Radiation detection device

Abstract

The present invention provides a radiation detection device that can suppress the deterioration of a light-receiving sensor caused by radiation incidence. [Solution] The radiation detection device 1 comprises a circuit board 2, a light receiving sensor 3 including a light receiving section 32 and a first terminal 33 positioned on one side in the Y direction relative to the light receiving section 32 when viewed from the Z direction, a fiber optic plate 6 having a light incident surface 6a, a light emission surface 6b, and a first side surface 6c, and positioned on the light receiving sensor 3 such that the light emission surface 6b faces the light receiving section 32, a scintillator layer 7 positioned on the light incident surface 6a, a first wire 4A stretched between the circuit board 2 and the first terminal 33, and a first shielding member 9A positioned on the first side surface 6c and formed of radiation shielding rubber. When viewed from the Z direction, the first shielding member 9A includes at least the first terminal 33.

Description

Technical Field

[0001] The present invention relates to a radiation detection device.

Background Art

[0002] As a conventional radiation detection device, there is known a radiation detection device including a circuit board, a light receiving sensor disposed on the circuit board, a fiber optic plate disposed on the light receiving portion of the light receiving sensor, a scintillator layer disposed on the fiber optic plate, and a wire stretched between the circuit board and the terminal of the light receiving sensor (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a radiation detection device, since the incidence of radiation to the light receiving portion of the light receiving sensor is suppressed by the fiber optic plate, it is possible to suppress the deterioration of the light receiving sensor caused by the deterioration of the light receiving portion. However, since a wire exists in the portion of the light receiving sensor where the terminal is provided, it may be difficult to dispose the fiber optic plate. In this case, radiation may enter the portion of the light receiving sensor where the terminal is provided, and the light receiving sensor may deteriorate.

[0005] An object of the present invention is to provide a radiation detection device capable of suppressing the deterioration of a light receiving sensor caused by the incidence of radiation.

Means for Solving the Problems

[0006] The radiation detection device of the present invention is [1] "a radiation detection device comprising: a circuit board having a mounting surface intersecting a first direction; a light receiving sensor disposed on the mounting surface, including a light receiving section and a first terminal disposed on one side in a second direction intersecting the first direction relative to the light receiving section when viewed from the first direction; a fiber optic plate having a light incident surface and a light emission surface facing each other in the first direction, and a first side surface extending in the first direction, disposed on the light receiving sensor such that the light emission surface faces the light receiving section; a scintillator layer disposed on the light incident surface; a first wire stretched between the circuit board and the first terminal; and a first shielding member disposed on the first side surface and formed of radiation shielding rubber, wherein when viewed from the first direction, the first shielding member includes at least the first terminal."

[0007] In the above-described radiation detection device, a first shielding member formed of radiation shielding rubber is positioned on the first side surface of the fiber optic plate, and when viewed from a first direction, the first shielding member includes at least a first terminal. As a result, in addition to the fiber optic plate and scintillator layer suppressing the incidence of radiation to the portion of the light-receiving sensor where the light-receiving part is provided, the first shielding member also suppresses the incidence of radiation to the portion of the light-receiving sensor where the first terminal is provided. Furthermore, because the first shielding member is formed of radiation shielding rubber, the occurrence of a gap between the first side surface of the fiber optic plate and the first shielding member is suppressed, and as a result, the incidence of radiation to the light-receiving sensor through the gap is also suppressed. Thus, the above-described radiation detection device can suppress the deterioration of the light-receiving sensor caused by radiation incidence.

[0008] The radiation detection device of the present invention may also be [2] "the radiation detection device according to [1], wherein the first terminal is each of a plurality of first terminals arranged in a third direction that intersects both the first direction and the second direction, and when viewed from the first direction, the first shielding member includes at least the plurality of first terminals." According to this radiation detection device, in a configuration in which a plurality of first terminals are arranged in a third direction, deterioration of the light receiving sensor caused by incident radiation can be suppressed.

[0009] The radiation detection device of the present invention may also be the radiation detection device according to [1] or [2], further comprising a second wire and a second shielding member, wherein the light receiving sensor further includes a second terminal located on the other side in the second direction relative to the light receiving portion when viewed from the first direction, the fiber optic plate further has a second side facing the first side in the second direction, the second wire is stretched between the circuit board and the second terminal, the second shielding member is located on the second side and is formed of radiation shielding rubber, and when viewed from the first direction, the second shielding member includes at least the second terminal. According to this radiation detection device, in a configuration in which the second terminal is located on the other side in the second direction relative to the light receiving portion when viewed from the first direction, deterioration of the light receiving sensor due to radiation incidence can be suppressed.

[0010] The radiation detection device of the present invention may also be the radiation detection device according to [3], wherein the second terminal is each of a plurality of second terminals arranged in a third direction that intersects both the first and second directions, and when viewed from the first direction, the second shielding member includes at least the plurality of second terminals. According to this radiation detection device, in a configuration in which a plurality of second terminals are arranged in a third direction, deterioration of the light receiving sensor caused by incident radiation can be suppressed.

[0011] The radiation detection device of the present invention may be [5] "the radiation detection device according to any one of [1] to [4], wherein the first shielding member is each of a plurality of first shielding members arranged in a first direction on the first side surface." According to this radiation detection device, the incidence of radiation to the portion of the light receiving sensor provided with the first terminal can be reliably suppressed. [Effects of the Invention]

[0012] According to this invention, it is possible to provide a radiation detection device that can suppress the deterioration of a light receiving sensor caused by the incidence of radiation. [Brief explanation of the drawing]

[0013] [Figure 1] This is a plan view of an example of a radiation detection device. [Figure 2] This is a cross-sectional view taken along the line II-II shown in Figure 1. [Figure 3] This is a cross-sectional view of a modified radiation detection device. [Modes for carrying out the invention]

[0014] An example of the present invention will be described in detail below with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0015] As shown in Figures 1 and 2, the radiation detection device 1 comprises a circuit board 2, a light receiving sensor 3, a plurality of first wires 4A, a plurality of second wires 4B, a first protective member 5A, a second protective member 5B, an FOP (fiber optic plate) 6, a scintillator layer 7, a protective film 8, a first shielding member 9A, and a second shielding member 9B. The radiation detection device 1 is a device that detects radiation emitted from a radiation source and transmitted through an object under inspection, and is used, for example, in industrial non-destructive testing. The radiation is, for example, X-rays, gamma rays, electron beams, etc.

[0016] The circuit board 2 has a mounting surface 2a that intersects with the Z direction (first direction). In this example, the mounting surface 2a is a surface perpendicular to the Z direction. For example, the mounting surface 2a has a rectangular shape with the X direction (second direction intersecting the first direction), which is perpendicular to the Z direction, as the longer side, and the Y direction (third direction intersecting both the first and second directions), which is perpendicular to both the Z and X directions, as the shorter side. The circuit board 2 is provided with a plurality of first pads 21 and a plurality of second pads 22. Each pad 21, 22 is provided on the circuit board 2 so as to be exposed to the outside on the mounting surface 2a. The plurality of first pads 21 are arranged on one side in the Y direction relative to the center of the mounting surface 2a in the Y direction and are aligned in the X direction. The plurality of second pads 22 are arranged on the other side in the Y direction relative to the center of the mounting surface 2a in the Y direction and are aligned in the X direction.

[0017] The circuit board 2 is further provided with a plurality of first lead pins 23 and a plurality of second lead pins 24. Each lead pin 23, 24 is provided on the circuit board 2 so as to protrude from the back surface 2b of the circuit board 2 along the Z direction. The back surface 2b is the surface of the circuit board 2 opposite to the mounting surface 2a. The plurality of first lead pins 23 are arranged on one side in the Y direction relative to the plurality of first pads 21 when viewed from the Z direction, and are aligned along the X direction. The plurality of second lead pins 24 are arranged on the other side in the Y direction relative to the plurality of second pads 22 when viewed from the Z direction, and are aligned along the X direction. On the circuit board 2, the corresponding first pads 21 and first lead pins 23 are electrically connected to each other via wiring (not shown), and the corresponding second pads 22 and second lead pins 24 are electrically connected to each other via wiring (not shown).

[0018] The light-receiving sensor 3 is positioned on the mounting surface 2a. The light-receiving sensor 3 is fixed to the mounting surface 2a so that it is positioned between a plurality of first pads 21 and a plurality of second pads 22 when viewed from the Z direction. As an example, the light-receiving sensor 3 has a rectangular plate shape with the X direction as the long side, the Y direction as the short side, and the Z direction as the thickness. The light-receiving sensor 3 has a semiconductor substrate 31. The semiconductor substrate 31 is provided with a light-receiving section 32, a plurality of first terminals 33, and a plurality of second terminals 34. The light-receiving section 32 is provided on the semiconductor substrate 31 so as to be located on the surface 31a side. Surface 31a is the surface of the semiconductor substrate 31 opposite to the circuit board 2. The light-receiving section 32 is composed of a plurality of pixels that perform photoelectric conversion. These plurality of pixels are arranged in a matrix, for example, with the X-axis direction as the row direction and the Y-axis direction as the column direction.

[0019] Each terminal 33, 34 is provided on the semiconductor substrate 31 so as to be exposed to the outside on the surface 31a. The multiple first terminals 33 are arranged on one side in the Y direction relative to the light receiving unit 32 when viewed from the Z direction, and are aligned in the X direction. The multiple second terminals 34 are arranged on the other side in the Y direction relative to the light receiving unit 32 when viewed from the Z direction, and are aligned in the X direction. In the light receiving sensor 3, the corresponding pixels and first terminals 33 are electrically connected to each other via wiring (not shown), and the corresponding pixels and second terminals 34 are electrically connected to each other via wiring (not shown). In this example, the light receiving sensor 3 is a TDI-CCD (Time Delay Integration - Charge Coupled Device).

[0020] Each first wire 4A is stretched between the circuit board 2 and each first terminal 33. Specifically, each first wire 4A is connected to each first terminal 33 at one end 4a and to each first pad 21 of the circuit board 2 at the other end 4b. That is, each first wire 4A electrically connects the corresponding first terminal 33 and first pad 21 to each other. The plurality of first wires 4A, the plurality of first pads 21, and the plurality of first terminals 33 are covered by a first protection member 5A. The first protection member 5A is formed of, for example, resin.

[0021] Each second wire 4B is stretched between the circuit board 2 and each second terminal 34. Specifically, each second wire 4B is connected to each second terminal 34 at one end 4c and to each second pad 22 of the circuit board 2 at the other end 4d. That is, each second wire 4B electrically connects the corresponding second terminal 34 and second pad 22 to each other. The plurality of second wires 4B, the plurality of second pads 22, and the plurality of second terminals 34 are covered by a second protection member 5B. The second protection member 5B is formed of, for example, resin.

[0022] FOP6 is an optical device composed of a bundle of a plurality of optical fibers 61. FOP6 is formed, for example, in a rectangular parallelepiped shape with the X direction as the longitudinal direction. FOP6 has a light incident surface 6a and a light emission surface 6b facing each other in the Z direction, and a first side surface 6c and a second side surface 6d facing each other in the Y direction. Each side surface 6c, 6d extends in the Z direction. FOP6 is arranged on the light receiving sensor 3 such that the light emission surface 6b faces the light receiving portion 32. FOP6 is fixed to the surface 31a of the semiconductor substrate 31. Each optical fiber 61 extends from the light incident surface 6a to the light emission surface 6b so as to enable light guiding to the light receiving portion 32.

[0023] The scintillator layer 7 is disposed on the light incident surface 6a of the FOP 6. The scintillator layer 7 emits light in response to the incidence of radiation. As an example, the scintillator layer 7 is formed by depositing, coating, or adhering a scintillator material including CsI, GOS, etc. on the light incident surface 6a.

[0024] The protective film 8 integrally covers the outer surfaces of the FOP 6 and the scintillator layer 7. The protective film 8 is formed of, for example, parylene (polyphenylene). The protective film 8 has a function of protecting the scintillator layer 7 from moisture and the like.

[0025] The first shielding member 9A is disposed on the first side surface 6c of the FOP 6 through the protective film 8. The first shielding member 9A is formed of tungsten rubber (rubber containing tungsten which is a radiation shielding material). As an example, the first shielding member 9A has a rectangular parallelepiped shape with the X direction as the longitudinal direction. When viewed from the Z direction, the first shielding member 9A includes a plurality of first terminals 33, a plurality of first wires 4A, a plurality of first pads 21, and a first protective member 5A. As an example, the first shielding member 9A may be supported by a support member (not shown) so as to contact the first side surface 6c of the FOP 6, or may be joined to the first side surface 6c of the FOP 6 by a joining member (not shown). Note that when one member includes another member when viewed from the Z direction, it means that the outer edge of one member is located outside the outer edge of the other member.

[0026] The second shielding member 9B is disposed on the second side surface 6d of the FOP 6 through the protective film 8. The second shielding member 9B is formed of tungsten rubber. As an example, the second shielding member 9B has a rectangular parallelepiped shape with the X direction as the longitudinal direction. When viewed from the Z direction, the second shielding member 9B includes a plurality of second terminals 34, a plurality of second wires 4B, a plurality of second pads 22, and a second protective member 5B. As an example, the second shielding member 9B may be supported by a support member (not shown) so as to contact the second side surface 6d of the FOP 6, or may be joined to the second side surface 6d of the FOP 6 by a joining member (not shown).

[0027] In the radiation detection device 1 configured as described above, when radiation is incident on the scintillator layer 7 from one side in the Z direction (the side opposite to the circuit board 2), light is emitted from the scintillator layer 7. The light emitted from the scintillator layer 7 is incident on the light incident surface 6a of the FOP 6, guided to the light emission surface 6b by each optical fiber 61 constituting the FOP 6, and emitted from the light emission surface 6b of the FOP 6. The light emitted from the light emission surface 6b is incident on the light receiving unit 32 and detected by the light receiving sensor 3. The electrical signal generated in the light receiving sensor 3 is output to the outside via the electrically connected terminals 33, 34, wires 4A, 4B, pads 21, 22, and lead pins 23, 24.

[0028] As described above, in the radiation detection device 1, a first shielding member 9A made of tungsten rubber is positioned on the first side surface 6c of the FOP 6, and when viewed from the Z direction, the first shielding member 9A includes a plurality of first terminals 33. Similarly, a second shielding member 9B made of tungsten rubber is positioned on the second side surface 6d of the FOP 6, and when viewed from the Z direction, the second shielding member 9B includes a plurality of second terminals 34. As a result, in addition to the FOP 6 and scintillator layer 7 suppressing the incidence of radiation to the portion of the light receiving sensor 3 where the light receiving part 32 is provided, the first shielding member 9A suppresses the incidence of radiation to the portion of the light receiving sensor 3 where the plurality of first terminals 33 are provided, and the second shielding member 9B suppresses the incidence of radiation to the portion of the light receiving sensor 3 where the plurality of second terminals 34 are provided. Furthermore, since the first shielding member 9A is made of tungsten rubber, the occurrence of a gap between the first side surface 6c of the FOP 6 and the first shielding member 9A is suppressed, and as a result, the incidence of radiation to the light receiving sensor 3 through the gap is also suppressed. Similarly, since the second shielding member 9B is made of tungsten rubber, the occurrence of a gap between the second side surface 6d of the FOP 6 and the second shielding member 9B is suppressed, and as a result, the incidence of radiation to the light receiving sensor 3 through the gap is also suppressed. Thus, with the radiation detection device 1, in a configuration in which a plurality of first terminals 33 and a plurality of second terminals 34 are aligned in the X direction, the deterioration of the light receiving sensor 3 caused by the incidence of radiation can be suppressed.

[0029] In the radiation detection device 1, when viewed from the Z direction, the first shielding member 9A includes not only a plurality of first terminals 33, but also a plurality of first wires 4A, a plurality of first pads 21, and a first protective member 5A. Similarly, when viewed from the Z direction, the second shielding member 9B includes not only a plurality of second terminals 34, but also a plurality of second wires 4B, a plurality of second pads 22, and a second protective member 5B. As a result, the incidence of radiation to the plurality of first wires 4A, the portion of the circuit board 2 where the plurality of first pads 21 are provided, and the first protective member 5A is suppressed by the first shielding member 9A, while the incidence of radiation to the plurality of second wires 4B, the portion of the circuit board 2 where the plurality of second pads 22 are provided, and the second protective member 5B is suppressed by the second shielding member 9B. Therefore, their deterioration caused by radiation incidence can also be suppressed.

[0030] This invention is not limited to the example described above. For example, as shown in Figure 3, a plurality of first shielding members 9A arranged in the Z direction may be placed on the first side surface 6c, and a plurality of second shielding members 9B arranged in the Z direction may be placed on the second side surface 6d. With such a configuration, the incidence of radiation to the portion of the light receiving sensor 3 provided with a plurality of first terminals 33 can be reliably suppressed, and the incidence of radiation to the portion of the light receiving sensor 3 provided with a plurality of second terminals 34 can also be reliably suppressed. Note that reducing the tungsten content of each shielding member 9A, 9B improves the flexibility of each shielding member 9A, 9B, but tends to decrease the radiation shielding performance of each shielding member 9A, 9B. Therefore, when the tungsten content of each shielding member 9A is reduced in order to improve adhesion to the first side surface 6c of the FOP 6, the radiation shielding performance of the plurality of first shielding members 9A as a whole can be improved by arranging a plurality of first shielding members 9A arranged in the Z direction on the first side surface 6c. Similarly, if the tungsten content of each shielding member 9B is reduced to improve adhesion to the second side surface 6d of the FOP6, the radiation shielding performance of the multiple second shielding members 9B as a whole can be improved by arranging multiple second shielding members 9B aligned in the Z direction on the second side surface 6d. Note that when multiple first shielding members 9A are used, multiple first shielding members 9A having different tungsten content may be combined. Similarly, when multiple second shielding members 9B are used, multiple second shielding members 9B having different tungsten content may be combined.

[0031] Furthermore, the light receiving sensor 3 does not have to include multiple second terminals 34, but may include multiple first terminals 33, in which case the first shielding member 9A is provided on the first side surface 6c of the FOP 6. In other words, in that case the second shielding member 9B is not provided on the second side surface 6d of the FOP 6. Also, the light receiving sensor 3 only needs to include at least one first terminal 33, and the first shielding member 9A only needs to include that at least one first terminal 33 when viewed from the Z direction.

[0032] Furthermore, the shielding members 9A and 9B are not limited to those formed in the shapes described above. For example, the first shielding member 9A may include a main body extending in the X direction and a plurality of protrusions (e.g., a pair of protrusions) each protruding to one side in the Y direction and extending in the X direction. Similarly, the second shielding member 9B may include a main body extending in the X direction and a plurality of protrusions (e.g., a pair of protrusions) each protruding to the other side in the Y direction and extending in the X direction. In these cases, the main body and the plurality of protrusions may be integrally formed from tungsten rubber. Also, the first shielding member 9A may be formed in an annular shape so as to surround the FOP 6. With such a configuration, the incidence of radiation to the portion where the first terminal 33 and the second terminal 34 are provided can be blocked by the first shielding member 9A alone, thus reducing the number of parts.

[0033] Furthermore, in FOP6, each side surface 6c, 6d may be inclined with respect to the Z direction, as long as it extends in the Z direction. Also, FOP6 may have one first side surface 6c, for example, when the side surface of FOP6 is a cylindrical surface.

[0034] Furthermore, in the light-receiving sensor 3, the light-receiving section 32 may be provided on the semiconductor substrate 31 so as to be located on the surface side opposite to the surface 31a. In other words, the light-receiving sensor 3 may be a back-incident solid-state image sensor. Also, the sides 6c, 6d of the FOP 6 may not be covered by the protective film 8, and the shielding members 9A, 9B may be directly arranged on the sides 6c, 6d of the FOP 6. In addition, the radiation detection device 1 may not be equipped with the first protective member 5A and the second protective member 5B.

[0035] Furthermore, in all of the above examples, each shielding member 9A, 9B is not limited to being made of tungsten rubber, as long as it is made of radiation shielding rubber (rubber containing radiation shielding material). The radiation shielding rubber may, for example, contain at least one substance selected from tungsten, lead, antimony, molybdenum, copper, bismuth, barium, etc., as a metal powder, or it may contain these substances as a compound such as barium sulfate. [Explanation of Symbols]

[0036] 1...Radiation detection device, 2...Circuit board, 2a...Mounting surface, 3...Light receiving sensor, 4A...First wire, 4B...Second wire, 6...FOP (Fiber Optic Plate), 6a...Light incident surface, 6b...Light emission surface, 6c...First side surface, 6d...Second side surface, 7...Scintillator layer, 9A...First shielding member, 9B...Second shielding member, 32...Light receiving section, 33...First terminal, 34...Second terminal.

Claims

1. A circuit board having a mounting surface intersecting the first direction, A light-receiving sensor is provided on the mounting surface, including a light-receiving section and a first terminal located on one side of a second direction that intersects the first direction with respect to the light-receiving section when viewed from the first direction. A fiber optic plate having an incident light surface and an outgoing light surface facing each other in the first direction, and a first side surface extending in the first direction, and disposed on the light receiving sensor such that the outgoing light surface faces the light receiving portion, A scintillator layer disposed on the light incident surface, A first wire stretched between the circuit board and the first terminal, The device comprises a first shielding member disposed on the first side surface and formed of radiation shielding rubber, A radiation detection device wherein, when viewed from the first direction, the first shielding member includes at least the first terminal.

2. The first terminal is each of a plurality of first terminals arranged in a third direction that intersects both the first direction and the second direction. The radiation detection device according to claim 1, wherein, when viewed from the first direction, the first shielding member includes at least the plurality of first terminals.

3. The second wire and Further comprising a second shielding member, The light receiving sensor further includes a second terminal positioned on the other side in the second direction relative to the light receiving portion when viewed from the first direction, The fiber optic plate further has a second surface facing the first surface in the second direction, The second wire is stretched between the circuit board and the second terminal. The second shielding member is positioned on the second side surface and is formed of radiation shielding rubber. The radiation detection device according to claim 1, wherein, when viewed from the first direction, the second shielding member includes at least the second terminal.

4. The second terminal is each of a plurality of second terminals arranged in a third direction that intersects both the first direction and the second direction. The radiation detection device according to claim 3, wherein, when viewed from the first direction, the second shielding member includes at least the plurality of second terminals.

5. The radiation detection device according to claim 1, wherein the first shielding member is each of a plurality of first shielding members arranged in a first direction on the first side surface.

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