KR20210121761A - Intraoral X-ray sensor and manufacturing method thereof - Google Patents

Abstract

An intraoral X-ray sensor for detecting an X-ray image in an oral cavity comprises: a sensor substrate equipped with a sensing region wherein a plurality of light-detection pixels are formed and a connection region separated from the sensing region; a readout circuit mounted on the sensor substrate to be located in the connection region; an interface board mounted on the sensor substrate to be located in the connection region; and a support sheet fixed to a rear surface of the sensor substrate. The sensor substrate is installed to be bent so that the connection region is located behind the support sheet. Therefore, the present invention is capable of achieving low manufacturing costs.

Description

Intraoral X-ray sensor and manufacturing method thereof

The present invention relates to an X-ray sensor for X-ray imaging, and more particularly, to an intraoral X-ray sensor that can be inserted into an oral cavity to perform X-ray imaging.

An X-ray sensor is a device that generates an electrical signal for detecting an image of a subject using X-rays. The X-ray sensor is used in various image detection equipment such as medical diagnostic equipment, and is also used as an intraoral X-ray sensor to obtain an X-ray image of a tooth in the oral cavity or surrounding tissues by being inserted into the oral cavity.

The intraoral X-ray sensor can be divided into a method using analog film and a method using a digital intraoral X-ray sensor. Recently, digital intraoral X-ray sensors have been widely used due to the fact that it takes a lot of time for the development process after taking an image, and it is difficult to store the film. The digital intraoral X-ray sensor includes a plurality of photo-sensing pixels each configured to detect transmitted X-rays and generate an electric signal according to an amount of X-rays transmitted. A plurality of photo-sensing pixels are arranged in a matrix form forming a plurality of rows and columns, and each photo-sensing pixel includes a photodiode that outputs an electric signal by X-rays and a switching element that transmits an electric signal output from the photodiode. do. A CMOS transistor is mainly used as a switching element of an intraoral X-ray sensor, and a thin film transistor (TFT) can also be used.

Since the CMOS transistor as a switching element includes a readout circuit vulnerable to X-rays inside the pixel, a fiber optic plate (FOP), an optical device, is additionally added to protect the readout circuit from X-rays. have This type of intraoral X sensor has a problem in that the manufacturing cost is relatively high due to the addition of FOP, and there is a limitation in the size of the sensor substrate due to the problem of the CMOS transistor itself, so it is difficult to manufacture a large amount at once. have a problem

On the other hand, an intraoral X-ray sensor using a thin film transistor as a switching element has an advantage that it is easy to be manufactured in a structure that can be bent by applying a flexible substrate. This type of intraoral X-ray sensor includes a plurality of photo-sensing pixels composed of a photodiode and a thin film transistor, and an input line for inputting an electrical signal to each photo-sensing pixel and It contains an output line for output. In this case, the readout circuit is connected to the output line, and the input line and the readout circuit are connected to the outside through an interface board.

Conventionally, a method of arranging a separate printed circuit board behind the sensor board and then installing the interface board on the printed circuit board is used. To this end, a separate wiring member for connecting the front surface of the board and the printed circuit board is required, so that the structure is complicated and the stability of the electrical connection is poor. In addition, since a readout circuit composed of an amplifier and a multiplexer is disposed on a substrate, there is a problem that the readout circuit may be damaged by X-rays or cause operational problems.

Laid-open Patent Publication No. 10-2009-0028884 (published on March 20, 2009) Laid-Open Patent Publication No. 10-2009-0102185 (published date: 2009.09.30) Laid-open Patent Publication No. 10-2017-0018881 (published date: 2017.02.20)

An object of the present invention is to provide an intraoral X-ray sensor capable of omitting a separate conductive connecting member for connecting an interface board and preventing a readout circuit from being damaged by X-rays.

The intraoral X-ray sensor for detecting an X-ray image in the oral cavity according to an embodiment of the present invention includes a sensor substrate having a sensing region in which a plurality of photo-sensing pixels are formed and a connection region separated from the sensing region, the connection region and a readout circuit mounted on the sensor substrate so as to be positioned in the , an interface board mounted on the sensor substrate to be positioned in the connection region, and a support sheet fixed to a rear surface of the sensor substrate. The sensor substrate is installed to be bent so that the connection area is located behind the support sheet.

The support sheet may include an X-ray blocking layer covering the readout circuit.

The sensor substrate may further include an intermediate region between the sensing region and the connection region, and the intermediate region may be formed to be curved along a side surface of the support sheet.

A manufacturing method for manufacturing an intraoral X-ray sensor for detecting an X-ray image in the oral cavity according to an embodiment of the present invention includes a sensing region in which a plurality of photo-sensing pixels are formed and a connection region separated from the sensing region preparing a sensor substrate; forming a readout circuit configured to receive the output signal of the photo-sensing pixel on the connection region; forming an interface board for input/output of a driving signal for driving on the connection region, fixing a support sheet to a rear surface of the sensor substrate, and the sensor substrate so that the connection region is located behind the support sheet including bending the

The manufacturing method for manufacturing an intraoral X-ray sensor according to an embodiment of the present invention may further include forming an X-ray blocking layer covering the readout circuit on the support sheet.

According to the present invention, by bending the sensor substrate so that the readout circuit and the interface board are located behind the support sheet, the photo-sensing pixel of the sensor substrate and the interface board can be connected through the conductive line on the sensor substrate without a separate connection member. A low manufacturing cost and a simple structure are achieved by this.

In addition, since the readout circuit is protected by the X-ray blocking layer provided on the support sheet, it is possible to prevent the readout circuit from being damaged by X-rays.

1 is a schematic plan view of an intraoral X-ray sensor according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an electrical circuit diagram of a photo-sensing pixel of an intraoral X-ray sensor according to an embodiment of the present invention.
3 is a cross-sectional view of an intraoral X-ray sensor according to an embodiment of the present invention.
4 schematically shows a manufacturing process of an intraoral X-ray sensor according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The intraoral X-ray sensor according to an embodiment of the present invention is inserted into the oral cavity and configured to generate an electrical signal for obtaining an X-ray image of a tooth or surrounding tissue. The intraoral X-ray sensor according to an embodiment of the present invention is configured to detect X-rays that are generated by an X-ray generating device and have passed through teeth or surrounding tissues and generate an electrical signal accordingly. The intraoral X-ray sensor of the present invention is configured to receive an electrical signal for operation from the outside and outputs an output electrical signal generated by X-ray sensing. The output electrical signal may be transmitted to an image display device and used to display a corresponding X-ray image.

1 is a schematic plan view of the intraoral X-ray sensor of the present invention, and the illustration of the support case, the outer housing, and the like is omitted from the drawing. The sensor substrate 10 may have a shape that can be inserted into the oral cavity, and can be accommodated in the outer housing. Although the sensor substrate is illustrated in FIG. 1 as an example, the shape of the sensor substrate is not limited thereto and may be variously changed.

The sensor substrate 10 may include a plurality of photo-sensing pixels 11 that detect X-rays and output an electrical signal according to the detected X-rays. The photo-sensing pixels 11 may be arranged in a matrix form to form a plurality of rows and columns. 1 exemplarily shows a case in which 30 photo-sensing pixels 11 are arranged to form 6 rows and 5 columns, but the number of photo-sensing pixels and the number of rows and columns are not limited thereto. The sensor substrate 10 may be configured by forming a plurality of photo-sensing pixels 11 on the substrate 101 configured to be flexible in order to secure the bendable characteristics of the intraoral X-ray sensor, , for example, the substrate 101 may be formed of a flexible polyamide (PI) material.

Each photo-sensing pixel 11 includes a thin film transistor 111 and a photodiode 112 . The thin film transistor 111 and the photodiode 112 may be connected to each other as known in the conventional X-ray sensor. The thin film transistor 111 may be a thin film transistor based on a low temperature polycrystalline silicon (LTPS) material. 1 and 2 , the thin film transistor 111 may include a gate electrode G, a source electrode S, and a drain electrode D, and a cathode of the photodiode 112 . may be electrically connected to the drain electrode D.

The intraoral X-ray sensor according to an embodiment of the present invention generates a photodetection electrical signal induced by the photodiode by X-rays in a state in which a reverse bias voltage is applied to the photodiode 112 (FIG. 1). and in the horizontal direction in FIG. 2) may be configured to be read sequentially in units. To this end, a plurality of bias lines 12 for application of a reverse bias voltage, and a plurality of gate lines for application of a gate signal for turning on the thin film transistors in a row unit to a plurality of photo-sensing pixel arrays. A gate line 13 and a plurality of data lines 14 for outputting a photodetection electrical signal of each pixel may be provided.

For example, the bias line 12 is provided for each column (up-and-down direction in FIGS. 1 and 2) and is connected to the anode of the photodiode 112 of the photo-sensing pixel 11 of each column. 112) is configured to apply a reverse bias voltage. The bias line 12 may be electrically connected to the connection pad 105 to which the interface board 30 for electrical connection with an external circuit is coupled through the bias connection line 17 .

The gate line 13 is provided for each row and is connected to the gate electrode G of the thin film transistor 111 of the photo-sensing pixel 11 of each row to apply a gate signal. In this case, the plurality of gate lines 13 may be connected to a gate driver 15 for a turn-on operation for each row. The gate driver 15 may be electrically connected to the connection pad 105 to which the interface board 30 for electrical connection with an external circuit is fastened through the gate connection line 16 , and receives the gate signal for each row. It works so that it can be applied sequentially.

The data line 14 may be provided for each column and is electrically connected to the source electrode S of the thin film transistor 111 of the photo-sensing pixel 11 of each column. The plurality of data lines 14 extend to the connection pad 104 to which the readout circuit 20 is connected. The output electrical signal of each photo-sensing pixel 11 is transmitted to the readout circuit 20 through the data line 14 . The readout circuit 20 may include a plurality of amplifiers and a multiplexer for amplifying an electrical signal, and the output signal output from the readout circuit 20 connects an external connection line through an interface board 30 . It is transmitted to the main controller of the X-ray imaging device through the

A reverse bias voltage is applied to the photodiode 112 through the bias line 12 in a state in which the X-rays passing through the teeth or surrounding tissues are irradiated to the sensor substrate 10 of the intraoral X-ray sensor, and the gate line 13 When the thin film transistors 111 are sequentially turned on for each row through , the electrical signal output from the photodiode 112 is applied to the data line 14 through the turned-on thin film transistor 111 . The output electrical signal is input to the readout circuit 20 connected to the data line 14 , amplified, and then output through the interface board 30 through an external connection line. At this time, since the photo-sensing pixels 11 are sequentially turned on in row units by the gate signal, the output electrical signal may also be transmitted to the readout circuit 20 in row units. Accordingly, the X-ray imaging apparatus may display the X-ray image by using the output electrical signal of the intraoral X-ray sensor.

In the intraoral X-ray sensor according to the embodiment of the present invention, the readout circuit 20 and the interface board 30 are not connected to the photo-sensing pixel 11 through a separate connection member, but rather to the substrate 101 . It is configured to electrically connect the readout circuit 20 and the interface board 30 positioned at the rear of the sensor board 10 by bending a part thereof backward.

The sensor substrate 10 may include a sensing region 102 in which a plurality of photosensitive pixels 11 are arranged, and a connection region 103 separated from the sensing region 102 . The readout circuit 20 may be mounted on the connection pad 104 formed in the connection area 103 , and the interface board 30 may also be mounted on the connection pad 105 formed in the connection area 103 . . The connection pads 104 and 105 may include conductive patterns for transmission of electrical signals, and the readout circuit 20 and the interface board 30 are respectively connected to the connection pads 104 and 105 through the corresponding conductive patterns. It may be electrically electrically connected.

According to the embodiment of the present invention, the support sheet 40 fixed to the rear surface of the sensor substrate 10 may be fixed, and the read-out circuit 20 and the interface board 30 are disposed on the rear side of the sensor substrate 10 . To be positioned, the substrate 101 may be installed in a bent state such that the connection region 103 is positioned behind the support sheet 40 . The support sheet 40 may be configured to be bendable to realize the bendable property of the intraoral X-ray sensor, and may be formed of, for example, a flexible synthetic resin material. A connector connected to the main body of the X-ray imaging apparatus is connected to the interface board 30 , whereby signal input/output with the sensor board 10 may be made.

In the case of the indirect type intraoral X-ray sensor, a scintillator layer 50 that converts X-rays into visible light may be formed on the sensor substrate 10 .

Meanwhile, the sensor substrate 10 may further include an intermediate region 104 connecting the sensing region 102 and the connection region 103 , and as shown in FIG. 3 , the intermediate region 104 includes a support sheet ( 40) is installed in a bent state along the side.

1 shows a state before the substrate 101 is bent in a state where the readout circuit 20 and the interface board 30 are not installed, and FIG. 3 shows the connection area 103 in the completed intraoral X-ray sensor. ) is shown in a state in which the substrate 101 is bent so that it is positioned at the rear of the support sheet 40 . As shown in FIG. 3 , since the substrate 101 is installed in a bent state, the readout circuit 20 and the interface board 30 connected to the connection area 103 of the substrate 101 are also supported by the support sheet 40 . is located behind the As a result, the readout circuit 20 and the interface board 30 may be disposed behind the sensing region 102 and the support sheet 40 due to the curved structure of the substrate 101 , and unlike the conventional method, a separate unit such as a COF Electrical connection can be implemented without a connecting member of

Meanwhile, according to an embodiment of the present invention, the support sheet 40 may include an X-ray blocking layer 41 covering the readout circuit 20 . For example, the X-ray blocking layer 41 may be formed of a coated copper film. Since the readout circuit 20 is covered by the X-ray blocking layer 41, it is possible to prevent the readout circuit 20 from being damaged by the X-rays.

Hereinafter, a method of manufacturing an intraoral X-ray sensor according to an embodiment of the present invention will be described with reference to FIG. 4 . 4, each process for manufacturing an intraoral X-ray sensor according to an embodiment of the present invention is shown in turn. The order of each process of the manufacturing method is not limited to that shown in FIG. 4 and may be changed according to necessity and process efficiency.

4A shows the sensor substrate 10 . The sensor substrate 10 may be the sensor substrate shown in FIG. 1 . Referring to FIG. 4B , the scintillator layer 50 may be formed on the sensor substrate 10 . As shown in FIGS. 4C and 4D , the readout circuit 20 and the interface board 40 may be respectively installed on connection pads provided in the connection region 103 of the sensor substrate 10 . . As shown in (e) of FIG. 4 , the support sheet 40 having the X-ray blocking layer 41 may be fixed to the rear surface of the sensor substrate 10 . In this case, the X-ray blocking layer 41 may be formed by coating after fixing the support sheet 40 to the rear surface of the sensor substrate 10 . As shown in (f) of FIG. 4 , the sensor substrate 10 is bent so that the connection region 103 in which the readout circuit 20 and the interface board 40 are disposed is located behind the support sheet 40 . It is fixed to the back side of the support sheet (40).

Although the embodiment of the present invention has been described above, the scope of the present invention is not limited thereto, and it is easily changed by a person skilled in the art from the embodiment of the present invention and recognized as equivalent. including all changes and modifications to the scope of

10: sensor board
101: substrate
102: sensing area
103: connection area
104: middle area
11: light-sensing pixel
111: thin film transistor
112: photodiode
12: bias line
13: gate line
14: data line
15: gate driver
16, 17: connecting line
20: readout circuit
30: interface board
104, 105: connection pad
40: support sheet
41: X-ray blocking layer
50: scintillator layer

Claims (5)

As an intraoral X-ray sensor for detection of X-ray images in the oral cavity,
A sensor substrate comprising a sensing region in which a plurality of photo-sensing pixels are formed and a connection region separated from the sensing region;
a readout circuit mounted on the sensor substrate to be located in the connection area;
an interface board mounted on the sensor board to be positioned in the connection area; and
A support sheet fixed to the rear surface of the sensor substrate
including,
The sensor substrate is installed to be bent so that the connection area is located behind the support sheet.
Intraoral X-ray sensor. In claim 1,
and the support sheet includes an X-ray blocking layer covering the readout circuit. In claim 1,
The sensor substrate further includes an intermediate region between the sensing region and the connection region,
The middle region is formed to be bent along the side surface of the support sheet.
Intraoral X-ray sensor. A manufacturing method for manufacturing an intraoral X-ray sensor for detection of an X-ray image in the oral cavity, comprising:
preparing a sensor substrate having a sensing region in which a plurality of photo-sensing pixels are formed and a connection region separated from the sensing region;
forming a read-out circuit formed to receive an output signal of the photo-sensing pixel on the connection region;
forming an interface board on the connection region for input/output of an output signal of the readout circuit and a driving signal for driving the photo-sensing pixel on the connection region;
fixing a support sheet to the rear surface of the sensor substrate, and
bending the sensor substrate so that the connection area is located behind the support sheet;
A manufacturing method comprising a. In claim 3,
The manufacturing method further comprising the step of forming an X-ray blocking layer covering the readout circuit on the support sheet.

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