JP2017040584A - Manufacturing method for scintillator panel and manufacturing method for radiation imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique advantageous for dividing a scintillator along a cross section of a divided base while maintaining structure of the scintillator.SOLUTION: The manufacturing method for scintillator panel comprises the steps of: preparing a support member which has grooves in a plane on which a scintillator is formed; forming a scintillator over the support member to cover the formed plane and grooves; and dividing the scintillator on a plane extending between the opposing walls along the opposing walls of the groove by applying a force to the support member in a width direction of the grooves.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a scintillator panel and a method for manufacturing a radiation imaging apparatus.

  In an indirect radiation imaging apparatus including a scintillator that converts radiation into light and a sensor panel on which a sensor that converts light into an electrical signal is disposed, these scintillators and the sensor panel occupy much of the cost. If a part of the scintillator is defective, the scintillator may be discarded even if the other part is normal, which may be one of the causes of a decrease in yield and an increase in cost.

  Patent Document 1 and Patent Document 2 show that a scintillator panel in which a scintillator is formed on a large base is divided into small scintillator panels. By dividing the large scintillator panel into small scintillator panels and arranging only the small scintillator panel without defects on the sensor panel, the normal part of the scintillator can be used effectively. By effectively utilizing the scintillator, the production yield of the scintillator panel can be improved and the cost of the radiation imaging apparatus can be suppressed.

JP 2012-172972 A JP 2008-213043 A

  In Patent Document 1, microcracks are formed on a base on which a scintillator is formed by laser ablation. A scintillator panel dividing method is shown in which the base is divided from the microcrack as a starting point so that the scintillator formed on the base is divided. However, in the method of Patent Document 1, since the microcracks are formed only on the base and not on the scintillator, the scintillator may not be divided along the divided cross section of the base during the division. Patent Document 1 also shows a method of dividing the scintillator panel with a blade. However, since the blade is directly applied to the scintillator, the outer peripheral portion of the scintillator may be destroyed, and the shape of the outer peripheral portion may be uneven. is there.

  Patent Documents 1 and 2 disclose that the scintillator panel is divided by a laser. When using a laser, unevenness of the outer peripheral portion can be suppressed. However, in the division using a laser, the outer periphery of the scintillator is melted. Therefore, when a scintillator having a columnar structure such as CsI: Tl is used, the columnar structure may be destroyed.

  An object of the present invention is to provide a technique advantageous for dividing a scintillator along a divided section of a base while maintaining the structure of the scintillator when dividing the scintillator.

  In view of the above problems, a scintillator panel manufacturing method according to some embodiments of the present invention covers a preparation step of preparing a support member having a groove on a surface on which the scintillator is formed, and the surface to be formed and the groove. Forming a scintillator on the support member, and applying a force to the support member in the direction in which the groove expands, thereby forming the scintillator along a plane passing between the opposing wall surfaces of the groove and between the opposing wall surfaces. And a dividing step of dividing.

  By the above means, when dividing the scintillator, a technique advantageous to dividing the scintillator along the divided cross section of the base is provided while maintaining the structure of the scintillator.

Process drawing which shows the manufacturing method of the scintillator panel which concerns on the 1st Embodiment of this invention. The enlarged view near the groove | channel of the base which formed the scintillator of this invention. The figure which shows the structure of the radiation imaging device using the scintillator panel of this invention. Process drawing which shows the manufacturing method of the scintillator panel which concerns on the 2nd Embodiment of this invention. The figure which shows the modification of a structure of the radiation imaging device of FIG. The figure which shows the modification of the supporting member of this invention. The figure explaining the structural example of the radiation imaging system using the scintillator panel which concerns on this invention.

  Hereinafter, specific embodiments of a method for manufacturing a scintillator panel according to the present invention will be described with reference to the accompanying drawings. Note that, in the following description and drawings, common reference numerals are given to common configurations over a plurality of drawings. Therefore, a common configuration is described with reference to a plurality of drawings, and a description of a configuration with a common reference numeral is omitted as appropriate. In the present invention, the light may include visible light and infrared light. In addition to α-rays, β-rays, γ-rays, etc., which are beams produced by particles (including photons) emitted by radiation decay, the radiation includes beams having the same or higher energy such as X-rays and particles. Lines, cosmic rays, etc. can also be included.

1st Embodiment With reference to FIGS. 1-3, the manufacturing method of the scintillator panel by embodiment of this invention is demonstrated. FIG. 1 is a process diagram showing a method of manufacturing a scintillator panel 100 according to the first embodiment of the present invention. As a preparation process for preparing a support member having a groove on the surface for forming a scintillator, first, as shown in FIG. 1A, a base 101 is prepared as a support member. The base 101 functions as a support substrate for the scintillator panel 100 as will be described later. The base 101 can be made of any material as long as it has a high radiation transmittance and can be divided by an expanding process described later. Examples of the material used for the base 101 include metal materials such as aluminum and molybdenum, silicon, resin, carbon fiber reinforced plastic (CFRP), and amorphous carbon. In this embodiment, a silicon wafer is used for the base 101.

  A groove 102 is formed on the surface of the base 101 where the scintillator is to be formed, as shown in FIG. Here, the depth of the groove 102 is shallower than the thickness of the base 101 and is a half cut that does not divide the base 101. As a method for forming the half-cut groove 102 in the base 101, a dicing blade 120 is used in the present embodiment. However, the method of forming the groove 102 is not limited to the method using a dicing blade, and may be formed using, for example, laser or etching.

Next, as shown in FIG. 1C, a forming process for forming the scintillator 103 is performed on the base 101 on which the groove 102 is formed. As the scintillator 103, either a particulate scintillator or a columnar scintillator may be used. As the particulate scintillator, for example, Gd ₂ O ₂ S: Tb to which a small amount of terbium is added can be used. As the scintillator having a columnar structure, CsI: Tl, CsI: Na, CsBr: Tl, NaI: Tl, LiI: Eu, KI: Tl, or the like can be used. The columnar scintillator can be formed on the base 101 by using, for example, a vapor deposition method. In this embodiment, CsI: Tl is formed as a scintillator 103 on the base 101 on which the groove 102 is formed by a vapor deposition method so as to cover the surface of the base 101 and the groove 102. FIG. 2 shows an enlarged view of a portion surrounded by a square A near the groove 102 when the scintillator 103 is formed on the base 101. As shown in FIG. 2, it can be confirmed that the scintillator 103 having the columnar structure is divided in advance and grows crystals in the portion above the groove 102. When dividing into the individual scintillator panels 100 by the division starting points 121 formed on the grooves 102, it passes along the cross-section of the base 101, along the opposing wall surfaces of the groove 102, and between the opposing wall surfaces. It becomes possible to divide in a plane. In addition, the division starting point 121 formed on the groove 102 can suppress the occurrence of unevenness in the cross section of the scintillator 103.

Before forming the scintillator 103, a reflective layer 110 that reflects light generated by the scintillator and an insulating layer 111 for preventing electrochemical corrosion between the reflective layer 110 and the base 101 and the scintillator 103 are formed. Also good. Only one of the reflective layer 110 and the insulating layer 111 may be formed, or a laminated structure of the reflective layer 110 and the insulating layer 111 may be formed as shown in FIG. A metal film such as aluminum or silver or a dielectric film such as TiO ₂ can be formed on the reflective layer 110 using, for example, a sputtering method. The insulating layer 111 can be made of an organic insulating material such as polyamideimide resin, polyetherimide resin, polyimide resin, epoxy resin, or silicone resin, or inorganic material such as SiO ₂ . The order of forming the reflective layer 110, the insulating layer 111, and the groove 102 may be such that the groove 102 may be formed after the reflective layer 110 and the insulating layer 111 are formed, as shown in FIG. The reflective layer 110 and the insulating layer 111 may be formed after forming 102. When the reflective layer 110 or the insulating layer 111 is formed after the formation of the groove 102, the reflective layer 110 and the insulating layer 111 may be formed so that the groove 102 is not filled. In order to improve the adhesion of the scintillator 103 to the reflective layer 110 and the insulating layer 111, the surface of the reflective layer 110 or the insulating layer 111 in contact with the scintillator 103 may be subjected to surface treatment such as plasma treatment or excimer UV treatment. .

  Next, as shown in FIG. 1 (d), a dicing tape coupling step is performed in which the back surface opposite to the surface on which the scintillator 103 of the base 101 is formed is fixed to the dicing tape 104. The dicing tape 104 may be of a type whose adhesive strength is reduced by ultraviolet rays, heat, or the like. As such a type of dicing tape, for example, Adwill D-series manufactured by Lintec Corporation may be used.

  After the base 101 is coupled to the dicing tape 104, the dicing tape 104 is attached to the back surface of the base 101 so that a force is applied to the base 101 in the direction in which the groove 102 expands, as shown in FIG. A dividing step of extending in the direction 105 along the line is performed. By extending (expanding) the dicing tape 104, the base 101 intersects the surface of the base 101 and is divided by a plane passing through the groove 102. In addition, as the base 101 is divided, the scintillators 103 that have been divided and grown in advance from the division starting point 121 at the upper part of the groove 102 as shown in FIG. 2 face along the mutually opposing wall surfaces of the groove 102. Divided by a plane passing between the walls. In this manner, the scintillator panel 100 in which the scintillator 103 is arranged on the base 101 that functions as a support substrate is formed. For example, when the dicing tape 104 whose adhesive strength is reduced by ultraviolet rays is used, the respective scintillator panels 100 are picked up after irradiating the ultraviolet rays after the division to lose the adhesiveness of the dicing tape 104.

  After peeling the scintillator panel 100 from the dicing tape 104, a protective layer 106 that covers the scintillator 103 may be formed as shown in FIG. When the scintillator 103 is formed of a material having deliquescence properties such as CsI: Tl, the columnar structure collapses when the scintillator 103 keeps touching moisture, and as a result, the characteristics deteriorate. In order to prevent this characteristic deterioration, a protective layer 106 that covers the scintillator 103 is formed. The protective layer 106 covers at least the scintillator 103 and may cover the base 101 as shown in FIG. Further, the protective layer 106 may not cover the base 101. As a material used for the protective layer 106, an organic material such as polyparaxylylene resin, silicone resin, acrylic resin, epoxy resin, and fluorine resin, or a hot-melt resin material such as polyester, polyolefin, or polyamide may be used. . The material used for the protective layer 106 is preferably a material with low moisture permeability. Further, in order to arrange the scintillator panels 100 covered with the protective layer 106 on the sensor array without gaps, it is necessary to make the thickness of the protective layer 106 as thin as possible. For this reason, for example, a polyparaxylylene resin having a thickness of about several μm formed by a CVD method or a fluororesin having a thickness of about several μm formed by a spray coating method can be used.

  Here, the effect of this embodiment will be described. In this embodiment, the scintillator 103 is formed after the groove 102 is formed on the surface of the base 101. Accordingly, as shown in FIG. 2, in the portion above the groove 102, the columnar scintillator 103 crystallizes in advance by dividing the starting point 121 as a starting point. Therefore, when the base 101 is separated, The scintillator 103 can be divided along the cross section 101. Further, for example, a dicing blade is not directly applied to the scintillator 103 to divide the scintillator 103, so that breakage at the outer periphery of the scintillator 103 is suppressed, and occurrence of unevenness in the cross section is suppressed. For this reason, it is possible to suppress variation in luminance caused by unevenness at the outer peripheral portion of the scintillator 103. Further, unlike the division method using a laser, a change in characteristics due to melting of the outer peripheral portion of the scintillator 103 and a destruction of the columnar structure do not occur. For this reason, it is possible to suppress deterioration of characteristics such as luminance variations and MTF deterioration in the outer periphery of the scintillator. As a result, when the scintillator panel 100 is divided, the structure of the scintillator 103 is maintained, and the scintillator 103 can be divided along the divided cross section of the base 101.

  Next, FIG. 3 shows a configuration of a radiation imaging apparatus 300 using the scintillator panel 100 manufactured according to this embodiment. The radiation imaging apparatus 300 includes a sensor panel 200 in which a plurality of small photoelectric conversion substrates 203 are arranged on a support substrate 201 via a fixing material 202 and converts light into an electrical signal. On the photoelectric conversion substrate 203, for example, a CMOS sensor using crystalline silicon, a PIN sensor or an MIS sensor using amorphous silicon are formed. A plurality of scintillator panels 100 are arranged so that the scintillator 103 and the photoelectric conversion substrate 203 face each other and cover the effective pixel region of the photoelectric conversion substrate 203. The scintillator panel 100 and the sensor panel 200 are coupled using, for example, an adhesive (not shown). If necessary, a sealing material (not shown) that prevents moisture from entering may be applied to the periphery of each scintillator panel 100 or the surface on which the scintillator panel 100 of the radiation imaging apparatus 300 is disposed. In this manner, the radiation imaging apparatus 300 using the scintillator panel 100 of the present embodiment is configured. When the radiation imaging apparatus 300 is exposed to radiation and when the captured image is displayed on the display, when the output changes between the scintillator panels 100, the captured image is processed by an arbitrary method using image processing, for example. You may adjust.

Second Embodiment A scintillator panel manufacturing method according to an embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a process diagram showing a method of manufacturing the scintillator panel 100 according to the second embodiment of the present invention. This embodiment is different from the above-described first embodiment in that a dicing before grinding (DBG) process is used for dividing the base 101 on which the scintillator 103 is formed. Other steps may be the same as those in the first embodiment.

  After the scintillator 103 is formed on the base 101 on which the groove 102 is formed as shown in FIG. 4A using the same steps as those shown in FIGS. Do. First, as shown in FIG. 4B, the dicing tape 107 is bonded to the surface of the scintillator 103. After fixing the base 101 on which the scintillator 103 is formed with a dicing tape 107, a back grind blade 108 is applied to the back surface of the base 101, and the back grind blade 108 is rotated on a surface 109 parallel to the back surface of the base 101. Thus, a polishing process is performed in which the back surface of the base 101 is polished. As shown in FIG. 4C, the back surface of the base 101 can be polished until the half-cut groove 102 is exposed on the back side of the base 101. The base 101 is divided by exposing the groove 102 on the back surface.

  Here, the dicing tape 107 used in the DBG process may be a tape dedicated to the DBG process. As such a dicing tape, for example, Adwill E-series manufactured by Lintec Corporation may be used. When the back surface of the base 101 is polished, the back grind blade 108 having a coarse abrasive particle size is first ground to a predetermined thickness and then the back grind blade 108 having a fine abrasive particle size is used. The flatness of the polished surface may be ensured. When the scintillator 103 is a scintillator having deliquescence such as CsI: Tl, the step of polishing the back surface of the base 101 can be performed by a dry method.

  Next, as shown in FIG. 4 (d), a dicing tape bonding step is performed in which the dicing tape 104 is bonded to the back surface of the base 101. After the dicing tape 107 attached to the surface of the scintillator 103 is removed, the dicing tape 104 is expanded (expanded) in a direction 105 parallel to the back surface of the base 101. In this way, the scintillator panel 100 in which the scintillator 103 is arranged on the base 101 is formed using the DBG process as shown in FIG. As shown in FIG. 4F, when the scintillator 103 exhibits deliquescence, a protective layer 106 that covers the scintillator 103 may be formed as in the first embodiment described above.

  Also in this embodiment, the scintillator 103 is formed after the groove 102 is formed on the surface of the base 101. As a result, in the portion above the groove 102, the columnar scintillator 103 grows in advance by dividing from the dividing starting point 121 as a starting point. Also in the manufacturing method of the present embodiment, the structure of the scintillator 103 is maintained when dividing into individual scintillator panels 100, and along the divided cross section of the base 101, as in the first embodiment described above. The scintillator 103 can be divided.

  Next, FIG. 5 shows a configuration of a radiation imaging apparatus 301 using the scintillator panel 100 manufactured according to this embodiment. The radiation imaging apparatus 301 includes a sensor panel 210 in which one large photoelectric conversion element 204 is arranged on a support substrate 201 via a fixing material 202 and converts light into an electrical signal. For example, a CMOS sensor using crystalline silicon, a PIN sensor or an MIS sensor using amorphous silicon are formed in the photoelectric conversion element 204. A plurality of scintillator panels 100 are arranged so that the scintillator 103 and the photoelectric conversion element 204 face each other and cover the effective pixel region of the photoelectric conversion element 204. The scintillator panel 100 and the sensor panel 210 are coupled using, for example, an adhesive (not shown). If necessary, a sealing material (not shown) that prevents moisture from entering may be applied to the periphery of each scintillator panel 100 or the surface on which the scintillator panel 100 of the radiation imaging apparatus 301 is disposed. In this way, the radiation imaging apparatus 301 using the scintillator panel 100 is configured.

  As mentioned above, although 2 form of embodiment which concerns on this invention was shown, this invention is not limited to those embodiment. Each embodiment mentioned above can be changed and combined suitably. For example, the scintillator panel 100 formed using the DBG process may be disposed on the sensor panel 200 in which a plurality of small photoelectric conversion substrates 203 are arranged on the support substrate 201 via the fixing material 202.

  In the above-described embodiment, the base 101 is used as a support member for forming the scintillator, and the groove 102 is formed by half-cutting the base 101. However, the method for forming the groove 102 is not limited to this. For example, as the support member having the groove 102, a support member having a laminated structure in which a base 101 serving as a support substrate of the scintillator panel 100 and a support body 601 are stacked as shown in FIG. In this case, the groove 102 may be formed in the support member from the base 101 side on the support body 601 using, for example, a dicing blade. At this time, the base 101 may be divided by the groove 102. Further, for example, a support member may be used in which a plurality of small bases 101 are arranged at intervals on the support 601 so that a gap between the adjacent small bases 101 becomes the groove 102. A scintillator 103 is formed on a support member having a laminated structure in which the grooves 102 are formed. Next, for example, after attaching a dicing tape to the surface of the scintillator 103 and removing the support 601, another dicing tape is attached to the back surface of the base 101 opposite to the scintillator 103. After removing the dicing tape on the front surface of the scintillator 103, the dicing tape on the back surface of the base 101 may be extended (expanded) to form the scintillator panel 100. Further, when the support body 601 is extensible, the scintillator panel 100 may be formed by directly extending the support body 601 after the scintillator 103 is formed.

  Hereinafter, application examples of the radiation imaging apparatuses 300 and 301 using the scintillator panel 100 of the present embodiment to the radiation imaging system 700 will be described with reference to FIG. FIG. 7 is a conceptual diagram of the radiation imaging system 700. The radiation imaging system 700 includes the radiation imaging apparatus 300 or 301 described above, a signal processing unit 701, a display unit 702, a C-arm 703, and a radiation generation apparatus 704 that generates radiation. The radiation imaging apparatus 300 or 301 and the radiation generation apparatus 704 are fixed to both ends of the C-type arm 703. The radiation imaging system 700 can perform radiation imaging (3D imaging) while changing the irradiation angle by rotating the C-arm 703. Captured image data obtained by the radiation imaging apparatus 300 or 301 is output to the signal processing unit 701 via, for example, a cable. The signal processing unit 701 forms a three-dimensional captured radiation image based on the captured image data, and displays it on the display unit 702. The captured image data generated by the image processing in the signal processing unit 701 can be transferred to a remote place by a transmission processing unit such as a telephone line. Thereby, it can be displayed on a display in another place such as a doctor room or stored in a recording medium such as an optical disk, and can be diagnosed by a remote doctor. The transmitted image data can be recorded as a film by a film processor.

100: scintillator panel, 101: base, 102: groove, 103: scintillator

Claims (17)

A method of manufacturing a scintillator panel,
A preparation step of preparing a support member having a groove on the surface forming the scintillator;
Forming a scintillator on the support member so as to cover the surface to be formed and the groove;
A dividing step of dividing the scintillator along a plane passing between the opposing wall surfaces along the opposing wall surfaces of the groove by applying a force to the support member in a direction in which the grooves expand;
The manufacturing method characterized by including. The support member includes a base;
The preparation step includes a step of forming a groove in a first surface of the base that forms the scintillator,
The manufacturing method according to claim 1, wherein the scintillator is formed so as to cover the first surface and the groove. Before the dividing step, further includes a dicing tape coupling step for coupling a dicing tape and a second surface of the base opposite to the first surface;
The manufacturing method according to claim 2, wherein the dividing step includes a step of extending the dicing tape in a direction along the second surface.   4. The method according to claim 3, further comprising a polishing step of polishing a second surface of the base opposite to the first surface after the forming step and before the dicing tape bonding step. Manufacturing method.   The manufacturing method according to claim 4, wherein the polishing step is performed by a dry method.   The manufacturing method according to claim 2, wherein the groove is formed by a dicing blade, a laser, or etching.   The manufacturing method according to claim 2, further comprising a step of forming a protective layer covering the scintillator and the base after the dividing step.   The manufacturing method according to claim 2, further comprising a step of forming an insulating layer on the first surface before the forming step.   8. The method according to claim 2, further comprising a step of forming a reflective layer that reflects light converted from radiation by the scintillator on the first surface before the forming step. The production method according to item.   The manufacturing method according to claim 9, further comprising a step of forming an insulating layer on the reflective layer before the forming step.   The manufacturing method according to claim 8, further comprising a step of performing plasma treatment or UV treatment on the surface of the insulating layer in order to improve adhesion of the scintillator.   The method according to claim 9, further comprising a step of performing plasma treatment or UV treatment on the surface of the reflective layer in order to improve the adhesion of the scintillator.   The manufacturing method according to claim 1, wherein the forming step includes crystal growth of the scintillator on the support member.   The manufacturing method according to claim 13, wherein the scintillator has a columnar structure. The support member includes a support and a base disposed on the support,
The manufacturing method according to claim 1, wherein the base is divided by the groove. Preparing a sensor panel having a sensor for converting light into an electrical signal;
Combining the sensor panel and the scintillator panel manufactured by the manufacturing method according to any one of claims 1 to 15,
A method for manufacturing a radiation imaging apparatus, comprising:   The method of manufacturing a radiation imaging apparatus according to claim 16, wherein the combining step combines a plurality of the scintillator panels with the sensor panel.