JPH0943356A - Radiation conversion element, manufacturing method thereof, and radiation imaging apparatus - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an excellent radiation conversion element capable of manufacturing a high-resolution and high-sensitivity radiation imaging apparatus at high speed and easily, a manufacturing method thereof, and a radiation imaging apparatus. A scintillator 1, which is an X-ray and radiation photo-conversion device, is divided into a grid shape to a size including at least one pixel 3 of a photo-detection panel 2 that converts light into an image signal, and the division surface and the photo-detection. The panels are made to face each other and bonded so that at least one pixel of the photodetection panel is included in the divided region of the element, and the grid-like processing forms a patterned protective layer on the element and irradiates with particles or particle beams. , Remove the exposed element portion between the protective layers, relatively move and irradiate the focused particle beam on the element, or pass the particle beam through a linear mask pattern to form an image of the mask pattern on the element By that,
A lattice-shaped separation layer is provided to prevent crosstalk and enable high-speed processing over a wide area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation conversion element for converting X-rays or radiation into light, a method for manufacturing the same, and a radiation image pickup apparatus using the radiation conversion element.

[0002]

2. Description of the Related Art A radiation image pickup apparatus is constructed by combining an element for converting X-rays or radiation into light (hereinafter referred to as a scintillator) and a light detection panel. As such a conventional technique, there is one in which a scintillator is attached to the entire surface of the light detection panel. Materials for the scintillator include CsI and yttrium terbium oxysulfide. However, if only the scintillator is attached to the entire surface, there are drawbacks that the resolution decreases due to the crosstalk of the scintillator and the photodetection panel is easily damaged.

On the other hand, there is also known a radiation imaging apparatus in which a scintillator is attached to the upper part of an optical fiber plate and the light passing through the optical fiber plate is received by a photodetection panel. However, the optical fiber plate is expensive and the device is large. Further, if the scintillator is made thick to increase the detection efficiency, the resolution is likely to be lowered.

In order to overcome these drawbacks, a method of forming a large number of irregularities on the surface of an optical fiber plate by etching and growing a scintillator on the protruding core is known.
For example, JP-A-61-185844 and JP-A-6-185844
No. 1-225684.

However, in these methods, it is difficult to accurately align the pixel and the core to optically couple them.
A method of forming a convex pattern on the pixels of the light detection panel and growing columnar crystals of a scintillator on the upper surface of the convex pattern is disclosed in, for example, Japanese Patent Laid-Open No. 9378/1993.
No. 0 publication. In FIG. 9, 40
Is a pixel, 41 is a convex pattern, 42 is a mask, 43 is a reflective film, 44 is a scintillator columnar crystal, 45 is a coating film, and 46 is a two-dimensional photosensor. First, a two-dimensional photodetection panel in which the pixels 40 are arranged is formed on a glass substrate by a thin film process. A convex pattern 41 is formed on the pixels 40 of the light detection panel, a mask 42 is provided only on the upper surface of the convex pattern 41, and a light reflection film 43 is formed on the side surface of the convex pattern 41. Next, the mask 42 is removed,
The columnar crystals 44 of the scintillator are grown on the upper surface of the convex pattern 41 by vapor deposition.

[0006]

However, in the above-mentioned conventional structure, since the scintillator is crystal-grown by vapor deposition, the process time is long, vapor is vapor-deposited on unnecessary portions of the photodetection panel, and the crystals are not properly separated from each other. It has a problem that it is difficult to grow at a certain distance.

The present invention solves the above-mentioned conventional problems, and provides a radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus capable of manufacturing a radiation imaging apparatus of high resolution and high sensitivity at high speed and easily. The purpose is to

[0008]

To achieve this object, a first radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus according to the present invention include an element for converting X-rays or radiation into light, and the element. A photodetection panel for converting the converted light into a video signal is provided, the element is divided into a lattice shape into a size including at least one pixel of the photodetection panel, and the division surface of the element and the photodetection panel. And are assembled so that at least one pixel of the photodetection panel is included in the divided region of the element.

In the above structure, it is preferable that the element is not divided into individual pieces. Further, it is preferable to bond the element and the light detection panel.

The adhesive is preferably transparent to the light converted by the device.

A second radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus of the present invention form a layer for converting X-rays or radiation into light on a substrate that transmits X-rays or radiation, and perform the above-mentioned light conversion. The layer is processed into a lattice shape.

In the above structure, it is preferable that the light conversion layer is formed on the substrate by a thick film printing method.

A third radiation conversion element, a method for manufacturing the same, and a radiation imaging apparatus of the present invention form a patterned protective layer on an element for converting X-rays or radiation into light,
The element is irradiated with particles or particle beams to remove the element portion exposed from the protective layer.

In the above structure, it is preferable that the material of the protective layer is durable and impermeable to irradiated particles or particle beams.

Further, it is preferable to use a photoresist as a material of the protective layer and perform patterning by a photolithography method.

Further, it is preferable that the protective layer transmits the light converted by the light conversion layer.

Further, it is preferable to remove the protective layer after removing the element portion. Further, it is preferable to remove the protective layer using a release agent.

Further, it is preferable to decompose and remove the protective layer by firing. A fourth radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus of the present invention irradiate a focused particle beam on an element that converts X-rays or radiation into light, and process the element into a lattice shape. .

In the above arrangement, the particle beam is preferably laser light. The laser light is preferably pulsed light.

A fifth radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus according to the present invention are provided with a three-layer structure in which a powder material for converting X-rays or radiation into light is sandwiched between substrates on one side. The laser light is radiated from the surface to process the element into a lattice shape.

In the above structure, at least the substrate to be irradiated with laser light in the element having the three-layer structure is preferably an organic film.

The wavelength of the laser light is preferably 0.3-5 μm. Further, in the element having the three-layer structure, it is preferable that the substrate on the back side of the laser light irradiation surface transmits the laser light.

A sixth radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus according to the present invention allow a particle beam to pass through a linear mask pattern to form the mask pattern on an element for converting X-rays or radiation into light. The element is processed into a lattice shape by forming an image and then irradiating with a particle beam in which the linear mask pattern is formed so as to be orthogonal to the pattern.

A seventh radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus according to the present invention include a laser oscillator, an optical device for converging laser light emitted from the laser oscillator, and X-ray or radiation conversion into light. A jig made of a material having a high transparency to the laser light is provided to hold the element, and processing is performed while moving the laser light irradiation part and the element relatively.

In the above structure, the material having high transparency to laser light is preferably glass.

According to an eighth aspect of the present invention, there is provided a radiation conversion element, a method of manufacturing the same, and a radiation imaging apparatus, which include a laser oscillator, an optical device for converging laser light emitted from the laser oscillator, and X-rays or radiation to light. A jig for holding the element in the air is provided, and processing is performed while moving the laser light irradiation section and the element relatively.

In the above structure, it is preferable that the jig for holding the element is moved in a lattice shape by a moving mechanism.

Further, it is preferable that the laser beam is scanned in a grid pattern on the element.

[0029]

With this structure, by providing the scintillator with the lattice-shaped separation layer, crosstalk can be prevented and a high-resolution and high-sensitivity radiation imaging apparatus can be provided. Moreover, since a large area can be processed at high speed by the method of irradiating particles or particle beams, high productivity can be realized.

[0030]

【Example】

(Embodiment 1) A first embodiment of a radiation converting element, a method of manufacturing the same, and a radiation imaging apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is an appearance of an element (hereinafter referred to as a scintillator) that converts X-rays or radiation that is divided into a lattice shape into light.

In FIG. 1, 1 is a scintillator, which is a plate-shaped sintered body. The scintillator 1 has lattice-shaped grooves 1a formed during or after sintering. However, the scintillator 1 is not divided into individual pieces by the groove 1a, but is connected at the bottom surface.

FIG. 2 is a conceptual diagram of the assembly of the scintillator and the light detection panel. (A) is before assembly, (b) is after assembly. Reference numeral 2 is a light detection panel, 3 is a pixel of the light detection panel 2, and 4 is an adhesive. The size of the grid-shaped division of the scintillator 1 can include the pixels 3. The divided surface of the scintillator 1 whose surface is divided by the plurality of grooves 1a and the pixels 3 of the photodetection panel 2 are made to correspond to each other and bonded. If the adhesive 4 is transparent to the light converted by the scintillator 1, the light going straight in the depth direction reaches the pixel 3. However, for light traveling in an oblique direction, the surface 1 of the groove 1a formed in the scintillator 1
It is reflected by b (side surface), and the adjacent pixel cannot be reached, so that crosstalk can be prevented.

(Embodiment 2) A second embodiment of the radiation converting element, the method of manufacturing the same, and the radiation imaging apparatus according to the present invention is shown in FIG.
Will be described with reference to. FIG. 3 is a conceptual diagram of a process of processing a scintillator by the sandblast method.

(A) is a scintillator before processing, (b) is a scintillator on which a patterned protective layer is formed,
(C) is a block diagram during processing by the sandblast method. The scintillator used in this example is one in which a layer 6 for converting X-rays or radiation into light is formed by a thick film printing method on a glass substrate 5 which transmits X-rays or radiation. The substrate may be an organic film. In the step (b) of forming the protective layer, a negative type liquid resist called OSBR-82R manufactured by Tokyo Ohka Kogyo Co., Ltd. is used as the resist 7 having sandblast resistance. The resist 7 is applied on the light conversion layer 6 by a spin coating method so as to have a film thickness of about 15 to 20 μm. After applying the resist, it is dried at a temperature of 70 ° C. for 15 minutes.

Next, a photomask capable of exposing parts other than the grid-like pattern to be removed by sandblasting is brought into close contact, and 15
After exposure with an exposure amount of mJ / cm ² , a 0.2 wt% sodium carbonate aqueous solution is sprayed for development, followed by development and washing with pure water to obtain a pattern.

In the sandblasting step (c), the resist pattern 7 is formed by using silica (SiO ₂ ) particles 8 with a sandblasting machine (manufactured by Alps Engineering Co., Ltd.).
Blast pressure 2 kgf / cm on the light conversion layer 6 on which
Spray with ² , and cut the part not covered with resist 7. Since the resist 7 is durable against sandblast and does not pass through particles, the light conversion layer 6 under the pattern is not processed. By setting the particle size of silica to 10 μm or less, it is possible to process a narrow groove width corresponding to the interval between pixels of the photodetection panel. After cutting, resist pattern 7
Is removed using a monoethanolamine-based resist stripping agent, the structure shown in FIG. 4 is obtained.

When a negative type dry film resist called ORDYL-BF205 manufactured by Tokyo Ohka Kogyo Co., Ltd. is used as a resist having sandblast resistance,
Cutting is possible in the same process. The removing method is not limited to the method using a stripping agent, and for example, the resist pattern may be removed by burning and burning without removing the resist pattern.

In these examples, photoresist was used as a sandblast mask. Although photoresist is most desirable for fine patterning, in addition to the groove-shaped pattern to be removed by sandblasting, a liquid having a sandblasting resistance such as polymethylmethacrylate dissolved in a paste form is applied by a screen printing method or the like, The same processing can be performed by using the dried product as a sandblasting mask.

If a material that transmits the light converted by the light conversion layer 6 is used as the material of the protective layer 7, it is possible to assemble the light detection panel as it is without removing the protective layer 7.

If a method such as ion irradiation or dry etching using plasma is used as the processing means,
The processing speed is slow, but finer and higher precision processing is possible.

(Embodiment 3) A third embodiment of the radiation converting element, the method of manufacturing the same, and the radiation imaging apparatus according to the present invention is shown in FIG.
Will be described with reference to. FIG. 5 is a configuration diagram of a laser processing apparatus for a scintillator.

In FIG. 5, 11 is a YAG laser oscillator, 12 is a laser beam, 13 is a collimator, 14 is a reflecting mirror, 15 is a lens, 16 is a scintillator, 17 is a glass plate, and 18 is a moving mechanism. The laser beam 12 emitted from the laser oscillator 11 is expanded by the collimator 13,
The light is guided to the lens 15 by the reflecting mirror 14 and focused on the scintillator 16. By moving the moving mechanism 18, the scintillator 16 can be processed into a lattice shape. However, for example, if a CsI plate-shaped sintered body is used for the scintillator 16, the laser light 12 can pass through the scintillator 16. Therefore, when a material that reflects or absorbs the laser light 12 is brought into contact with the bottom of the scintillator 16, the back surface of the scintillator 16 is reworked by the reflected laser light or ejected matter, and the surface condition deteriorates. In this embodiment, the glass plate 17 holding the scintillator 16 has a wavelength of 1.06.
Almost no reflection of μm laser light, and glass plate 1
Since the moving mechanism under 7 is not exposed to the ejected substances when it is processed, the reprocessing of the scintillator 16 can be prevented.

In the present embodiment, the relative movement between the laser light irradiation section and the scintillator is carried out by the moving mechanism, but the laser light may be scanned by a reflecting mirror or the like.

(Embodiment 4) A fourth embodiment of the radiation converting element, the method of manufacturing the same, and the radiation imaging apparatus according to the present invention is shown in FIG.
Will be described with reference to. FIG. 6 is a conceptual diagram of a processed state of the scintillator. (A) is before processing, (b) is after processing. The difference between the fourth embodiment and the third embodiment is that the scintillator has a three-layer structure in which a light conversion material 19 of yttrium terbium oxysulfide powder is sandwiched between substrates 20 and 21.

With a three-layer structure, it is possible to use a powder material. The laser light 12 focused by the lens 15 is emitted from one surface of the scintillator having the three-layer structure. When an organic film such as polyethylene terephthalate (PET) is used for the substrate 20 on the irradiation side, the wavelength of 0.
Since the laser light of 3 to 5 μm is transmitted, when the YAG laser light suitable for microfabrication is irradiated, it is absorbed by the light conversion material 19. The laser irradiation portion of the light conversion material 9 becomes hot and jets out.

Since the substrate 20 is an organic film, the substrate 20 is easily broken by the ejected matter, and the processing proceeds in the depth direction. If the laser light 12 is pulsed light, since the laser intensity is high, the processing proceeds more easily, and the damage to the substrate 21 on the back side is small. If the substrate 21 on the back side is an organic film or glass, the laser light is transmitted therethrough, so that the substrate 21 on the back side is less damaged by the laser light 12 that has passed through the light conversion material 19.

It goes without saying that the substrate 20 for irradiating the laser light may be an absorber of the laser light 12.

(Embodiment 5) A fifth embodiment of the radiation converting element, the method of manufacturing the same, and the radiation imaging apparatus according to the present invention is shown in FIG.
Will be described with reference to. The difference between the fifth embodiment and the fourth embodiment is that the scintillator 16 is held in the air by a holding jig 22. Also in this method, reprocessing of the scintillator 16 due to the reflected laser light or ejected matter can be prevented as in the fourth embodiment.

(Sixth Embodiment) A sixth embodiment of the radiation converting element, the method for manufacturing the same, and the radiation imaging apparatus according to the present invention will be described with reference to FIG.
Will be described with reference to. The sixth embodiment differs from the fourth or fifth embodiment in that the laser light 12 that has passed through the mask 23 having a linear pattern is reduced and image-projected onto the scintillator 16. Thereby, first, linear processing is performed. Next, the mask 24 having a linear pattern orthogonal to the above pattern is replaced by the rotating mechanism 25, and the pattern is imaged. By moving the scintillator 16 and repeating these processes, a lattice-shaped process can be performed on the scintillator 16. In reduced projection,
It is also possible to process complicated fine patterns.

[0050]

As described above, the present invention comprises an element for converting X-rays or radiation into light and a light detection panel for converting the light converted by the element into an image signal. The element is divided into a lattice shape in a size including at least one pixel, the division surface of the element and the photodetection panel are made to face each other, and at least one pixel of the photodetection panel is provided in the division region of the element. Assembling them so as to include them, or forming a layer that converts X-rays or radiation into light on a substrate that transmits X-rays or radiation, and processing the light conversion layer into a lattice shape, or A device for forming a patterned protective layer on a device for converting to light and irradiating the device with particles or particle beams to remove a device portion exposed from the protective layer, or a device for converting X-rays or radiation into light. Converge on By irradiating a particle beam and processing the element into a lattice shape, or for a three-layer structure element in which a powder material that converts X-rays or radiation into light is sandwiched between substrates on both sides, laser light is emitted from one side. The element is irradiated to process the element into a lattice shape, or a particle beam is passed through a linear mask pattern to form an image of the mask pattern on an element that converts X-rays or radiation into light. X-rays are irradiated with a particle beam in which the linear mask pattern is imaged to process the element into a lattice shape, or a laser oscillator and an optical device for converging laser light emitted from the laser oscillator; A jig made of a material having high transparency to the laser light for holding an element that converts a line or radiation into light is provided, and while moving the laser light irradiation unit and the element relatively. Process or laser Device, an optical device for converging the laser light emitted from the laser oscillator, and a jig for holding an element for converting X-rays or radiation into light in the air. It is possible to realize an excellent radiation conversion element capable of manufacturing a high-resolution and high-sensitivity radiation imaging apparatus at high speed and easily, a method of manufacturing the same, and a radiation imaging apparatus by processing while moving the radiation imaging apparatus.

[Brief description of drawings]

FIG. 1 is an external view of a scintillator according to an embodiment of the present invention.

2 (a) and 2 (b) are conceptual diagrams of the assembly of the scintillator and the light detection panel.

3 (a) to (c) are conceptual diagrams of scintillator processing by the sandblasting method.

FIG. 4 is a view showing a scintillator after the sandblasting.

FIG. 5 is a configuration diagram of a laser processing device of the scintillator.

6 (a) and 6 (b) are conceptual diagrams of the processed state of the scintillator having the same three-layer structure.

FIG. 7 is a block diagram of a laser processing device of the scintillator.

FIG. 8 is a configuration diagram of a laser processing device of the scintillator.

9 (a) to 9 (d) are process conceptual diagrams of a conventional scintillator crystal growth method.

[Explanation of symbols]

 1 Scintillator 2 Photodetection panel 3 Pixel of photodetection panel 4 Adhesive 5 Substrate 6 Photoconversion layer 7 Resist 8 Silica particle 11 YAG laser oscillator 15 Lens 16 Scintillator 17 Glass plate 18 Moving mechanism 19 Photoconversion material 20 Organic film 21 Substrate 22 Holding jig 23 Mask 24 Mask

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasutoshi Omori 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Company (72) Inventor Ken Abe 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (26)

[Claims] 1. An element for converting X-rays or radiation into light,
A light detection panel for converting the light converted by the element into a video signal, and dividing the element in a grid shape to include at least one pixel of the light detection panel, A radiation imaging apparatus characterized in that both are assembled so that they are opposed to each other and at least one pixel of the photodetection panel is included in a divided region of the element. 2. The radiation imaging apparatus according to claim 1, wherein the element is not divided into individual pieces. 3. The radiation imaging apparatus according to claim 1, wherein the element and the light detection panel are bonded to each other. 4. A radiation conversion element for converting X-rays or radiation into light, which has a dividing surface divided by a plurality of grooves on the surface. 5. An X-ray or a radiation-transparent substrate is provided with X-rays.
A method for manufacturing a radiation conversion element, comprising forming a layer for converting rays or radiation into light and processing the light conversion layer into a lattice shape. 6. The method of manufacturing a radiation conversion element according to claim 5, wherein the light conversion layer is formed on the substrate by a thick film printing method. 7. A method of forming a patterned protective layer on an element for converting X-rays or radiation into light, irradiating the element with particles or a particle beam, and removing an element portion exposed from the protective layer. A method of manufacturing a radiation conversion element having a feature. 8. The method of manufacturing a radiation conversion element according to claim 7, wherein the material of the protective layer is durable and opaque to irradiated particles or particle beams. 9. The method of manufacturing a radiation conversion element according to claim 8, wherein a photoresist is used as a material of the protective layer, and patterning is performed by a photolithography method. 10. The method of manufacturing a radiation conversion element according to claim 7, wherein the protective layer transmits the light converted by the light conversion layer. 11. The method of manufacturing a radiation conversion element according to claim 7, wherein the protective layer is removed after removing the element portion. 12. The method of manufacturing a radiation conversion element according to claim 11, wherein the protective layer is removed by using a release agent. 13. The method of manufacturing a radiation conversion element according to claim 11, wherein the protective layer is decomposed and removed by firing. 14. A method of manufacturing a radiation conversion element, which comprises irradiating an element for converting X-rays or radiation to light with a convergent particle beam and processing the element into a lattice shape. 15. The method of manufacturing a radiation conversion element according to claim 14, wherein the particle beam is laser light. 16. The method for manufacturing a radiation conversion element according to claim 15, wherein the laser light is pulsed light. 17. A device having a three-layer structure in which a powder material for converting X-rays or radiation into light is sandwiched between substrates on both sides, and a laser beam is irradiated from one face to process the device into a lattice shape. A method of manufacturing a radiation conversion element, comprising: 18. The method for manufacturing a radiation conversion element according to claim 17, wherein among the elements having the three-layer structure, at least the substrate irradiated with laser light is an organic film. 19. The method of manufacturing a radiation conversion element according to claim 18, wherein the wavelength of the laser light is 0.3 to 5 μm. 20. The method of manufacturing a radiation conversion element according to claim 17, wherein among the elements having the three-layer structure, the substrate on the back side of the laser light irradiation surface transmits the laser light. 21. The linear mask is formed by passing a particle beam through a linear mask pattern to form an image of the mask pattern on an element for converting X-rays or radiation into light, and then making the mask orthogonal to the pattern. A method for manufacturing a radiation conversion element, which comprises irradiating a particle beam on which a pattern is imaged and processing the element into a lattice shape. 22. A material having high transparency to the laser light for holding a laser oscillator, an optical device for converging laser light emitted from the laser oscillator, and an element for converting X-rays or radiation into light. Equipped with a jig made in
A method for manufacturing a radiation conversion element, characterized in that the radiation conversion section and the element are processed while relatively moving. 23. The method of manufacturing a radiation conversion element according to claim 22, wherein the material having high transparency to the laser light is glass. 24. A laser beam irradiator, comprising a laser oscillator, an optical device for converging a laser beam emitted from the laser oscillator, and a jig for holding an element for converting X-rays or radiation into light in the air. And a method for manufacturing a radiation conversion element, which comprises processing while moving the element relatively. 25. The holding jig for holding the element is moved in a lattice by a moving mechanism.
4. The method for manufacturing the radiation conversion element according to 4. 26. The method of manufacturing a radiation conversion element according to claim 22, wherein the laser beam scans the element in a grid pattern.