JP2015200528A - Radiation imaging apparatus, method of manufacturing the same and radiation imaging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation imaging apparatus which allows a frame to be narrowed while maintaining uniformity of a structure and layer thickness distribution in a peripheral part of a scintillator layer.SOLUTION: A method of manufacturing a radiation imaging apparatus comprises the steps of: arranging a mask on a base so as to regulate a region on the base where a scintillator layer should be formed; forming the scintillator layer on the base and the mask; removing a part of the scintillator layer formed on the base by removing the mask from the base; connecting a support substrate for supporting the scintillator layer to the side opposite to the side of the base of the scintillator layer via an adhesion layer; peeling the base from the scintillator layer; and connecting a sensor panel to the side opposite to the side of the support substrate of the scintillator layer.

Description

  The present invention relates to a radiation imaging apparatus that detects radiation, a manufacturing method thereof, and a radiation imaging system.

  There are a direct-type manufacturing method and an indirect-type manufacturing method as a method for manufacturing a radiation imaging apparatus. In the direct manufacturing method, a scintillator layer that converts radiation into light is directly formed on a sensor panel having a photoelectric conversion element that detects light from a phosphor. In the indirect manufacturing method, a scintillator layer formed on a base is bonded onto the sensor panel.

  Patent Document 1 discloses an indirect method of manufacturing a radiation imaging apparatus using a CsI scintillator layer. Specifically, in Patent Document 1, a support layer is formed on a CsI scintillator layer formed by vapor deposition on a vapor deposition substrate, and after peeling the vapor deposition substrate from the CsI scintillator layer, the CsI scintillator layer and the support layer are fixed to the sensor substrate. A manufacturing method is disclosed.

  On the other hand, among radiation imaging devices, the mammography sensor (mammary X-ray device) is a so-called narrow frame where the distance from the pixel array to the edge of the radiation imaging device is short and the area where the chest wall side cannot be imaged is narrow. It is required to have high sharpness.

JP 2012-127698 A

  In the manufacturing method described in Patent Document 1, disorder may occur in the columnar structure and the layer thickness distribution in the peripheral portion of the CsI scintillator layer. For this reason, the indirect manufacturing method described in Patent Document 1 cannot achieve a narrow frame of the radiation imaging apparatus.

  It is an object of the present invention to provide a radiation imaging apparatus that achieves a narrow frame while maintaining the uniformity of the structure and layer thickness distribution in the peripheral portion of the scintillator layer.

  The present invention is a method of manufacturing a radiation imaging apparatus, the step of disposing a mask on the base so as to define a region on the base on which the scintillator layer is to be formed, and the scintillator layer with the base Forming on the mask, removing the mask from the base to remove a part of the scintillator layer formed on the base, and supporting the scintillator layer A connecting step of connecting a substrate to the side of the scintillator layer opposite to the base side via an adhesive layer; a step of peeling the base from the scintillator layer; and a sensor panel for supporting the scintillator layer And a step of connecting to a side opposite to the side of the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the radiation imaging device which achieved the frame narrowing can be provided, maintaining the structure in the peripheral part of a scintillator layer, and the uniformity of layer thickness distribution.

The schematic block diagram of a radiation imaging device. Sectional drawing of a radiation imaging device. The flowchart explaining the manufacturing method of a radiation imaging device. The top view explaining the process of arrange | positioning a mask. The top view and sectional drawing explaining the process of arrange | positioning a scintillator layer. The top view and sectional drawing explaining the process of removing a mask. The top view and sectional drawing explaining the process of connecting a support substrate to a scintillator layer. The top view and sectional drawing explaining the process of peeling a base. The top view and sectional drawing explaining the process of connecting a scintillator panel to a sensor panel. 1 is a schematic configuration diagram of a radiation imaging system.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the present invention, light includes visible light and infrared rays, and radiation includes X-rays, α rays, β rays, and γ rays.

[Radiation imaging equipment]
A schematic configuration example of a radiation imaging apparatus 100 according to the present invention will be described with reference to FIG. The radiation imaging apparatus 100 of this embodiment can include a sensor panel (imaging substrate) 110, a scintillator panel (phosphor substrate) 120, and a connection member 130. In FIG. 1, the sensor panel 110, the scintillator panel 120, and the connection member 130 are illustrated separately for the sake of explanation. However, as will be described later, the sensor panel 110 and the scintillator panel 120 are actually connected via the connection member 130. Connected.

  FIG. 2 is a cross-sectional view taken along line A-A ′ in FIG. 1. The sensor panel 110 includes a plurality of sensors (photoelectric conversion elements) 111 and a sensor substrate 112 arranged in a matrix at a predetermined pitch. In the scintillator panel 120, a scintillator layer (phosphor layer) 123 is disposed on a support substrate 121 via an adhesive layer 122. The support substrate 121 supports the scintillator layer 123 via the adhesive layer 122. The adhesive layer 122 can also be a reflective layer that reflects light converted from radiation by the scintillator layer 123. The sensor panel 110 and the scintillator panel 120 are connected via a connection member 130. The radiation exposed toward the subject from the direction of the arrow 140 in FIG. 1 is incident on the scintillator panel 120 after being attenuated by the subject. The scintillator particles in the scintillator layer 123 convert this radiation into light having a wavelength that can be detected by the photoelectric conversion element 111 (for example, visible light). The light converted by the scintillator particles enters the sensor panel 110, is converted into an electric signal by the photoelectric conversion element 111, and an image is generated based on the electric signal. A moving image can also be obtained by the radiation imaging apparatus 100 repeating this operation.

  Subsequently, a manufacturing method according to an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart illustrating a method for manufacturing the radiation imaging apparatus.

(Step 1)
As shown in FIG. 4, in S <b> 1, a peelable tape (mask) 151 is disposed on at least a part of the periphery of the base 150. The tape 151 is disposed so as to define an area on the base on which the scintillator layer 123 is to be formed. That is, the tape 151 masks an area outside the area where the scintillator layer 123 is to be formed. The tape 151 is arranged in, for example, a linear shape, a polygonal shape, a circular shape, or the like. As the tape 151, a single-sided adhesive tape excellent in heat resistance, such as a polyimide-based adhesive tape, can be used. The base 150 is selected so that the scintillator can be deposited, the adhesion with the scintillator layer 123 is weak, and the scintillator layer 123 can be easily peeled from the base 150.

(Step 2)
Next, as shown in FIG. 5, in S2, a scintillator layer 123 is formed on the surface of the base 150 where the tape 151 is disposed. The scintillator layer 123 is formed so that the end region 123b of the scintillator layer having a non-uniform thickness is positioned on the tape 151. As a method of forming the scintillator layer 123, for example, there is a method of forming columnar CsI (cesium iodide) particles or the like to which Tl (thallium) is added as an activator by vacuum deposition. FIG. 5A is a plan view when the scintillator layer 123 is formed, and FIG. 5B is a cross-sectional view taken along the line BB ′ of FIG.

(Step 3)
Next, as shown in FIG. 6, in S <b> 3, the tape 151 is removed by peeling from the base 150. Then, the end region 123b of the scintillator layer having a non-uniform layer thickness disposed on the tape 151 is also removed from the base 150 at the same time, and the scintillator layer 123a having one end 153 and a uniform layer thickness is removed from the base 150. A fluorescent plate 160 formed on the substrate is formed. 6A is a plan view when the tape 151 is removed, and FIG. 6B is a cross-sectional view taken along line BB ′ of FIG. 6A.

(Step 4)
Next, as shown in FIG. 7, S <b> 4 is a connection process in which the support substrate 121 is bonded and connected to the fluorescent plate 160 via the adhesive layer 122. FIG. 7A is a plan view when the support substrate 121 is connected to the fluorescent plate 160. 7B is a cross-sectional view taken along the line BB ′ of FIG. 7A, and FIG. 7C is a partially enlarged view of FIG. 7B. The adhesive layer 122 is disposed up to the lower surface of the support substrate 121 between one end 153 of the scintillator layer 123 and one end 156 of the support substrate 121. As described above, the adhesive layer 122 also serves as a reflective layer.
As shown in FIG. 7B, the adhesive layer 122 can absorb the height of the abnormally grown portion 157 of the scintillator generated on the formation end surface of the CsI scintillator. As shown in FIG. 7C, the adhesive layer 122 penetrates to the gap between the tip portions of the columnar scintillator particles, so that the adhesion with the scintillator layer 123 is improved. As a result, the adhesive force between the support substrate 121 and the scintillator layer 123 is improved, and the base 150 can be easily detached from the scintillator layer 123 in a subsequent process. As the adhesive layer 122, for example, an epoxy resin containing titanium oxide can be used. The edge part of the contact bonding layer 122 is located in the area | region 155 between the end 153 of the scintillator layer 123a with uniform layer thickness, and the end of the base 150. FIG. The scintillator layer 123 at this stage is composed only of the scintillator layer 123a having a uniform layer thickness from which the end region 123b of the scintillator layer having a nonuniform layer thickness has already been removed.

(Step 5)
Next, as shown in FIG. 8, in S <b> 5, the base 150 is peeled from the scintillator layer 123 to which the support substrate 121 is bonded via the adhesive layer (reflective layer) 122. As a peeling method, for example, there is a method of promoting peeling by utilizing thermal expansion and contraction of the base 150 by heating or cooling. For example, a member having a large thermal expansion coefficient such as polyethylene terephthalate (thermal expansion coefficient 70 × 10 ⁻⁶ ) or aluminum (thermal expansion coefficient 23 × 10 ⁻⁶ ) is used as the base 150. Thermal expansion of amorphous carbon (thermal expansion coefficient 2 × 10 ⁻⁶ ), glass (thermal expansion coefficient 7 × 10 ⁻⁶ ), carbon fiber reinforced plastic (thermal expansion coefficient 0.1 × 10 ⁻⁶ ) or the like as the support substrate 121. A member with a small coefficient may be used. FIG. 8A is a plan view when the base 150 is peeled off, and FIG. 8B is a cross-sectional view taken along the line BB ′ of FIG.

(Step 6)
Next, as shown in FIG. 9, in S <b> 6, the scintillator panel 120 including the support substrate 121, the reflective layer 122, and the scintillator layer 123 is connected to the sensor panel 110 via the connection member 130. In S <b> 6, the sensor panel 110 is connected to the side of the support substrate 121, the reflective layer 122, and the scintillator layer 123 that is opposite to the support substrate 121. The scintillator panel 120 and the sensor panel 110 are connected such that one end 153 of the scintillator layer 123 having a uniform film thickness is positioned on or outside the pixel of the outermost photoelectric conversion element 111 of the sensor panel 110.

  The radiation imaging apparatus 100 of this embodiment is manufactured by an indirect manufacturing method. Therefore, the radiation imaging apparatus 100 of the present embodiment achieves a narrow frame with a short interval between the periphery of the scintillator layer 123 and the periphery of the sensor panel 110. Since the radiation imaging apparatus 100 of the present embodiment is manufactured by an indirect manufacturing method, the interface on the sensor panel 110 side of the scintillator layer 123 has a structure in which the peeling process of S5 is performed first. In addition, since the radiation imaging apparatus 100 of the present embodiment removes the peripheral portion 123b of the scintillator layer having a nonuniform structure and layer thickness distribution, the structure and the layer thickness are uniform, and at least a part of the periphery of the sensor A scintillator layer 123 having a side surface perpendicular to the surface of the panel 110 is provided.

[Radiation imaging system]
FIG. 8 relates to a radiation imaging system including the radiation imaging apparatus 100 described above. As shown in FIG. 8, X-rays (radiation) 211 generated by an X-ray tube (radiation source) 210 passes through a chest 221 of a patient or subject 220 and enters the radiation imaging apparatus 100. This incident X-ray includes information inside the body of the patient 220. The scintillator (phosphor) emits light in response to the incidence of X-rays, and this light emission is photoelectrically converted by the sensor (photoelectric conversion element) 111 of the sensor panel 110 to obtain electrical information. This electrical information is converted into digital data, subjected to image processing by a signal processing unit (image processor) 230, and can be observed by a display unit (display) 240.

  Information processed by the image processor 230 can be transferred to a remote place by a transmission processing unit 250 such as a network such as a telephone, a LAN, and the Internet. Therefore, the information processed by the image processor 230 can be displayed on a display unit (display) 241 such as a doctor room in another place, or can be stored in a recording unit such as an optical disk. Can be diagnosed by Information processed by the image processor 230 can also be recorded on the film 261 by the film processor 260.

  The radiation imaging apparatus of the present invention can be applied to a medical radiation imaging apparatus, a non-medical analysis or inspection apparatus using radiation, such as a nondestructive inspection apparatus.

100: Radiation imaging apparatus. 110: Sensor panel. 121: Support substrate. 122: Adhesive layer. 123: Scintillator layer. 150: Base. 151: Mask.

Claims (10)

Placing a mask on the base to define a region on the base on which the scintillator layer is to be formed;
Forming a scintillator layer on the base and the mask;
Removing a part of the scintillator layer formed on the base by removing the mask from the base;
A connecting step of connecting a support substrate supporting the scintillator layer to the side of the scintillator layer opposite to the base side via an adhesive layer;
Peeling the base from the scintillator layer;
Connecting a sensor panel to the side of the scintillator layer opposite to the side of the support substrate;
A method for manufacturing a radiation imaging apparatus, comprising:   The manufacturing method according to claim 1, wherein the base is separated from the scintillator layer by heating or cooling the base.   The manufacturing method according to claim 2, wherein the base has a larger thermal expansion coefficient than the support substrate.   The manufacturing method according to claim 3, wherein the base includes polyethylene terephthalate or aluminum, and the support substrate includes amorphous carbon, glass, or carbon fiber reinforced plastic.   5. The manufacturing method according to claim 1, wherein, in the connecting step, the adhesive layer enters a gap between scintillator particles constituting the scintillator layer.   The manufacturing method according to claim 1, wherein the adhesive layer is a reflective layer.   The manufacturing method according to any one of claims 1 to 6, wherein the scintillator layer includes columnar cesium iodide added with thallium.   The manufacturing method according to claim 1, wherein the adhesive layer includes an epoxy resin containing titanium oxide.   It is manufactured by the manufacturing method according to any one of claims 1 to 8, and the interface on the sensor panel side of the scintillator layer has a structure in which a peeling process is performed first, and the scintillator layer is A radiation imaging apparatus having a side surface perpendicular to the surface of the sensor panel at least at a part of the periphery thereof. A radiation imaging apparatus according to claim 9;
A signal processing unit for processing a signal from the radiation imaging apparatus;
A display unit for displaying a signal from the signal processing unit;
A radiation source for generating the radiation;
A radiation imaging system comprising:

Images