JP2021018135A - Scintillator panel and radiation detector - Google Patents

Abstract

To provide a scintillator panel capable of preventing a space between the scintillator panel and an array substrate from occurring, and a radiation detector.SOLUTION: The scintillator panel comprises: a tabular base part including at least one prepreg having a plurality of carbon fibers and capable of transmitting a radiation; a scintillator provided on one surface side of the base part; a reflection part provided between the base part and the scintillator; a protection part provided between the reflection part and the scintillator; and a relaxation part of the base part provided on the side opposite to the side having the reflection part. The reflection part provided on the scintillator side includes a reflective layer capable of reflecting fluorescence generated in the scintillator and a first resin layer provided on the base part side and including a resin. The relaxation part includes a second resin layer including a resin. The thickness of the base part is 0.4 mm or less. The total of the thicknesses of the first resin layer and the thicknesses of the second resin layer is larger than the thickness of the base part.SELECTED DRAWING: Figure 3

Description

Embodiments of the present invention relate to scintillator panels and radiation detectors.

There is a scintillator panel that converts incident radiation (eg, 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.

Such a scintillator panel can be used for a radiation detector. For example, the radiation detector may be provided with a scintillator panel and an array substrate having a plurality of photoelectric conversion units. In this case, the side of the scintillator panel from which the fluorescence is emitted can be bonded onto the region of the array substrate where a plurality of photoelectric conversion units are provided.

Here, the photoelectric conversion unit is provided with a photoelectric conversion element, a thin film transistor, or the like. Therefore, a step may occur in a region where a plurality of photoelectric conversion units are provided due to variations in the thickness of these elements. If there is a step in the region where the plurality of photoelectric conversion units are provided, a gap may be partially generated when the scintillator panel is joined to the array substrate. Such gaps cause sensitivity spots.
Therefore, a technique has been proposed in which a flexible substrate is provided on the scintillator panel, and the scintillator panel is deformed according to a step when the scintillator panel is joined to the array substrate.

However, when the scintillator is formed on one surface side of the substrate, the substrate is heated. Therefore, when a flexible substrate is used, the scintillator panel is likely to be warped or deformed as the substrate is heated and cooled. In this case, if warpage occurs due to the difference in the coefficient of thermal expansion between the scintillator and the substrate, the shape of the warp or the like becomes a simple quadric surface. If the shape such as warpage is a simple quadric surface, it can be corrected to a substantially flat shape when the scintillator panel is pressed against the array substrate, so that a gap is generated between the scintillator panel and the array substrate. It can be suppressed. However, when warpage occurs due to material shrinkage or thermal deformation due to heat, the shape of the warp or the like becomes an irregular curved surface, so when the scintillator panel is pressed against the array substrate, it can be corrected to a substantially flat shape. It gets harder.

In this case, a substrate using polyethylene terephthalate (PET), polyimide (PI), Teflon (registered trademark) (PTFE), which has relatively high rigidity among resins, or polyetheretherketone (PEEK), which has high heat resistance, is used. However, it is difficult to solve the above-mentioned problems of material shrinkage and thermal deformation. For example, even if the thickness of the substrate formed from these resins is about 0.5 mm, it is difficult to suppress the above-mentioned material shrinkage and thermal deformation.

That is, if the substrate is simply made of high rigidity, there is a possibility that a gap due to the above-mentioned step may occur. On the other hand, if the substrate is simply flexible, there is a possibility that a gap may occur due to material shrinkage or thermal deformation that occurs when the scintillator panel is manufactured.
Therefore, it has been desired to develop a technique capable of suppressing the formation of a gap between the scintillator panel and the array substrate.

Japanese Unexamined Patent Publication No. 2012-47487

An object to be solved by the present invention is to provide a scintillator panel and a radiation detector capable of suppressing the formation of a gap between the scintillator panel and the array substrate.

The scintillator panel according to the embodiment has a plate-like shape, has at least one prepreg having a plurality of carbon fibers, has a base capable of transmitting radiation, a scintillator provided on one surface side of the base, and the scintillator. The reflective portion provided between the base portion and the scintillator, the protective portion provided between the reflective portion and the scintillator, and the side of the base portion provided with the reflective portion It is equipped with a relaxation section provided on the opposite side. The reflecting portion has a reflecting layer provided on the scintillator side and capable of reflecting the fluorescence generated in the scintillator, and a first resin layer provided on the base side and containing a resin. The relaxation portion has a second resin layer containing a resin. The thickness of the base is 0.4 mm or less. The sum of the thickness of the first resin layer and the thickness of the second resin layer is larger than the thickness of the base portion.

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 base. (A) and (b) are schematic views for exemplifying the case where the relaxation portion is not provided. 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.

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, for example, 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 may 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 circuits 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 substrate, or these circuits can be provided separately on a plurality of substrates.

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 thin film transistor 2b2 is turned on by the control signal S1 input to the control line 2c1, and the electric charge (image data signal S2) from the storage capacitor 2b3 can be read out.

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. By doing so, 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 16) 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 may be provided with a substrate 11, a protective portion 15, a scintillator 16, and a moisture-proof portion 17.
The substrate 11 has a plate shape and is capable of transmitting X-rays. The substrate 11 can have a base portion 12, a reflection portion 13, and a relaxation portion 14.

The base 12 may be, for example, plate-shaped and may contain carbon-Fiber-Reinforced Plastic (CFRP). As will be described later, the base 12 can have, for example, at least one prepreg having a plurality of carbon fibers. In this case, the base 12 may have a plurality of types of prepregs in which the plurality of carbon fibers 121 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 base 12, can be, for example, a quadrangle. The prepreg has a plate shape, and for example, a plurality of carbon fibers 121 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 to 0.12 mm. The base portion 12 can be formed, for example, by laminating a plurality of prepregs and subjecting them to pressure heat treatment.

Here, the rigidity of the prepreg changes depending on the direction in which the carbon fibers 121 in the prepreg extend. That is, the rigidity of the prepreg is anisotropy depending on the direction in which the carbon fibers 121 in the prepreg are stretched.

FIG. 4 is a schematic perspective view for exemplifying the relationship between the extending direction of the carbon fiber 121 and the rigidity.
Considering only the direction in which the carbon fiber 121 is stretched without considering the planar shape of the prepreg, the bending strength B in the direction orthogonal to the direction A in which the carbon fiber 121 is stretched is the bending in the direction parallel to the direction A in which the carbon fiber 121 is stretched. 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 121 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 121 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 base 12.
The rigidity of the prepreg 12a provided on the surface (both ends in the thickness direction) of the base 12 at the position farthest from the line 120 (center) passing through the center of the base 12 in the thickness direction is the most rigid of the base 12. Contribute. Therefore, it is preferable to set the direction A in which the carbon fiber 121 extends in consideration of the planar shape of the prepreg 12a.

Further, by increasing the types of prepregs provided on the base portion 12 (types in the direction in which the carbon fibers 121 extend), the anisotropy of the rigidity at the base portion 12 can be reduced. However, if the number of types of prepregs is increased too much, the number of prepregs becomes too large and the manufacturing cost of the base 12 increases, or the rigidity of the base 12 becomes too large and the space between the array substrate 2 and the scintillator panel 10 increases. There is a risk of gaps.

For example, as shown in FIG. 5, three prepregs having a thickness of about 0.1 mm to 0.12 mm can be laminated. In this case, a plurality of carbon fibers 121 extend from the prepreg provided at a position symmetrical with respect to the line 120 (center portion) passing through the center of the base portion 12 in the thickness direction (position symmetrical with respect to the thickness direction). It is preferable that the directions are substantially the same.

For example, as shown in FIG. 5, the prepreg 12a can be provided at a position farthest from the line 120 passing through the center of the base portion 12 in the thickness direction, that is, on the front surface side and the back surface side of the base portion 12. The direction in which the carbon fibers 121 in the prepreg 12a, which most contributes to the rigidity of the base portion 12, extends can be a direction substantially parallel to the long side of the prepreg 12a (base portion 12).

The prepreg 12b can be provided between the prepreg 12a provided on the front surface side and the prepreg 12a provided on the back surface side. The direction in which the carbon fibers 121 extend in the prepreg 12b can be an angle of approximately 90 ° with respect to the long side of the prepreg 12b (base 12). The direction in which the carbon fibers 121 in the prepreg 12b extend may be an angle of more than 0 ° and 90 ° or less with respect to the long side of the prepreg 12b (base 12). However, if the extending direction of the carbon fibers 121 in the prepreg 12b is substantially orthogonal to the extending direction of the carbon fibers 121 in the prepreg 12a, it is possible to effectively suppress the occurrence of anisotropy in the rigidity of the base 12. ..

In the above, the case where the plane shape of the base 12 (prepregs 12a and 12b) is rectangular has been illustrated, but a part of the base 12 may be chamfered to form a polygon, or the corners of the base 12 may be chamfered with R or C. It can also be given.

Here, the base 12 (prepreg) formed of the carbon fiber reinforced plastic is less deformed by heat as compared with a general heat-resistant resin. Therefore, if the substrate 11 is provided with the base portion 12, it is possible to prevent the scintillator panel 10 from being warped or deformed even if the substrate 11 is heated when the scintillator 16 is formed on one surface side of the substrate 11. be able to.

Further, in the case of a general heat-resistant resin, the material shrinks or deforms easily due to heat, so that the shape of the warp or deformation becomes an irregular curved surface. On the other hand, in the case of the base portion 12 (prepreg) formed of carbon fiber reinforced plastic, the shape of the warp or deformation tends to be a simple quadric surface. Therefore, even if the scintillator panel 10 is warped or deformed, it can be easily corrected so that the scintillator panel 10 becomes substantially flat when pressed against the array substrate 2.

That is, if the base portion 12 is made of carbon fiber reinforced plastic, it is possible to suppress warpage and deformation when the scintillator 16 is formed. Further, even when warpage or deformation occurs, the shape of the warp or deformation that occurs in the scintillator panel 10 can be made into a simple shape that can be easily corrected.

In this case, for example, the degree of warpage or deformation that occurs may change depending on the formation conditions of the scintillator 16. Therefore, the number of prepregs provided on the base 12 and the type of prepreg (the type in the direction in which the carbon fibers 121 extend) can be appropriately determined according to the degree of warpage or deformation that occurs.

For example, if the warp or deformation becomes large to some extent, the number of prepregs and the types of prepregs can be increased. By doing so, the rigidity of the base portion 12 can be increased, so that warpage and deformation can be suppressed when the scintillator 16 is formed.

For example, if the warp and deformation can be reduced to some extent, the number of prepregs and the types of prepregs can be reduced. By doing so, since the rigidity of the base portion 12 can be reduced, it becomes easy to correct the scintillator panel 10 so that it becomes substantially flat when pressed against the array substrate 2.

According to the knowledge obtained by the present inventor, when the X-ray detector 1 is used for general medical treatment or the like, the number of prepregs is preferably 3 or less. For example, if the number of prepregs is three, the prepregs 12b can be provided between the prepregs 12a provided on the front surface side and the prepregs 12a provided on the back surface side, as illustrated in FIG. .. If the number of prepregs is two, for example, one prepreg 12a and one prepreg 12b can be provided. If the number of prepregs is one, prepregs 12a or prepregs 12b can be provided. If the number of prepregs is one, it is preferable to provide the prepregs 12a having a higher rigidity than the prepregs 12b.

As shown in FIGS. 2 and 3, the reflecting portion 13 can be provided on one surface of the base portion 12. The reflecting portion 13 can be provided, for example, so as to cover the entire area of one surface of the base portion 12. The reflection unit 13 can be provided in order to increase the utilization efficiency of fluorescence and improve the sensitivity characteristics. For example, the reflecting unit 13 reflects the light that is directed to the side opposite to the side where the photoelectric conversion unit 2b is provided among the fluorescence generated in the scintillator 16 so that the light is directed to the photoelectric conversion unit 2b. That is, the reflecting portion 13 is provided between the base portion 12 and the scintillator 16, and can reflect the fluorescence generated in the scintillator 16.

Further, as shown in FIG. 2, X-rays are incident on the scintillator 16 via the reflecting portion 13. Therefore, the reflecting unit 13 can transmit X-rays and have a high reflectance to fluorescence. As mentioned above, the base 12 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 base 12, or to directly attach the film to the surface of the base 12. Therefore, the reflective portion 13 can be a laminated structure including at least the resin layer 13a (corresponding to an example of the first resin layer) and the reflective layer 13c. The resin layer 13a is provided on the base 12 side and may contain a resin. The reflective layer 13c is provided on the scintillator 16 side, and can reflect the fluorescence generated in the scintillator 16.
For example, the reflective portion 13 may have a plate shape and may have a resin layer 13a, a bonding layer 13b, and a reflective layer 13c.

The resin layer 13a can be formed of, for example, a resin such as polyethylene terephthalate (PET). If the resin layer 13a is formed of resin, it becomes easy to join the resin layer 13a and the base portion 12 formed of carbon fiber reinforced plastic. Therefore, it becomes easy to join the resin layer 13a side of the reflective portion 13 to the surface of the base portion 12. The resin layer 13a side of the reflective portion 13 can be adhered to, for example, the base portion 12.

The bonding layer 13b can be provided between the resin layer 13a and the reflective layer 13c. As the bonding layer 13b, for example, the resin layer 13a and the reflective layer 13c can be bonded. The bonding layer 13b can be, for example, an adhesive layer containing a polyester resin. The resin layer 13a and the reflective layer 13c can also be directly bonded. For example, the plate-shaped resin layer 13a and the plate-shaped reflective layer 13c can be integrated by an autoclave molding method.

The reflective layer 13c may contain a metal such as aluminum or silver. The reflective layer 13c can be formed from, for example, an aluminum foil or a silver foil.

Here, if the thickness of the reflective layer 13c is made too thin, pinholes may occur or the reflectance may decrease. On the other hand, if the thickness of the reflective layer 13c is made too thick, the thermal stress generated by the heat when forming the scintillator 16 becomes large, and the base 12 is likely to be warped or the like. Therefore, the thickness of the reflective layer 13c is preferably 25 μm or more and 50 μm or less, for example.

The relaxation portion 14 can be provided on the surface of the base portion 12 opposite to the side on which the reflection portion 13 is provided. Here, when the scintillator 16 is formed, the base portion 12 and the reflecting portion 13 are heated.
6 (a) and 6 (b) are schematic views for exemplifying a case where the relaxation unit 14 is not provided.
FIG. 6A shows the state before the formation of the scintillator 16.
FIG. 6B shows the state after the formation of the scintillator 16.
Since the base portion 12 and the reflecting portion 13 have different coefficients of thermal expansion, their respective amounts of thermal expansion are different. Therefore, distortion or the like may occur when the scintillator 16 is formed, and as shown in FIG. 6B, warpage or the like may occur in the base portion 12 and the reflecting portion 13.

If the relaxation portion 14 is provided on the surface of the base portion 12 opposite to the reflection portion 13 side, the thermal stress generated on one surface side of the base portion 12 is canceled by the thermal stress generated on the other surface side. be able to. Therefore, it is possible to prevent the scintillator panel 10 from being warped or deformed when the scintillator 16 is formed.

The relaxation portion 14 may be provided, for example, in the entire area of the other surface of the base portion 12, or may be provided in a predetermined region of the surface of the base portion 12. In this case, it is preferable that the coefficient of thermal expansion and rigidity of the relaxation unit 14 are as close as possible to the coefficient of thermal expansion and rigidity of the reflection unit 13. For example, as shown in FIG. 3, the configuration of the relaxation unit 14 can be the same as the configuration of the reflection unit 13.

For example, the relaxation portion 14 may have a plate shape and may have a resin layer 14a (corresponding to an example of the second resin layer), a bonding layer 14b, and a reflective layer 14c. The thickness and material of the resin layer 14a can be the same as the thickness and material of the resin layer 13a. The thickness and material of the bonding layer 14b can be the same as the thickness and material of the bonding layer 13b. The thickness and material of the reflective layer 14c can be the same as the thickness and material of the reflective layer 13c. Since the rigidity of the bonding layer 14b and the reflective layer 14c is small, the bonding layer 14b and the reflective layer 14c can be omitted. That is, the bonding layer 14b may be provided as the relaxation portion 14. However, if the configuration of the relaxation unit 14 is the same as the configuration of the reflection unit 13, the manufacturing process can be simplified and the manufacturing cost can be reduced.

Here, as described above, the photoelectric conversion unit 2b is provided with a photoelectric conversion element 2b1 and a thin film transistor 2b2. Therefore, a step may occur in the region where the plurality of photoelectric conversion units 2b are provided due to the variation in the thickness of these elements. If there is a step in the region where the plurality of photoelectric conversion units 2b are provided, a gap may be partially generated when the scintillator panel 10 is joined to the array substrate 2. Such gaps cause sensitivity spots.

Therefore, if the thickness of the base portion 12 is made too thick, it becomes difficult to deform the substrate 11 and eventually the scintillator panel 10, so that it becomes difficult to join the scintillator panel 10 to the array substrate 2 without a gap. On the other hand, if the thickness of the base portion 12 is made too thin, the effect of suppressing warpage or deformation of the scintillator panel 10 when forming the scintillator 16 becomes small.

The reflecting portion 13 and the relaxing portion 14 also contribute to the rigidity of the substrate 11. In this case, the thin bonding layer 13b, the reflective layer 13c, the bonding layer 14b, and the reflective layer 14c have lower rigidity than the resin layer 13a and the resin layer 14a. Therefore, the rigidity of the substrate 11 is greatly affected by the rigidity of the base portion 12, the rigidity of the resin layer 13a, and the rigidity of the resin layer 14a.

In this case, if the rigidity of the base portion 12, the rigidity of the resin layer 13a, and the rigidity of the resin layer 14a are balanced, it becomes easy to join the scintillator panel 10 to the array substrate 2 without a gap, and the scintillator 16 is formed. At that time, it is possible to prevent the scintillator panel 10 from being warped or deformed.

According to the knowledge obtained by the present inventor, the thickness of the base 12 is preferably 0.4 mm or less. For example, if the thickness of the prepreg is about 0.1 mm to 0.12 mm, the number of laminated prepregs may be 3 or less.
Further, the total thickness of the resin layer 13a and the thickness of the resin layer 14a is preferably larger than the thickness of the base 12.

The reflective layer 13c is exposed on the surface of the reflective portion 13 opposite to the base 12 side. Further, the scintillator 16 is provided on the side of the reflecting portion 13 opposite to the base portion 12 side. In this case, when the reflective layer 13c and the scintillator 16 come into direct contact with each other, for example, the highly reducing metal contained in the reflective layer 13c and the highly oxidizing iodine contained in the scintillator 16 are contained in the air. A redox reaction may occur due to the slight amount of water vapor generated, and corrosion may occur in the reflective layer 13c. When corrosion occurs in the reflective layer 13c, the gloss of the reflective layer 13c may decrease, resulting in 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 a protective portion 15. The protective portion 15 can be provided on the surface of the reflective portion 13 opposite to the base 12 side. That is, the protective portion 15 can be provided between the reflective portion 13 (reflective layer 13c) and the scintillator 16. The protection unit 15 is, for example. A resin such as a polyimide resin can be included. The thickness of the protective portion 15 can be, for example, 5 μm or more and 20 μm or less.

The protective portion 15 has a film shape, and can be formed by a thermal CVD (thermal chemical vapor deposition) method or the like. In this case, as shown in FIG. 3, the protective portion 15 may be provided so as to cover the substrate 11 (base portion 12, reflection portion 13, relaxation portion 14).

The scintillator 16 can be provided on the reflecting portion 13 via the protective portion 15. The scintillator 16 can convert the incident X-rays into fluorescence (visible light). The scintillator 16 can be formed using, for example, cesium iodide (CsI): thallium (Tl), sodium iodide (NaI): thallium (Tl), or the like. The thickness of the scintillator 16 can be, for example, about 100 μm to 1500 μm. The scintillator 16 can be formed by, for example, a vacuum vapor deposition method or the like. If the scintillator 16 is formed by using a vacuum vapor deposition method or the like, the scintillator 16 composed of an aggregate of columnar crystals is formed. In this case, there is a gap between the columnar crystals.

Here, if the rigidity of the scintillator 16 becomes too large, the scintillator 16 may peel off from the substrate 11 when the scintillator panel 10 is deformed.
According to the findings obtained by the present inventor, the theoretical density of the scintillator 16 (the density when there is no gap between columnar crystals) is ρ (g / cm ³ ), and the projected area of the scintillator 16 in a plan view is determined. When S (cm ² ), the average thickness of the scintillator 16 is d (cm), and the weight of the scintillator 16 is W (g), “{W / (ρSd)} ≦ 0.811” is set. Is preferable. By doing so, the gap between the columnar crystals becomes large, so that it is possible to prevent the scintillator 16 from peeling off from the substrate 11 when the scintillator panel 10 is deformed. The plan view is a case where the scintillator 16 is viewed along the incident direction of X-rays.

The moisture-proof portion 17 can be provided in order to suppress deterioration of the characteristics of the scintillator 16 due to water vapor contained in the air. The moisture-proof portion 17 has a film shape and can be provided so as to cover the exposed portions of the base portion 12, the reflection portion 13, the protection portion 15, the scintillator 16, and the relaxation portion 14. The moisture-proof portion 17 can be formed of a material having a light-transmitting property and a small moisture-permeable coefficient. The moisture-proof portion 17 can be formed from, for example, polyparaxylylene, polymonochloroparaxylylene, polyfluoroparaxylylene, polydimethylparaxylylene, polydiethylparaxylylene and the like. The moisture-proof portion 17 can be formed by, for example, a thermal CVD method or the like.

When the scintillator 16 is an aggregate of columnar crystals, if the moisture-proof portion 17 is formed by using the thermal CVD method, the moisture-proof portion 17 can penetrate into the gap between the columnar crystals to some extent. Therefore, even if the surface of the scintillator 16 has irregularities due to columnar crystals, it is possible to form the moisture-proof portion 17 having a substantially uniform film thickness.

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 16 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 may 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 hardened by irradiation with ultraviolet rays.

Next, the scintillator panel 110 and the X-ray detector 1a according to another embodiment will be illustrated.
FIG. 7 is a schematic cross-sectional view of the scintillator panel 110 and the X-ray detector 1a.
FIG. 8 is a schematic cross-sectional view of the scintillator panel 110.
As shown in FIG. 7, the X-ray detector 1a may be provided with an array substrate 2, a scintillator panel 110, and a joint portion 20. Similar to the X-ray detector 1 described above, the X-ray detector 1a may be provided with the circuit board 3 and the image constituent unit 4.

The scintillator panel 110 may be provided with a substrate 111, a scintillator 16, and a moisture-proof portion 17.
The substrate 111 has a plate shape and is capable of transmitting X-rays. The substrate 111 can have a base 12, a reflecting 113, and a relaxation 114.

The reflecting portion 113 can be provided on one surface of the base portion 12. The reflecting portion 113 can be provided, for example, so as to cover the entire area of one surface of the base portion 12. The reflection unit 113 can be provided in order to increase the utilization efficiency of fluorescence and improve the sensitivity characteristics. For example, the reflection unit 113 reflects light that is directed to the side opposite to the side where the photoelectric conversion unit 2b is provided among the fluorescence generated in the scintillator 16 so that the light is directed to the photoelectric conversion unit 2b. That is, the reflecting portion 113 is provided between the base portion 12 and the scintillator 16, and can reflect the fluorescence generated in the scintillator 16.

Further, as shown in FIG. 7, X-rays enter the scintillator 16 via the reflecting portion 113. Therefore, the reflecting unit 113 can transmit X-rays and have a high reflectance to fluorescence. As mentioned above, the base 12 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 base 12, or to directly attach the film to the surface of the base 12. Therefore, the reflecting portion 113 may have a plate-shaped resin portion 113a and a plurality of light-scattering particles 113b provided inside the resin portion 113a. The light scattering particles 113b can be dispersed inside the resin portion 113a.

The resin portion 113a can be formed from, for example, polyethylene terephthalate. When the resin portion 113a contains polyethylene terephthalate and the moisture-proof portion 17 contains polyparaxylylene or the like formed by the thermal CVD method, the portion where the reflection portion 113 (resin portion 113a) and the moisture-proof portion 17 are in contact with each other has moisture. It has a high deterrent effect against the invasion of. Therefore, the scintillator panel 110 having high moisture-proof performance can be obtained.

The light scattering particles 113b can be, for example, TiO ₂ particles. If the reflective portion 113 has the resin portion 113a, it becomes easy to join the reflective portion 113 and the base portion 12 formed of carbon fiber reinforced plastic. The reflective portion 113 can be adhered to, for example, the base portion 12.

Further, the reflective portion 113 does not contain metal. Therefore, even if the scintillator 16 is directly formed on the reflecting portion 113, the reflecting portion 113 does not corrode. Therefore, the above-mentioned protection unit 15 can be omitted.

The relaxation portion 114 can be provided on the surface of the base portion 12 opposite to the side on which the reflection portion 113 is provided. Similar to the relaxation portion 14 described above, the relaxation portion 114 can be provided to cancel the thermal stress generated on one surface side of the base portion 12 with the thermal stress generated on the other surface side.

The relaxation portion 114 may be provided, for example, over the entire other surface of the base portion 12, or may be provided in a predetermined region of the surface of the base portion 12. In this case, it is preferable that the coefficient of thermal expansion and rigidity of the relaxation unit 114 are as close as possible to the coefficient of thermal expansion and rigidity of the reflection unit 113. For example, the relaxation portion 114 may have light-scattering particles 113b dispersed inside the plate-shaped resin portion 114a. The material and thickness of the resin portion 114a can be the same as the material and thickness of the resin portion 113a.

Since the light scattering particles 113b contained in the resin portion 114a have a small effect on the rigidity, the relaxation portion 114 does not have to include the light scattering particles 113b. That is, the resin portion 114a may be provided as the relaxation portion 114. However, if the configuration of the relaxation unit 114 is the same as that of the reflection unit 113, the manufacturing process can be simplified and the manufacturing cost can be reduced.

Further, as in the case of the scintillator panel 10 described above, the thickness of the base portion 12 is preferably 0.4 mm or less. Further, the total thickness of the resin portion 113a and the thickness of the resin portion 114a is preferably larger than the thickness of the base portion 12. In this way, it becomes easy to balance the rigidity of the base portion 12, the rigidity of the resin portion 113a, and the rigidity of the resin portion 114a. Therefore, it becomes easy to join the scintillator panel 110 to the array substrate 2 without a gap, and it is possible to prevent the scintillator panel 110 from being warped or deformed when the scintillator 16 is formed.

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.

1 X-ray detector, 1a X-ray detector, 2 array board, 2a board, 2b photoelectric conversion part, 3 circuit board, 4 image component part, 10 scintillator panel, 11 board, 12 bases, 12a, 12b prepreg, 13 reflection Part, 13a resin layer, 13b bonding layer, 13c reflective layer, 14 relaxation part, 14a resin layer, 14b bonding layer, 14c reflective layer, 15 protective part, 16 scintillator, 17 moisture-proof part, 110 scintillator panel, 111 substrate, 113 reflection Part, 113a resin layer, 113b light scattering particles, 114 relaxation part, 114a resin layer

Claims (5)

A base that is plate-shaped, has at least one prepreg with multiple carbon fibers, and is permeable to radiation,
A scintillator provided on one side of the base and
A reflective portion provided between the base portion and the scintillator,
A protective portion provided between the reflective portion and the scintillator,
A relaxation portion of the base portion provided on the side opposite to the side on which the reflection portion is provided, and a relaxation portion.
With
The reflective part is
A reflective layer provided on the scintillator side and capable of reflecting the fluorescence generated in the scintillator,
A first resin layer provided on the base side and containing a resin,
Have,
The relaxation portion has a second resin layer containing a resin, and has a second resin layer.
The thickness of the base is 0.4 mm or less.
A scintillator panel in which the sum of the thickness of the first resin layer and the thickness of the second resin layer is larger than the thickness of the base portion. A base that is plate-shaped, has at least one prepreg with multiple carbon fibers, and is permeable to radiation,
A scintillator provided on one side of the base and
A reflective portion provided between the base portion and the scintillator and having a resin portion and a plurality of light-scattering particles provided inside the resin portion.
A relaxation portion of the base portion, which is provided on the side opposite to the side where the reflection portion is provided and has a resin portion,
With
The thickness of the base is 0.4 mm or less.
A scintillator panel in which the sum of the thickness of the resin portion of the reflection portion and the thickness of the resin portion of the relaxation portion is larger than the thickness of the base portion. The theoretical density of the scintillator is ρ (g / cm ³ ), the projected area of the scintillator in plan view is S (cm ² ), the average thickness of the scintillator is d (cm), and the weight of the scintillator is W (g). The scintillator panel according to claim 1 or 2, which satisfies the following equation when
{W / (ρSd)} ≤ 0.811 The base 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 base portion is any one of claims 1 to 3 in which the directions in which the plurality of carbon fibers extend are substantially the same. The scintillator panel described in. An array board with multiple photoelectric conversion units and
The scintillator panel according to any one of claims 1 to 4 provided on the plurality of photoelectric conversion units.
Radiation detector equipped with.

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