality of times, a phosphor layer having a predetermined thickness can be formed. . After the phosphor layer having a predetermined thickness is obtained, as shown in FIG.
The semiconductor detection device of the present invention can be manufactured by forming the lower surface protection layer 16 and bonding the lower surface protection layer 16 to the photodetector shown in the embodiment 1 through the adhesive layer 17.

The manufacturing method, material and thickness of the phosphor layers 5 and 6 are the same as those of the embodiment 1. Adhesive layer 17 and bottom protective layer 16
Can be used as long as it is a material having good transparency, and may have any thickness as long as the transmittance is increased. However, it is preferable that the thickness is as thin as possible because brightness and sharpness can be increased.
Here, the thickness is approximately 20 μm or less.

[0050]

EXAMPLE 1 A method of manufacturing the radiation detecting apparatus of the present invention shown in FIG. 1 will be described below.

A photoelectric conversion element 2 made of amorphous silicon and a photoelectric conversion element gap 3 made of an electric element such as a TFT are formed on an alkali-free glass substrate which is a photodetector substrate 1 having a thickness of 1.0 mm. A semiconductor protective film 3 made of SiNx was formed on it, and a photodetector was produced.

The printing paste for the small particle size phosphor layer 5 was prepared by using 100 parts by mass of Gd ₂ O ₂ S: Tb having an average particle size of 3 μm, 10 parts by mass of ethyl cellulose and 20 parts by mass of terpineol.
It was prepared by mixing and dispersing 10 parts by mass of xylene with a sand mill.

Next, as a printing screen plate for printing the small particle size phosphor layer shown in FIG. 2, a plate frame having a size of 550 mm square, a pattern area of 230 mm square, a pattern pitch of 160 μm, and a size of the mask pattern 10 having a size of 120 μm square is 325. A stainless mesh plate (trade name SS325-16: manufactured by Sonocom Co., Ltd.) having a mesh and a wire diameter of 16 μm was prepared.

Using the above printing paste and the screen plate, printing is performed by a printing device (MT-550TV: manufactured by Microtec), and the photoelectric conversion element gap 3 of each photodetector is used.
And a small particle size phosphor layer 5 was formed. Screen printing conditions include a squeegee speed of 60 mm / sec,
Printing pressure: 2.0 kg / cm, drying conditions: 80 ° C, 3
It was made in minutes. A film thickness of 13 μm was obtained by one printing, and a small particle size phosphor phosphor layer 5 having a thickness of 40 μm could be obtained by performing overprinting three times.

Next, the printing paste for the large particle size phosphor layer 6 was used as 100 parts by mass of Gd ₂ O ₂ S: Tb having an average particle size of 20 μm, 10 parts by mass of ethyl cellulose and 20 parts of terpineol.
Parts by mass and 10 parts by mass of xylene were mixed and dispersed in a sand mill to prepare.

Next, as a printing screen plate for printing the large particle size phosphor layer shown in FIG. 2, a plate frame of 550 mm square, a pattern area of 230 mm square, a pattern pitch of 160 μm, and a size of the opening pattern 10 of 120 μm square were used. Screen (Product name Metal foil mask: Nickel, film thickness 5
0 μm: manufactured by Sonocom Co., Ltd.) was prepared.

Using the above printing paste and the screen plate, printing was carried out by a printing device (MT-550TV: manufactured by Microtec Co., Ltd.), and a large particle size phosphor layer matched with the photoelectric conversion element 2 of each photodetector. 6 was formed. Screen printing conditions were squeegee speed 60 mm / sec, printing pressure 2.0 kg / cm, and drying conditions were 80 ° C. and 3 minutes. A film thickness of 40 μm was obtained with one printing.

In the same manner, the small particle size phosphor layer and the large particle size phosphor layer are alternately printed seven times to obtain 320 μm.
The phosphor layer of was formed. On this phosphor layer, 3000 Å of nickel was formed by a sputtering method to form a reflective layer 14.

Finally, in order to protect the phosphor layers 5 and 6, a polyethylene terephthalate film (manufactured by Toray Industries, Inc .: trade name Lumirror E22) containing reflective fine particles of titanium oxide with a thickness of 100 μm on the reflective layer 14 is provided. To
By laminating as the protective layer 15, the radiation detecting device shown in FIG. 4 was manufactured.

As a result of observing the cross section with a laser microscope, it was found that the phosphor layer composed of the large particle size phosphor layer 6 and the small particle size phosphor layer 5 had no bubbles and the large particle size phosphor layer could be formed in a rectangular shape. Therefore, it was confirmed that the large particle size phosphor layer was formed without sagging by printing.

Example 2 Similar to FIG. 1A, a photoelectric conversion element 2 having amorphous silicon and an electric element such as a TFT are formed on a non-alkali glass substrate which is a photodetector substrate 1. A photodetector was produced by forming the conversion gap 3 and forming the semiconductor protective film 4 made of SiNx on the conversion gap 3. On the upper surface phosphor protective layer 15 made of an amorphous carbon substrate having a thickness of 2 mm, 0.3 is formed by a sputtering method.
A gold thin film having a thickness of μm was formed and used as the light reflection layer 14.

Next, as shown in FIGS. 5A to 5D, a large particle size phosphor layer and a small particle size phosphor layer are alternately screen-printed by the same material and method as in Example 1, and 320 μm.
The phosphor layer of was formed.

As a result of observing the cross section with a laser microscope, no bubbles were observed between the large particle size phosphor layer 6 and the small particle size phosphor layer 5, and the large particle size phosphor layer could be formed in a rectangular shape. Therefore, it was confirmed that the large particle size phosphor layer was formed without sagging by printing.

Next, in order to protect the phosphor layer 6, a lower surface protective layer 16 made of a polyethylene terephthalate film having a thickness of 6 μm was laminated on the phosphor layer 6.

Finally, as shown in FIG. 5 (e), the phosphor layer and the photodetector have the acrylic adhesive (Kyoritsu Chemical Co., Ltd.) as the adhesive layer 17 so as to have the structure shown in FIG. :Product name
World lock NO. XSG-5) was connected to manufacture a radiation detection device.

[0066]

As described above, by using the manufacturing method according to the present invention, since bubbles are not generated inside the phosphor layer, it is possible to manufacture at low cost without any special process or device, and the fluorescent material without printing sag. Since the body layer can be formed, a radiation detector having high sharpness can be manufactured.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a method for manufacturing a radiation detection apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a screen printing screen plate used in the present invention.

FIG. 3 is a diagram illustrating screen printing used in the present invention.

FIG. 4 is a sectional view of the radiation detection apparatus according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a method for manufacturing the radiation detection apparatus according to the second embodiment of the present invention.

FIG. 6 is a sectional view of a radiation detection apparatus according to a second exemplary embodiment of the present invention.

[Explanation of symbols]

1 Photodetector substrate 2 Photoelectric conversion element 3 Photoelectric conversion element gap 4 Semiconductor protection layer 5 Small particle size phosphor layer 6 Large particle size phosphor layer Frame of 7 screen version 8 mesh 9 screen 10 openings or masks 11 Photodetector 12 Printing paste 13 Squeegee 14 Reflective layer 15 Protective layer 16 Bottom surface protective layer 17 Adhesive

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C09K 11/00 H01L 27 / 14K DF term (reference) 2G088 EE01 FF02 GG16 GG19 GG20 JJ05 JJ37 LL12 LL13 LL15 4H001 CA02 CA08 XA08 XA16 XA64 YA65 4M118 AA10 AB01 BA05 CA32 CA34 CB05 CB11 FB13 GA10 GD14 5F088 AB05 BA10 BA20 BB07 EA08 GA02 HA11 HA15 LA08

Claims (3)

[Claims] 1. A phosphor of a phosphor layer formed on a gap between photoelectric conversion elements as compared with a particle size of phosphor particles of a plurality of photoelectric conversion elements and a phosphor layer formed on each of the photoelectric conversion elements. A method of manufacturing a radiation detection device having a small particle size, comprising a step of performing the following first step and then the second step on a photodetector a plurality of times. A method of manufacturing a radiation detection apparatus including: a) a first step of performing screen printing and drying once or a plurality of times using a mesh screen to form phosphor layers corresponding one-to-one on the gaps between photoelectric conversion elements B) A second step of performing screen printing and drying one or more times using a metal screen to form a phosphor layer corresponding to the photoelectric conversion element on a one-to-one basis. 2. A phosphor of a phosphor layer formed on a gap between photoelectric conversion elements as compared with a particle diameter of phosphor particles of a plurality of photoelectric conversion elements and a phosphor layer formed on each of the photoelectric conversion elements. A method for manufacturing a radiation detecting device having a small particle size, wherein a phosphor layer is produced by repeating the following first step and then the second step a plurality of times to produce a photodetector. A method for manufacturing a radiation detecting apparatus, which comprises the step of connecting the respective photoelectric conversion elements and the respective phosphor layers in a one-to-one correspondence with the respective photoelectric conversion elements by an adhesive layer in a aligned state: a) A mesh screen Screen printing and drying using one or more times to form a phosphor layer corresponding one-to-one in the gaps between photoelectric conversion elements, b) One or more screens using a metal screen Print and dry, A second step of forming a phosphor layer corresponding to the photoelectric conversion elements in a one-to-one correspondence. 3. The average particle diameter of the phosphor particles in the phosphor layer formed corresponding to the photoelectric conversion element is 5 μm or more and 50 μm.
The method for manufacturing a radiation detecting apparatus according to claim 1 or 2, wherein the average particle diameter of the phosphor particles of the phosphor layer formed corresponding to the photoelectric conversion element gap is 1 μm or more and less than 5 μm.