Flat panel detector based on narrow frame packaging and preparation method thereof

Abstract

The invention provides a flat panel detector based on narrow frame packaging and a preparation method thereof, and the method comprises the steps: forming a waterproof layer at the periphery of the flat panel detector after the flat panel detector is prepared from a substrate and a scintillator layer, so as to prevent the scintillator layer from deliquescing, forming a reflection layer above the scintillator layer, and finally forming a packaging layer on the side wall of the flat panel detector. The packaging layer covers the side wall of the substrate and the side wall of the scintillator layer and is connected with the reflecting layer located on the surface of the scintillator layer. In the flat panel detector provided by the invention, the packaging layer is arranged on the side wall of the flat panel detector, and the distance from the edge of the scintillator layer to the edge of the substrate can be reduced to a micron level, so that narrow-frame packaging is realized, the effective area of the scintillator layer is increased, the size of the flat panel detector is reduced, and the utilization rate of the flat panel detector is improved; in addition, the narrow-edge flat panel detector can be prepared by using the preparation method of the flat panel detector provided by the invention, so that more production requirements can be met.

Description

Technical Field

[0001] The present invention belongs to the field of X-ray flat panel detectors, and in particular, relates to a flat panel detector based on narrow frame packaging and a preparation method thereof. Background Art

[0002] Detectors made of inorganic scintillator materials are currently being widely used in various fields such as nuclear physics, nuclear medicine, radiology, industrial CT, address surveying, security detection, and resource exploration. Among them, cesium iodide scintillator, an inorganic scintillator of alkali metal halides, is the most widely used because of its advantages of high brightness, high resolution, and high detection efficiency.

[0003] Cesium iodide is hygroscopic. When it is exposed to the air, it easily absorbs moisture in the air and deliquesces. Once deliquesced, its main performance such as image resolution will be reduced or even fail. Therefore, we need to encapsulate the scintillator accordingly to isolate water vapor. However, the scintillator coating surface and the substrate surface are relatively smooth, so a layer of packaging film is required to cover the entire contact surface between the scintillator and the air. Usually, the middle of the packaging film is bonded to the scintillator layer, and the edge of the packaging film is bonded to the substrate. For general coated substrates, such as TFT (Thin Film Transistor) glass, the surface is very smooth, so it is necessary to use sealant to ensure adhesion, but this requires a certain contact area with the substrate, so it is usually necessary to leave a millimeter-level or even a centimeter-level edge packaging width. This undoubtedly cannot complete the preparation of detectors with narrow edge requirements, and due to the increase in size, it causes a waste of resources and costs. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, the present invention provides a flat-panel detector based on narrow-frame packaging and a preparation method thereof. After the flat-panel detector is prepared from a substrate and a scintillator layer, a waterproof layer is first formed around the flat-panel detector to prevent the scintillator layer from deliquescing, and then a reflective layer is formed above the scintillator layer. Finally, a packaging layer is formed on the side wall of the flat-panel detector. The packaging layer covers the side wall of the substrate and the side wall of the scintillator layer, and is connected to the reflective layer located on the surface of the scintillator layer. In the flat-panel detector provided by the present invention, the packaging layer is arranged on the side wall of the flat-panel detector, and the distance from the edge of the scintillator layer to the edge of the substrate can be reduced to the micron level, thereby realizing narrow-frame packaging, which is conducive to increasing the effective area of ​​the scintillator layer, reducing the size of the flat-panel detector, and improving the utilization rate of the flat-panel detector; in addition, the preparation method of the flat-panel detector provided by the present invention can be used to prepare a narrow-frame flat-panel detector to meet more production needs.

[0005] To achieve the above-mentioned and other related purposes, the present invention provides a method for preparing a flat panel detector based on narrow frame packaging, comprising:

[0006] Providing a substrate, the substrate having a signal side and a packaging side, the signal side being provided with a chip;

[0007] A scintillator layer is formed on the surface of the substrate, and on the packaging side, the scintillator layer is flush with the side wall of the substrate, and on the signal side, the scintillator layer and the substrate form a step structure;

[0008] forming a reflective layer, wherein the reflective layer covers a side of the scintillator layer facing away from the substrate and a side wall of the scintillator layer close to the signal side;

[0009] A packaging layer is formed on the packaging side, and the packaging layer covers the side wall of the substrate and the side wall of the scintillator layer, and is connected to the reflection layer located on the surface of the scintillator layer.

[0010] Optionally, after the scintillator layer is formed on the surface of the substrate, the method further includes: on the packaging side, cutting the substrate and the scintillator layer so that the side walls of the substrate and the scintillator layer are flush with each other on the packaging side.

[0011] Optionally, before forming the reflective layer, the method further includes: forming a waterproof layer around the cut structure, wherein the waterproof layer covers the substrate and the scintillator layer.

[0012] Optionally, the waterproof layer is made of a material selected from the group consisting of polyparaxylene, polyparadichlorotoluene, polytetrafluoroethylene, polymethyl methacrylate, and polycarbonate.

[0013] Optionally, the waterproof layer has a thickness between 3 μm and 50 μm.

[0014] Optionally, the reflective layer is made of a metal composite material.

[0015] Optionally, forming the encapsulation layer on the encapsulation side includes: placing the above structure in a fixed mold with the encapsulation side facing upward, and then coating the encapsulation layer.

[0016] Optionally, the encapsulation layer is made of one of epoxy resin glue, polyurethane glue, acrylate glue, silicone glue, and polyurethane silicone glue.

[0017] The present invention further provides a flat panel detector based on narrow frame packaging, and the flat panel detector is formed by any of the above-mentioned methods for preparing the flat panel detector.

[0018] The flat panel detector based on narrow frame packaging and the preparation method thereof provided by the present invention have at least the following beneficial effects:

[0019] In the flat-panel detector provided by the present invention, the packaging layer is arranged on the side wall of the flat-panel detector, and the distance from the edge of the scintillator layer to the edge of the substrate can be reduced to the micron level, thereby realizing narrow-frame packaging, which is beneficial to increasing the effective area of ​​the scintillator layer, reducing the size of the flat-panel detector, and improving the utilization rate of the flat-panel detector.

[0020] In addition, the method for preparing a flat panel detector provided by the present invention can be used to prepare a narrow-edge flat panel detector to meet more production requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1a The diagram shows a top view of the substrate in step S1 of the first embodiment.

[0022] Figure 1b It is a side view of the substrate in step S1 of the first embodiment.

[0023] Figure 2a It is a top view showing the formation of a scintillator layer on the surface of the substrate in step S2 of the first embodiment.

[0024] Figure 2b It is a side view showing the formation of a scintillator layer on the surface of the substrate in step S2 of the first embodiment.

[0025] Figure 3a The diagram shows a top view of the substrate after being cut in step S2 of the first embodiment.

[0026] Figure 3b It is a side view of the substrate after being cut in step S2 of the first embodiment.

[0027] Figure 4 It shows a side view of forming a waterproof layer in step S2 of the first embodiment.

[0028] Figure 5 It is a side view showing the formation of a reflective layer in step S3 of the first embodiment.

[0029] Figure 6 It is a schematic diagram of the structure of forming a packaging layer in step S4 of the first embodiment.

[0030] Figure 7 Shown is a schematic structural diagram of a flat panel detector based on narrow-frame packaging provided in the second embodiment.

[0031] Component number description

[0032] 10 substrate

[0033] 101 Signal side

[0034] 102 Package side

[0035] 110 Chip

[0036] 20 Scintillator layer

[0037] 30 Waterproof layer

[0038] 40 Reflection layer

[0039] 50 Fixed mold

[0040] 60 Encapsulation Layer DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0042] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation, the form, quantity, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of this party, and the component layout form may also be more complicated.

[0043] Embodiment 1

[0044] This embodiment provides a method for preparing a flat panel detector based on narrow frame packaging, comprising the following steps:

[0045] S1: providing a substrate, wherein the substrate has a signal side and a packaging side, and the signal side is provided with a chip;

[0046] like Figure 1a and 1b As shown, a substrate 10 is provided. In this embodiment, the substrate 10 has two signal sides 101 and two packaging sides 102. In other optional embodiments, the substrate 10 may have three signal sides 101 and one packaging side 102. A pixel circuit (not shown in the figure) is provided on the surface of the substrate 10 as a visible light sensor of a flat panel detector. A chip 110 is installed on the signal side 101. The chip 110 is used to input or read out a voltage signal. The chip 110 is not provided on the packaging side 102 for subsequent packaging.

[0047] As an example, the substrate 10 is a substrate on which a thin film transistor (TFT) is prepared, and can be a silicon-based TFT or a glass-based TFT. In this embodiment, the substrate 10 is a glass substrate.

[0048] S2: forming a scintillator layer on the surface of the substrate, wherein on the packaging side, the scintillator layer is flush with the side wall of the substrate, and on the signal side, the scintillator layer and the substrate form a step structure;

[0049] like Figure 2a and 2b As shown, a scintillator layer 20 is formed on the surface of the substrate 10. As an example, the scintillator layer 20 is used to convert X-rays into visible light, and the material of the scintillator layer 20 includes but is not limited to any one of cesium iodide, cesium iodide doped with thallium, or cesium iodide doped with sodium; the thickness of the scintillator layer 20 is between 100 μm and 1500 μm; the preparation method of the scintillator layer 20 includes but is not limited to thermal evaporation.

[0050] As an example, the surface of the substrate 10 has a pixel area and a non-pixel area. In order to make the pixel area have a larger proportion and ensure the imaging quality of the flat panel detector, it is necessary to first cut and remove the non-pixel area of ​​the substrate 10. During the cutting process, the substrate 10 and the scintillator layer 20 are cut on the packaging side 102. The cutting position should be as close to the pixel area as possible, and the pixel area and the scintillator layer 20 directly above the pixel area should not be damaged. In this embodiment, laser cutting can be used for cutting.

[0051] like Figure 3a and 3b As shown, after the cutting is completed, on the packaging side 102 , the sidewalls of the substrate 10 and the scintillator layer 20 are flush; on the signal side 101 , the scintillator layer 20 and the substrate 10 form a step structure.

[0052] like Figure 4 As shown, a waterproof layer 30 is formed around the cut structure, and the waterproof layer 30 covers the substrate 10 and the scintillator layer 20, so as to prevent the scintillator layer 20 from contacting with air and deliquescing. As an example, the waterproof layer 30 is made of a transparent waterproof material, which has a waterproof effect and does not affect the imaging of the detector, such as polyparaxylene, polyparadichlorotoluene, polytetrafluoroethylene, polymethyl methacrylate, polycarbonate, etc.; the thickness of the waterproof layer 30 is between 3μm and 50μm; the method of forming the waterproof layer 30 includes but is not limited to chemical vapor deposition (CVD).

[0053] S3: forming a reflective layer, wherein the reflective layer covers a side of the scintillator layer facing away from the substrate and a side wall of the scintillator layer close to the signal side;

[0054] like Figure 5As shown, a reflective layer 40 is formed, and the reflective layer 40 covers the side of the scintillator layer 20 facing away from the substrate 10, and the side wall of the scintillator layer 20 close to the signal side 101. The reflective layer 40 is used to reflect the visible light generated by the scintillator layer 20, so that the visible light is transmitted to the visible light sensor. In this embodiment, the reflective layer 40 is formed by bonding. On the signal side 101, the reflective layer 40 covers the side wall of the scintillator layer 20 and is connected to the surface of the substrate 10; on the packaging side 102, the reflective layer 40 is flush with the side wall of the substrate 10 and the side wall of the scintillator layer 20.

[0055] As an example, the reflective layer 40 is made of a metal composite material, such as an aluminum composite film, a silver composite film, etc., which improves the light reflectivity while ensuring the reliability of the structure. In this embodiment, the thickness of the reflective layer 40 is between 100 μm and 500 μm.

[0056] S4: forming a packaging layer on the packaging side, wherein the packaging layer covers the side wall of the substrate and the side wall of the scintillator layer and is connected to the reflective layer located on the surface of the scintillator layer.

[0057] First, a fixed mold 50 is provided. The fixed mold 50 is a hollow cubic structure with two open surfaces, that is, it has two adjacent open surfaces, and the remaining surfaces are closed surfaces.

[0058] Then, if Figure 6 As shown, the structure obtained in step S3 is placed in the fixed mold 50 so that the packaging side 102 corresponds to the open surface of the fixed mold 50, that is, the packaging side 102 is exposed.

[0059] In the process of forming the encapsulation layer 60, the encapsulation side 102 of the encapsulation layer 60 to be coated faces upward, and the encapsulation layer 60 is coated on the encapsulation side 102 so that the encapsulation layer 60 covers the side wall of the substrate 10 and the side wall of the scintillator layer 20, and is connected to the reflective layer 40 located on the surface of the scintillator layer 20. After curing, the fixed mold 50 is turned over so that the encapsulation side 102 of the encapsulation layer 60 to be coated on the other side faces upward, and the above steps are repeated. After the encapsulation layer 60 is cured, the coating is completed.

[0060] As an example, the encapsulation layer 60 is selected from one of epoxy resin glue, polyurethane glue, acrylate glue, silicone glue, and polyurethane silicone. In this embodiment, the encapsulation layer 60 is made of epoxy resin glue.

[0061] Finally, the fixed mold 50 is removed to obtain a flat panel detector based on narrow frame packaging. In the flat panel detector provided in this embodiment, the packaging layer is arranged on the side wall of the flat panel detector, and the distance from the edge of the scintillator layer to the edge of the substrate can be reduced to the micron level, thereby realizing narrow frame packaging, which is conducive to increasing the effective area of ​​the scintillator layer, reducing the size of the flat panel detector, and improving the utilization rate of the flat panel detector; in addition, the flat panel detector preparation method provided in this embodiment can be used to prepare a narrow edge flat panel detector to meet more production needs.

[0062] Embodiment 2

[0063] This embodiment provides a flat panel detector based on narrow frame packaging, such as Figure 7 As shown, it includes a substrate 10, a scintillator layer 20, a waterproof layer 30, a reflective layer 40 and a packaging layer 60, wherein the substrate 10 and the scintillator layer 20 form a flat panel detector, the waterproof layer 30 is formed around the flat panel detector, the reflective layer 40 is located above the scintillator layer 20, and the packaging layer 60 covers the side walls of the substrate 10 and the side walls of the scintillator layer 20, and is connected to the reflective layer 40 located on the surface of the scintillator layer.

[0064] As an example, the flat panel detector is formed by the preparation method of the flat panel detector based on narrow frame packaging provided in the first embodiment. For its specific structure, please refer to the description of the first embodiment, which will not be repeated here.

[0065] In the flat-panel detector provided in this embodiment, the packaging layer is arranged on the side wall of the flat-panel detector, and the distance from the edge of the scintillator layer to the edge of the substrate can be reduced to the micron level, thereby realizing narrow-frame packaging, which is beneficial to increasing the effective area of ​​the scintillator layer, reducing the size of the flat-panel detector, and improving the utilization rate of the flat-panel detector.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a flat panel detector based on narrow frame packaging, It is characterized in that include: Providing a substrate, the substrate having a signal side and a packaging side, the signal side being provided with a chip; A scintillator layer is formed on the surface of the substrate, and on the packaging side, the scintillator layer is flush with the side wall of the substrate, and on the signal side, the scintillator layer and the substrate form a step structure; forming a reflective layer, wherein the reflective layer covers a side of the scintillator layer facing away from the substrate and a side wall of the scintillator layer close to the signal side; A packaging layer is formed on the packaging side, and the packaging layer covers the side wall of the substrate and the side wall of the scintillator layer, and is connected to the reflection layer located on the surface of the scintillator layer.

2. The method for preparing a flat panel detector according to claim 1, It is characterized in that After the scintillator layer is formed on the surface of the substrate, the method further includes: on the packaging side, cutting the substrate and the scintillator layer so that the side walls of the substrate and the scintillator layer are flush with each other on the packaging side.

3. The method for preparing a flat panel detector according to claim 2, It is characterized in that Before forming the reflective layer, the method further includes: forming a waterproof layer around the cut structure, wherein the waterproof layer covers the substrate and the scintillator layer.

4. The method for preparing a flat panel detector according to claim 3, It is characterized in that The waterproof layer is made of one of the following materials: polyparaxylene, polyparadichlorotoluene, polytetrafluoroethylene, polymethyl methacrylate, and polycarbonate.

5. The method for preparing a flat panel detector according to claim 3, It is characterized in that The thickness of the waterproof layer is between 3 μm and 50 μm.

6. The method for preparing a flat panel detector according to claim 1, It is characterized in that The reflective layer is made of a metal composite material.

7. The method for preparing a flat panel detector according to claim 1, It is characterized in that Forming the encapsulation layer on the encapsulation side includes: placing the structure in a fixed mold with the encapsulation side facing upward, and then coating the encapsulation layer.

8. The method for preparing a flat panel detector according to claim 1, It is characterized in that The encapsulation layer is made of one of epoxy resin glue, polyurethane glue, acrylate glue, silicone glue and polyurethane silicone glue.

9. A flat panel detector based on narrow frame packaging, It is characterized in that The flat panel detector is formed by the method for preparing the flat panel detector according to any one of claims 1 to 8.

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