Scintillator panel, radiation detector, scintillator panel manufacturing method, and radiation detector manufacturing method

A scintillator panel includes: a first flexible support body having a first surface and a second surface on a side opposite to the first surface; a scintillator layer formed on the first surface and containing a plurality of columnar crystals; a second flexible support body provided on the second surface; an inorganic layer provided on the second flexible support body so as to be interposed between the second surface and the second flexible support body; and a first adhesive layer bonding the second surface and the inorganic layer to each other. A radiation detector includes: the scintillator panel; and a sensor panel including a photoelectric conversion element, in which the scintillator panel is provided on the sensor panel such that the first surface is on the sensor panel side with respect to the second surface.

TECHNICAL FIELD

The present disclosure relates to a scintillator panel, a radiation detector, a scintillator panel manufacturing method, and a radiation detector manufacturing method.

BACKGROUND ART

A scintillator panel is described in Patent Literature 1. In this scintillator panel, a phosphor layer converting radiation into light is provided on a support body. In addition, the scintillator panel has a metal thin film layer having a thickness in the range of 1 to 500 nm on the surface of the support body on the side opposite to the surface having the phosphor layer. The support body is a roll-shaped scintillator panel support body cut to a predetermined size. Further, the light-emitting and side surfaces of the phosphor layer and the side surface of the support body are covered with a moisture-resistant protective film.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In the scintillator panel described above, moisture resistance is improved by the metal thin film layer and the moisture-resistant protective film. In the technical field described above, moisture resistance improvement is desired as described above. Meanwhile, in the scintillator panel described above, the surface of the metal thin film layer on the side opposite to the support body is exposed to the outside. Accordingly, it is difficult to ensure handleability in the scintillator panel described above.

An object of the present disclosure is to provide a scintillator panel, a radiation detector, a scintillator panel manufacturing method, and a radiation detector manufacturing method enabling moisture resistance improvement while ensuring handleability.

Solution to Problem

A scintillator panel according to the present disclosure includes: a first flexible support body having a first surface and a second surface on a side opposite to the first surface; a scintillator layer formed on the first surface and containing a plurality of columnar crystals; a second flexible support body provided on the second surface; an inorganic layer provided on the second flexible support body so as to be interposed between the second surface and the second flexible support body; and a first adhesive layer bonding the second surface and the inorganic layer to each other.

In this scintillator panel, the scintillator layer is formed on the first surface of the first flexible support body. Meanwhile, the inorganic layer is provided on the second surface of the first flexible support body via the first adhesive layer. Accordingly, in this scintillator panel, the inorganic layer suppresses moisture infiltration from the second surface side into the scintillator layer via the first flexible support body. Meanwhile, the inorganic layer may deteriorate due to contact during handling if the inorganic layer is exposed. On the other hand, the second flexible support body in this scintillator panel is disposed on the side of the inorganic layer opposite to the second surface of the first flexible support body, and thus the inorganic layer is protected from contact and deterioration of the inorganic layer is suppressed during handling. In this manner, in this scintillator panel, moisture resistance is improved while handleability is ensured. It should be noted that the side of the scintillator layer opposite to the first surface of the first flexible support body is usually provided with a sensor panel and so on and thus the necessity of moisture resistance improvement is relatively low.

The scintillator panel according to the present disclosure may include a protective layer provided so as to cover the first flexible support body, the scintillator layer, the second flexible support body, and the inorganic layer. In this case, the overall moisture resistance and handleability are further improved.

The scintillator panel according to the present disclosure may include a second adhesive layer bonding the inorganic layer and the second flexible support body to each other. In this manner, the inorganic layer may be bonded to the second flexible support body by an adhesive layer. In this case, the joining between the inorganic layer and the second flexible support body becomes stronger than in a case where, for example, the inorganic layer is formed by evaporation with respect to the second flexible support body.

In the scintillator panel according to the present disclosure, the first flexible support body and the second flexible support body may have a thickness of 50 μm or more and 250 μm or less in a first direction intersecting with the first surface, and the inorganic layer may have a thickness of 10 μm or more and 100 μm or less in the first direction and may be thinner than the first flexible support body and the second flexible support body in the first direction. By configuring the thickness of the inorganic layer relatively large in the range in which the inorganic layer is thinner than the first flexible support body and the second flexible support body as described above, radiolucency can be ensured and moisture resistance can be further improved at the same time.

In the scintillator panel according to the present disclosure, a difference between the thickness of the first flexible support body and the thickness of the second flexible support body in the first direction may be 0 or more and 90 μm or less. In this case, the overall warpage is suppressed since the difference in thickness is small between the first flexible support body and the second flexible support body.

In the scintillator panel according to the present disclosure, the inorganic layer may contain Al, Cu, Ti, Fe, or SUS as a material. In addition, in the scintillator panel according to the present disclosure, the first flexible support body and the second flexible support body may contain PET, PEN, PI, PP, PE, or PMMA as a material.

A radiation detector according to the present disclosure includes: the scintillator panel described above; and a sensor panel including a photoelectric conversion element, in which the scintillator panel is provided on the sensor panel such that the first surface is on the sensor panel side with respect to the second surface. This radiation detector includes the scintillator panel described above. Accordingly, with this radiation detector, handleability is ensured and moisture resistance is improved at the same time.

A scintillator panel manufacturing method according to the present disclosure includes: a step of forming a scintillator layer containing a plurality of columnar crystals on a first surface of a first flexible support body by an evaporation method; a step of preparing a second flexible support body provided with an inorganic layer; and a step of bonding the inorganic layer to the first flexible support body with a first adhesive layer such that the inorganic layer is interposed between a second surface of the first flexible support body on a side opposite to the first surface and the second flexible support body.

The scintillator layer is formed on the first surface of the first flexible support body by this manufacturing method. Meanwhile, the inorganic layer is provided on the second surface of the first flexible support body via an adhesive layer. Accordingly, in this scintillator panel, the inorganic layer suppresses moisture infiltration from the second surface side into the scintillator layer via the first flexible support body. Meanwhile, the inorganic layer may deteriorate due to contact during handling if the inorganic layer is exposed. On the other hand, by this method, the second flexible support body is disposed on the side of the inorganic layer opposite to the second surface of the first flexible support body, and thus the inorganic layer is protected from contact and deterioration of the inorganic layer is suppressed during handling. In this manner, the scintillator panel capable of improving moisture resistance while ensuring handleability is manufactured by this manufacturing method. It should be noted that the side of the scintillator layer opposite to the first surface of the first flexible support body is usually provided with a sensor panel and so on and thus the necessity of moisture resistance improvement is relatively low.

A radiation detector manufacturing method according to the present disclosure includes: a step of preparing the scintillator panel described above; a step of preparing a sensor panel including a photoelectric conversion element; and a step of providing the scintillator panel on the sensor panel such that the first surface is on the sensor panel side with respect to the second surface. The scintillator panel described above is used in this manufacturing method. Accordingly, a radiation detector capable of improving moisture resistance while ensuring handleability is manufactured.

Advantageous Effects of Invention

According to the present disclosure, a scintillator panel, a radiation detector, a scintillator panel manufacturing method, and a radiation detector manufacturing method enabling moisture resistance improvement while ensuring handleability can be provided.

DESCRIPTION OF EMBODIMENTS

Hereinafter, one embodiment will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding elements may be denoted by the same reference numerals with redundant description omitted.

The scintillator panel (and the radiation detector) according to the present embodiment converts (and detects) radiation such as X-rays into scintillation light such as visible light. In addition, the scintillator panel and the radiation detector (radiation imager) according to the present embodiment can be used in, for example, a medical X-ray diagnostic imaging apparatus such as a mammography apparatus, a chest examination apparatus, a CT apparatus, a dental intraoral imaging apparatus, and a radiation camera and a non-destructive inspection apparatus.

FIG.1is a schematic cross-sectional view illustrating the radiation detector according to the present embodiment. As illustrated inFIG.1, a radiation detector1includes a scintillator panel10and a sensor panel20. The scintillator panel10includes a first flexible support body11, a scintillator layer12, a second flexible support body13, an inorganic layer14, a first adhesive layer15, a second adhesive layer16, a protective layer18, and a protective layer19.

The first flexible support body11is formed in a flat plate shape here and has a first surface11aand a second surface11bon the side opposite to the first surface11a. The first surface11aand the second surface11bare parallel to each other. The first flexible support body11is flexible. Being flexible means being elastically deformable. Examples of the material of the first flexible support body11include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polypropylene (PP), polyethylene (PE), and acrylic (PMMA). As an example, the material of the first flexible support body11is PET, PEN, PI, PP, PE, or PMMA. Here, the material of the first flexible support body11is PET. It should be noted that the first flexible support body11may have an anchor coat layer made of a thermoplastic resin (e.g. acrylic) on the forming surface of the scintillator layer12so that adhesiveness is enhanced in relation to the scintillator layer12. When the scintillator layer12is configured by a plurality of columnar crystals in particular, the crystallinity of the roots of the columnar crystals is improved by the anchor coat layer.

The scintillator layer12is formed on the first surface11a. The scintillator layer12generates scintillation light in response to radiation incidence from the second surface11bside. The scintillator layer12contains a plurality of columnar crystals. As an example, the scintillator layer12is made of a plurality of columnar crystals. The scintillator layer12is suitable for high-resolution imaging by each columnar crystal having a light guide effect.

Examples of the material of the scintillator layer12include a material containing cesium iodide (CsI) as a main component such as CsI:Tl and CsI:Na, a material containing sodium iodide (NaI) as a main component such as Nat Tl, strontium iodide (SrI3), lutetium iodide (LuI3), barium fluoride (BaF2), and GOS. Here, the material of the scintillator layer12is a material containing CsI as a main component. The scintillator layer12can be formed by, for example, an evaporation method. The thickness of the scintillator layer12is, for example, 10 μm or more and 3000 μm or less. As a specific example, the thickness is 600 μm.

The second flexible support body13is formed in, for example, a flat plate shape. The second flexible support body13is flexible. Examples of the material of the second flexible support body13include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polypropylene (PP), polyethylene (PE), and acrylic (PMMA). As an example, the material of the second flexible support body13is PET, PEN, PI, PP, PE, or PMMA. Here, the material of the second flexible support body13is PET. In addition, the material of the first flexible support body11and the material of the second flexible support body13are, for example, the same.

The inorganic layer14is interposed between the second surface11bof the first flexible support body11and the second flexible support body13. The inorganic layer14is provided on the second flexible support body13. The second flexible support body13provided with the inorganic layer14is bonded to the second surface11bof the first flexible support body11by the first adhesive layer15. In other words, the first adhesive layer15bonds the second surface11band the inorganic layer14to each other.

The second adhesive layer16is interposed between the inorganic layer14and the second flexible support body13. The inorganic layer14is bonded to the second flexible support body13by the second adhesive layer16. In other words, the second adhesive layer16bonds the inorganic layer14and the second flexible support body13to each other. In this manner, the scintillator layer12, the first flexible support body11, the inorganic layer14, and the second flexible support body13are laminated in this order to form a laminated body17and are integrated by the first adhesive layer15and the second adhesive layer16.

The inorganic layer14is made of an inorganic material. As an example, the material of the inorganic layer14is a metal. More specifically, examples of the material of the inorganic layer14include aluminum (Al), copper (Cu), titanium (Ti), iron (Fe), and SUS. As an example, the material of the inorganic layer14is Al.

A thickness T11of the first flexible support body11in a first direction intersecting with the first surface11a(and the second surface11b) is, for example, 50 μm or more and 250 μm or less. Likewise, a thickness T13of the second flexible support body13in the first direction is, for example, 50 μm or more and 250 μm or less. The difference between the thickness T11of the first flexible support body11and the thickness T13of the second flexible support body13is, for example, 0 or more and 90 μm or less. As an example, the thickness T11of the first flexible support body11is equal to the thickness T13of the second flexible support body13(the difference in thickness is 0). A thickness T14of the inorganic layer14in the first direction is, for example, 10 μm or more and 100 μm or less. The thickness T14is smaller than the thickness T11of the first flexible support body11and the thickness T13of the second flexible support body13. The thickness T14of the inorganic layer14is, for example, 30 μm.

The protective layer18is provided on the surface of the scintillator layer12on the side opposite to the first flexible support body11. The protective layer19is provided so as to cover the laminated body17(that is, the first flexible support body11, the scintillator layer12, and the inorganic layer14) and the protective layer18. As a result, the plurality of (two here) protective layers18and19are disposed on the surface of the scintillator layer12on the side opposite to the first flexible support body11. The material of the protective layers18and19is, for example, an organic material such as a resin, examples of which include parylene (polyparaxylene).

The sensor panel20includes a photoelectric conversion element. The sensor panel20detects the scintillation light generated by the scintillator panel10and outputs a signal corresponding to the scintillation light. The sensor panel20has a mounting surface21. A protective layer22is formed on the mounting surface21. Examples of the material of the protective layer22include an oxide film, a nitride film, a fluorine-based resin, and an aromatic resin. It should be noted that the protective layer22may not be formed.

The scintillator panel10is mounted on the mounting surface21via the protective layer22. More specifically, the scintillator panel10is mounted on the mounting surface21such that the first surface11aof the first flexible support body11and the scintillator layer12face the mounting surface21. A third adhesive layer23is interposed between the scintillator panel10and the mounting surface21(protective layer22). The scintillator panel10and the sensor panel20are bonded to each other by the third adhesive layer23. It should be noted that the first adhesive layer15, the second adhesive layer16, and the third adhesive layer23can be configured by any adhesive and sticky material, examples of which include a tape-shaped adhesive material (double-sided tape).

A method for manufacturing the radiation detector according to the present embodiment will be described below.FIGS.2and3are schematic cross-sectional views illustrating one step of the method for manufacturing the radiation detector1illustrated inFIG.1. As illustrated inFIGS.2and3, in this manufacturing method, a first step of preparing the scintillator panel10and a second step of preparing the sensor panel20are carried out first. The first step and the second step may be carried out in any order. The first step is a method for manufacturing the scintillator panel according to the present embodiment.

In the first step, a third step of preparing a first structure P1and a fourth step of preparing a second structure P2are carried out first as illustrated inFIGS.2(a) and2(b). The third step and the fourth step may be carried out in any order. In the third step, the first structure P1is configured by the inorganic layer14being bonded to one surface of the second flexible support body13by the second adhesive layer16. In other words, the third step is a step of preparing the second flexible support body13provided with the inorganic layer14. In the fourth step, the second structure P2is configured by the scintillator layer12being formed on the first surface11aof the first flexible support body11by, for example, an evaporation method.

As illustrated inFIG.2(c), in the first step, a fifth step of configuring the laminated body17by laminating the first structure P1and the second structure P2on each other is carried out subsequently. In the fifth step, the first structure P1is bonded to the second structure P2by the first adhesive layer15such that the inorganic layer14is interposed between the second surface11bof the first flexible support body11and the second flexible support body13. Here, the inorganic layer14is bonded to the second surface11b.

As illustrated inFIG.3(a), in the first step, a sixth step of configuring the scintillator panel10by providing the protective layers18and19with respect to the laminated body17is carried out subsequently. In the sixth step, the protective layer18is formed first on the surface of the scintillator layer12on the side opposite to the first flexible support body11(one surface of the laminated body17). In the sixth step, the protective layer19is subsequently formed so as to cover the entire laminated body17and the entire protective layer18. The scintillator panel10is manufactured as a result.

Meanwhile, in the second step, the sensor panel20is prepared as illustrated inFIG.3(b). The third adhesive layer23is provided on the mounting surface21of the sensor panel20via the protective layer22.

Then, in this manufacturing method, a seventh step of providing the scintillator panel10on the sensor panel20after the first step and the second step is carried out. In the seventh step, the scintillator panel10is provided on the sensor panel20such that the first surface11ais on the sensor panel20side with respect to the second surface11bof the first flexible support body11. More specifically, in a state where the surface of the scintillator layer12on the side opposite to the first flexible support body11faces the mounting surface21, the surface is bonded to the mounting surface21by the third adhesive layer23(via the protective layers18,19, and22). The radiation detector illustrated inFIG.1is manufactured as a result.

FIGS.4and5are diagrams for describing a moisture resistance-related effect.FIG.4(a)is a schematic cross-sectional view of a scintillator panel10A according to an embodiment, andFIG.4(b)is a schematic cross-sectional view of a scintillator panel10B according to a comparative example. The scintillator panel10A is the same as the scintillator panel10except that the protective layers18and19are not provided. The scintillator panel10B differs from the scintillator panel10A in that the scintillator panel10B does not include the inorganic layer14and the second flexible support body13. Both the scintillator panels10A and10B are mounted on a mounting surface21A of a glass substrate20A for testing.

As illustrated inFIG.5, in each of the scintillator panel10A and the scintillator panel10B according to the comparative example, the resolution declines with time due to the deliquescence of the scintillator layer12attributable to moisture infiltration from the side surface. However, the decline in resolution in the scintillator panel10A is suppressed as compared with the scintillator panel10B. It is conceivable that this is because the inorganic layer14suppresses the moisture infiltration from the side opposite to the glass substrate20A.

As described above, in the scintillator panel10, the scintillator layer12is formed on the first surface11aof the first flexible support body11. Meanwhile, the inorganic layer14is provided on the second surface11bof the first flexible support body11via the first adhesive layer15. Accordingly, in the scintillator panel10, the inorganic layer14suppresses moisture infiltration from the second surface11bside into the scintillator layer12via the first flexible support body11. Meanwhile, the inorganic layer14may deteriorate due to contact during handling if the inorganic layer14is exposed.

On the other hand, the second flexible support body13in the scintillator panel10is disposed on the side of the inorganic layer14opposite to the second surface11bof the first flexible support body11, and thus the inorganic layer14is protected from contact and deterioration of the inorganic layer14is suppressed during handling. In this manner, in the scintillator panel10, moisture resistance is improved while handleability is ensured. It should be noted that the side of the scintillator layer12opposite to the first surface11aof the first flexible support body11is usually provided with the sensor panel20and so on and thus the necessity of moisture resistance improvement is relatively low.

In addition, the scintillator panel10includes the protective layer19provided so as to cover the laminated body17including the first flexible support body11, the scintillator layer12, the second flexible support body13, and the inorganic layer14. Accordingly, the overall moisture resistance and handleability are further improved.

In addition, the scintillator panel10includes the second adhesive layer16bonding the inorganic layer14and the second flexible support body13to each other. Accordingly, the joining between the inorganic layer14and the second flexible support body13becomes stronger than in a case where, for example, the inorganic layer14is formed by evaporation with respect to the second flexible support body13.

In addition, in the scintillator panel10, the thicknesses T11and T13of the first flexible support body11and the second flexible support body13in the first direction intersecting with the first surface11aare 50 μm or more and 250 μm or less. In addition, the thickness T14of the inorganic layer14in the first direction is 10 μm or more and 100 μm or less and is smaller than the thicknesses T11and T13of the first flexible support body11and the second flexible support body13in the first direction. By configuring the thickness T14of the inorganic layer14relatively large in the range in which the inorganic layer14is thinner than the first flexible support body11and the second flexible support body13as described above, radiolucency can be ensured and moisture resistance can be further improved at the same time. In addition, a pinhole is likely to be generated in the inorganic layer14and moisture resistance is likely to be impaired if the thickness T14of the inorganic layer14is, for example, approximately several hundred nanometers.

In addition, in the scintillator panel10, the difference between the thickness T11of the first flexible support body11and the thickness T13of the second flexible support body13in the first direction is 0 or more and 90 μm or less. Accordingly, the overall warpage is suppressed since the difference in thickness is small between the first flexible support body11and the second flexible support body13.

In addition, the radiation detector1includes the scintillator panel10. Accordingly, with the radiation detector1, handleability is ensured and moisture resistance is improved at the same time.

In addition, the scintillator layer12is formed on the first surface11aof the first flexible support body11by the scintillator panel manufacturing method according to the present embodiment. Meanwhile, the inorganic layer14is provided on the second surface11bof the first flexible support body11via the first adhesive layer15. Accordingly, in the scintillator panel10obtained by this manufacturing method, the inorganic layer14suppresses moisture infiltration from the second surface11bside into the scintillator layer12via the first flexible support body11. Meanwhile, the inorganic layer14may deteriorate due to contact during handling if the inorganic layer14is exposed.

On the other hand, by this manufacturing method, the second flexible support body13is disposed on the side of the inorganic layer14opposite to the second surface11bof the first flexible support body11, and thus the inorganic layer14is protected from contact and deterioration of the inorganic layer14is suppressed during handling. In this manner, the scintillator panel10capable of improving moisture resistance while ensuring handleability is manufactured by this manufacturing method. It should be noted that the side of the scintillator layer12opposite to the first surface11aof the first flexible support body11is usually provided with the sensor panel20and so on and thus the necessity of moisture resistance improvement is relatively low.

Further, the scintillator panel10is used in the radiation detector manufacturing method according to the present embodiment. Accordingly, the radiation detector1capable of improving moisture resistance while ensuring handleability is manufactured.

One form of the present disclosure has been described in the above embodiment. Accordingly, the present disclosure is not limited to the above embodiment and various modifications can be made.

INDUSTRIAL APPLICABILITY

According to the present disclosure, a scintillator panel, a radiation detector, a scintillator panel manufacturing method, and a radiation detector manufacturing method enabling moisture resistance improvement while ensuring handleability are provided.

REFERENCE SIGNS LIST