Display module, preparation method of display module and display device

Abstract

The embodiment of the invention provides a display module, a preparation method of the display module and a display device, and relates to the technical field of display. The display module comprises a display substrate and a back film, the display substrate comprises a display area, a bending area and a binding area, the bending area and the binding area are located on one side of the display area, the bending area is located between the display area and the binding area, the bending area is bent to enable the binding area to be located on the backlight side of the display substrate, and the binding area comprises a first binding pin and a second binding pin; the first binding pin is located on the backlight side of the display substrate; the back film is arranged on the backlight side of the display substrate; the surface of the side, away from the display substrate, of the back film comprises a fingerprint module area and a fingerprint module binding area, and the fingerprint module binding area is arranged on the side, close to the binding area, of the fingerprint module area. The fingerprint module area is provided with a fingerprint identification module; the fingerprint module binding area is provided with a fingerprint pin, the fingerprint pin is electrically connected with the fingerprint identification module, and the fingerprint pin is in binding connection with the first binding pin. According to the embodiment of the invention, the integration of the display substrate and the fingerprint identification module is realized, the preparation process of the display module can be simplified, the production cost is reduced, and the preparation efficiency and yield of the display module are improved.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a display module, a preparation method of the display module, and a display device. Background Art

[0002] With the development of display technologies, fingerprint recognition technology has been widely applied to various scenarios such as mobile phone unlocking and mobile payment due to its uniqueness, stability, convenience, etc., and different types have emerged with the iteration of the technology. Among them, the in-screen fingerprint recognition technology places the fingerprint recognition sensor under the screen glass, so that no additional fingerprint recognition window needs to be set on the front of the screen, thereby increasing the screen-to-body ratio and bringing a better visual effect.

[0003] In the ultrasonic fingerprint recognition technology in the related art, due to the strong penetration of ultrasonic waves, fingerprints can be recognized even when there are water stains or stains on the finger surface. Therefore, the ultrasonic fingerprint recognition technology has become a new development direction of in-screen fingerprint recognition. Summary of the Invention

[0004] The present application provides a display module, which is beneficial to improving the problems of complex assembly process and low efficiency of the fingerprint recognition module and the display substrate in the prior art.

[0005] According to one aspect of the present application, a display module is provided. The display module includes:

[0006] A display substrate, including a display area, a bending area and a bonding area located on one side of the display area. The bending area is located between the display area and the bonding area. The bending area is bent so that the bonding area is located on the backlight side of the display substrate. The bonding area includes a first bonding pin and a second bonding pin. The first bonding pin is located on the backlight side of the display substrate. The second bonding pin is located on the side away from the bending area of the first bonding pin. The second bonding pin is electrically connected to the first bonding pin. The second bonding pin is configured to bond a circuit board provided with a fingerprint module driving chip.

[0007] A back film, disposed on the backlight side of the display substrate. The surface of the back film away from the display substrate includes a fingerprint module area and a fingerprint module bonding area. The fingerprint module bonding area is disposed on the side of the fingerprint module area close to the bonding area. A fingerprint recognition module is provided in the fingerprint module area. A fingerprint pin is provided in the fingerprint module bonding area. The fingerprint pin is electrically connected to the fingerprint recognition module. The fingerprint pin is bonded and connected to the first bonding pin.

[0008] In a possible implementation manner, the display substrate includes a substrate layer. The substrate layer is provided with an opening located in the bonding area. At least a part of the orthographic projection of the first bonding pin on the plane where the substrate layer is located is located within the opening, so that the first bonding pin is exposed from the opening on the backlight side of the display substrate.

[0009] In a possible implementation, the above-mentioned first bonding pins are multiple, and the multiple first bonding pins are arranged in an array in the first direction and the second direction. The first direction intersects the second direction, and the display area, the bending area, and the bonding area are arranged in sequence in the second direction;

[0010] There are multiple openings, and the multiple openings are arranged at intervals in the first direction. The orthographic projection of a column of first bonding pins on the plane where the substrate layer is located is located within one opening.

[0011] In another possible implementation, the above-mentioned display module further includes a circuit board, on which a fingerprint module driving chip and a fingerprint pad are provided. The fingerprint module driving chip is electrically connected to the fingerprint pad, and the fingerprint pad is bonded and connected to the second bonding pin.

[0012] In another possible implementation, the above-mentioned fingerprint recognition module includes:

[0013] A circuit structure layer is provided on one side of the back film and includes a transistor layer and a receiving electrode layer. The transistor layer is located between the back film and the receiving electrode layer; the transistor layer includes multiple transistors, the receiving electrode layer is electrically connected to the drain of the transistor, and the fingerprint pin is electrically connected to the receiving electrode layer;

[0014] A piezoelectric layer is provided on the side of the circuit structure layer away from the back film;

[0015] An emission electrode layer is provided on the side of the piezoelectric layer away from the back film.

[0016] In another possible implementation, the above-mentioned transistor layer may include a stacked gate metal layer and source-drain metal layer; the fingerprint pin is provided on the same layer as the gate metal layer or the source-drain metal layer in the transistor layer.

[0017] In another possible implementation, the above-mentioned fingerprint recognition module further includes a barrier layer provided between the back film and the transistor layer.

[0018] In another possible implementation, the above-mentioned display substrate includes: a substrate layer and a pixel driving layer provided on the side of the substrate layer away from the back film; the pixel driving layer is located in the display area, and the pixel driving layer includes at least one gate metal layer and at least one source-drain metal layer;

[0019] The second bonding pin is provided on the same layer as the source-drain metal layer of the pixel driving layer;

[0020] The display substrate includes a bonding metal layer provided on the side of at least one source-drain metal layer of the pixel driving layer close to the substrate layer. The bonding metal layer includes a first bonding pin and a first trace electrically connected to the first bonding pin. The first trace is electrically connected to the second bonding pin through a via.

[0021] In another possible implementation, the above display module further includes: a heat dissipation layer disposed on a side of the back film away from the display substrate. A groove is provided on a side of the heat dissipation layer close to the back film. Along a direction perpendicular to the back film, the depth of the groove is less than the thickness of the heat dissipation layer. The fingerprint recognition module is disposed in the groove.

[0022] In another possible implementation, the depth of the above groove is equal to the thickness of the fingerprint recognition module.

[0023] According to another aspect of the present application, there is provided a display device including the display module shown in the first aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of a fingerprint recognition module provided by an embodiment of the present application;

[0026] Figure 2 It is a schematic structural diagram of an OLED module with a fingerprint recognition module provided by an embodiment of the present application;

[0027] Figure 3 It is a schematic structural diagram of a display module provided by an embodiment of the present application;

[0028] Figure 4 It is a schematic structural diagram of the light-emitting side of a display substrate in a display module provided by an embodiment of the present application;

[0029] Figure 5 It is a schematic structural diagram of a back film in a display module provided by an embodiment of the present application;

[0030] Figure 6 It is a schematic structural diagram of the backlight side in a display module provided by an embodiment of the present application;

[0031] Figure 7 It is a schematic structural diagram of another display module provided by an embodiment of the present application;

[0032] Figure 8 It is a schematic structural diagram of the backlight side of a substrate layer of a display substrate provided by an embodiment of the present application;

[0033] Figure 9 It is a schematic diagram of the bonding between a display module and a circuit board provided by an embodiment of the present application;

[0034] Figure 10 Schematic diagram of the structure of a display module after bending provided by an embodiment of the present application;

[0035] Figure 11 Cross-sectional view of a display module before bending provided by an embodiment of the present application;

[0036] Figure 12 Cross-sectional view of a display module after bending provided by an embodiment of the present application;

[0037] Figure 13 Cross-sectional structure diagram of a display substrate provided by an embodiment of the present application;

[0038] Figure 14 Flow schematic diagram of a method for manufacturing a display module provided by an embodiment of the present application;

[0039] Figures 15-1 to 15-4 Schematic diagram of the structure in the manufacturing process of a display module provided by an embodiment of the present application;

[0040] Figures 16-1 to 16-5 Schematic diagram of the structure in the manufacturing process of an ultrasonic sensing film provided by an embodiment of the present application. Detailed implementation manners

[0041] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.

[0042] Various schematic diagrams of structures according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0043] In the context of the present disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element can be directly on the other layer / element, or there can be an intermediate layer / element between them. Additionally, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element can be "under" the other layer / element.

[0044] "The 'A and B are arranged on the same layer' described in this article means that A and B are formed simultaneously through the same lithography process. For example, the formation process may include: first, forming at least one film layer using the same film formation process, and then performing the same lithography process on this at least one film layer to form a layer structure including a specific pattern. Depending on the different specific patterns, the lithography process may include multiple photoresist coating, exposure, development, or etching processes, and the specific patterns in the formed layer structure may be continuous or discontinuous, and these specific patterns may also be at different heights (or thicknesses).

[0045] In recent years, with the popularization of full-screen mobile phones, in-screen fingerprint technology has replaced traditional front capacitive fingerprint recognition technology, providing a higher screen-to-body ratio for mobile phones or other terminal devices and a better display experience for users. In-screen fingerprint recognition technology has become the current mainstream fingerprint recognition solution. For in-screen fingerprint recognition technology, the main categories are optical fingerprint recognition and ultrasonic fingerprint recognition. Optical fingerprint recognition requires the transmittance of the screen to be greater than 1.5%. Due to the development and popularization of LTPO (Low Temperature Polysilicon Oxide) screens and COE (Color filter On Encapsulation) technology, the transmittance of the screen is getting lower and lower, unable to support optical fingerprint recognition. Therefore, ultrasonic fingerprint recognition has become a new development direction.

[0046] In related technologies, after opening a window in the heat dissipation layer on the backlight side of the OLED (Organic Light-Emitting Diode), an externally purchased ultrasonic fingerprint recognition module is attached to the backlight side of the OLED module. As Figure 1 The externally purchased ultrasonic fingerprint recognition module shown includes a fingerprint recognition substrate layer 111, a piezoelectric layer 112, a cathode layer 113, and an insulating layer 114 arranged in layers; among them, the thickness of the fingerprint recognition substrate layer 111 is generally 90μm to 110μm, including a substrate and a thin film transistor layer formed on the substrate through processes such as exposure, development, and etching. The substrate is generally glass-based or silicon-based; the piezoelectric layer 112 generally uses PVDF (polyvinylidene fluoride) or other piezoelectric materials and is made by spin coating or coating, with a thickness of 10μm; the cathode layer 113 can use a silver alloy material and is made by screen printing, with a thickness of 20μm to 30μm; the insulating layer 114 can use materials such as OC (Organic Compound), ink, etc., and is made by coating, with a thickness of 10μm to 20μm.

[0047] The fingerprint recognition module and the OLED module are attached as Figure 2As shown in the figure, the OLED module includes an OLED substrate 201, a heat dissipation layer 202, and a back film 204. The thickness of the above ultrasonic fingerprint recognition module plus the thickness of the PSA (Pressure Sensitive Adhesive) layer 203 (usually 15μm) is generally greater than 150μm, and the height of the fingerprint recognition module after assembly is higher than the height of the heat dissipation layer 202. In addition, the ultrasonic fingerprint circuit board 105 needs to be manufactured, and the ultrasonic fingerprint chip is printed on the ultrasonic fingerprint circuit board 105. The ultrasonic fingerprint circuit board 105 is first bonded to the ultrasonic fingerprint module and then inserted into the OLED circuit board.

[0048] In order to ensure its reliability, it is necessary to perform a dispensing process on the edge of the fingerprint recognition module. And because its thickness is higher than that of the heat dissipation layer on the backlight side of the OLED module, etc., a protrusion is formed, and the OLED module needs to consider avoiding it during the assembly with the whole machine. At the same time, due to the too high assembly thickness of the fingerprint recognition module, it is easily extruded by external forces, which may cause or exacerbate the film printing defect of the module. Therefore, the assembly process of the externally purchased ultrasonic fingerprint recognition module and the OLED module is cumbersome and complex, and the application of the ultrasonic fingerprint recognition module reduces the production yield of the product and increases the production cost.

[0049] Based on the above technical problems, in some embodiments of the present application, a first bonding pin and a second bonding pin are provided in the bonding area of the display substrate. The first bonding pin and the second bonding pin are respectively located on different surfaces of the display substrate. Then, a fingerprint module area and a fingerprint module bonding area are provided on the surface of the back film away from the display substrate, where the fingerprint module bonding area is provided on the side of the fingerprint module area close to the bonding area; the fingerprint recognition module in the fingerprint module area is electrically connected to the fingerprint pins in the fingerprint module bonding area; in the embodiments of the present application, by configuring the fingerprint recognition module on the back film, the fingerprint pins can be bonded and connected to the first bonding pins. At the same time, the first bonding pin and the second bonding pin are electrically connected, and the second bonding pin can be bonded to a circuit board provided with a fingerprint module driving chip. This circuit board can be the circuit board of the display substrate, that is to say, the fingerprint module driving chip can be integrated into the circuit board of the display substrate, and the electrical connection between the fingerprint recognition module and the fingerprint module driving chip can be realized through the first bonding pin; the embodiments of the present application realize the integration of the display substrate and the fingerprint recognition module, which can simplify the manufacturing process of the display module, reduce the production cost, and improve the manufacturing efficiency and yield of the display module.

[0050] Next, specific embodiments will be used to detail the technical solutions of the present application and how the technical solutions of the present application solve the above technical problems. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Next, the embodiments of the present application will be described with reference to the drawings.

[0051] In an embodiment of the present application, a display module is provided, as Figure 3 shown, including a display substrate 301 and a back film 302, and the back film 302 is disposed on the backlight side of the display substrate 301.

[0052] Among them, as Figure 4 shown, the display substrate includes a display area 401, a bending area 402 and a bonding area 403 located on one side of the display area. The bending area 402 is located between the display area 401 and the bonding area 403, and the bonding area 403 includes a first bonding pin 404. As Figure 4 shown is a schematic structural diagram of the light-emitting side of the display substrate 301. The first bonding 404 pin is located on the backlight side of the display substrate 301 and is invisible from the light-emitting side, so it is indicated by a dotted line. The above display substrate 301 is a flexible display substrate. For example, it can be an OLED, QLED, OLCD (Organic Liquid Crystal Display), MICRO-LED (micro light-emitting diode display), etc. display substrate, which is not specifically limited in the embodiment of the present application.

[0053] Figure 5 is a schematic structural diagram of the back film 302. As Figure 5 shown, the surface of the back film 302 away from the display substrate 301 includes a fingerprint module area 501 and a fingerprint module bonding area 502; a fingerprint recognition module 504 is disposed in the fingerprint module area 501; a fingerprint pin 503 is disposed in the fingerprint module bonding area 502, and the fingerprint pin 503 is electrically connected to the fingerprint recognition module 504 through a second trace 505.

[0054] Figure 6 is a schematic structural diagram of the backlight side of the display module. As Figure 6 shown, the fingerprint module bonding area 503 is disposed on the side of the fingerprint module area 501 close to the bonding area 403, and the fingerprint pin 503 can be configured to bond the first bonding pin 404.

[0055] As Figure 3 shown, in some embodiments, the above display module further includes a heat dissipation layer 303, which is disposed on the side of the back film 302 away from the display substrate 301. A groove 308 is disposed on the side of the heat dissipation layer 303 close to the back film 302. Along the direction perpendicular to the back film 302, the depth h of the groove 308 is less than the thickness t of the heat dissipation layer 303, and the fingerprint recognition module 504 is disposed in the groove 308.

[0056] In some embodiments, the above heat dissipation layer 303 may be a super clean foam (SCF) composite film or SUS (stainless steel) material. The heat dissipation layer can buffer the stress acting on the display module and can dissipate the heat generated when the display module is working, providing a certain protection effect for the display module.

[0057] In an embodiment of the present application, a possible implementation is provided. The depth of the above groove 308 is approximately equal to the thickness of the fingerprint recognition module 504. It can be understood that the above approximate equality can be exact equality or approximate equality within the process error range.

[0058] In an embodiment of the present application, when the groove depth of the heat dissipation layer 308 is equal to the thickness of the fingerprint recognition module 504, the fingerprint recognition module 504 can be protected in the heat dissipation layer 308, without reliability risks, and the existing technology of dispensing on the edge of the fingerprint recognition module 504 is avoided, simplifying the production process flow of the display module, improving the product yield and production efficiency. At the same time, since the thickness of the fingerprint recognition module 504 becomes smaller, the distance between the fingerprint recognition module 504 and the finger during the recognition process can be reduced, effectively improving the accuracy of ultrasonic fingerprint recognition.

[0059] In an embodiment of the present application, a possible implementation is provided, as Figure 3 shown, the above fingerprint recognition module 504 may include a circuit structure layer 304, a piezoelectric layer 305, a transmitting electrode layer 306, and an insulating layer 307.

[0060] Among them, the circuit structure layer 304 may be disposed on one side of the back film 302.

[0061] According to an embodiment of the present application, as Figure 7 shown, the circuit structure layer 304 may include a transistor layer 3041 and a receiving electrode layer 3042. The transistor layer 3041 is located between the back film 302 and the receiving electrode layer 3042; optionally, the material for forming the receiving electrode layer 3042 may include indium tin oxide (ITO).

[0062] In some embodiments, the transistor layer 3041 may include a plurality of transistors arranged in an array. For example, the transistor layer 3041 may include an active layer, a gate insulating layer, a gate metal layer, an interlayer insulating layer, and a source-drain metal layer sequentially stacked on the back film 302. The gate metal layer is at least configured to form the gate of the transistor, and the source-drain metal layer is at least configured to form the source and drain of the transistor. For example, the fingerprint pin 503 may be disposed on the same layer as the gate metal layer or the source-drain metal layer in the transistor layer 3041.

[0063] For example, in some embodiments, a fingerprint pin 503 may be formed on one side of the gate metal layer close to the back film 302 through a metal coating or patterning process, and the fingerprint pin 503 may be electrically connected to the gate metal layer or the source-drain metal layer through a via hole.

[0064] The fingerprint pin 503 may be electrically connected to the receiving electrode layer 3042, and the receiving electrode layer 3042 may be electrically connected to at least one of the gate, source, and drain of the transistor. For example, the circuit structure layer 304 may further include a planar layer disposed between the source-drain metal layer and the receiving electrode layer 3042, and the drain of the transistor and the receiving electrode layer 3042 may be electrically connected through a via hole penetrating the planar layer.

[0065] The piezoelectric layer 305 is disposed on the side of the circuit structure layer 304 away from the back film 302. The material for forming the piezoelectric layer 305 may be PVDF (polyvinylidene difluoride) or other piezoelectric materials.

[0066] The emitting electrode layer 306 is disposed on the side of the piezoelectric layer 305 away from the back film 302. The material for forming the emitting electrode layer 306 may include silver (Ag).

[0067] The insulating layer 307 is disposed on the side of the emitting electrode layer 306 away from the back film 302. The material for forming the insulating layer 307 may include insulating protection materials such as OC to protect the emitting electrode layer 306.

[0068] A possible implementation manner is provided in the embodiments of the present application. As Figure 7 shown, the above-mentioned fingerprint recognition module 504 may further include a barrier layer 308 disposed between the back film 302 and the transistor layer 3041; the barrier layer 308 may prevent electron leakage between different metal layers.

[0069] In the embodiment of the present application, the transistor layer 3041 receives the electrical signal sent by the circuit board, then processes and amplifies the electrical signal, and transmits it to the piezoelectric layer 305; after receiving the electrical signal processed and amplified by the transistor layer 3041, based on the inverse piezoelectric effect, the piezoelectric layer 305 converts the electrical signal into an ultrasonic signal and emits the ultrasonic wave to the light-emitting side of the display substrate 301. These ultrasonic waves penetrate the display substrate 301 and reach the finger surface; when the ultrasonic wave reaches the finger surface, due to the uneven structure of the fingerprint pattern, the distances from the wave peaks and wave valleys to the display substrate are different: at the wave peaks, the propagation distance of the ultrasonic wave is relatively short; at the wave valleys, the propagation distance of the ultrasonic wave is relatively long. Therefore, there are time differences and phase differences between the ultrasonic waves reflected from the fingerprint wave peaks and wave valleys, and the reflected ultrasonic waves carry the information of the fingerprint pattern. When receiving the reflected ultrasonic wave, the piezoelectric layer 305 converts these ultrasonic signals into electrical signals based on the direct piezoelectric effect. The transistor layer 3041 plays a role again, amplifying and preprocessing the weak electrical signals converted by the piezoelectric layer 305 to improve the quality and intensity of the signals for subsequent processing. Finally, after receiving the electrical signals amplified and preprocessed by the transistor layer 3041, the fingerprint chip performs digital processing and analysis on them. Usually, complex algorithms and models are integrated inside the fingerprint chip, which can convert the received electrical signals into fingerprint images and compare them with the pre-stored fingerprint templates to determine whether they are matching fingerprints, and finally complete the fingerprint recognition process.

[0070] In a possible implementation provided in the embodiment of the present application, the above display substrate 301 may include a substrate layer, such as Figure 8 As shown, it is a schematic structural diagram of the backlight side of the substrate layer of the display substrate 301. The substrate layer may be provided with an opening 801 located in the bonding area 403, and at least a part of the orthographic projection of the first bonding pin 404 on the plane where the substrate layer is located is located within the opening 801, so as to expose the first bonding pin 404 from the opening 801 on the backlight side of the display substrate.

[0071] In a possible implementation provided in the embodiment of the present application, as Figure 8 shown, the above first bonding pins 404 may be multiple, and the multiple first bonding pins 404 are arranged in an array in the first direction and the second direction, the first direction intersects with the second direction, and the display area 401, the bending area 402, and the bonding area 403 are arranged in sequence in the second direction;

[0072] Specifically, the openings 801 may be multiple, and the multiple openings 801 are arranged at intervals in the first direction, and the orthographic projection of a column of first bonding pins 404 parallel to the second direction on the plane where the substrate layer is located is located within one opening 801.

[0073] In some embodiments, taking Figure 8For example, at each opening 801 on the backlight side of the display substrate, three first bonding pins 404 can be exposed.

[0074] In some other embodiments, a plurality of openings 801 can be arranged at intervals in the second direction. The orthographic projection of a row of first bonding pins 404 parallel to the first direction on the plane where the substrate layer is located can be located at one opening 801.

[0075] In still other embodiments, there can be one opening 801, and the orthographic projection of the first bonding pins 404 arranged in an array on the plane where the substrate layer is located can be located within the opening 801.

[0076] A possible implementation manner is provided in the embodiments of the present application. As Figure 9 shown, it is a schematic diagram of the bonding between the display module and the circuit board. The above-mentioned bonding area 403 further includes a second bonding pin 901. The second bonding pin 901 is located on the side of the first bonding pin 404 away from the bending area 402. The second bonding pin 901 is electrically connected to the first bonding pin 404, and the second bonding pin 901 is configured to bond with the circuit board 902.

[0077] A possible implementation manner is provided in the embodiments of the present application. The above-mentioned display module further includes a circuit board 902. A fingerprint module driving chip 903 and a fingerprint pad are arranged on the circuit board 902. The fingerprint module driving chip 903 is electrically connected to the fingerprint pad, and the fingerprint pad is bonded and connected to the second bonding pin 901.

[0078] A possible implementation manner is provided in the embodiments of the present application. The above-mentioned bending area 402 can be bent so that the bonding area 403 is located on the backlight side of the display substrate, and the fingerprint pin 503 is bonded and connected to the first bonding pin 404.

[0079] As Figure 10 shown, it is a schematic structural diagram of the display module after bending. The bonding area is bent to the backlight side of the display substrate, so that the fingerprint pin 503 contacts and is bonded and connected to the first bonding pin 404 on the backlight side of the display substrate. At the same time, the circuit board 902 is also bent to the backlight side of the display substrate.

[0080] As Figure 11 shown, it is a cross-sectional view of the display module before bending. The fingerprint recognition module 1101 is electrically connected to the fingerprint pin 503 through the second trace 505, and the first bonding pin 404 is electrically connected to the second bonding pin 901 through the first trace 1102.

[0081] As Figure 12As shown in the figure, it is a cross-sectional view of the display module after bending. The bonding area is bent to the backlight side of the display substrate, so that the fingerprint pin 503 contacts and is bonded to the first bonding pin 404 on the backlight side of the display substrate. At the same time, the circuit board 902 is also bent to the backlight side of the display substrate.

[0082] In an embodiment of the present application, a possible implementation manner is provided. The above display substrate includes: a substrate layer and a pixel driving layer provided on the side of the substrate layer away from the back film; the pixel driving layer is located in the display area, and the pixel driving layer includes at least one gate metal layer and at least one source-drain metal layer.

[0083] In an embodiment of the present application, the second bonding pin may be provided on the same layer as at least one of the at least one gate metal layer in the above pixel driving layer and at least one of the at least one source-drain metal layer.

[0084] Figure 13 The structural schematic diagram of the display substrate of some embodiments of the present application is shown. As Figure 13 shown, the pixel driving layer may include: a first active layer 241, a first gate dielectric layer 242, a first gate metal layer 243, a second gate dielectric layer 244, a second gate metal layer 245, a first interlayer insulating layer 246, a second buffer layer 247, a second active layer 248, a third gate dielectric layer 249, a third gate metal layer 251, a second interlayer insulating layer 252, a first source-drain metal layer 253, a passivation layer 254, a first planarization layer 255, a second source-drain metal layer 256, a second planarization layer 257, a third source-drain metal layer 258, and a third planarization layer 259. For example, the material of the first active layer 241 includes low-temperature polysilicon to form a low-temperature polysilicon transistor. The material of the second active layer 248 includes a metal oxide such as IGZO (Indium Gallium Zinc Oxide) to form an oxide transistor. The first gate metal layer 243 (Gate1), the second gate metal layer 245 (Gate2), and the third gate metal layer 251 (Gate3) can be configured to form the gates of the transistors in the pixel driving circuit, form capacitors, and form scan signal lines; the first source-drain metal layer 253 (SD1) can be configured to form data signal lines and the sources and drains of the transistors; the second source-drain metal layer 256 (SD2) can be configured to form power signal lines; the third source-drain metal layer 258 (SD3) can be configured to form the anode connection part of the light-emitting device, and the pixel driving circuit can be electrically connected to the anode of the light-emitting device through the anode connection part.

[0085] As Figure 13As shown, the display layer 10 may further include a second barrier layer 210, a metal shielding layer (Bottom Shield Metal, BSM) 220, and a first buffer layer 230 disposed between the substrate layer 100 and the driving circuit layer. For example, the second barrier layer 210 may include a first sub-barrier layer 211 and a second sub-barrier layer 212. The metal shielding layer 220 may be disposed between the first sub-barrier layer 211 and the second sub-barrier layer 212, and the first buffer layer 230 is disposed between the second sub-barrier layer 212 and the first active layer 241. In some embodiments, the orthographic projection of the metal shielding layer 220 on the substrate layer 100 may cover the orthographic projection of the driving transistor in the pixel driving circuit on the substrate layer 100, which is beneficial to shielding the influence of static electricity on the driving transistor and reducing the influence of external light incident from one side of the substrate layer 100 on the active layer of the driving transistor.

[0086] For example, in Figure 13 the corresponding embodiment, the second bonding pin may be disposed on the same layer as at least one of the above-mentioned first gate metal layer 243, second gate metal layer 245, third gate metal layer 251, first source-drain metal layer 253, second source-drain metal layer 256, third source-drain metal layer 258, and metal shielding layer 220.

[0087] Alternatively, in some other embodiments, the second bonding pin 404 may be disposed on the side of the passivation layer 254 away from the substrate layer 100, and may be fabricated by a metal coating or patterning process. The second bonding pin 404 is electrically connected to at least one of the above-mentioned first gate metal layer 243, second gate metal layer 245, third gate metal layer 251, first source-drain metal layer 253, second source-drain metal layer 256, and third source-drain metal layer 258 through vias.

[0088] As Figure 13 shown, the substrate layer 100 may include a first flexible substrate layer 101, a second flexible substrate layer 103, and a first barrier layer 102 stacked between the first flexible substrate layer 101 and the second flexible substrate. The material of the flexible substrate layer may include, for example, a PI (Polyimide) substrate, a PET (Polyethylene Terephthalate) substrate, or a PEN (Polyethylene naphthalate two formic acid glycolester) substrate, etc.

[0089] The display substrate may further include a pixel defining layer 260 and a plurality of light-emitting devices 270. The pixel defining layer 260 is disposed on a side of the second insulating layer 130 away from the substrate layer 100. The pixel defining layer 260 has a plurality of pixel openings 261 spaced apart from each other in the display area. The light-emitting devices 270 are disposed at the pixel openings 261, and the pixel openings 261 are configured to define the light-emitting regions of the light-emitting devices 270. For example, one light-emitting device 270 may be disposed at one pixel opening 261. For example, Figure 13 the pixel defining layer 260 in Figure 13 is disposed on a side of the third planar layer 259 away from the substrate layer 100.

[0090] For example, taking the light-emitting device 270 as an OLED device as an example, in a direction away from the substrate layer 100, the light-emitting device 270 may include an anode layer 271, a light-emitting layer 272, and a cathode layer 273 that are sequentially stacked. The anode layer 271 is disposed between the pixel defining layer 260 and the driving circuit layer. The anode layers 271 of two adjacent light-emitting devices 270 are spaced apart from each other and are insulated from each other. The anode layer 271 is electrically connected to the pixel driving circuit, and at least a partial region of the anode layer 271 is exposed at the pixel opening 261. For example, the lower port of the pixel opening 261 (i.e., the opening 131 on the surface closer to the substrate layer 100) is within the orthographic projection range of the anode layer 271 on the substrate layer 100.

[0091] The light-emitting layer 272 is disposed on a side of the anode away from the substrate layer 100. For example, at least a partial region of the light-emitting layer 272 is within the pixel opening 261 of the corresponding sub-pixel and forms an electrical connection with the anode layer 271 of the light-emitting device 270 to which it belongs. In some embodiments, the light-emitting layer 272 may include a light-emitting material layer (EML) and a functional material layer stacked with the light-emitting material layer. For example, the functional material layer may include one or more of: a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL), which are specifically set according to actual needs, and the present disclosure does not limit this.

[0092] The cathode layer 273 is stacked on a side of the light-emitting layer 272 away from the substrate layer 100. In some embodiments, the cathode layers 273 of adjacent light-emitting devices 270 may be connected to each other, such as Figure 13 being integrally disposed as shown, so as to facilitate access to the cathode voltage signals of the respective light-emitting devices 270. In other embodiments, the cathode layers 273 of the respective light-emitting devices 270 may also be spaced apart from each other, and electrical connection between them is achieved through an additional conductive structure such as a metal isolation column.

[0093] In some embodiments, the anode layer 271 may be a composite structure formed by sequentially laminating a transparent conductive oxide film / a metal film / a transparent conductive oxide film. Among them, the material of the above transparent conductive oxide film is, for example, any one of ITO (Indium tin oxide) and IZO (Indium zinc oxide), and the material of the above metal film may be, for example, any one or more of aluminum (Al), silver (Ag), titanium (Ti), molybdenum (Mo), etc. In some other embodiments, the anode layer 271 may also be a single-layer structure, and the material of the single-layer structure may be any one of aluminum (Al), silver (Ag), titanium (Ti), molybdenum (Mo).

[0094] In some embodiments, the cathode layer 273 may be made of any one of metal materials such as lithium (Li), aluminum (Al), magnesium (Mg), silver (Ag), etc., or an alloy of any of the above materials such as a magnesium-silver alloy and an aluminum-lithium alloy. In some embodiments, the anode layer 271 may serve as a reflective electrode, and the cathode layer 273 is configured to transmit and reflect part of the light emitted by the light-emitting layer 272. By using the microcavity effect, the light-emitting device 270 can achieve a better color gamut and luminous efficiency.

[0095] As Figure 13 shown, the display substrate further includes a packaging layer 280. The packaging layer 280 covers the above-mentioned plurality of light-emitting devices 270 to protect the light-emitting devices 270 from water and oxygen erosion. For example, the packaging layer 280 may include a first inorganic packaging layer, an organic packaging layer, and a second inorganic packaging layer that are stacked. For example, the first inorganic packaging layer and the second inorganic packaging layer may be made of an inorganic insulating material such as a nitride, an oxide, a oxynitride, a nitrate, a carbide, or any combination thereof. The organic packaging layer may be made of an organic insulating material such as acrylic fiber, hexamethyldisiloxane, polyacrylate, polycarbonate, or polystyrene.

[0096] In some embodiments, the display substrate 10 may further include a touch control structure layer 290 disposed on the side of the encapsulation layer away from the substrate layer 100 to facilitate the implementation of the touch control function. For example, the touch control structure layer 290 may be prepared by using the FMLOC (Flexible MultiLayer On Cell, a flexible multi-layer structure on the display substrate 10) technology. For details, reference may be made to the related art. For example, the touch control structure layer 290 may include a first touch control metal layer, a second touch control metal layer, and a touch control insulating layer disposed between the first touch control metal layer and the second touch control metal layer. The orthographic projections of the first touch control metal layer and the second touch control metal layer on the substrate layer 100 do not overlap with the orthographic projection of the pixel opening 261 on the substrate layer 100. One of the first touch control metal layer and the second touch control metal layer is configured to dispose a first touch control electrode and a second touch control electrode, and the other is configured to dispose a bridging portion for bridging the first touch control electrode or the second touch control electrode. The extending directions of the first touch control electrode and the second touch control electrode intersect with each other. For example, they may be perpendicular to each other. Taking the first touch control metal layer as the bridging electrode and the second touch control metal layer as the first touch control electrode and the second touch control electrode as an example, the second touch control electrode includes a plurality of electrode units. Adjacent two electrode units are disconnected at the position where they cross the first touch control electrode, and vias are provided in the touch control insulating layer, and are bridged by the bridging electrode provided in the first touch control metal layer.

[0097] In some embodiments, the display substrate 10 may further include a protective layer 300 (which may also be referred to as TOC) disposed on the side of the pixel defining layer 260 away from the substrate layer 100. For example, when the display substrate 10 includes the touch control structure layer 290, the protective layer 300 may be disposed on the side of the touch control structure layer 290 away from the substrate layer 100 to protect the display substrate 10 from being eroded by water and oxygen in the air. For example, the protective layer 300 may cover the display area, the fan-out area, and the bending area BEND, and is set according to the needs of the actual product.

[0098] The display substrate includes a bonding metal layer disposed on the side of at least one source-drain metal layer of the pixel driving layer close to the substrate layer. The bonding metal layer includes a first bonding pin and a first trace electrically connected to the first bonding pin. The first trace is electrically connected to a second bonding pin through a via.

[0099] In the embodiment of the present application, a first bonding pin is provided in the bonding area of the display substrate, and then a fingerprint module area and a fingerprint module bonding area are provided on the surface of the back film away from the display substrate side, wherein the fingerprint module bonding area is arranged on the side of the fingerprint module area close to the bonding area; a fingerprint recognition module is arranged in the fingerprint module area; a fingerprint pin is arranged in the fingerprint module bonding area, and the fingerprint pin is electrically connected to the fingerprint recognition module; in the embodiment of the present application, a fingerprint recognition module is configured on the back film. Since the fingerprint pin is configured to bond the first bonding pin, the electrical connection between the fingerprint recognition module and the fingerprint module driving circuit can be realized through the first bonding pin; the embodiment of the present application realizes the integration of the display substrate and the fingerprint recognition module, which can simplify the manufacturing process of the display module, reduce the production cost, and improve the manufacturing efficiency and yield of the display module.

[0100] The embodiment of the present application provides a method for manufacturing a display module, which is applied to manufacturing the display module shown in the first aspect of the present application, as Figure 14 shown, the method includes:

[0101] S101, providing a display substrate, the display substrate includes: a display area and a bending area and a bonding area located on one side of the display area, the bending area is located between the display area and the bonding area, and the bonding area includes a first bonding pin.

[0102] S102, providing a back film.

[0103] S103, forming a fingerprint recognition module and a fingerprint pin on the first side of the back film, and attaching the second side of the back film to the backlight side of the display substrate, the fingerprint pin is located on the side of the fingerprint recognition module close to the bonding area; the fingerprint pin is electrically connected to the fingerprint recognition module, and the fingerprint pin is configured to bond the first bonding pin.

[0104] In a possible implementation manner provided in the embodiment of the present application, the above forming a fingerprint recognition module and a fingerprint pin on the first side of the back film, and attaching the second side of the back film to the backlight side of the display substrate may include:

[0105] S201, attaching the second side of the back film to a support substrate.

[0106] Wherein, the above support substrate may be a glass substrate.

[0107] Specifically, as Figure 15-1 shown, the second side of the back film 601 is attached to the glass substrate 603 through a photosensitive adhesive 602.

[0108] S202, forming a circuit structure layer and a fingerprint pin on the first side of the back film.

[0109] Wherein, the circuit structure layer includes: a transistor layer and a receiving electrode layer.

[0110] Specifically, asFigure 15-2 As shown, the circuit structure layer 604 is fabricated on the first side of the back film 601.

[0111] S203: Separate the back film from the support substrate, and attach the second side of the back film with the formed circuit structure layer and fingerprint pins to the backlight side of the display substrate.

[0112] Specifically, as Figure 15-3 shown, the back film 601 and the glass substrate 603 can be separated by a laser lift-off process, and the protective film 605 is attached to the upper and lower surfaces. Then, as Figure 15-4 shown, the second side of the back film 601 with the formed circuit structure layer 604 is attached to the backlight side of the display substrate 606.

[0113] S204: Provide an ultrasonic sensing film, which includes a pressure-sensitive adhesive layer, a piezoelectric layer, and an emitting electrode layer sequentially laminated on the pressure-sensitive adhesive layer.

[0114] Specifically, as Figure 16-1 shown, using the first protective film 607 as the substrate, the PSA, i.e., the pressure-sensitive adhesive layer 608, is coated on the protective film; as Figure 16-2 shown, the piezoelectric layer 609 is fabricated by a spin coating or coating process, and the thickness of the piezoelectric layer 609 can be 10 μm; then, as Figure 16-3 shown, the Ag electrode is fabricated by a screen printing process as the emitting electrode layer 610, and the thickness of the emitting electrode layer 610 can be between 20 μm and 30 μm. For example, it can be 20 μm, 25 μm, or 30 μm; further, as Figure 16-4 shown, the insulating layer 611 is fabricated by a coating process to protect the cathode, and the thickness of the insulating layer 611 can be between 10 μm and 20 μm. For example, it can be 10 μm, 12 μm, or 15 μm; as Figure 16-5 shown, the second protective film 612 is attached to the upper surface of the insulating layer.

[0115] S205: Attach the ultrasonic sensing film to the side of the circuit structure layer away from the back film 302.

[0116] In the embodiment of the present application, the transistor layer of the fingerprint recognition module is integrated into the display substrate, and the mask plate in the process can be reused for the production projects of other fingerprint recognition display modules, effectively reducing the R & D and production costs. At the same time, integrating the transistor layer of the fingerprint recognition module into the display substrate can also reduce the circuit board bonding process of the fingerprint recognition module and the plugging process of the circuit board of the fingerprint recognition module and the display substrate in the prior art, simplify the module process flow, improve the yield and production efficiency; further, the thickness of the fingerprint recognition module in the present application is effectively reduced, and only a half-window needs to be opened in the heat dissipation layer of the display substrate, so that the back surface of the display substrate is flat, which can improve the mold printing and avoid the aggravation of the film printing caused by the interference problem.

[0117] The method of the embodiment of the present application can be applied to prepare the display module provided by the embodiment of the present application, and its implementation principle is similar. The steps in the method of each embodiment of the present application correspond to the film layer structures in the display modules of each embodiment of the present application. For the detailed function description of the film layer structures of the method, reference can be specifically made to the description in the corresponding display module shown in the foregoing text, and details are not described herein again.

[0118] In the embodiment of the present application, a first bonding pin is arranged in the bonding area of the display substrate, and then a fingerprint module area and a fingerprint module bonding area are arranged on the surface of the back film away from the display substrate, wherein the fingerprint module bonding area is arranged on the side of the fingerprint module area close to the bonding area; a fingerprint recognition module is arranged in the fingerprint module area; a fingerprint pin is arranged in the fingerprint module bonding area, and the fingerprint pin is electrically connected to the fingerprint recognition module; in the embodiment of the present application, the fingerprint recognition module is configured on the back film. Since the fingerprint pin is configured to bond the first bonding pin, the electrical connection between the fingerprint recognition module and the fingerprint module driving circuit can be realized through the first bonding pin; the embodiment of the present application realizes the integration of the display substrate and the fingerprint recognition module, which can simplify the display module preparation process, reduce the production cost, and improve the preparation efficiency and yield of the display module.

[0119] The embodiment of the present application provides a display device, including the display module shown in the first aspect of the embodiment of the present application. The display device can include various application forms of electronic display devices such as mobile phones, tablet computers, planar, foldable, and curable, and can be applicable to various fields such as mobile communication, vehicle-mounted, and medical, which are not specifically limited in the embodiment of the present application.

[0120] In the above description, no detailed description is made on the technical details such as the layout of each layer. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. with the required shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not exactly the same as the methods described above. In addition, although the above embodiments are described separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination.

[0121] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0122] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A display module, characterized in that: include: A display substrate, comprising a display area, and a bending area and a binding area located on one side of the display area, wherein the bending area is located between the display area and the binding area, the bending area is bent so that the binding area is located on the backlight side of the display substrate, and the binding area comprises a first binding pin and a second binding pin; the first binding pin is located on the backlight side of the display substrate, the second binding pin is located on a side of the first binding pin away from the bending area, the second binding pin is electrically connected to the first binding pin, and the second binding pin is configured to bind a circuit board provided with a fingerprint module driver chip; A back film is arranged on the backlight side of the display substrate; the surface of the back film away from the display substrate includes a fingerprint module area and a fingerprint module binding area, and the fingerprint module binding area is arranged on the side of the fingerprint module area close to the binding area; the fingerprint module area is provided with a fingerprint recognition module; the fingerprint module binding area is provided with a fingerprint pin, the fingerprint pin is electrically connected to the fingerprint recognition module, and the fingerprint pin is bound and connected to the first binding pin.

2. The display module according to claim 1, characterized in that: The display substrate comprises a substrate layer, the substrate layer is provided with an opening located in the binding area, and the orthographic projection of the first binding pin on the plane where the substrate layer is located is at least partially located in the opening, so as to expose the first binding pin from the opening on the backlight side of the display substrate.

3. The display module according to claim 2, characterized in that: There are a plurality of first binding pins, and the plurality of first binding pins are arranged in an array in a first direction and a second direction, the first direction intersects the second direction, and the display area, the bending area, and the binding area are arranged in sequence in the second direction; There are a plurality of openings, and the plurality of openings are arranged at intervals along the first direction, and an orthographic projection of a column of the first binding pins on the plane where the substrate layer is located is located within one of the openings.

4. The display module according to claim 1, characterized in that: The display module also includes a circuit board, on which a fingerprint module driving chip and a fingerprint pad are arranged, the fingerprint module driving chip is electrically connected to the fingerprint pad, and the fingerprint pad is bound and connected to the second binding pin.

5. The display module according to claim 1, characterized in that: The fingerprint recognition module comprises: A circuit structure layer, arranged on one side of the back film, comprising a transistor layer and a receiving electrode layer, wherein the transistor layer is located between the back film and the receiving electrode layer; the transistor layer comprises a plurality of transistors, the receiving electrode layer is electrically connected to the drain of the transistor, and the fingerprint pin is electrically connected to the receiving electrode layer; A piezoelectric layer is arranged on a side of the circuit structure layer away from the back film; The emitting electrode layer is arranged on a side of the piezoelectric layer away from the back film.

6. The display module according to claim 5, characterized in that: The transistor layer may include a gate metal layer and a source-drain metal layer that are stacked; the fingerprint pin is arranged in the same layer as the gate metal layer or the source-drain metal layer in the transistor layer.

7. The display module according to claim 6, characterized in that: The fingerprint recognition module further includes a blocking layer disposed between the back film and the transistor layer.

8. The display module according to claim 1, characterized in that: The display substrate comprises: a substrate layer and a pixel driving layer arranged on a side of the substrate layer away from the back film; the pixel driving layer is located in the display area, and the pixel driving layer comprises at least one gate metal layer and at least one source-drain metal layer; The second binding pin is arranged on the same layer as the source and drain metal layer of the pixel driving layer; The display substrate includes a binding metal layer, which is arranged on a side of at least one source-drain metal layer of the pixel driving layer close to the substrate layer. The binding metal layer includes the first binding pin and a first routing line electrically connected to the first binding pin. The first routing line is electrically connected to the second binding pin through a via.

9. The display module according to claim 1, characterized in that: Also includes: The heat dissipation layer is arranged on the side of the back film away from the display substrate. The side of the heat dissipation layer close to the back film is provided with a groove. Along the direction perpendicular to the back film, the depth of the groove is less than the thickness of the heat dissipation layer. The fingerprint recognition module is arranged in the groove.

10. The display module according to claim 9, characterized in that: The depth of the groove is equal to the thickness of the fingerprint recognition module.

11. A display device, characterized in that: A display module comprising any one of claims 1-10.

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