X-RAY FLAT PANEL DETECTOR, METHOD FOR MANUFACTURING X-RAY FLAT PANEL DETECTOR, DETECTION DEVICE AND IMAGING SYSTEM

An X-ray flat panel detector, a method for manufacturing the X-ray flat panel detector, a detection device and an imaging system are provided. The X-ray flat panel detector includes: a substrate; a back plate layer arranged on the substrate and including a plurality of thin film transistors, each thin film transistor including a source/drain electrode layer; a wiring layer arranged at a side of the back plate layer distal to the substrate and including a plurality of connection lines; and a photosensitive element layer arranged at a side of the wiring layer distal to the substrate and including first electrodes. Each first electrode is electrically connected to the source/drain electrode layer of a corresponding thin film transistor through a corresponding connection line, and an orthogonal projection of the first electrode onto the substrate does not overlap an orthogonal projection of the corresponding thin film transistor onto the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims a priority of the Chinese patent application No. 202011311373.2 filed in China on Nov. 20, 2020, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of detection technology, in particular to an X-ray flat panel detector, a method for manufacturing the X-ray flat panel detector, a detection device and an imaging system.

BACKGROUND

Digital Radiography (DR) is a new X-ray photographic technique developed in the 1990s, and it becomes a leading direction of the X-ray photographic technique and has been recognized by clinical organizations and imaging specialists all over the world due to such significant advantages as higher imaging speed, more convenient operation and higher image resolution. As a DR technical core, a flat panel detector is a precise and valuable device, and plays a decisive role in imaging quality. In the related art, the flat panel detectors mainly include two types, one for indirect detection and one for direct detection.

In the related art, the indirect X-ray flat panel detector mainly includes a substrate, and thin film transistors, photodiodes and a scintillation layer arranged at a side of the substrate one on another. The scintillation layer is configured to convert an X-ray into visible light, each photodiode is configured to convert the visible light into charge carriers and store them, and each thin film transistor serves as a switch. The thin film transistors are turned on progressively under the control of an external scanning control circuitry, so as to read the charge carriers stored in the photodiode and transmit them to a data processing circuitry.

However, it is found that, in the current X-ray flat panel detector, the photodiode is arranged parallel to the thin film transistor, the photodiode is arranged at a pixel region, and a filling rate is restrained by a size of the thin film transistor and a metal line, so a resolution of the X-ray flat panel detector is adversely affected. In addition, in the related art, it is impossible for a back plate with large-size pixels to be compatible with photodiodes with different sizes, so the manufacture cost may increase.

SUMMARY

An object of the present disclosure is to provide an X-ray flat panel detector, a method for manufacturing the X-ray flat panel detector, a detection device and an imaging system.

In one aspect, the present disclosure provides in some embodiments an X-ray flat panel detector, including:

a substrate;

a back plate layer arranged on the substrate and including a plurality of thin film transistors, each of the thin film transistors including a source/drain electrode layer;

a wiring layer arranged at a side of the back plate layer distal to the substrate and including a plurality of connection lines; and

a photosensitive element layer arranged at a side of the wiring layer distal to the substrate and including a plurality of first electrodes,

wherein each of the first electrodes is electrically connected to the source/drain electrode layer of a respective one of the thin film transistors through a respective one of the connection lines, and an orthogonal projection of the first electrode onto the substrate does not overlap an orthogonal projection of the respective thin film transistor onto the substrate.

In a possible embodiment of the present disclosure, an area of an orthogonal projection of the photosensitive element layer onto the substrate is smaller than an area of an orthogonal projection of the back plate layer onto the substrate.

In a possible embodiment of the present disclosure, the back plate layer includes a passivation layer;

the passivation layer is arranged at a side of the thin film transistor distal to the substrate and covers the substrate, a plurality of first via-holes is formed in the passivation layer and penetrates through the passivation layer, each of the first via-holes exposes a source electrode or a drain electrode of a respective one of the thin film transistors;

each of the connection lines is electrically connected to a source electrode or a drain electrode of a respective one of the thin film transistor through the respective first via-hole.

In a possible embodiment of the present disclosure, the wiring layer includes a planarization layer, the planarization layer is arranged at a side of the photosensitive element layer proximate to the substrate and covers the connection lines, a plurality of second via-holes is formed in the planarization layer at predetermined positions and penetrates through the planarization layer;

each of the first electrodes is electrically connected to a respective one of the connection lines through a respective one of the second via-hole.

In a possible embodiment of the present disclosure, the photosensitive element layer includes a photodiode and a second electrode;

the photodiode is arranged at a side of the first electrode distal to the substrate;

the second electrode is arranged at a side of the photodiode distal to the first electrode.

In a possible embodiment of the present disclosure, the first electrode is a bar-shaped electrode, and the second electrode is a planar electrode; or

the first electrode is a bar-shaped electrode, the second electrode is a bar-shaped electrode, and an orthogonal projection of the second electrode onto the substrate covers an orthogonal projection of the first electrode onto the substrate.

In a possible embodiment of the present disclosure, the X-ray flat panel detector further includes a protection layer, wherein the protection layer is arranged at a side of the photosensitive element layer distal to the substrate and covers the substrate;

an area of an orthogonal projection of the protection layer onto the substrate is greater than an area of the orthogonal projection of the photosensitive element layer onto the substrate.

In another aspect, the present disclosure provides in some embodiments an X-ray flat panel detection device, including a plurality of the above-mentioned X-ray flat panel detectors arranged in an array form. Adjacent X-ray flat panel detectors are spliced with each other, and the photosensitive element layer is arranged proximate to a position where the adjacent X-ray flat panel detectors are spliced.

In yet another aspect, the present disclosure provides in some embodiments an X-ray imaging system, including the above-mentioned X-ray flat panel detector or X-ray flat panel detection device.

In still yet another aspect, the present disclosure provides in some embodiments a method for manufacturing an X-ray flat panel detector, including:

providing a substrate, and forming a back plate layer on the substrate through a patterning process, wherein the back plate layer includes thin film transistors and a passivation layer;

forming a plurality of connection lines at a side of the back plate layer distal to the substrate through a patterning process, wherein each of the connection lines is electrically connected to a source electrode or a drain electrode of a respective one of the thin film transistors through a respective first via-hole, the first via-hole penetrates through the passivation layer;

forming a planarization layer at a side of the connection line distal to the substrate through a patterning process; and forming a photosensitive element layer at a side of the planarization layer distal to the substrate through a patterning process,

wherein the photosensitive element layer includes a plurality of first electrodes, each of the first electrodes is electrically connected to a respective one of the connection lines through a respective second via-hole, the second via-hole penetrates through the planarization layer, and an orthogonal projection of the first electrode onto the substrate does not overlap an orthogonal projection of a thin film transistor whose source electrode or drain electrode is electrically connected to the first electrode onto the substrate.

In a possible embodiment of the present disclosure, the forming the back plate layer on the substrate through the patterning process includes:

forming a buffer layer on the substrate;

forming a gate electrode, a gate insulation layer, an active layer, a source electrode and a drain electrode sequentially on the buffer layer through a patterning process; and

forming the passivation layer on the source electrode and the drain electrode through a patterning process.

In a possible embodiment of the present disclosure, the forming the plurality of connection lines at the side of the back plate layer distal to the substrate through the patterning process includes:

depositing a metal layer on the passivation layer; and

patterning the metal layer to form the plurality of connection lines,

wherein an orthogonal projection of each of the connection lines onto the substrate covers an orthogonal projection of the first via-hole onto the substrate and an orthogonal projection of the second via-hole onto the substrate.

In a possible embodiment of the present disclosure, the forming the photosensitive element layer at the side of the planarization layer distal to the substrate through the patterning process includes:

forming the plurality of first electrodes on the planarization layer through a patterning process, wherein each of the first electrodes is electrically connected to a respective one of the connection lines through the respective second via-hole penetrating through the planarization layer;

forming a photodiode on the first electrode through a patterning process;

forming a second electrode on each photodiode through a patterning process.

The above description is merely an overview of the schemes in the embodiments of the present disclosure, and the schemes may be implemented in accordance with contents involved in the description so as to enable a person skilled in the art to understand the technical means of the present disclosure in a clearer manner. In order to make the objects, the technical solutions and the advantages of the present disclosure more apparent, the present disclosure will be described hereinafter in a clear manner in conjunction with the drawings and embodiments.

DETAILED DESCRIPTION

The present disclosure will be described hereinafter in conjunction with the drawings and embodiments. The following embodiments are for illustrative purposes only, but shall not be used to limit the scope of the present disclosure. Actually, the embodiments are provided so as to facilitate the understanding of the scope of the present disclosure.

Unless otherwise defined, such words as “one” or “one of” are merely used to represent the existence of at least one member, rather than to limit the number thereof. Such words as “include” or “including” intend to indicate that there are the features, integers, steps, operations, elements and/or assemblies, without excluding the existence or addition of one or more other features, integers, steps, operations, elements, assemblies and/or combinations thereof. In addition, the expression “and/or” is used to indicate the existence of all or any one of one or more of listed items, or combinations thereof.

Unless otherwise defined, any technical or scientific term used herein shall have the common meaning understood by a person of ordinary skills. Any term defined in a commonly-used dictionary shall be understood as having the meaning in conformity with that in the related art, shall not be interpreted idealistically and extremely.

FIG. 1shows a structure of a X-ray flat panel detector in related art. As shown inFIG. 1, as a body structure, the X-ray flat panel detector includes a substrate1, a thin film transistor arranged on the substrate1, a photodiode9juxtaposed with the thin film transistor, and a scintillation layer (not shown) arranged above the photodiode9. The thin film transistor includes a gate electrode3, a gate insulation layer4, an active layer5and a source/drain electrode layer6. The photodiode9includes a P-type semiconductor layer, an N-type semiconductor layer, and an intrinsic semiconductor layer arranged between the P-type semiconductor layer and the N-type semiconductor layer. A first electrode8is connected to a drain electrode of the thin film transistor, and a second electrode10is arranged on the photodiode9. In addition, a buffer layer2is arranged between the substrate1and the thin film transistor, and a protection layer (not shown) is arranged on the second electrode10.

A working principle of the X-ray flat panel detector will be described as follows. An X-ray is modulated by a human body on a transmission path of the X-ray, and the modulated X-ray is converted by the scintillation layer into visible light. The visible light is absorbed by the photodiode and converted into charge carriers, and the charge carriers are stored in a storage capacitor or a capacitor of the photodiode itself to form image charges. The thin film transistors are turned on progressively through an external scanning control circuitry, and the image charges are read simultaneously by the thin film transistors in each row and outputted to an external data processing circuitry. The image charges read by each thin film transistor corresponds to a dose of an incident X-ray, and the image charges are processed by the external data processing circuitry to determine an amount of charges for each pixel point, thereby to determine a dose of the X-ray for each pixel point.

However, it is found that, due to an insufficient evenness of a film layer above a projection of the thin film transistor, with a level difference of above 5000 Å, so during the design of pixels, an active photosensitive part of the photodiode is provided with an insufficient area to cover the thin film transistor. In other words, in the related art, the thin film transistor is juxtaposed with the photodiode, so a filling rate of the flat panel detector is seriously adversely affected by this design mode, thereby a resolution and detection performance of the X-ray flat panel detector are adversely affected.

In addition, it is found that, when a back plate layer (including such film layers as the thin film transistor) has a relatively large size and a detection surface of the X-ray flat panel detector has a relatively small area, it is necessary to manufacture the back plate layer with a small size, so as to match the photodiode with a small size, thereby to meet the requirement on the detection surface of the X-ray flat panel detector. In the related art, it is impossible for the back plate layer to be compatible with the photodiodes with different sizes, so the manufacture cost may increase. In addition, a yield of the back plate layer may be adversely affected to some extent.

An object of the present disclosure is to provide a new X-ray flat panel detector and a method for manufacturing the X-ray flat panel detector, so as to solve the problems in the related art where the X-ray flat panel detector has a low resolution when a filling rate is restrained by a size of the thin film transistor and a metal wiring, and the manufacture cost of the X-ray flat panel detector is relatively high.

The X-ray flat panel detector in the embodiments of the present disclosure will be described in more details hereinafter in conjunction with the drawings.

The present disclosure provides in some embodiments an X-ray flat panel detector20which, as shown inFIG. 2, includes a substrate1, a back plate layer21, a wiring layer and a photosensitive element layer26. The back plate layer21is arranged on the substrate1, and includes a plurality of thin film transistors22. Each thin film transistor22includes a gate electrode3, a gate insulation layer4, an active layer5and a source/drain electrode layer6. The wiring layer is arranged at a side of the back plate layer21distal to the substrate1, and includes a plurality of connection lines23and a planarization layer25. The photosensitive element layer26is arranged at a side of the wiring layer distal to the substrate1, and includes a plurality of first electrodes8. Each first electrode8is electrically connected to the source/drain electrode layer6of a corresponding thin film transistor22through a corresponding connection line23, and an orthogonal projection of each first electrode8onto the substrate1does not overlap an orthogonal projection of the corresponding thin film transistor22onto the substrate1.

Because the photosensitive element layer26of the X-ray flat panel detector20in the embodiments of the present disclosure is arranged at a side of the wiring layer distal to the substrate1and the wiring layer is arranged at a side of the back plate layer21distal to the substrate1, the photosensitive element layer26and the back plate layer21are arranged sequentially in a direction perpendicular to the substrate1. As compared with the related art where the thin film transistor is juxtaposed with the photosensitive element layer, in the embodiments of the present disclosure, the design of the photosensitive element layer26is not adversely affected by the thin film transistor22, so it is able to increase a filling rate of the X-ray flat panel detector20, thereby to increase a resolution and detection performance of the X-ray flat panel detector20. In addition, in the embodiments of the present disclosure, each first electrode8is electrically connected to the source/drain electrode layer6of the corresponding thin film transistor22through the corresponding connection line23, and the orthogonal projection of the first electrode8onto the substrate1does not overlap the orthogonal projection of the corresponding thin film transistor22onto the substrate1. Through the arrangement of the connection lines23, an orthogonal projection of each pixel in the back plate layer21onto the substrate1does not overlap an orthogonal projection of a corresponding pixel in the photosensitive element layer26onto the substrate1, so it is able to further increase the resolution of the X-ray flat panel detector20, thereby to enable the X-ray flat panel detector to be applied to a high-resolution application scenario, e.g., for the detection of mammary gland and industrial detection. Further, through the arrangement of the connection lines, it is able for the large-size back plate layer21to be compatible with the small-size photosensitive element layer26, thereby to reduce the manufacture cost.

It should be appreciated that, the thin film transistor22in the embodiments of the present disclosure is an amorphous-silicon thin film transistor, an oxide thin film transistor, a low-temperature poly-silicon thin film transistor, or an organic transistor. In addition, the thin film transistor22is a top-gate thin film transistor, a side-gate thin film transistor or a bottom-gate thin film transistor.

In a possible embodiment of the present disclosure, as shown inFIG. 2, an area of an orthogonal projection of the photosensitive element layer26onto the substrate1is smaller than an area of an orthogonal projection of the back plate layer21onto the substrate1. Due to the arrangement of the connection lines23, each thin film transistor22is electrically connected to the photosensitive element layer26through the corresponding connection line23, and a position of the orthogonal projection of the photosensitive element layer26onto the substrate1is changed through the connection line23. In the embodiments of the present disclosure, the area of the orthogonal projection of the photosensitive element layer26onto the substrate1is smaller than the area of the orthogonal projection of the back plate layer21onto the substrate1, so in the case of a small detection area, i.e., when the photosensitive element layer26has a small size, it is able for the large-size back plate layer21to match the small-size photosensitive element layer26through the connection lines23, without any necessity to manufacture the small-size back plate layer21separately, thereby to reduce the manufacture cost. It should be noted that, in actual design, the area of the orthogonal projection of the photosensitive element layer26onto the substrate1may be alternatively greater than the area of the orthogonal projection of the back plate layer21onto the substrate1, so as to be adapted to different detection areas.

During the implementation, the X-ray flat panel detector in the embodiments of the present disclosure is a mammary gland flat panel detector which is usually used for previous diagnosis of breast cancer. In order to find any tiny calcified points in the mammary gland, a current detection member has a pixel size of 50 μm to 75 μum, but the back plate layer connected to the detection member has a pixel size of 140 μm. According to the X-ray flat panel detector in the embodiments of the present disclosure, through the arrangement of the connection lines23, the orthogonal projection of the pixel in the back plate layer21onto the substrate does not overlap the orthogonal projection of the pixel in the photosensitive element layer26(i.e., the detection member) onto the substrate, so it is able for each pixel in the large-size back plate layer to be connected to a corresponding pixel in the small-size photosensitive element layer26, thereby to provide the X-ray flat panel detector with a high resolution.

In a possible embodiment of the present disclosure, as shown inFIGS. 2 and 3, the back plate layer21includes a passivation layer7arranged at a side of the thin film transistor22distal to the substrate1and covering the substrate1, a plurality of first via-holes27is formed in the passivation layer7, a source electrode or a drain electrode of each thin film transistor22is exposed through a corresponding first via-hole27, and each connection line23is electrically connected to a source electrode or a drain electrode of a corresponding thin film transistor22through a corresponding first via-hole27.

FIG. 3shows the arrangement of the first via-holes27penetrating through the passivation layer7. As shown inFIG. 3, the back plate layer21includes first spaces arranged in an array form, each first space corresponds to one pixel in the back plate layer21, and one first via-hole27is formed in each first space. To be specific, each first space has a first length a and a first width b, e.g., each of the first length a and the first width b is 140 μm.

In a possible embodiment of the present disclosure, as shown inFIGS. 2 and 4, the wiring layer includes a planarization layer25arranged at a side of the photosensitive element layer26proximate to the substrate1and covering the connection lines23, a plurality of second via-holes28is formed in the planarization layer25at predetermined positions, and each first electrode8is electrically connected to a corresponding connection line23through a corresponding second via-hole28. Here, the predetermined position is a position where the first electrode8needs to be connected to the corresponding connection line23, and it is set according to the practical need. Through the arrangement of the planarization layer25, it is able to prevent the occurrence of a level difference for the film layer at a position where the thin film transistor22is located, and provide an even film layer above the projection of the thin film transistor22. In this regard, the photosensitive element layer26and the back plate layer21are arranged sequentially in the direction perpendicular to the substrate1, so as to increase the filling rate of the X-ray flat panel detector20, thereby to improve the resolution and the detection performance of the X-ray flat panel detector20.

FIG. 4shows the arrangement of the second via-holes28penetrating through the planarization layer25. As shown inFIG. 4, the photosensitive element layer26includes a plurality of second spaces arranged in an array form, each second space corresponds to one pixel in the photosensitive element layer26, and a respective one second via-hole28is formed in each second space. To be specific, each second space has a second length c and a second width d, e.g., each of the second length c and the second width d is 70 μm. The value of each of the second length c and the second width d is set in such a manner as to meet the requirement on a small pixel in the detection of mammary gland and the industrial detection, but an area of each second space may also be modified according to the practical need.

In a possible embodiment of the present disclosure, the photosensitive element layer26is arranged in any of four corner regions of the substrate1. As shown inFIG. 5, the photosensitive element layer26is arranged in an upper right corner of the substrate1. It should be noted that, in actual design, the photosensitive element layer26may alternatively arranged at a lower right corner, an upper left corner or a lower left corner of the substrate1. In another possible embodiment of the present disclosure, the photosensitive element layer26may alternatively be arranged in a middle region of the substrate1. A specific position of the photosensitive element layer26on the substrate1is set according to the practical need, which will thus not be particularly defined herein.

In a possible embodiment of the present disclosure, as shown inFIG. 2, the photosensitive element layer26includes a photodiode9and a second electrode10, the photodiode9is arranged at a side of the first electrode8distal to the substrate1, and the second electrode10is arranged at a side of the photodiode9distal to the first electrode8. To be specific, in the embodiments of the present disclosure, the first electrode8is made of molybdenum (Mo), and a thickness of the first electrode8in the direction perpendicular to the substrate1is 2200 Å. The second electrode10is made of a same material as the first electrode8, and a thickness of the second electrode10in the direction perpendicular to the substrate1is 1350 Å. The photodiode9includes a P-type semiconductor layer, an N-type semiconductor layer, and an intrinsic semiconductor layer arranged between the P-type semiconductor layer and the N-type semiconductor layer.

In a possible embodiment of the present disclosure, as shown inFIG. 2, the first electrode8is a bar-shaped electrode and the second electrode10is a planar electrode; or as shown inFIG. 9, the first electrode8is a bar-shaped electrode, the second electrode10is a bar-shaped electrode too, and an orthogonal projection of the second electrode10onto the substrate1covers an orthogonal projection of the first electrode8onto the substrate1.

In a possible embodiment of the present disclosure, as shown inFIG. 2, in order to further protect the photosensitive element layer26, the X-ray flat panel detector20further includes a protection layer11arranged at a side of the photosensitive element layer26distal to the substrate1and covering the substrate1. An area of an orthogonal projection of the protection layer11onto the substrate1is greater than the area of the orthogonal projection of the photosensitive element layer26onto the substrate1.

Based on a same inventive concept, the present disclosure further provides in some embodiments an X-ray flat panel detection device, which includes a plurality of the above-mentioned X-ray flat panel detectors20arranged in an array form. Adjacent X-ray flat panel detectors20are spliced with each other, and the photosensitive element layer26is arranged proximate to a position where the adjacent X-ray flat panel detectors are spliced. The X-ray flat panel detection device includes the above-mentioned X-ray flat panel detector20, so it has a same beneficial effect as the X-ray flat panel detector20, which will thus not be particularly defined herein.

In actual use, in order to increase a detection area of the X-ray flat panel detector20and enable the back plate layer to be compatible with the photosensitive element layers26with different sizes, in the embodiments of the present disclosure, the photosensitive element layers26may be designed in a spliced manner. As shown inFIG. 6, four small-size photosensitive element layers26are spliced to form a large-size photosensitive element layer.

To be specific, as shown inFIG. 7which shows a situation where the adjacent X-ray flat panel detectors20are connected to each other in a spliced manner, the photosensitive element layer26is arranged proximate to a splicing position, i.e., located in a middle region of the entire X-ray flat panel detection device. The photosensitive element layer26is arranged at a corner region of each individual X-ray flat panel detector20. According to the X-ray flat panel detection device acquired after splicing, it is able to further improve the resolution without adversely affecting the design of the connection lines.

Based on a same inventive concept, the present disclosure further provides in some embodiments an X-ray imaging system, which includes the above-mentioned X-ray flat panel detector20or the above-mentioned X-ray flat panel detection device. Because the X-ray imaging system includes the above-mentioned X-ray flat panel detector20or the above-mentioned X-ray flat panel detection device, it has a same beneficial effect as the above-mentioned X-ray flat panel detector20or the above-mentioned X-ray flat panel detection device, which will thus not be particularly further defined herein.

Based on a same inventive concept, the present disclosure further provides in some embodiments a method for manufacturing the X-ray flat panel detector20which, as shown inFIG. 8, includes: S101of providing the substrate1and forming the back plate layer21on the substrate1through a patterning process, the back plate layer21including the thin film transistor22and the passivation layer7; S102of forming a plurality of connection lines23at a side of the back plate layer21distal to the substrate1through a patterning process, each connection line23being electrically connected to a source electrode or a drain electrode of a corresponding thin film transistor22though a corresponding first via-hole27penetrating through the passivation layer7; S103of forming the planarization layer25at a side of the connection line23distal to the substrate1through a patterning process; and S104of forming the photosensitive element layer26at a side of the planarization layer25distal to the substrate1through a patterning process. The photosensitive element layer26includes a plurality of first electrodes8, each first electrode8is electrically connected to a corresponding connection line23through a corresponding second via-hole28penetrating through the planarization layer25, and an orthogonal projection of each first electrode8onto the substrate1does not overlap an orthogonal projection of the thin film transistor22of the back plate layer21whose source electrode or drain electrode is electrically connected to the first electrode8onto the substrate1.

Because the X-ray flat panel detector20in the embodiments of the present disclosure is provided with the planarization layer25, the photosensitive element layer26and the back plate layer21are arranged sequentially in a direction perpendicular to the substrate1. As compared with the related art where the thin film transistor is juxtaposed with the photosensitive element layer, in the embodiments of the present disclosure, the design of the photosensitive element layer26is not adversely affected by the thin film transistor22, so it is able to increase a filling rate of the X-ray flat panel detector20, thereby to increase a resolution and detection performance of the X-ray flat panel detector20. In addition, in the embodiments of the present disclosure, each first electrode8of the photosensitive element layer26is electrically connected to one connection line23through the corresponding second via-hole28in the planarization layer25, so an orthogonal projection of each pixel in the back plate layer21onto the substrate1does not overlap an orthogonal projection of a corresponding pixel in the photosensitive element layer26onto the substrate1. As a result, it is able to further increase the resolution of the X-ray flat panel detector20, thereby to enable the X-ray flat panel detector to be applied to a high-resolution application scenario, e.g., for the detection of mammary gland and industrial detection. Further, through the arrangement of the connection lines, it is able for the large-size back plate layer21to be compatible with the small-size photosensitive element layer26, thereby to reduce the manufacture cost.

In a possible embodiment of the present disclosure, the forming the back plate layer21on the substrate1through a patterning process includes: forming1buffer layer2on the substrate1; forming a gate electrode3, a gate insulation layer4, an active layer5, a source electrode and a drain electrode sequentially on the buffer layer2through a patterning process; and forming the passivation layer7on the source electrode and the drain electrode through a patterning process.

During the implementation, the forming the passivation layer7on the source electrode and the drain electrode through a patterning process includes coating an insulation film layer onto the source electrode and the drain electrode, and patterning the insulation film layer to form the passivation layer7. The plurality of first via-holes27is formed in the passivation layer7.

In a possible embodiment of the present disclosure, the forming the plurality of connection lines23at a side of the back plate layer21distal to the substrate1through a patterning process includes: depositing a metal layer, e.g., an aluminum (Al) or copper (Cu) layer, on the passivation layer7; and patterning the metal layer to form the plurality of connection lines23. An orthogonal projection of each connection line23onto the substrate1covers an orthogonal projection of a corresponding first via-hole27onto the substrate1and an orthogonal projection of a corresponding second via-hole28onto the substrate1. To be specific, as shown inFIG. 2, each connection line23formed after patterning needs to extend to the corresponding first via-hole27and the corresponding second via-hole28, so that one end of the connection line23is capable of being connected to the source electrode or drain electrode of the thin film transistor22and the other end is capable of being connected to the corresponding first electrode8.

In a possible embodiment of the present disclosure, the forming the photosensitive element layer26at a side of the planarization layer25distal to the substrate1through a patterning process includes: forming the plurality of first electrodes8on the planarization layer25through a patterning process, each first electrode8being electrically connected to a corresponding connection line23through a corresponding second via-hole28in the planarization layer25; forming the photodiode9on each first electrode8through a patterning process; and forming the second electrode10on each photodiode9through a patterning process.

During the implementation, the forming the photodiode9on the first electrode8through a patterning process includes forming an N-type semiconductor layer, an intrinsic semiconductor layer and a P-type semiconductor layer sequentially in that order on the first electrode8through a patterning process.

1. Because the photosensitive element layer26of the X-ray flat panel detector20in the embodiments of the present disclosure is arranged at a side of the wiring layer distal to the substrate1and the wiring layer is arranged at a side of the back plate layer21distal to the substrate1, the photosensitive element layer26and the back plate layer21are arranged sequentially in a direction perpendicular to the substrate1. As compared with the related art where the thin film transistor is juxtaposed with the photosensitive element layer, in the embodiments of the present disclosure, the design of the photosensitive element layer26is not adversely affected by the thin film transistor22, so it is able to increase a filling rate of the X-ray flat panel detector20, thereby to increase a resolution and detection performance of the X-ray flat panel detector20. In addition, in the embodiments of the present disclosure, each first electrode8is electrically connected to the source/drain electrode layer6of the corresponding thin film transistor22through the corresponding connection line23, and the orthogonal projection of the first electrode8onto the substrate1does not overlap the orthogonal projection of the corresponding thin film transistor22onto the substrate1. Through the arrangement of the connection lines23, an orthogonal projection of each pixel in the back plate layer21onto the substrate1does not overlap an orthogonal projection of a corresponding pixel in the photosensitive element layer26onto the substrate1, so it is able to further increase the resolution of the X-ray flat panel detector20, thereby to enable the X-ray flat panel detector to be applied to a high-resolution application scenario, e.g., for the detection of mammary gland and industrial detection. Further, through the arrangement of the connection lines, it is able for the large-size back plate layer21to be compatible with the small-size photosensitive element layer26, thereby to reduce the manufacture cost.

2. The X-ray flat panel detection device in the embodiments of the present disclosure includes a plurality of the above-mentioned X-ray flat panel detectors20. The adjacent X-ray flat panel detectors20are spliced with each other, and the photosensitive element layer26is arranged proximate to a splicing position. Through this arrangement, it is able to increase a detection area of the X-ray flat panel detector, thereby to further improve the resolution, and enable the back plate layer to be compatible with the photosensitive element layers26with different sizes.

It should be appreciated that, steps, measures and schemes in various operations, methods and processes that have already been discussed in the embodiments of the present disclosure may be replaced, modified, combined or deleted. In a possible embodiment of the present disclosure, the other steps, measures and schemes in various operations, methods and processes that have already been discussed in the embodiments of the present disclosure may also be replaced, modified, rearranged, decomposed, combined or deleted. In another possible embodiment of the present disclosure, steps, measures and schemes in various operations, methods and processes that are known in the related art and have already been discussed in the embodiments of the present disclosure may also be replaced, modified, rearranged, decomposed, combined or deleted.

It should be further appreciated that, such words as “center”, “on”, “under”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner” and “outer” are used to indicate directions or positions as viewed in the drawings, and they are merely used to facilitate the description in the present disclosure, rather than to indicate or imply that a device or member must be arranged or operated at a specific position.

In addition, such words as “first” and “second” may merely be adopted to differentiate different features rather than to implicitly or explicitly indicate any number or importance, i.e., they may be adopted to implicitly or explicitly indicate that there is at least one said feature. Further, such a phrase as “a plurality of” may be adopted to indicate that there are two or more features, unless otherwise specified.