KR20100043654A - Flexible x-ray image sensor - Google Patents

Abstract

PURPOSE: A flexible X-ray image sensor is provided to improve the availability for the whole medical areas by manufacturing a flexible X-ray image sensor which has a wide area. CONSTITUTION: A flexible X-ray image sensor comprises a flexible polymer flat plate(30), a photo-detection device(10), and a scintillator panel(20). The photo-detection device comprises a substrate and a plurality of photo diode units(13) formed in a single-side of the substrate. The photo diode unit comprises a computation circuit which is an ASIC, a photo diode, and a TFT. The scintillator panel is combined in the single-side of the photo-detection device. The scintillator panel changes the X-rays to the sensible wavelength band of the photo diode unit. The polymer layer is combined in the scintillator.

Description

Flexible X-ray Image Sensor

The present invention relates to a flexible X-ray image sensor, and more particularly, to an X-ray image sensor that can be flexibly bent when photographing a curved structure.

Since X-rays were discovered by Wilhlem Conrad Reontgen in Germany in 1895, they were able to see the inside of the human body, allowing them to diagnose bone fractures, tuberculosis and pneumonia. Such X-rays have been used in the diagnosis and treatment fields to directly show human clinical information. However, since X-ray is a F / S (Film Screen) method, when the medical image by X-ray increases every year, it is difficult to store and manage the film, and many problems such as inconvenience of using existing data have emerged. The developed countries began to find solutions to these problems. In 1971, CT (Computer Tomography) was developed by Godfrey Hunsfield of EMI in the UK, and human tomography began to be used in medical diagnostics. Recently, with the advent of digital imaging devices such as CT (Computed Tomography) and CR (Computed Radiography), attention to the development and dissemination of PACS (Picture Archiving and Communication System) Is concentrated. In Korea, since Samsung Seoul Hospital adopted PACS in 1994, the domestic medical industry is changing from an F / S analog system to a digital imaging device. Also, in 1999, as the number of medical insurance coverage for PACS was applied, many domestic hospitals have competitively installed PACS.

In general, high frequency digital X-ray imaging apparatus has a direct conversion method (Direct Conversion Method) and indirect conversion method (Indirect Conversion Method). The direct conversion method is based on a thin film transistor (TFT) that directly generates an image by receiving an electrical signal of a photoconductor induced in X-rays. In addition, the indirect conversion method is a TFT-based indirect conversion method for generating an image by converting light of an X-ray-induced scintillator into an electrical signal using a light receiving element, and converting the light of the X-ray-induced scintillator into a CCD (Charge Couple Device). Or, it is distributed by an indirect conversion method that produces an image using a complementary metal oxide semiconductor (CMOS). In particular, in the field of dental medical diagnosis, digital X-ray imaging apparatuses are in the spotlight due to the need for rapid inspection / diagnosis and high resolution.

The X-ray image sensor using the conventional indirect conversion method is composed of a scintillator coupled to a crystalline or amorphous silicon thin film transistor based device in which a photodetecting device and a switch coexist. In the conventional image sensor, the image sensor does not flex flexibly because the photodetecting device has a rigid solid panel as a multilayer flat plate structure. Therefore, the digital X-ray image sensor for dental imaging used in dentistry caused a great inconvenience to the patient during intraoral imaging due to the rigid solid substrate.

The present invention is to solve the above problems. An object of the present invention is to provide a flexible X-ray image sensor excellent in user convenience.

The flexible X-ray image sensor according to the present invention includes a flexible polymer plate, a flexible photodetector, and a flexible scintillator panel. The photodetecting device includes a substrate and a plurality of photodiode units and is formed on one surface of the polymer flat plate. The photodiode unit includes a photodiode, a TFT, and an ASIC operation circuit and is coupled to one surface of the substrate. The scintillator panel includes a scintillator and a polymer layer and is coupled to one surface of the photodetecting device. The scintillator may correspond to the photodiode unit and convert X-rays to a wavelength that the photodiode unit can detect.

In the X-ray image sensor, the scintillator is preferably selected from the group consisting of Gd ₂ O ₂ S: Tb, CsI: Na, NaI: Tl, CsBr: Eu, LiI: Eu, and CsI: Tl.

In the X-ray image sensor, the scintillator panel may further include a reflective layer formed between the polymer layer and the scintillator.

In the X-ray image sensor, the thickness of the scintillator is preferably 1 to 10,000 micrometers.

In the X-ray image sensor, the scintillator may have a lattice structure spaced at regular intervals.

The X-ray image sensor may further include an external molder surrounding the polymer plate, the photodetecting device, and the scintillator panel.

In addition, the X-ray image sensor may further include a support inserted into the outer mold to prevent the concentration of stress in the junction between the polymer plate, the photodetecting device and the scintillator panel when the image sensor is bent.

The X-ray image sensor may further include a stopper inserted into the external molder to prevent the image sensor from being excessively bent.

In addition, the X-ray image sensor may further include a support inserted into the polymer plate to prevent stress concentration at the junction between the polymer plate, the photodetecting element and the scintillator panel when the image sensor is bent.

The X-ray image sensor may further include a stopper inserted into the polymer plate to prevent the image sensor from being excessively bent.

According to the present invention, by providing a flexible X-ray image sensor using a flexible scintillator panel, a flexible light detector and a flexible polymer flat plate, it is possible to accurately photograph a three-dimensional shape having a curved surface.

In addition, according to the present invention, a wider area of the flexible X-ray image sensor can be produced, the scope of application is also applicable to the entire medical field beyond the dental, animal applications and industrial applications.

1 is a conceptual diagram of an embodiment of a flexible X-ray image sensor according to the present invention, FIG. 2 is a conceptual diagram in which the embodiment shown in FIG. 1 is bent, and FIG. 3 is a cross-sectional view of the embodiment shown in FIG. 4 is a conceptual diagram of a photodetector device in the embodiment illustrated in FIG. 1, FIG. 5 is a conceptual diagram of a scintillator panel in the embodiment illustrated in FIG. 1, and FIG. 6 is a cross-sectional view of the scintillator panel illustrated in FIG. 5. An embodiment of a flexible X-ray image sensor according to the present invention will be described with reference to FIGS. 1 to 6.

The flexible X-ray image sensor according to the present invention includes a flexible photodetector 10, a flexible scintillator panel 20, a flexible polymer flat plate 30, and an outer mold 40.

The photodetector 10 includes a substrate 11 and a photodiode unit 13, and is coupled to one surface of the scintillator panel 20 using an adhesive.

The photodiode unit 13 includes a photodiode, a TFT, and an ASIC-calculated circuit, and includes amorphous silicon, polycrystalline silicon, single-crystalline silicon, and compound semiconductor ( It may be manufactured based on a solid semiconductor material such as Compound Semiconductor.

In addition, the photodiode unit 13 may be fabricated using an organic semiconductor. In order to form the photodiode unit 13 using the organic semiconductor, it is necessary to form an organic semiconductor thin film pattern layer for photodetection. The organic semiconductor thin film pattern layer includes a hole transfer layer, an active layer bonded to one surface of the hole transport layer, and an electron transfer layer bonded to one surface of the active layer. In this case, each of the thin film pattern layers may be further added or excluded to improve photodetection efficiency. The material used as the hole transport layer is TPD (N, N'-diphenyl-N, N'-bis- (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine), PEDOT: PSS ( Poly3,4-ethylenedioxythiophene-polystyrenesulfonate), NPB (N, N-di (naphthalene-1-yl) -N, N-diphenyl-benzidene), HfOx, TFB (Poly [2,7- (9,9-di- n-octylfluorene) -co- (1,4-phenylene-[(4-sec-butylphenyl) imino] -1,4-phenylene)]). The material used as the active layer includes a p-type material and an n-type material. The p-type material is copper Phthalcyanine, Polyacetylene, Merocyanine, Polythiophene, Phthalocyanine, Poly (3-hexythiophene), Poly (3-alkylthiophene), Pentacene, A-sexithiophene, A-dihexyl-sexithiophene, Polythienylenevinylene, Bis (dithienothiophene), Dihexyl-anthradithiophene, Tolyl-substituted Oligothiophene, Poly-3-hexylthiophene, Dioctadecyldithiaanthracene, 2,2'-dihexylbenzodithiophene, Poly (2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene). The n-type material is Pentacene, Phenyl C61-butyric Acid Methylester, Regioregular Poly (3-hexylthiophene), Perylene, Naphthalene, Rose Bengal, C60, Perylene Tetracarboxyllic Anhydride Derivative, Quinodimethane Compound, Phthalocyanine Derivative, N, N-bis (2 , 5-di-tert-butylphenyl) 3,4,9,10-perylene Dicarboximide and Double-stranded Poly (benzobisimidazophenanthroline). The active layer may be formed by coating a p-type material and an n-type material in a sequential manner, mixing and coating the same, and using a single material. Examples of the material used for the electron transport layer include LiF, SeF, Alq 3, Ca, Cs, Ba, and PDI (N, N'-bis (1-ethylpropyl) -3,4,9,10-perylene Tetracarboxy Diimide). .

In addition, the photodiode unit 13 may be manufactured using a dye. In order to form a photodetector using a dye, it is necessary to form a dye-sensitized type photodetector layer for photodetection. The dye-sensitized photodetecting layer is composed of a nano-sized oxide layer, a dye, an electrolyte solution, and a counter electrode. Materials used as the nanoparticle oxide layer include TiO ₂ , SnO ₂ , ZnO and the like. Materials used for the dyes include quantum dot inorganic compounds such as Ru-based organometallic compounds (N3, N719, N749), organic compounds (NKX-2311), InP, and CdSe. The electrolyte solution is an iodine-based redox electrolyte, Acetonitrile, Polyacrylonitrile (PAN), Poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF), acryl-ionic liquid combination, Pyridine, Poly (ethyleneoxide) (PEO) and the like can be used. And the material of the iodine ion of the electrolyte is Alkalammonium Iodine, Imidazolium Iodine, LiI, NaI and the like. Pt is a material used as the counter electrode.

The photodiode unit 13 may be manufactured by collecting the materials and characteristics of the solid semiconductor photodetector, the organic semiconductor photodetector, and the dye photodetector in a single device to improve efficiency and ease of fabrication.

The substrate 11 may be manufactured in various ways such as a commercial wafer substrate, a glass substrate, a ceramic substrate, a metal substrate, a polymer substrate, and the like. The commercial wafer substrate may be made of silicon, a compound semiconductor, or the like. The glass substrate may be made of quartz, boro-silicate glass (BSG), boro phosphor silicate glass (BPSG), slide glass, or the like. The ceramic substrate may be made of alumina (Al ₂ O ₃ ), beryllia (BeO), steatite (MgO · SiO ₂ ), forsterite (2MgO · SiO ₂ ), or the like. The metal substrate may be made of various metals and metal alloys including copper, aluminum, nickel, magnesium, titanium, iron, stainless alloys (SUS), and the like. The polymer substrate may be variously made of Polyimide (Kapton), Polyethylenenaphalate (PEN), Polyetheretherketone (PEEK), Polyethersulphone (PES), Polyetherimide (PEI), or PET (Polyester).

The photodetector 10 may be fabricated by processing the substrate 11 on which the plurality of photodiode units 13 are fabricated as thin as about 5 nanometers to 100 micrometers, as shown in FIG. . The wire 50 for transmitting the signal detected by the photodiode unit 13 is coupled to the photodetecting device 10.

Alternatively, the photodetector 10_1 may be manufactured by combining the plurality of photodiode units 13 on the substrate 12 that is made very thin as shown in FIG. 4B. .

The flexible scintillator panel 20 includes a polymer layer 21, a scintillator 23, and a reflective layer 25. The scintillator 23 has a lattice structure having a thickness of 1 to 10,000 micrometers and a plurality of spaced apart from each other at regular intervals, and is inserted into the polymer layer 21. The polymer layer 21 may be made of polymethyl methacrylate (PMMA), polyethylene (PE), polyamide (PA), polyethylene terephthalate (PET), polypropylene (PP), polyvinyl chloride (PVC), polycarbonate (PC), polyimide (PI), Polyacetal (POM), Polybuthylene Terephthalate (PBT), Polystyrene (PS), Acrylonitrile Butadiens Styrene (PS), Poly Phenylene Oxide (PPO), Polyphenylene Sulfide (PPS), Polyetherimide (PEI), Polyether sulfone (PES), Polylatelate ), Poly (etheretherketone) (PEEK), Polyamideimide (PAI), Poly Vinylidene Fluoride (PVDF), Polydimethyl Siloxane (PDMS), Cyclic Olefin Copolymer (COC), Photoresist, Teflon, Nylon, Polyester, Polyvinyl, Various rubbers may be used in addition to various thermoplastic polymers including Kapton, silicone rubber, and the like, thermosetting polymers, and photocurable polymers.

The reflective layer 25 is formed between one surface of the polymer layer 21 and the grating of the scintillator 23. The reflective layer 25 may be formed of various inorganic materials including silicon oxide film, quartz, silicon, ceramic, and the like, and materials of the polymer layer 21, which may be totally reflected by using a difference in refractive index of light. In addition, the reflective layer 25 may be a variety of metals and metal alloys, including aluminum, gold, silver, chromium, copper, nickel, ruthenium, titanium, iron, stainless alloys (SUS), magnesium, and the like, by reflecting light. Metallic materials may be used. In addition, when the refractive index difference between the polymer layer 21 and the scintillator 23 is used, the reflective layer 25 may be omitted.

In the scintillator panel 20 illustrated in FIG. 5, the scintillator 23 is formed in a lattice structure, but the scintillator may be formed in a film form without the lattice structure.

The polymer layer 30 is bonded to the other surface of the photodetecting device 10. As an adhesive for bonding the polymer layer 30 to the photodetector device 10, a starch system including starch paste, modified starch, oxidized starch, starch derivatives, and the like Formalin treatment of adhesives, serum of human blood proteins, humans, cattle and pigs; protein-based adhesives such as milk and soybeans; Glue / Gelatin-based adhesives including Soluble Material and Fish Glue, Seaweed-based adhesives including Sodium Alginate and Gloioleltis Furcata, Asphalt Petroleum-based adhesives including asphalt, sodium silicate, potassium silicate, silica sol, sandarac gum, stick lac, shellac , Damar, Pine Resin, Latex, Gum Arabic, Lacquer Poison, etc. Natural resin-based adhesives, including polysaccharides and gums such as Karaya Gum, Iocust bean gum, Tragacanth Gum, Guar Gum, Konjac Mann Glucomannan (Gum) adhesives, cellulose-based adhesives including cellulose ethers, esters, etc., phenolic resins, urea resins, melamine resins ), Xylene Resin, Epoxy Resin, Isocyanate, Vinyl Acetate, Polyester, Polyvinyl Alcohol, Acrylate Synthetic Polymer-based adhesives including) -based, Cyanoacrylate-based, Synthetic Rubber-based, and the like, and thermoplastic film adhesives such as various polymers. .

The outer mold 40 surrounds the scintillator panel 20, the photodetecting device 10, and the polymer flat plate 30. Outer mold is PMMA (Polymethyl Methacrylate), PE (Polyethylene), PA (Polyamide), PET (Polyetylene Terephthalate), PP (Polypropylene), PVC (Polyvinyl Chloride), PC (Poly Carbonate), PI (Polyimide), POM (Polyacetal) ), PBT (Polybuthylene Terephthalate), PS (Polystyrene), ABS (Acrylonitrile Butadiens Styrene), PPO (Poly Phenylene Oxide), PPS (Polyphenylene Sulfide), PEI (Polyetherimide), PES (Polyether sulfone), PAR (Polyarylate), PEEK (Poly (etheretherketone)), PAI (Polyamideimide), PVdF (Poly Vinylidene Fluoride), PDMS (Polydimethyl Siloxane), COC (Cyclic Olefin Copolymer), Photoresist, Teflon, Nylon, Polyester, Polyvinyl, Kapton, In addition to various thermoplastic polymers including silicone rubber, thermosetting polymers and photocurable polymers, various rubbers such as silicone rubbers, chloroprene rubbers and ethylene propylene rubbers can be used. Can be.

The image sensor shown in FIG. 1 is formed by combining the flexible photodetector 10, the flexible polymer flat plate 30, and the flexible scintillator panel 20, and is surrounded by an outer mold 40, thereby flexibly as shown in FIG. 2. It can be modified. Therefore, Figure 2 shows that it can be applied to a flexible X-ray image sensor that can be applied to fit the shape of the oral cavity and oral structure.

7 is a cross-sectional view of another embodiment of a flexible X-ray image sensor according to the present invention, Figure 8 is a cross-sectional view of another embodiment of a flexible X-ray image sensor according to the present invention, Figure 9 is another view of a flexible X-ray image sensor according to the present invention A cross section of another embodiment. 10 is a cross-sectional view of another embodiment of a flexible X-ray image sensor according to the present invention, FIG. 11 is a conceptual diagram in which the embodiment shown in FIG. 10 is bent, and FIG. 12 is a view of another embodiment of the flexible X-ray image sensor according to the present invention. It is a cross section. 7 to 12, various embodiments of the flexible X-ray image sensor according to the present invention will be described.

The image sensor shown in FIG. 7 further includes supports 41 and 45 as compared to the image sensor shown in FIG. 1. The image sensor is flexible and easily bent. When the image sensor is bent, the coupling portions of the polymer flat plate 30, the photodetecting device 10, and the scintillator panel 20 are greatly deformed, so that stress is concentrated on the coupling portions. Therefore, the coupling parts are most likely to be broken. The supports 41 and 45 serve to prevent stress from concentrating on the junction between the polymer flat plate 30, the photodetecting device 10, and the scintillator panel 20 when the image sensor is bent. To this end, the first support 41 is inserted into the outer mold 40, and the second support 45 is inserted into the polymer flat plate 30. Even when the image sensor is bent, the supports 41 and 45 may be deformed to prevent excessive deformation of the coupling parts. The shape and position of the supports 41 and 45 may be variously modified.

8 and 9 are embodiments in which the shapes and positions of the supports 42, 43, 45, and 46 are different from those of the image sensor of FIG. 7.

The image sensor illustrated in FIG. 10 further includes a stopper 51 as compared to the image sensor illustrated in FIG. 7. The image sensor is flexible and can be bent excessively. The stopper 51 serves to prevent the image sensor from being excessively bent. To this end, the stopper 51 is coupled to one side of the outer mold 40. The stopper 51 is cut out so that a plurality of gaps may be formed on one surface. Therefore, as shown in FIG. 11, only one gap may be bent in one direction. Therefore, adjusting the size of the gap may limit the range in which the image sensor is bent. The shape and position of the stopper 51 may be variously modified.

12 is an embodiment in which the position of the stopper 51 is different from that of the image sensor of FIG. 10. In FIG. 12, the stopper 51 is inserted into the polymer flat plate 30.

An embodiment of the present invention described above should not be construed as limiting the technical idea of the present invention. The protection scope of the present invention is limited only by the matters described in the claims, and those skilled in the art can change and change the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

1 is a conceptual diagram of an embodiment of a flexible X-ray image sensor according to the present invention;

2 is a conceptual diagram in which the embodiment shown in FIG. 1 is bent;

3 is a cross-sectional view of the embodiment shown in FIG.

4 is a conceptual diagram of a photodetector device in the embodiment shown in FIG. 1;

5 is a conceptual diagram of a scintillator panel in the embodiment shown in FIG. 1;

6 is a cross-sectional view of the scintillator panel shown in FIG. 5;

7 is a cross-sectional view of another embodiment of a flexible x-ray image sensor according to the present invention;

8 is a cross-sectional view of another embodiment of a flexible X-ray image sensor according to the present invention;

9 is a cross-sectional view of another embodiment of a flexible X-ray image sensor according to the present invention;

10 is a cross-sectional view of another embodiment of a flexible x-ray image sensor according to the present invention;

11 is a conceptual diagram in which the embodiment shown in FIG. 10 is bent;

12 is a cross-sectional view of another embodiment of a flexible X-ray image sensor according to the present invention.

<Brief Description of Drawings>

10 photodetector 11 substrate

13: photodiode unit 20: scintillator panel

21 polymer layer 23 scintillator

25 reflection layer 30 polymer plate

40: outer mold 41: support

50: wire 51: stopper

Claims (10)

Flexible polymer plates, A flexible photodetector device having a substrate, a photodiode, a TFT and an ASIC operation circuit, and having a plurality of photodiode units formed on one surface of the substrate and coupled to one surface of the polymer plate; And a flexible scintillator panel corresponding to the photodiode unit and having a scintillator capable of converting X-rays to a wavelength detectable by the photodiode unit, and a polymer layer bonded to the scintillator and coupled to one surface of the photodetector. Flexible X-ray image sensor. The method of claim 1, The scintillator is a flexible X-ray image sensor, characterized in that selected from the group consisting of Gd ₂ O ₂ S: Tb, CsI: Na, NaI: Tl, CsBr: Eu, LiI: Eu, CsI: Tl. The method of claim 2, The scintillator panel further comprises a reflective layer formed between the polymer layer and the scintillator. The method of claim 3, Flexible x-ray image sensor, characterized in that the thickness of the scintillator is 1 to 10,000 micrometers. The method of claim 4, wherein The scintillator is a flexible X-ray image sensor, characterized in that the grid structure spaced at regular intervals. 6. The method according to any one of claims 1 to 5, And an external molder surrounding the polymer flat plate, the photodetecting device, and the scintillator panel. The method of claim 6, And a support inserted into the outer mold to prevent stress from concentrating on the junction between the polymer flat plate, the photodetecting device, and the scintillator panel when the image sensor is bent. The method of claim 7, wherein And a stopper inserted into the outer mold to prevent the image sensor from being excessively bent. The method of claim 6, And a support inserted into the polymer plate to prevent stress from being concentrated at the junction between the polymer plate, the photodetecting device, and the scintillator panel when the image sensor is bent. 10. The method of claim 9, And a stopper inserted into the polymer plate to prevent excessive bending of the image sensor.

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