X-ray detector

Abstract

The present invention provides an X-ray detector including: a sensor panel including a photoelectric conversion element arranged on a substrate; a printed circuit board disposed on a rear surface of the sensor panel and including a bias pad; and a conductive sheet covering the sensor panel and the printed circuit board and connected to the photoelectric conversion element and the bias pad.

Description

Technical Field

[0001] The invention relates to an X-ray detector. Background Art

[0002] Recently, digital detectors are widely used in X-ray imaging. Digital detectors can be divided into indirect conversion type and direct conversion type.

[0003] An indirect conversion type X-ray detector is equipped with a phosphor to convert X-rays into visible light and then convert the visible light into an electrical signal, while a direct conversion type X-ray detector has the advantage of directly converting into an electrical signal without using a photoconductor to convert X-rays into visible light.

[0004] In a direct conversion X-ray detector, a photoelectric conversion element is arranged on the front surface of a sensor panel, and the photoelectric conversion element includes a first electrode as a pixel electrode or a lower electrode, a photoconductor, and a second electrode as a common electrode or an upper electrode, and a bias voltage is applied to the upper electrode.

[0005] To this end, a transmission line for connecting a bias pad of a printed circuit board arranged on the rear surface of the sensor panel and an upper electrode is used, and the transmission line is arranged to cross the side of the sensor panel.

[0006] With this bias voltage application structure, it is difficult to coat (coat) a packaging film required for protecting the transmission line or preventing moisture from penetrating into the interior of the sensor panel. Summary of the invention

[0007] Technical issues The technical problem of the present invention is to provide a method for stably sealing a sensor panel and the like by improving a bias voltage application structure of a direct conversion type X-ray detector.

[0008] Technical Solution In order to solve the technical problems mentioned above, the present invention provides an X-ray detector, comprising: a sensor panel, comprising a photoelectric conversion element arranged on a substrate; a printed circuit board, arranged on the rear surface of the sensor panel and comprising a bias pad; and a conductive sheet, covering the sensor panel and the printed circuit board and connected to the photoelectric conversion element and the bias pad.

[0009] The X-ray detector may further include: a packaging film covering at least a portion of a sensor assembly, wherein the sensor assembly includes the sensor panel, a printed circuit board, and a conductive sheet.

[0010] The packaging film may include Parylene.

[0011] The printed circuit board may include a connector disposed on a rear surface thereof, and the packaging film may cover the conductive sheet and cover the rear surface of the printed circuit board except for the connector.

[0012] The photoelectric conversion element may include a first electrode on the substrate, a photoconductive layer on the first electrode, and a second electrode on the photoconductive layer and connected to the conductive sheet.

[0013] The photoconductive layer may include at least one of perovskite (PV), CdTe, CdZnTe, PbO, PbI2, HgI2, GaAs, Se, TlBr, and BiI3.

[0014] The bias pad may be arranged in at least one corner side region among a plurality of corner side regions constituting an edge of the printed circuit board.

[0015] The conductive sheet may include a foil or a mesh of a metal composed of gold (Au), platinum (Pt), or an alloy thereof.

[0016] Effects of the Invention According to the present invention, the bias voltage can be applied from the bias pad to the second electrode using the conductive sheet in close contact with the sensor panel, the photoelectric conversion element, and the printed circuit board.

[0017] According to this, the uniformity of the bias voltage of the second electrode can be maximized, and the inflow of external noise can be effectively blocked.

[0018] Also, the conductive sheet can suppress moisture or foreign matter from penetrating into the sensor panel and protect the sensor panel, and can more firmly bond the sensor panel and the printed circuit board.

[0019] Furthermore, the conductive sheet does not cause a substantial change in the shape of the X-ray detector, and thus the difficulty of coating a packaging film when using a transmission line can be effectively eliminated. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a perspective view schematically showing a direct type X-ray detector according to an embodiment of the present invention.

[0021] Figure 2 is a cross-sectional view schematically showing an X-ray detector according to an embodiment of the present invention.

[0022] Figure 3 is a perspective view schematically showing a sensor assembly according to an embodiment of the present invention.

[0023] Figure 4 is an exploded perspective view schematically showing a sensor assembly according to an embodiment of the present invention.

[0024] Figure 5 is a cross-sectional view schematically showing a portion of a sensor panel according to an embodiment of the present invention.

[0025] Figure 6 is a plan view schematically showing a printed circuit board according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0027] Figure 1 is a perspective view schematically showing a direct type X-ray detector according to an embodiment of the present invention. Figure 2 As a cross-sectional view schematically showing an X-ray detector according to an embodiment of the present invention, Figure 1 The interception line II-II' is illustrated. Figure 3 is a perspective view schematically showing a sensor assembly according to an embodiment of the present invention, Figure 4 is an exploded perspective view schematically showing a sensor assembly according to an embodiment of the present invention. Figure 5 is a cross-sectional view schematically showing a portion of a sensor panel according to an embodiment of the present invention. Figure 6 is a plan view schematically showing a printed circuit board according to an embodiment of the present invention.

[0028] Reference Figures 1 to 6 The direct type X-ray detector 10 according to the embodiment of the present invention can directly detect X-rays and generate electrical signals. The X-ray detector 10 can be used as various types of X-ray sensors such as intra oral sensors, panoramic sensors, and CT sensors.

[0029] The X-ray detector 10 may include a sensor assembly 100 and a packaging film (or, a protective film) 300 directly covering the outside of the sensor assembly 100 .

[0030] The sensor assembly 100 may include a sensor panel 110 , a conductive sheet 200 disposed in front of the sensor panel 110 , and a printed circuit board 150 disposed in rear of the sensor panel 110 .

[0031] The sensor panel 110 corresponds to a direct conversion type sensor panel that directly converts X-rays incident through its front surface (or incident surface) into electrical signals.

[0032] In such a sensor panel 110 , pixels P, which are basic units that perform a photoelectric conversion function in an effective area (ie, an active area) for acquiring an image, may be arranged in a matrix form along a plurality of row lines and a plurality of column lines.

[0033] Furthermore, although not specifically shown, in the sensor panel 110, a plurality of scanning wirings may extend along one direction (e.g., a row direction), a plurality of reading wirings may extend along a direction intersecting the scanning wirings (e.g., a column direction), and each pixel P may be connected to the corresponding scanning wiring and reading wiring.

[0034] Reference Figure 5 Looking at an example of the structure of the pixels P of the sensor panel 110 , in each pixel P, a photoelectric conversion element PC that converts X-rays into an electrical signal may be formed on the substrate 111 .

[0035] Here, as the substrate 111 for the sensor panel 110, for example, a CCD substrate, a CMOS substrate, a TFT substrate, etc. may be used, but it is not limited thereto. In the embodiment of the present invention, for the sake of convenience of description, a case of using a CMOS substrate is taken as an example.

[0036] A protective film 115 may be formed on the surface of the substrate 111. In addition, a pad hole 117 may be formed in the protective film 115 of each pixel P. A lower electrode 120 of each pixel P may be formed in the pad hole 117. The lower electrode 120 is an electrode constituting the photoelectric conversion element PC, and corresponds to a first electrode (or pixel electrode) 120. A driving voltage may be applied to the first electrode 120.

[0037] A photoconductive layer 125 may be formed on the substrate 111 formed with the first electrode 120. If the photoconductive layer 125 is incident with X-rays, electron-hole pairs may be generated.

[0038] A material having excellent charge transfer characteristics, high absorption coefficient, low dark current, and low electron-hole pair generation energy can be used as the photoconductive layer 125. For example, at least one of a photoconductive material group such as perovskite (PV), CdTe, CdZnTe, PbO, PbI2, HgI2, GaAs, Se, TlBr, and BiI3 can be used.

[0039] An upper electrode 130 may be formed on the substrate 111 formed with the photoconductive layer 125. The upper electrode 130 is another electrode constituting the photoelectric conversion element PC, and corresponds to a second electrode (or common electrode) 130. Such a second electrode 130 may be formed in common over the entire effective area where the pixels P of the sensor panel 110 are formed.

[0040] Such a second electrode 130 may be applied with a bias voltage, and the bias voltage may have a potential lower than a driving voltage of the first electrode 120 .

[0041] The printed circuit board 150 may be disposed on the rear surface of the sensor panel 110 configured as described above. For example, the printed circuit board 150 may be attached to the rear surface of the sensor panel 110 by an adhesive.

[0042] The printed circuit board 150 may be provided with a connector 155 and a bias pad 157 .

[0043] The connector 155 is connected to an external system through a cable, and various signals can be transmitted and received through the connector 155 , and a driving power source can be received from the outside. Such a connector 155 can be arranged on the rear surface of the printed circuit board 150 .

[0044] The bias pad 157 corresponds to a terminal that outputs a bias voltage applied to the sensor panel 110 .

[0045] Such a bias pad 157 may be disposed on the rear surface of the printed circuit board 150. Further, the bias pad 157 may be disposed on the edge of the rear surface of the printed circuit board 150.

[0046] At this time, the bias pad 157 may be formed in at least one of a plurality of corner side regions constituting the edge of the printed circuit board 150. In the present embodiment, the case where the bias pad 157 is formed in two corner side regions facing each other is taken as an example.

[0047] The conductive sheet 200 may be configured in the form of a thin metal foil or a film, and may be configured to cover the sensor panel 110 and the printed circuit board 150 .

[0048] In this regard, the conductive sheet 200 may include: a cover portion 210, which covers the entire front surface of the sensor panel 110 corresponding to the front surface thereof and is connected to the second electrode 130; and a connecting portion (or, an extension portion) 220, which has a shape extending outward from the cover portion 210 and is connected to the bias pad 157 of the printed circuit board 150.

[0049] In this way, the bias voltage may be transmitted from the bias pad 157 to the second electrode 130 of the sensor panel 110 through the conductive sheet 200 formed of the connection portion 220 and the cover portion 210 .

[0050] The conductive sheet 200 may be made of a metal having excellent electrical conductivity and ductility, such as gold (Au), platinum (Pt), or an alloy thereof, but is not limited thereto.

[0051] The cover 210 may have substantially the same shape as the sensor panel 110 in a plane. The cover 210 may be attached to the front surface of the sensor panel 110 and electrically connected to the second electrode 130 of the sensor panel 110 .

[0052] In this regard, for example, a conductive adhesive (for example, an anisotropic conductive film) may be formed on the inner surface of the cover 210 , and the cover 210 may be attached to the sensor panel 110 through the conductive adhesive.

[0053] According to this, the cover part 210 and the second electrode 130 may have an electrically connected state.

[0054] The connection portion 220 may be attached to the side surface of the sensor panel 110 and the side surface of the printed circuit board 150 , and further, may be attached to the edge of the rear surface of the printed circuit board 150 .

[0055] As such, since the connection portion 220 is attached to the edge of the rear surface of the printed circuit board 150 , the connection portion 220 may be electrically connected to the bias pad 157 located at the edge of the printed circuit board 150 .

[0056] At this time, a conductive adhesive may be formed on the inner surface of the connection portion 220 similarly to the cover portion 210 , and the connection portion 220 may be attached to the sensor panel 110 and the printed circuit board 150 by the conductive adhesive.

[0057] In addition, the connection portion 220 may be formed to have a shape cut corresponding to the corner of the sensor panel 110. That is, the connection portion 220 may have a shape removed corresponding to the corner of the sensor panel 110. Accordingly, the connection portion 220 may be configured as a divided portion corresponding to each of the side surfaces (or corners) of the sensor panel 110 and the printed circuit board 150.

[0058] As described above, since the connection portion 220 is connected to the bias pad 157 and the cover portion 210 is connected to the second electrode 130 , the bias voltage output from the bias pad 157 may be provided to the second electrode 130 through the conductive sheet 200 .

[0059] As described above, in the bias voltage applying structure of this embodiment, by using the conductive sheet 200 which is a conductive body in a planar form overlapping the entire surface of the second electrode 130 , the uniformity of the bias voltage in the second electrode 130 can be maximized.

[0060] Furthermore, by using the conductive sheet 200 which is a planar conductive body, the inflow of external noise can be effectively blocked.

[0061] Furthermore, since the conductive sheet 200 can be configured to substantially surround the sensor panel 110 and function as a packaging film, it can play a role in suppressing moisture or foreign matter from penetrating into the sensor panel 110 and protecting the sensor panel 110 .

[0062] In addition, the conductive sheet 200 is attached to both the sensor panel 110 and the printed circuit board 150 , and thus the conductive sheet 200 can play a role in more firmly combining the sensor panel 110 and the printed circuit board 150 .

[0063] As described above, the sensor assembly 100 in which the conductive sheet 200 , the sensor panel 110 and the printed circuit board 150 are combined may be coated with a packaging material to form a packaging film 300 , thereby manufacturing the X-ray detector 10 .

[0064] At this time, as the encapsulating material, a high molecular weight material such as polyparaxylene may be used, but is not limited thereto.

[0065] In addition, in this embodiment, the sensor assembly 100 can be formed by attaching the conductive sheet 200 in a planar form to the sensor panel 110 and the printed circuit board 150. Accordingly, the conductive sheet 200 does not cause a substantial change in the shape of the X-ray detector 10, so the difficulty of coating the packaging film when using the transmission line can be effectively eliminated. At this time, if necessary, the conductive sheet 200 can also present a grid shape in addition to the planar shape.

[0066] As described above, by directly coating the packaging material on the sensor component 100 , the packaging film 300 can be formed in a form that is in direct contact with the outer surface of the sensor component 100 .

[0067] At this time, the connector 155 of the printed circuit board 150 is combined with the cable, and thus, the packaging film 300 may be formed in such a manner that a portion of the connector 155 is removed (ie, the connector 155 is exposed).

[0068] In other words, the packaging film 300 may be formed in such a manner as to substantially cover the entirety of the conductive sheet 200 and the rear surface of the printed circuit board 150 except for the connector 155 .

[0069] As such, the packaging film 300 may be formed in a manner of covering the sensor assembly 100 except for the connector 155. Accordingly, it is possible to prevent moisture or foreign matter from penetrating into the sensor panel 110.

[0070] Furthermore, the packaging film 300 can function as a cover covering the outermost contours of the sensor panel 110 , the printed circuit board 150 , and the conductive sheet 200 , thereby protecting the sensor panel 110 , the printed circuit board 150 , and the conductive sheet 200 and firmly combining them.

[0071] As described above, according to an embodiment of the present invention, the bias voltage may be applied from the bias pad to the second electrode by using a conductive sheet that is in close contact with the sensor panel and the printed circuit board.

[0072] According to this, the uniformity of the bias voltage of the second electrode can be maximized, and the inflow of external noise can be effectively blocked.

[0073] Also, the conductive sheet can suppress the penetration of moisture or foreign matter into the sensor panel and protect the sensor panel, and can more firmly bond the sensor panel and the printed circuit board.

[0074] Furthermore, the conductive sheet does not cause a substantial change in the shape of the X-ray detector, and thus the difficulty of coating a packaging film when using a transmission line can be effectively eliminated.

Claims

1. An X-ray detector, comprising: A sensor panel including a photoelectric conversion element arranged on a substrate; a printed circuit board disposed on a rear surface of the sensor panel and including a bias pad; as well as The conductive sheet covers the sensor panel and the printed circuit board and is connected to the photoelectric conversion element and the bias pad.

2. The X-ray detector according to claim 1, further comprising: The packaging film covers at least a portion of the sensor assembly, wherein the sensor assembly includes the sensor panel, a printed circuit board and a conductive sheet.

3. The X-ray detector according to claim 2, wherein: The encapsulation film includes polyparaxylene.

4. The X-ray detector according to claim 2, wherein: The printed circuit board includes a connector arranged on a rear surface thereof, The packaging film covers the conductive sheet and covers the rear surface of the printed circuit board except for the connector.

5. The X-ray detector according to claim 1, wherein: The photoelectric conversion element includes a first electrode on the substrate, a photoconductive layer on the first electrode, and a second electrode on the photoconductive layer and connected to the conductive sheet.

6. The X-ray detector according to claim 5, wherein: The photoconductive layer includes at least one of perovskite (PV), CdTe, CdZnTe, PbO, PbI2, HgI2, GaAs, Se, TlBr and BiI3.

7. The X-ray detector according to claim 1, wherein: The bias pad is arranged in at least one corner side region among a plurality of corner side regions constituting an edge of the printed circuit board.

8. The X-ray detector according to claim 1, wherein: The conductive sheet includes a foil or a mesh of a metal made of gold (Au), platinum (Pt), or an alloy thereof.

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