WO2021038899A1

WO2021038899A1 - Scintillator panel and radiation detector

Info

Publication number: WO2021038899A1
Application number: PCT/JP2020/000150
Authority: WO
Inventors: 槙子紺野; 篤也吉田; 中山　剛士
Original assignee: キヤノン電子管デバイス株式会社
Priority date: 2019-08-28
Filing date: 2020-01-07
Publication date: 2021-03-04
Also published as: JP2021032817A

Abstract

A scintillator panel according to an embodiment is provided with: a substrate that can transmit radiation and that has at least one prepreg having a plurality of carbon fibers; a scintillator provided on one side of the substrate; a reflective layer that is provided between the substrate and the scintillator and that can reflect fluorescence generated at the scintillator; and a protective layer provided between the reflective layer and the scintillator. In a view from a direction perpendicular to a surface of the substrate, a peripheral edge of the protective layer is provided between a peripheral edge of the scintillator and a peripheral edge of the substrate.

Description

Scintillator panel and radiation detector

An embodiment of the present invention relates to a scintillator panel and a radiation detector.

There is a scintillator panel that converts incident radiation (for example, X-rays) into fluorescence (visible light). The scintillator panel is provided with a substrate, a reflective layer provided on one surface of the substrate, a protective layer covering the reflective layer, and a scintillator provided on the protective layer to convert incident radiation into fluorescence. Has been done.

Further, the radiation detector is provided with a scintillator panel and an array substrate having a plurality of photoelectric conversion units. The side where the fluorescence of the scintillator panel is emitted is bonded on the region of the array substrate where a plurality of photoelectric conversion portions are provided.

Generally, the reflective layer is provided so as to cover one surface of the substrate. Further, the reflective layer is formed of a metal having a high reflectance to fluorescence, for example, aluminum. In this case, when the scintillator is directly formed on the reflective layer formed of a metal such as aluminum, the metal contained in the reflective layer reacts with the halogen contained in the scintillator, and the reflective layer is corroded. May be done. When the reflective layer is corroded, the gloss of the surface is reduced, which may lead to a decrease in reflection performance, a decrease in sensitivity characteristics, and a decrease in resolution characteristics. Therefore, a reflective layer is provided over the entire surface of one surface of the substrate, and a protective layer is provided to cover the reflective layer. Then, a scintillator is provided on the protective layer.

Here, the scintillator is formed by using a vacuum vapor deposition method or the like. Therefore, if the protective layer is provided over the entire surface of one surface of the substrate, the jig or mask used for forming the scintillator comes into contact with the protective layer provided above the peripheral region of the substrate. In this case, when the scintillator is deposited, the jig and the substrate are heated, but since the coefficient of thermal expansion of the jig and the like is different from the coefficient of thermal expansion of the substrate and the like, the respective thermal expansion amounts are different. It becomes. Therefore, rubbing may occur between the jig and the protective layer, and the protective layer may be scratched or peeled off. Since the scintillator is provided on the protective layer, the scintillator may be peeled off starting from scratches or peeling of the protective layer. When the scintillator is peeled off, the sensitivity characteristics and the resolution characteristics may be deteriorated or changed.
Therefore, it has been desired to develop a technique capable of suppressing damage to the protective layer when forming the scintillator.

Japanese Unexamined Patent Publication No. 2004-95820

An object to be solved by the present invention is to provide a scintillator panel capable of suppressing damage to the protective layer when forming a scintillator, and a radiation detector.

The scintillator panel according to the embodiment has at least one prepreg having a plurality of carbon fibers, a substrate capable of transmitting radiation, a scintillator provided on one surface side of the substrate, the substrate, and the scintillator. A reflective layer provided between the two, and capable of reflecting the fluorescence generated in the scintillator, and a protective layer provided between the reflective layer and the scintillator are provided. When viewed from a direction perpendicular to the surface of the substrate, the peripheral edge of the protective layer is provided between the peripheral edge of the scintillator and the peripheral edge of the substrate.

It is a schematic perspective view for exemplifying the scintillator panel and the X-ray detector which concerns on this embodiment. It is a schematic cross-sectional view of a scintillator panel and an X-ray detector. It is a schematic cross-sectional view of a scintillator panel. It is a schematic perspective view for exemplifying the relationship between the direction in which carbon fibers extend and the rigidity. It is a schematic exploded view for exemplifying the structure of a substrate. It is a schematic cross-sectional view for exemplifying a reflective layer, a protective layer, a scintillator, and a relaxation layer. It is a schematic diagram for exemplifying the case where the scintillator is formed on the protective layer which concerns on a comparative example. It is a schematic diagram for exemplifying the case where the scintillator is formed on the protective layer which concerns on this embodiment. It is a schematic cross-sectional view for exemplifying the scintillator panel which concerns on another embodiment.

Hereinafter, embodiments will be illustrated with reference to the drawings. In each drawing, similar components are designated by the same reference numerals and detailed description thereof will be omitted as appropriate.
The radiation detector according to the embodiment of the present invention can be applied to various types of radiation such as γ-rays in addition to X-rays. Here, as an example, the case of X-rays as a typical example of radiation will be described as an example. Therefore, by replacing "X-ray" in the following embodiment with "other radiation", it can be applied to other radiation.

Further, the X-ray detector 1 illustrated below can be an X-ray plane sensor that detects an X-ray image which is a radiation image. The X-ray detector 1 can be used, for example, in general medical care. However, the use of the X-ray detector 1 is not limited to general medical care.

FIG. 1 is a schematic perspective view for exemplifying the scintillator panel 10 and the X-ray detector 1 according to the present embodiment.
FIG. 2 is a schematic cross-sectional view of the scintillator panel 10 and the X-ray detector 1.
In addition, in order to avoid complication, in FIG. 2, the control line 2c1, the data line 2c2, the circuit board 3, the image configuration unit 4, and the like are omitted.
FIG. 3 is a schematic cross-sectional view of the scintillator panel 10.
As shown in FIGS. 1 and 2, the X-ray detector 1 may be provided with an array substrate 2, a circuit board 3, an image component 4, a scintillator panel 10, and a junction 20.
The array substrate 2 can convert the fluorescence converted from X-rays by the scintillator panel 10 into electric charges.
The array substrate 2 may be provided with a substrate 2a, a photoelectric conversion unit 2b, a control line (or gate line) 2c1, a data line (or signal line) 2c2, an insulating layer 2f, and the like. The numbers of the photoelectric conversion unit 2b, the control line 2c1, the data line 2c2, and the like are not limited to those illustrated.

The substrate 2a has a plate shape and is formed of a translucent material such as non-alkali glass. The planar shape of the substrate 2a can be, for example, a quadrangle.
A plurality of photoelectric conversion units 2b may be provided on one surface of the substrate 2a. The photoelectric conversion unit 2b has a rectangular shape and can be provided in a region defined by the control line 2c1 and the data line 2c2. The plurality of photoelectric conversion units 2b can be provided side by side in a matrix. One photoelectric conversion unit 2b corresponds to one pixel of the X-ray image.

A photoelectric conversion element 2b1 and a thin film transistor (TFT) 2b2, which is a switching element, can be provided in each of the plurality of photoelectric conversion units 2b.
Further, a storage capacitor 2b3 for accumulating the electric charge converted by the photoelectric conversion element 2b1 can be provided. The storage capacitor 2b3 has, for example, a rectangular flat plate shape, and can be provided under each thin film transistor 2b2. However, depending on the capacity of the photoelectric conversion element 2b1, the photoelectric conversion element 2b1 can also serve as the storage capacitor 2b3.

The photoelectric conversion element 2b1 can be, for example, a photodiode or the like.
The thin film transistor 2b2 can switch the accumulation and emission of electric charges in the storage capacitor 2b3. The thin film transistor 2b2 can have a gate electrode, a drain electrode, and a source electrode. The gate electrode of the thin film transistor 2b2 can be electrically connected to the corresponding control line 2c1. The drain electrode of the thin film transistor 2b2 can be electrically connected to the corresponding data line 2c2. The source electrode of the thin film transistor 2b2 can be electrically connected to the corresponding photoelectric conversion element 2b1 and the storage capacitor 2b3. Further, the anode side of the photoelectric conversion element 2b1 and the storage capacitor 2b3 can be connected to the ground.

A plurality of control lines 2c1 can be provided in parallel with each other at predetermined intervals. The control line 2c1 may extend in the row direction, for example. One control line 2c1 can be electrically connected to one of a plurality of wiring pads provided near the peripheral edge of the substrate 2a. One of a plurality of wirings provided on the flexible printed circuit board 2e1 can be electrically connected to one wiring pad. The other ends of the plurality of wirings provided on the flexible printed circuit board 2e1 can be electrically connected to the readout circuit provided on the circuit board 3, respectively.

A plurality of data lines 2c2 may be provided in parallel with each other at predetermined intervals. The data line 2c2 can, for example, extend in the column direction orthogonal to the row direction. One data line 2c2 can be electrically connected to one of a plurality of wiring pads provided near the periphery of the substrate 2a. One of a plurality of wirings provided on the flexible printed circuit board 2e2 can be electrically connected to one wiring pad. The other ends of the plurality of wirings provided on the flexible printed circuit board 2e2 can be electrically connected to the signal detection circuit provided on the circuit board 3, respectively.
The control line 2c1 and the data line 2c2 can be formed by using a low resistance metal such as aluminum or chromium.

The insulating layer 2f can cover the photoelectric conversion unit 2b, the control line 2c1, the data line 2c2, and the like. The insulating layer 2f can include, for example, at least one of an oxide insulating material, a nitride insulating material, an oxynitride insulating material, and a resin.

The circuit board 3 can be provided on the side of the array board 2 opposite to the side on which the scintillator panel 10 is provided. A read circuit and a signal detection circuit can be provided on the circuit board 3. It should be noted that these circuits can be provided on one board, or these circuits can be provided separately on a plurality of boards.

The readout circuit can switch between the on state and the off state of the thin film transistor 2b2. For example, the readout circuit can sequentially input the control signal S1 for each control line 2c1 via the flexible printed circuit board 2e1. The control signal S1 input to the control line 2c1 turns on the thin film transistor 2b2, and the electric charge (image data signal S2) from the storage capacitor 2b3 can be received.

The signal detection circuit can have a plurality of integrating amplifiers, a plurality of selection circuits, and a plurality of AD converters.
One integrating amplifier can be electrically connected to one data line 2c2. The integrating amplifier can sequentially receive the image data signal S2 from the photoelectric conversion unit 2b. Then, the integrating amplifier can integrate the current flowing within a fixed time and output the voltage corresponding to the integrated value to the selection circuit. In this way, it is possible to convert the value (charge amount) of the current flowing through the data line 2c2 into a voltage value within a predetermined time. That is, the integrating amplifier can convert the image data information corresponding to the intensity distribution of fluorescence generated in the scintillator panel 10 (scintillator 14) into potential information.

The selection circuit can select an integrating amplifier to be read out and sequentially read out the image data signal S2 converted into potential information.
The AD converter can sequentially convert the read image data signal S2 into a digital signal. The image data signal S2 converted into a digital signal can be input to the image configuration unit 4.

The image configuration unit 4 can be electrically connected to the readout circuit (AD converter) of the circuit board 3 via the wiring 4a. Data communication between the image configuration unit 4 and the circuit board 3 can also be performed wirelessly. Further, the image component 4 and the circuit board 3 may be integrated. The image configuration unit 4 can configure an X-ray image based on the image data signal S2 converted into a digital signal by a plurality of AD converters. The configured X-ray image data can be output from the image configuration unit 4 to an external device.

As shown in FIGS. 2 and 3, the scintillator panel 10 can be provided with a substrate 11, a reflective layer 12, a protective layer 13, a scintillator 14, a relaxation layer 15, and a moisture-proof portion 16.
The substrate 11 has a plate shape and can be formed of a material that transmits X-rays. The substrate 11 can be formed from, for example, carbon-Fiber-Reinforced Plastic (CFRP). The substrate 11 can have, for example, at least one prepreg having a plurality of carbon fibers. In this case, the substrate 11 can have a plurality of types of prepregs in which the plurality of carbon fibers 111 extend in different directions (see FIG. 5). A plurality of types of prepregs can be laminated in the thickness direction. The planar shape of the prepreg, and thus the planar shape of the substrate 11, can be, for example, a quadrangle. The prepreg has a plate shape, and for example, carbon fibers arranged in a desired direction may be impregnated with a thermosetting resin. The thickness of the prepreg can be, for example, about 0.1 mm. The substrate 11 can be formed, for example, by laminating a plurality of prepregs and subjecting them to heat treatment under pressure.

Here, when the rigidity of the substrate 11 is low, the rigidity of the substrate 11 is highly anisotropic, or the warp generated in the substrate 11 is large, the positional relationship between the array substrate 2 and the scintillator panel 10 is determined. The quality of the X-ray image may deteriorate due to deviation from a predetermined position (predetermined image plane).

In this case, if the number of prepregs is increased, the rigidity of the substrate 11 can be increased, the anisotropy of the rigidity of the substrate 11 can be reduced, and the warp generated in the substrate 11 can be reduced. However, simply increasing the number of prepregs will increase the manufacturing cost of the substrate 11. Further, the rigidity of the prepreg changes depending on the direction in which the carbon fibers 111 in the prepreg extend. That is, the rigidity of the prepreg is anisotropy depending on the direction in which the carbon fibers 111 in the prepreg are stretched.

FIG. 4 is a schematic perspective view for exemplifying the relationship between the extending direction of the carbon fiber 111 and the rigidity.
Considering only the direction in which the carbon fibers 111 extend without considering the planar shape of the prepreg, the bending strength B in the direction orthogonal to the direction A in which the carbon fibers 111 extend is the bending in the direction parallel to the direction A in which the carbon fibers 111 extend. It becomes smaller than the strength C.

On the other hand, considering only the planar shape of the prepreg, the bending strength B on the short side is larger than the bending strength C on the long side.
Therefore, in order to reduce the anisotropy of rigidity, it is preferable to set the direction A in which the carbon fiber 111 extends in consideration of the planar shape of the prepreg. For example, as shown in FIG. 4, when the planar shape of the prepreg is rectangular, the direction A in which the carbon fibers 111 extend is preferably a direction parallel to the long side (longitudinal direction).

FIG. 5 is a schematic exploded view for exemplifying the configuration of the substrate 11.
The rigidity of the prepreg 11a provided on the surface (both ends in the thickness direction) of the substrate 11 at the position farthest from the line 110 passing through the center in the thickness direction of the substrate 11 contributes most to the rigidity of the substrate 11. Therefore, it is preferable to set the direction A in which the carbon fiber 111 extends in consideration of the planar shape of the prepreg 11a.

Further, if the types of prepregs provided on the substrate 11 (types in the direction in which the carbon fibers are stretched) are increased, the anisotropy of rigidity in the substrate 11 can be reduced. However, if there are too many types of prepregs, the number of prepregs becomes too large, the manufacturing cost of the substrate 11 increases, and the rigidity of the substrate 11 becomes too high, so that the joining work between the array substrate 2 and the scintillator panel 10 is performed. May become difficult.

For example, when the X-ray detector 1 is used for general medical treatment or the like, it is preferable to provide two each of four types of prepregs 11a to 11d as shown in FIG. Further, it is preferable that the carbon fibers 111 in the prepreg provided at a position line-symmetrical with respect to the line 110 passing through the center in the thickness direction of the substrate 11 extend in substantially the same direction. Further, it is preferable that the angles between the extending directions of the carbon fibers 111 are substantially equal.

As shown in FIG. 5, the prepreg 11a can be provided at a position farthest from the line 110 passing through the center in the thickness direction of the substrate 11, that is, on the surface (front and back) of the substrate 11. The direction in which the carbon fibers 111 in the prepreg 11a, which most contributes to the rigidity of the substrate 11, is extended can be a direction substantially parallel to the long side of the prepreg 11a (board 11).

The prepreg 11b can be provided on the central surface of the substrate 11 of the prepreg 11a. The direction in which the carbon fibers 111 in the prepreg 11b extend can have an angle of 45 ° with respect to the direction parallel to the long side of the prepreg 11b (board 11).

The prepreg 11c can be provided on the central surface of the substrate 11 of the prepreg 11b. The direction in which the carbon fibers 111 in the prepreg 11c extend can have an angle of 90 ° with respect to the direction parallel to the long side of the prepreg 11c (substrate 11).

The prepreg 11d can be provided on the central surface of the substrate 11 of the prepreg 11c. The direction in which the carbon fibers 111 in the prepreg 11d extend can have an angle of 135 ° with respect to the direction parallel to the long side of the prepreg 11d (substrate 11).

In the above, the case where the planar shape of the substrate 11 (prepregs 11a to 11d) is rectangular has been illustrated, but a part of the substrate 11 may be chamfered to form a polygon, or an R portion or C may be formed at a corner portion of the substrate 11. It can also be chamfered.

If the substrate 11 has the above configuration, it is possible to suppress the occurrence of distortion and reduce the anisotropy of the rigidity of the substrate 11. Further, it is possible to suppress the occurrence of warpage when the reflective layer 12, the protective layer 13, the scintillator 14, the relaxation layer 15, and the moisture-proof portion 16 are formed on the substrate 11.

As shown in FIGS. 2 and 3, the reflective layer 12 can be provided on one surface of the substrate 11. The reflective layer 12 can be provided so as to cover the entire area of one surface of the substrate 11. The reflective layer 12 is provided to increase the utilization efficiency of fluorescence and improve the sensitivity characteristics. That is, the reflective layer 12 reflects the light generated in the scintillator 14 toward the side opposite to the side where the photoelectric conversion unit 2b is provided so as to be directed toward the photoelectric conversion unit 2b. That is, the reflective layer 12 is provided between the substrate 11 and the scintillator 14, and can reflect the fluorescence generated in the scintillator 14.

Further, X-rays are incident on the side of the scintillator 14 where the reflection layer 12 is provided. Therefore, the reflective layer 12 can be formed of a material that transmits X-rays and has a high reflectance for fluorescence. For example, the reflective layer 12 may contain aluminum, silver, or the like. However, the substrate 11 is made of carbon fiber reinforced plastic. Therefore, it is difficult to directly form a film containing aluminum, silver, or the like on the surface of the substrate 11 or directly attach it to the surface of the substrate 11. Therefore, the reflective layer 12 can be a laminated structure including the resin layer 12a and the metal layer 12b.

FIG. 6 is a schematic cross-sectional view for illustrating the reflective layer 12, the protective layer 13, the scintillator 14, and the relaxation layer 15.
In addition, in order to avoid complication, in FIG. 6, some prepregs constituting the substrate 11 are omitted.
As shown in FIG. 6, the reflective layer 12 includes a resin layer 12a bonded to the surface of the substrate 11 and a metal layer 12b provided on the surface of the resin layer 12a opposite to the substrate 11 side. Can be done. The reflective layer 12 can be formed by integrating the sheet-shaped resin layer 12a and the sheet-shaped metal layer 12b (for example, aluminum foil or the like) by, for example, an autoclave molding method.

The resin layer 12a can be easily bonded to the substrate 11 formed of carbon fiber reinforced plastic. Therefore, the resin layer 12a side of the reflective layer 12 can be bonded to the surface of the substrate 11. The resin layer 12a side of the reflective layer 12 can be adhered to the substrate 11, for example.

The resin layer 12a can be formed from, for example, polyethylene terephthalate (PET) or the like.
The metal layer 12b may contain, for example, a metal such as aluminum or silver. The metal layer 12b can be formed of, for example, an aluminum foil, a silver foil, or the like.
The thickness of the resin layer 12a can be, for example, 50 μm or more and 190 μm or less.

Here, if the thickness of the metal layer 12b is made too thin, pinholes may occur or the reflectance may decrease. On the other hand, if the thickness of the metal layer 12b is made too thick, the thermal stress generated by the heat when forming the scintillator 14 becomes large, and the substrate 11 may be warped or the like. Therefore, the thickness of the metal layer 12b is preferably 25 μm or more and 50 μm or less, for example.
The thickness of the reflective layer 12 (the total thickness of the resin layer 12a and the metal layer 12b) can be, for example, 75 μm or more and 240 μm or less.

If the resin layer 12a is provided, it is easy to imitate the unevenness of the surface of the substrate 11, and the impact from the outside is alleviated to prevent damage to the metal layer 12b. Can be done. Therefore, it becomes easy to maintain the barrier performance and the reflection performance of the reflection layer 12. Further, if the resin layer 12a is provided, the thermal stress generated between the substrate 11 having a small coefficient of thermal expansion and the metal layer 12b having a large coefficient of thermal expansion when a temperature change such as a thermal cycle or a thermal shock occurs. It is also possible to relax.

The metal layer 12b is exposed on the surface of the reflective layer 12 opposite to the substrate 11 side. Further, the scintillator 14 is provided on the side of the reflective layer 12 opposite to the substrate 11 side. In this case, when the metal layer 12b and the scintillator 14 come into direct contact with each other, the highly reducing metal contained in the metal layer 12b, the highly oxidizing iodine contained in the scintillator 14, and the highly oxidizing iodine contained in the scintillator 14 are contained in the air. There is a risk that the metal layer 12b will be corroded due to a redox reaction caused by the slight amount of water vapor. When the metal layer 12b is corroded, the gloss of the metal layer 12b is reduced, which may lead to a decrease in reflection performance, a decrease in sensitivity characteristics, and a decrease in resolution characteristics.

Therefore, the scintillator panel 10 according to the present embodiment is provided with the protective layer 13. The protective layer 13 can be provided on the surface of the reflective layer 12 opposite to the substrate 11 side. That is, the protective layer 13 can be provided between the reflective layer 12 (metal layer 12b) and the scintillator 14. The protective layer 13 can contain, for example, a resin such as a polyparaxylylene resin. The thickness of the protective layer 13 can be, for example, 5 μm or more and 20 μm or less. The protective layer 13 can be formed by, for example, a thermal CVD (thermal chemical vapor deposition) method or the like.

Here, the scintillator 14 can be formed on the protective layer 13 by using a vacuum deposition method or the like.
FIG. 7 is a schematic view for exemplifying a case where the scintillator 14 is formed on the protective layer 113 according to the comparative example.
As shown in FIG. 7, the reflective layer 12 is provided over the entire surface of one surface of the substrate 11. The protective layer 113 according to the comparative example covers the entire area of the reflective layer 12. That is, the protective layer 113 is also provided above the peripheral region of the substrate 11. The thickness and material of the protective layer 113 can be the same as the thickness and material of the protective layer 13 according to the present embodiment.

As shown in FIG. 7, when the scintillator 14 is formed by a vacuum vapor deposition method or the like, a positioning jig 200, a mask for film formation, or the like is used. The positioning jig 200 or the like holds or supports the peripheral region of the substrate 11. Therefore, if the protective layer 113 is also provided above the peripheral region of the substrate 11, the positioning jig 200 or the like comes into contact with the protective layer 113. When the scintillator 14 is vapor-deposited, the positioning jig 200, the substrate 11, the protective layer 113, and the like are heated, but since the respective thermal expansion coefficients are different, the respective thermal expansion amounts are different. Therefore, rubbing may occur between the positioning jig 200 and the protective layer 113, and the protective layer 113 may be scratched or peeled off. Since the scintillator 14 is provided on the protective layer 113, if the protective layer 113 is scratched or peeled off, the scintillator 14 may be peeled off starting from the scratch or peeling. If the scintillator 14 is peeled off, the sensitivity characteristics and the resolution characteristics may be lowered or changed.

FIG. 8 is a schematic view for exemplifying a case where the scintillator 14 is formed on the protective layer 13 according to the present embodiment.
As shown in FIG. 8, the protective layer 13 according to the present embodiment is provided in the central region of the substrate 11 and not in the peripheral region of the substrate 11. As described above, the protective layer 13 is provided to prevent the scintillator 14 from being formed directly on the reflective layer 12. Therefore, the protective layer 13 may be provided in the region where the scintillator 14 of the reflective layer 12 is formed. However, there is a manufacturing deviation (error in film formation) at the formation position of the scintillator 14. Therefore, when the scintillator panel 10 is viewed from the direction perpendicular to the surface of the substrate 11, the peripheral edge of the protective layer 13 may be provided between the peripheral edge of the scintillator 14 and the peripheral edge of the substrate 11. preferable.

In this case, if the distance L1 between the peripheral edge of the protective layer 13 and the peripheral edge of the scintillator 14 is increased, the allowable range of the positional deviation of the scintillator 14 can be increased. Therefore, the scintillator 14 can be easily manufactured. Further, in order to suppress the interference between the positioning jig 200 and the like described above and the protective layer 13, it is preferable that the distance L2 between the peripheral edge of the protective layer 13 and the peripheral edge of the substrate 11 is set to a predetermined size.

However, when the distance L1 is increased, the distance L3 between the peripheral edge of the substrate 11 and the peripheral edge of the scintillator 14 is increased. In recent years, it has been desired to reduce the size of the X-ray detector 1 and the scintillator panel 10. Therefore, if the distance L1 is made too large, the distance L3 becomes too large, and it becomes difficult to reduce the size of the scintillator panel 10.

According to the knowledge obtained by the present inventor, if the distance L1 is 1 mm or more and 5 mm or less, interference between the positioning jig 200 or the like and the protective layer 13 can be suppressed, so that when the scintillator 14 is formed, , It becomes easy to suppress the occurrence of damage to the protective layer 13. Further, since the scintillator 14 can be displaced, the scintillator 14 can be easily manufactured. Further, the scintillator panel 10 can be downsized, and the X-ray detector 1 can be downsized.

Next, returning to FIGS. 2 and 3, the scintillator 14, the relaxation layer 15, and the moisture-proof portion 16 will be described.
As shown in FIGS. 2 and 3, the scintillator 14 can be provided on the reflective layer 12 via the protective layer 13. The scintillator 14 can convert the incident X-rays into fluorescence (visible light). The scintillator 14 can be formed using, for example, cesium iodide (CsI): thallium (Tl), sodium iodide (NaI): thallium (Tl), or the like. The thickness of the scintillator 14 can be, for example, about 600 μm. The scintillator 14 can be formed by, for example, a vacuum vapor deposition method or the like. When the scintillator 14 is formed by using a vacuum vapor deposition method or the like, the scintillator 14 composed of an aggregate of columnar crystals is formed. In this case, the thickness of the columnar crystal (pillar) can be about 8 μm to 12 μm on the outermost surface.

Here, a reflective layer 12, a protective layer 13, and a scintillator 14 are provided on one surface of the substrate 11. Further, when the protective layer 13 and the scintillator 14 are formed, the substrate 11 and the reflective layer 12 and the like are heated. Since the coefficients of thermal expansion of the substrate 11, the reflective layer 12, the protective layer 13, and the scintillator 14 are different, the amount of thermal expansion of each is different. Therefore, distortion or the like may occur during the manufacture of the scintillator panel 10, and the substrate 11 may be warped or the like. Therefore, the scintillator panel 10 is provided with a relaxation layer 15 in order to suppress the occurrence of warpage or the like on the substrate 11.

The relaxation layer 15 can be provided on the surface of the substrate 11 opposite to the reflection layer 12 side. The relaxation layer 15 can contain, for example, a metal such as aluminum or silver. The relaxation layer 15 may have, for example, an aluminum foil, a silver foil, or the like. Further, as in the case of the reflective layer 12 described above, the relaxation layer 15 having the metal layer 15b and the resin layer 15a can be formed in consideration of the bondability with the substrate 11 formed of the carbon fiber reinforced plastic. .. In this case, the metal layer 15b can be the same as the metal layer 12b of the reflection layer 12. The resin layer 15a can be the same as the resin layer 12a of the reflective layer 12.
The relaxation layer 15 can be provided over the entire surface of the substrate 11, or can be provided in a predetermined region of the surface of the substrate 11.

In this case, the metal layer 15b mainly has a function of suppressing warpage or the like generated on the substrate 11. Therefore, it is preferable to appropriately change the material, thickness, size, arrangement position, and the like of the metal layer 15b according to the warp generated on the substrate 11. For example, the material, thickness, size, arrangement position, etc. of the metal layer 15b can be appropriately determined by conducting experiments, simulations, and the like. In this case, the thickness of the metal layer 15b can be, for example, 25 μm or more and 250 μm or less.

It should be noted that the reflective layer 12 can also be provided on the surface of the substrate 11 opposite to the reflective layer 12 side to serve as the relaxation layer 15. By doing so, it is possible to simplify the manufacturing process and reduce the manufacturing cost.

The moisture-proof portion 16 can be provided in order to suppress deterioration of the characteristics of the scintillator 14 due to water vapor contained in the air. The moisture-proof portion 16 has a film shape and can be provided so as to cover the exposed portions of the substrate 11, the reflective layer 12, the protective layer 13, the scintillator 14, and the relaxation layer 15. The moisture-proof portion 16 can be formed of a material having a light-transmitting property and a small moisture-permeable coefficient. The moisture-proof portion 16 can be formed from, for example, polyparaxylylene, polymonochloroparaxylylene, polyfluoroparaxylylene, polydimethylparaxylylene, polydiethylparaxylylene and the like. The moisture-proof portion 16 can be formed by, for example, a thermal CVD method or the like.

When the scintillator 14 is an aggregate of columnar crystals, if the moisture-proof portion 16 is formed by using the thermal CVD method, the moisture-proof portion 16 can be penetrated to some extent into the gap between the columnar crystals. Therefore, even if the surface of the scintillator 14 has irregularities due to columnar crystals, the moisture-proof portion 16 having a substantially uniform film thickness can be formed.

Further, when the reflective layer 12 contains polyethylene terephthalate and the moisture-proof portion 16 contains polyparaxylylene or the like formed by the thermal CVD method, the portion where the reflective layer 12 (resin layer 12a) and the moisture-proof portion 16 are in contact with each other is formed. , It has a high deterrent effect against the invasion of water. Therefore, the scintillator panel 10 having high moisture-proof performance can be obtained.

The joint portion 20 can be provided between the array substrate 2 and the scintillator panel 10. The joining portion 20 has translucency, and can join the array substrate 2 and the scintillator panel 10. In this case, the scintillator 14 of the scintillator panel 10 can be bonded onto the region of the array substrate 2 provided with the plurality of photoelectric conversion units 2b.

The joint portion 20 can be, for example, an optical double-sided tape (OCA tape (Optical Clear Adhesive Tape)) or the like. Further, the joint portion 20 may be formed by curing, for example, an optical adhesive or an optical gel. In this case, the joint portion 20 can be cured by irradiation with ultraviolet rays.

Next, the scintillator panel 30 according to another embodiment will be illustrated.
FIG. 9 is a schematic cross-sectional view for exemplifying the scintillator panel 30 according to another embodiment.
As shown in FIG. 9, the scintillator panel 30 can be provided with a substrate 31, a protective layer 13, a scintillator 14, and a moisture-proof portion 16.

The substrate 31 has a plate shape and can be formed of a material that transmits X-rays and reflects the fluorescence generated in the scintillator 14. The substrate 31 may contain, for example, a metal such as aluminum or silver. The thickness of the substrate 31 can be, for example, 0.6 mm or more and 1.2 mm or less.

If the substrate 31 is made of metal, it can reflect fluorescence, so it is not necessary to provide the reflection layer 12 as in the scintillator panel 10 described above. Further, since the substrate 31 made of metal has high rigidity, warpage and the like are unlikely to occur. Therefore, unlike the scintillator panel 10 described above, it is not necessary to provide the relaxation layer 15.

However, if the scintillator 14 is directly provided on the substrate 31 made of metal, the surface of the substrate 31 may be corroded, resulting in a decrease in reflection performance, a decrease in sensitivity characteristics, and a decrease in resolution characteristics. Therefore, the scintillator panel 30 can be provided with the protective layer 13 in the same manner as the scintillator panel 10 described above. The protective layer 13 can be provided between the substrate 31 and the scintillator 14. The material, thickness, arrangement position, and the like of the protective layer 13 can be the same as those of the protective layer 13 provided on the scintillator panel 10.

If the scintillator panel 30 is used, the configuration is simplified and the manufacturing cost can be reduced.

As in the case of the scintillator panel 10, the scintillator panel 30 can be joined to the array substrate 2 via the joining portion 20.

Although some embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof. In addition, the above-described embodiments can be implemented in combination with each other.

Claims

A substrate having at least one prepreg having a plurality of carbon fibers and capable of transmitting radiation,
A scintillator provided on one surface side of the substrate and
A reflective layer provided between the substrate and the scintillator and capable of reflecting the fluorescence generated in the scintillator.
A protective layer provided between the reflective layer and the scintillator,
With
A scintillator panel in which the peripheral edge of the protective layer is provided between the peripheral edge of the scintillator and the peripheral edge of the substrate when viewed from a direction perpendicular to the surface of the substrate.
The scintillator panel according to claim 1, which is provided on the surface of the substrate opposite to the reflective layer side and further includes a relaxation layer containing metal.
The scintillator panel according to claim 1 or 2, wherein the reflective layer has a resin layer bonded to the substrate and a metal layer of the resin layer provided on a surface opposite to the substrate side.
The resin layer contains polyethylene terephthalate and contains
The scintillator panel according to claim 3, wherein the metal layer contains at least one of aluminum and silver.
The scintillator panel according to claim 3 or 4, wherein the metal layer includes at least one of aluminum foil and silver foil.
The scintillator panel according to any one of claims 1 to 5, wherein the distance between the peripheral edge of the protective layer and the peripheral edge of the scintillator is 1 mm or more and 5 mm or less.
The substrate has a plurality of types of the prepreg in which the plurality of carbon fibers extend in different directions.
The plurality of types of prepregs are laminated and
The prepreg provided at a position symmetrical with respect to the central portion in the thickness direction of the substrate has substantially the same direction in which the plurality of carbon fibers extend.
In the prepregs provided at both ends in the thickness direction, the direction in which the plurality of carbon fibers extend is substantially parallel to the longitudinal direction of the substrate.
The scintillator panel according to any one of claims 1 to 6, wherein the bending strength in the longitudinal direction of the substrate is larger than the bending strength in the lateral direction of the substrate.
A plate-like substrate that contains metal and is permeable to radiation,
A scintillator provided on one surface side of the substrate and
A protective layer provided between the substrate and the scintillator,
With
A scintillator panel in which the peripheral edge of the protective layer is provided between the peripheral edge of the scintillator and the peripheral edge of the substrate when viewed from a direction perpendicular to the surface of the substrate.
The scintillator panel according to claim 8, wherein the distance between the peripheral edge of the protective layer and the peripheral edge of the scintillator is 1 mm or more and 5 mm or less.
An array board having multiple photoelectric conversion units and
The scintillator panel according to any one of claims 1 to 9 provided on the plurality of photoelectric conversion units.
Radiation detector equipped with.