US-12624993-B2 - Sensing device and method for fabricating the same

Abstract

A sensing device includes a flexible substrate, a reflective layer, a planarization layer, plural switching elements and plural sensing elements. The flexible substrate has plural recesses on a surface. The reflective layer is located on the flexible substrate and conforms to an inner surface of the plural recesses. The planarization layer is disposed on the reflective layer. The plural switching elements are disposed on the planarization layer. The plural sensing elements are disposed on the planarization layer and electrically connected to the plural switching elements respectively. A method for fabricating a sensing device is also provided.

Inventors

• Te-Ming Chen
• TSUNG-HAN CHEN

Assignees

• AUO Corporation

Dates

Publication Date

20260512

Application Date

20220818

Priority Date

20220617

Claims (12)

1. 1 . A sensing device, comprising: a flexible substrate, having a plurality of recesses on a surface; a reflective layer, located on the flexible substrate and conforming to an inner surface of the recesses; a planarization layer, located on the reflective layer; a plurality of switching elements, located on the planarization layer; and a plurality of sensing elements, located on the planarization layer and electrically connected to the switching elements respectively, wherein the reflective layer extends continuously along the surface with the recesses of the flexible substrate.
2. 2 . The sensing device according to claim 1 , wherein the inner surface of the recesses has a side surface and a bottom surface that are planar.
3. 3 . The sensing device according to claim 2 , wherein an opening width of the recesses is greater than a width of the bottom surface.
4. 4 . The sensing device according to claim 1 , wherein the recesses have a mesh-like pattern.
5. 5 . The sensing device according to claim 1 , wherein a ratio of a depth of the recesses to a thickness of the planarization layer is 0.5 to 0.95.
6. 6 . The sensing device according to claim 1 , wherein the reflective layer has a floating potential or a grounding potential.
7. 7 . The sensing device according to claim 1 , wherein a refractive index difference between the reflective layer and the planarization layer is not less than 0.4.
8. 8 . The sensing device according to claim 1 , further comprising a data line and a scan line, electrically connected to the switching elements, wherein a gap between an orthographic projection of the data line, the scan line, and the sensing element on the flexible substrate completely overlaps an orthographic projection of the recesses on the flexible substrate.
9. 9 . The sensing device according to claim 1 , wherein the flexible substrate is a film type polyimide (PI).
10. 10 . The sensing device according to claim 9 , wherein a thickness of the flexible substrate is 40 μm to 400 μm.
11. 11 . The sensing device according to claim 1 , wherein the planarization layer includes varnish polyimide (PI).
12. 12 . The sensing device according to claim 11 , wherein a thickness of the planarization layer is 5 μm to 50 μm.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority benefit of U.S. provisional application Ser. No. 63/300,734, filed on Jan. 19, 2022 and Taiwan application serial no. 111122700, filed on Jun. 17, 2022. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. BACKGROUND Technical Field The disclosure relates to a photoelectric device and a method for fabricating the same, and in particular relates to a sensing device and a method for fabricating the same. Description of Related Art Due to its excellent performance, optical sensors have been widely used in security inspection, industrial inspection, medical diagnosis, and other fields. For example, in medical diagnosis, X-ray sensors may be used for image capture of human chest cavity, blood vessels, teeth, etc. Generally speaking, such sensors mainly include thin film transistors (TFTs) and photodiodes. The photodiode may convert light energy into electrical signals, and the thin film transistor is used to read the electrical signal measured by the photodiode. Traditionally, an electrostatic protection layer is bonded on the back of the substrate of this type of sensor, usually an aluminum film or a conductive film. However, when the substrate is bonded with a conductive film, gaps, such as air bubbles, may be formed because the substrate may not be completely bonded, which causes an interference of light reflection that penetrates the gap and reaches the conductive film, resulting in uneven brightness of the sensing image which affects the sensing quality. SUMMARY The disclosure provides a sensing device with good sensing quality. The disclosure provides a method for fabricating a sensing device, which may provide a sensing device with good sensing quality. An embodiment of the disclosure provides a sensing device, including: a flexible substrate having multiple recesses on a surface; a reflective layer is located on the flexible substrate and conforms to an inner surface of the recesses; a planarization layer, located on the reflective layer; multiple switching elements located on the planarization layer; and multiple sensing elements located on the planarization layer and electrically connected to the switching elements respectively. In an embodiment of the disclosure, the inner surface of the recesses has a side surface and a bottom surface that are planar, or an arc-shaped surface. In an embodiment of the disclosure, an opening width of the recesses is greater than a width of the bottom surface. In an embodiment of the disclosure, the recesses surround one sensing element and one switching element, or the recesses surround four sensing elements and four switching elements. In an embodiment of the disclosure, a ratio of a depth of the recesses to a thickness of the planarization layer is 0.5 to 0.95. In an embodiment of the disclosure, the reflective layer has a floating potential or a grounding potential. In an embodiment of the disclosure, a refractive index difference between the reflective layer and the planarization layer is not less than 0.4. In an embodiment of the disclosure, the sensing device further includes a data line and a scan line, which are electrically connected to the switching elements. A gap between an orthographic projection of the data line, the scan line, and the sensing element on the flexible substrate completely overlaps an orthographic projection of the recesses on the flexible substrate. In an embodiment of the disclosure, the flexible substrate is a film type polyimide (PI). In an embodiment of the disclosure, a thickness of the flexible substrate is 40 μm to 400 μm. In an embodiment of the disclosure, the planarization layer includes varnish polyimide (PI). In an embodiment of the disclosure, a thickness of the planarization layer is 5 μm to 50 μm. An embodiment of the disclosure provides a method for fabricating a sensing device, including the following process. A flexible substrate is formed on a carrier, and a surface of the flexible substrate has multiple recesses. A reflective layer is formed on the flexible substrate, and the reflective layer conforms to an inner surface of the recesses. A planarization layer is formed on the reflective layer, and the planarization layer fills the recesses. In an embodiment of the disclosure, the carrier is a glass substrate. In an embodiment of the disclosure, the recesses are formed by imprinting. In an embodiment of the disclosure, a surface flatness of the planarization layer is not less than 90%. In an embodiment of the disclosure, the method for fabricating the sensing device further includes forming multiple switching elements and multiple sensing elements on the planarization layer. The sensing elements are electrically connected to the switching elements respectively. In an embodiment of the disclosure, the method for fabricating the sensing device further inclu