Ultrasonic fingerprint recognition module and manufacturing method thereof, display panel, and display device

Abstract

Embodiments of the present invention disclose an ultrasonic fingerprint recognition module, a manufacturing method thereof, a display panel, and a display device. The present invention arranges a microlens array structure before the piezoelectric material layer, so that the shape of the piezoelectric material layer can be set according to the morphology of the microlens array structure. Therefore, by precisely controlling the aperture and arch height of the microlens, the spherical center of the microlens is made to fall exactly on the touch surface of the base substrate. In this way, the spherical center of the piezoelectric material layer also falls exactly on the touch surface of the base substrate, thereby accurately focusing the ultrasonic waves emitted outward by the piezoelectric material layer on the target fingerprint, increasing the signal amount reflected by the fingerprint, and thus improving the contrast and signal-to-noise ratio.

Description

Technical Field

[0001] The present invention relates to the field of fingerprint recognition technology, and in particular to an ultrasonic fingerprint recognition module and a manufacturing method thereof, a display panel, and a display device. Background Art

[0002] With the continuous development of science and technology, fingerprint recognition technology has gradually been applied to people's daily lives. Fingerprint recognition technology can be used to identify people by comparing the detailed feature points of different fingerprints. Generally, fingerprint recognition technology can be divided into optical fingerprint recognition technology, silicon chip fingerprint recognition technology, and ultrasonic fingerprint recognition technology.

[0003] At present, ultrasonic fingerprint recognition technology is a popular research direction for major manufacturers. The ultrasonic fingerprint recognition structure is mainly a three-layer structure, including a transmitting electrode, a receiving electrode, and a piezoelectric material layer located between the two. When a driving voltage is applied to the transmitting electrode and the receiving electrode, the piezoelectric material layer is excited by the voltage to produce an inverse piezoelectric effect, which generates vibrations and emits a first ultrasonic wave outward. After the first ultrasonic wave contacts the finger, it is reflected back by the finger as a second ultrasonic wave. Since the fingerprint includes valleys and ridges, the vibration intensity of the second ultrasonic wave reflected back to the piezoelectric material layer by the fingerprint varies. At this time, the piezoelectric material layer can convert the second ultrasonic wave into a voltage signal. The receiving electrode receives the piezoelectric signal and transmits it to the fingerprint calculation module. The position of the valleys and ridges in the fingerprint is determined based on the voltage signal, thereby realizing the fingerprint recognition function. Summary of the Invention

[0004] The embodiments of the present invention provide an ultrasonic fingerprint recognition module and its manufacturing method, a display panel, and a display device, which can accurately focus the ultrasonic waves emitted outward by the piezoelectric material layer on the target fingerprint, increase the signal amount reflected by the fingerprint, and thus improve the contrast and signal-to-noise ratio.

[0005] An embodiment of the present invention provides an ultrasonic fingerprint recognition module, comprising: a base substrate, a receiving electrode layer located on the base substrate, a microlens array structure located on the side of the receiving electrode layer facing away from the base substrate, a piezoelectric material layer located on the side of the microlens array structure facing away from the base substrate, and an emitting electrode layer located on the side of the piezoelectric material layer facing away from the base substrate; wherein the piezoelectric material layer is arranged according to the morphology of the microlens array structure, and the emitting electrode layer is arranged according to the morphology of the piezoelectric material layer.

[0006] Optionally, in the above-mentioned ultrasonic fingerprint recognition module provided in an embodiment of the present invention, the microlens array structure includes a plurality of microlenses arranged in an array, the surface of the base substrate facing away from the microlenses is a touch surface, the touch surface has a plurality of ultrasonic focusing points corresponding one-to-one to the microlenses, and the distance between any point on the surface of the microlens facing away from the base substrate and the corresponding ultrasonic focusing point is equal.

[0007] Optionally, in the ultrasonic fingerprint recognition module provided by an embodiment of the present invention, the distance between any point on the surface of the microlens facing away from the substrate and the corresponding ultrasonic focal point, the aperture of the microlens, and the arch height of the microlens satisfy the following relationship:

[0008]

[0009] Wherein, R is the distance between any point on the surface of the microlens away from the substrate and the corresponding ultrasonic focusing point, D is the aperture of the microlens, and H is the arch height of the microlens.

[0010] Optionally, the ultrasonic fingerprint recognition module provided in the embodiment of the present invention further includes a reflective layer located on a side of the emitting electrode layer away from the base substrate.

[0011] Optionally, the ultrasonic fingerprint recognition module provided in the embodiment of the present invention further includes a first buffer layer located between the receiving electrode layer and the microlens array.

[0012] Optionally, in the above-mentioned ultrasonic fingerprint recognition module provided in an embodiment of the present invention, the receiving electrode layer includes a plurality of receiving electrodes corresponding to the microlens array, the piezoelectric material layer is a structure arranged on the entire surface, the transmitting electrode layer is a structure arranged on the entire surface, or the transmitting electrode layer includes a plurality of transmitting electrodes corresponding to the receiving electrodes.

[0013] Optionally, in the above-mentioned ultrasonic fingerprint recognition module provided in an embodiment of the present invention, it also includes a fingerprint recognition circuit layer located between the base substrate and the receiving electrode layer, the fingerprint recognition circuit layer includes a plurality of fingerprint recognition circuits corresponding one-to-one to the receiving electrodes, and the fingerprint recognition circuits are electrically connected to the corresponding receiving electrodes.

[0014] Optionally, in the ultrasonic fingerprint recognition module provided by an embodiment of the present invention, the material of the microlens array includes photosensitive resin.

[0015] Optionally, in the ultrasonic fingerprint recognition module provided by an embodiment of the present invention, the material of the piezoelectric material layer includes polyvinylidene fluoride, polyvinylidene fluoride trifluoroethylene, polyvinyl chloride, polycarbonate, polyvinylidene fluoride, polymethyl methacrylate, polymethyl methacrylate or polytetrafluoroethylene.

[0016] Correspondingly, an embodiment of the present invention further provides a display panel, comprising a display module and any one of the above-mentioned ultrasonic fingerprint recognition modules provided by an embodiment of the present invention.

[0017] Correspondingly, an embodiment of the present invention further provides a display device, comprising the above-mentioned display panel provided by an embodiment of the present invention.

[0018] Accordingly, an embodiment of the present invention further provides a method for manufacturing an ultrasonic fingerprint recognition module, which is used to manufacture any of the above-mentioned ultrasonic fingerprint recognition modules provided by the embodiment of the present invention. The manufacturing method includes:

[0019] forming a receiving electrode layer on the base substrate;

[0020] forming a microlens array structure on a side of the receiving electrode layer facing away from the base substrate;

[0021] forming a piezoelectric material layer on a side of the microlens array structure facing away from the substrate;

[0022] An emitting electrode layer is formed on a side of the piezoelectric material layer facing away from the base substrate; wherein the piezoelectric material layer is arranged according to the morphology of the microlens array structure, and the emitting electrode layer is arranged according to the morphology of the piezoelectric material layer.

[0023] Optionally, in the above manufacturing method provided by an embodiment of the present invention, forming a microlens array structure on a side of the receiving electrode layer away from the base substrate specifically includes:

[0024] forming a photosensitive resin layer on the receiving electrode layer;

[0025] exposing and developing the photosensitive resin layer to form a patterned microlens pattern;

[0026] The structure formed with the microlens pattern is placed on a heating platform, and the microlens array structure is formed through a thermal reflow process.

[0027] The beneficial effects of the embodiments of the present invention are as follows:

[0028] Embodiments of the present invention provide an ultrasonic fingerprint recognition module and a manufacturing method thereof, a display panel, and a display device. The ultrasonic fingerprint recognition module includes: a substrate, a receiving electrode layer located on the substrate, a microlens array structure located on the receiving electrode layer facing away from the substrate, a piezoelectric material layer located on the side of the microlens array structure facing away from the substrate, and an emitting electrode layer located on the side of the piezoelectric material layer facing away from the substrate. The piezoelectric material layer is configured according to the morphology of the microlens array structure, and the emitting electrode layer is configured according to the morphology of the piezoelectric material layer. The present invention provides a microlens array structure before the piezoelectric material layer, so that the shape of the piezoelectric material layer can be configured according to the morphology of the microlens array structure. Therefore, by precisely controlling the aperture and arch height of the microlenses, the spherical center of the microlenses is precisely located on the touch surface of the substrate. Thus, the spherical center of the piezoelectric material layer is precisely located on the touch surface of the substrate. This allows the ultrasonic waves emitted by the piezoelectric material layer to be accurately focused on the target fingerprint, increasing the signal reflected by the fingerprint, thereby improving contrast and signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of an ultrasonic fingerprint recognition module provided in an embodiment of the present invention;

[0030] Figure 2 for Figure 1 A partial enlarged schematic diagram;

[0031] Figure 3 A schematic diagram of the specific structure of the ultrasonic fingerprint recognition module provided in an embodiment of the present invention;

[0032] Figure 4 for Figure 3 Schematic diagram of the vertical flip structure;

[0033] Figure 5 A schematic flow chart of a method for manufacturing an ultrasonic fingerprint recognition module provided by an embodiment of the present invention;

[0034] Figures 6A-6D A schematic structural diagram of a method for manufacturing an ultrasonic fingerprint recognition module provided by an embodiment of the present invention after executing each step;

[0035] Figure 7 A schematic flow chart of a method for manufacturing an ultrasonic fingerprint recognition module provided by an embodiment of the present invention;

[0036] Figures 8A-8C A schematic structural diagram of a method for manufacturing an ultrasonic fingerprint recognition module provided by an embodiment of the present invention after executing each step. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following is a detailed description of the specific implementation methods of the ultrasonic fingerprint recognition module and its manufacturing method, display panel, and display device provided by the embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described below are only used to illustrate and explain the present invention and are not intended to limit the present invention. In addition, the embodiments and features in the embodiments of this application can be combined with each other if there is no conflict.

[0038] The thickness, size and shape of each film layer in the accompanying drawings do not reflect the actual proportions of the ultrasonic fingerprint recognition module, and are only intended to illustrate the content of the present invention.

[0039] The embodiment of the present invention provides an ultrasonic fingerprint recognition module, such as Figure 1 As shown, it includes: a base substrate 1, a receiving electrode layer 2 located on the base substrate 1, a microlens array structure 3 located on the side of the receiving electrode layer 2 facing away from the base substrate 1, a piezoelectric material layer 4 located on the side of the microlens array structure 3 facing away from the base substrate 1, and an emitting electrode layer 5 located on the side of the piezoelectric material layer 4 facing away from the base substrate 1; wherein, the piezoelectric material layer 4 is set according to the morphology of the microlens array structure 3, and the emitting electrode layer 5 is set according to the morphology of the piezoelectric material layer 4.

[0040] The above-mentioned ultrasonic fingerprint recognition module provided by the embodiment of the present invention sets a layer of microlens array structure 3 before the piezoelectric material layer 4, so that the shape of the piezoelectric material layer 4 can be set according to the morphology of the microlens array structure 3, that is, the embodiment of the present invention sets the piezoelectric material layer 4 into a curved structure, and the ultrasonic signal generated by the piezoelectric material layer 4 can be converged in the direction away from the transmitting electrode layer. In this way, ultrasonic focusing is achieved by optimizing the structure of the piezoelectric material layer 4, so that the ultrasonic wave resonates / resonates at the intersection point, which can enhance the energy and intensity of the ultrasonic signal and has a higher recognition degree in the presence of noise. Therefore, the ultrasonic fingerprint recognition module provided by the embodiment of the present invention can perform fingerprint recognition in the form of ultrasonic focusing, and can achieve improved fingerprint recognition accuracy. Specifically, as Figure 2 As shown, Figure 2 for Figure 1 In the local structural diagram, by precisely controlling the aperture D and arch height H of the microlens 31, the spherical center of the microlens 31 (ultrasound focusing point F) is precisely located on the touch surface 11 of the base substrate 1. In this way, the spherical center of the piezoelectric material layer 4 also precisely locates on the touch surface 11 of the base substrate 1. As a result, the ultrasonic waves emitted outward by the piezoelectric material layer 4 can be accurately focused on the target fingerprint, increasing the signal reflected by the fingerprint and thus improving the contrast and signal-to-noise ratio.

[0041] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 1 and Figure 2As shown, the microlens array structure 3 includes multiple microlenses 31 arranged in an array. The surface of the substrate 1 facing away from the microlenses 31 is the touch surface 11. The touch surface 11 has multiple ultrasonic focusing points F corresponding one-to-one with the microlenses 31. The distance between any point on the surface of the microlenses 31 facing away from the substrate 1 and the corresponding ultrasonic focusing point F is equal. This allows the ultrasonic waves emitted from the piezoelectric material layer to be accurately focused on the target fingerprint, increasing the amount of signal reflected from the fingerprint, thereby improving the contrast and signal-to-noise ratio.

[0042] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 2 As shown, according to the Pythagorean theorem, R 2 =(D / 2) 2 +(RH) 2 By deriving this equation, it can be seen that the distance between any point on the surface of the microlens 31 facing away from the substrate 1 and the corresponding ultrasonic focal point, the aperture of the microlens, and the arch height of the microlens satisfy the following relationship:

[0043]

[0044] Here, R is the distance between any point on the surface of the microlens 31 facing away from the base substrate 1 and the corresponding ultrasound focal point F, D is the aperture of the microlens 31, and H is the arch height of the microlens 31. Thus, when manufacturing the microlens array 3, the aperture D and the arch height H of the microlens 31 can be precisely controlled so that the spherical center of the microlens 31 (the ultrasound focal point F) falls exactly on the touch surface 11 of the base substrate 1.

[0045] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 1 As shown, the material of the microlens array 3 may include photosensitive resin. In this way, the microlens array may be manufactured using a thermal reflow process, that is, using photosensitive resin to form patterned microlens areas under photolithography, and then heating and reflowing to form a microlens structure.

[0046] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 1 As shown, the piezoelectric material layer 4 is made of a piezoelectric material that can be excited by voltage to produce an inverse piezoelectric effect and can also be excited by vibration to produce a direct piezoelectric effect. The material of the piezoelectric material layer 4 can include, but is not limited to, polyvinylidene fluoride, polyvinylidene fluoride trifluoroethylene, polyvinyl chloride, polycarbonate, polyvinylidene fluoride, polymethyl methacrylate, polymethyl methacrylate, polytetrafluoroethylene, piezoelectric ceramics, or piezoelectric crystals.

[0047] In specific implementation, in order to further improve the ability of the ultrasonic waves emitted outward by the piezoelectric material layer to focus on the target fingerprint, in the above-mentioned ultrasonic fingerprint recognition module provided by the embodiment of the present invention, Figure 1 As shown, a reflective layer 6 is further included, which is located on the side of the emitting electrode layer 5 facing away from the substrate 1 .

[0048] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 1 As shown, the first buffer layer 7 is further included and located between the receiving electrode layer 2 and the microlens array 3. Specifically, the first buffer layer 7 can be composed of silicon nitride SiNx, silicon oxide SiOx or silicon oxynitride SiNO, and the receiving electrode layer 2 is embedded in the first buffer layer 7 at intervals.

[0049] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 1 As shown, the receiving electrode layer 2 includes a plurality of receiving electrodes 21 corresponding to the microlens array 3, the piezoelectric material layer 4 can be a structure provided on the entire surface, and the emitting electrode layer 5 can also be a structure provided on the entire surface, or the emitting electrode layer 5 includes a plurality of emitting electrodes corresponding to the receiving electrodes 21. Specifically, the embodiment of the present invention is illustrated by taking the structure in which the emitting electrode layer 5 is provided on the entire surface as an example. In this way, the present invention simplifies the film layer manufacturing process on the basis of realizing the fingerprint recognition function by patterning the receiving electrode layer 2, while the piezoelectric material layer 4 and the emitting electrode layer 5 are both provided on the entire surface. Of course, the piezoelectric material layer 4 and the emitting electrode layer 5 can also be patterned, and the design can be selected according to actual needs.

[0050] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 3 As shown, the fingerprint recognition circuit layer further includes a fingerprint recognition circuit layer located between the base substrate 1 and the receiving electrode layer 2. The fingerprint recognition circuit layer includes a plurality of fingerprint recognition circuits 8 corresponding one to one with the receiving electrodes 21. The fingerprint recognition circuits 8 are electrically connected to the corresponding receiving electrodes 21. Specifically, the fingerprint recognition circuit 8 includes an active layer 81, a gate insulating layer 82, a gate 83, an interlayer dielectric layer 84, a source 85, and a drain 86 stacked on the base substrate 1. The source 85 and the drain 86 are electrically connected to the active layer 81, respectively. The source 85 of each fingerprint recognition circuit 8 is electrically connected to the corresponding receiving electrode 21 to transmit the received electrical signal to the signal receiver. The drain 86 of the fingerprint recognition circuit 8 is electrically connected to the electrical signal processor to transmit the electrical signal to the electrical signal processor.

[0051] In specific implementation, in the ultrasonic fingerprint recognition module provided in the embodiment of the present invention, Figure 3As shown, the device further includes: a planar layer 9 located between the fingerprint recognition circuit 81 and the receiving electrode layer 2; a second buffer layer 11 located between the base substrate 1 and the fingerprint recognition circuit 81; and a bonding electrode (pad) 12 provided on the same layer as the source 85 and drain 86. The receiving electrode 21 is electrically connected to the source 85 through a via extending through the planar layer 9.

[0052] It should be noted that the ultrasonic fingerprint recognition module provided by the embodiment of the present invention can be integrated into a flexible display panel or a rigid display panel that cannot be deformed. When the ultrasonic fingerprint recognition module is integrated into a flexible display panel, the base substrate 1 provided by the embodiment of the present invention is a flexible substrate (such as PI); when the ultrasonic fingerprint recognition module is integrated into a rigid display panel, the base substrate 1 provided by the embodiment of the present invention is a rigid substrate (such as glass).

[0053] Specifically, if Figure 4 As shown, Figure 4 for Figure 3 After the structure is flipped vertically 180°, when the ultrasonic fingerprint recognition module is in working state, the transmitting electrode layer 5 and the receiving electrode layer 2 input an alternating voltage (AC voltage) (for example: an AC square wave is applied to the transmitting electrode layer 5, and the receiving electrode layer 2 is grounded). Then, there is a voltage difference on both sides of the piezoelectric material layer 4, and the piezoelectric material layer 4 will deform due to the inverse piezoelectric effect or drive the membrane layers above and below the piezoelectric material layer 4 to vibrate together, thereby generating a first ultrasonic wave, and the first ultrasonic wave is emitted in a direction away from the piezoelectric material layer 4. The first ultrasonic wave emitted by the ultrasonic fingerprint recognition module is reflected after reaching the fingerprint 30, and the reflected ultrasonic wave is used as the second ultrasonic wave. After reaching the piezoelectric material layer 4, the second ultrasonic wave will drive the piezoelectric material layer 4 to deform or vibrate, and due to the positive piezoelectric effect, a voltage difference will be generated on both sides of the piezoelectric material layer 4. At this time, the transmitting electrode layer 5 is grounded, and the receiving electrode layer 2 can be used to receive electrical signals generated by the positive piezoelectric effect. Because the fingerprint 30 of a finger includes valleys 31 and ridges 32, they have different reflective abilities for ultrasound (the valleys 31 have a stronger reflective ability for ultrasound), resulting in different intensities of the second ultrasound reflected by the valleys 31 and ridges 32. Therefore, the receiving electrodes 21 at different positions can respectively receive the second ultrasound reflected by the fingerprint 30 at the corresponding position. The electrical signal processor can determine whether the ultrasound is the second ultrasound reflected by the valleys 31 or the ridges 32 based on the voltage received by the receiving electrodes 21, thereby achieving fingerprint recognition. Compared with optical fingerprint recognition modules, ultrasonic fingerprint recognition modules have higher recognition efficiency and accuracy under extreme conditions such as when the human finger is stained.

[0054] In the embodiment of the present invention, a microlens array structure is provided before the piezoelectric material layer. Thus, the shape of the piezoelectric material layer can be set according to the morphology of the microlens array structure. Therefore, by precisely controlling the aperture and arch height of the microlens, the spherical center of the microlens is precisely located on the touch surface of the substrate. In this way, the spherical center of the piezoelectric material layer also precisely locates on the touch surface of the substrate. As a result, the ultrasonic waves emitted outward by the piezoelectric material layer can be accurately focused on the target fingerprint, thereby increasing the signal reflected by the fingerprint and improving the contrast and signal-to-noise ratio.

[0055] Based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing an ultrasonic fingerprint recognition module, which is used to manufacture the ultrasonic fingerprint recognition module provided by an embodiment of the present invention. Figure 5 As shown, the production method may include:

[0056] S501, forming a receiving electrode layer on a base substrate;

[0057] Specifically, if Figure 6A As shown, a second buffer layer 11 , a fingerprint recognition circuit 8 , a planar layer 9 , and a receiving electrode layer 2 are sequentially stacked on a base substrate 1 .

[0058] S502, forming a microlens array structure on a side of the receiving electrode layer facing away from the substrate;

[0059] Specifically, if Figure 6B As shown, a first buffer layer 7 is formed on the side of the receiving electrode layer 2 facing away from the substrate 1 , and a microlens array structure 3 is formed on the side of the first buffer layer 7 facing away from the substrate 1 .

[0060] S503, forming a piezoelectric material layer on a side of the microlens array structure facing away from the substrate;

[0061] Specifically, if Figure 6C As shown, a piezoelectric material layer 4 is formed on the side of the microlens array structure 3 facing away from the substrate 1 .

[0062] S504, forming an emitting electrode layer on a side of the piezoelectric material layer facing away from the substrate; wherein the piezoelectric material layer is arranged according to the morphology of the microlens array structure, and the emitting electrode layer is arranged according to the morphology of the piezoelectric material layer;

[0063] Specifically, if Figure 6D As shown, an emitting electrode layer 5 is formed on the side of the piezoelectric material layer 4 facing away from the substrate 1 , and a reflecting layer 6 is formed on the side of the emitting electrode layer 5 facing away from the substrate 1 .

[0064] In specific implementation, in the above manufacturing method provided by the embodiment of the present invention, the above step S502 forms a micro lens array structure on the side of the receiving electrode layer away from the base substrate, such as Figure 7Specifically, it may include:

[0065] S701, forming a photosensitive resin layer on the receiving electrode layer;

[0066] Specifically, if Figure 8A As shown, a photosensitive resin layer 3" is formed on the first buffer layer 7.

[0067] S702, exposing and developing the photosensitive resin layer to form a patterned microlens pattern;

[0068] Specifically, if Figure 8B As shown, the photosensitive resin layer 3" is exposed and developed to form a patterned microlens pattern 3'; the microlens pattern 3 can be, but is not limited to, rectangular, circular or long strip.

[0069] S703, placing the structure with the microlens pattern formed on a heating platform, and forming a microlens array structure through a thermal reflow process;

[0070] Specifically, if Figure 8C As shown, the structure with the microlens pattern 3' is placed on a heating platform and a thermal reflow process is performed to form a microlens array structure. By selecting the photosensitive resin material and controlling the temperature and heating time of the thermal reflow process, the aperture D and arch height H of the microlenses are precisely controlled so that the spherical center of the microlenses falls exactly on the touch surface of the base substrate 1.

[0071] It should be noted that in the above-mentioned method for manufacturing an ultrasonic fingerprint recognition module provided in an embodiment of the present invention, a corresponding patterning process is used when manufacturing each film layer. This patterning process may include only photolithography, or may include photolithography and etching steps, and may also include other processes such as printing and inkjet printing to form a predetermined pattern. Photolithography refers to a process that uses photoresist, a mask, an exposure machine, etc. to form a pattern, including film formation, exposure, and development processes. In specific implementations, the corresponding patterning process can be selected based on the structure formed in the present invention.

[0072] Based on the same inventive concept, an embodiment of the present invention further provides a display panel, comprising any of the above-mentioned ultrasonic fingerprint recognition modules provided by the embodiment of the present invention.

[0073] The display panel provided in the embodiment of the present invention may be a flexible display panel or a rigid display panel that cannot be deformed.

[0074] Based on the same inventive concept, embodiments of the present invention further provide a display device comprising the aforementioned display panel. The display device can be any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigation system. The implementation of the display device can be referenced to the aforementioned embodiments of the ultrasonic fingerprint recognition module, and any repetitive details will not be repeated.

[0075] Embodiments of the present invention provide an ultrasonic fingerprint recognition module and a manufacturing method thereof, a display panel, and a display device. The ultrasonic fingerprint recognition module includes: a substrate, a receiving electrode layer located on the substrate, a microlens array structure located on the receiving electrode layer facing away from the substrate, a piezoelectric material layer located on the side of the microlens array structure facing away from the substrate, and an emitting electrode layer located on the side of the piezoelectric material layer facing away from the substrate. The piezoelectric material layer is configured according to the morphology of the microlens array structure, and the emitting electrode layer is configured according to the morphology of the piezoelectric material layer. The present invention provides a microlens array structure before the piezoelectric material layer, so that the shape of the piezoelectric material layer can be configured according to the morphology of the microlens array structure. Therefore, by precisely controlling the aperture and arch height of the microlenses, the spherical center of the microlenses is precisely located on the touch surface of the substrate. Thus, the spherical center of the piezoelectric material layer is precisely located on the touch surface of the substrate. This allows the ultrasonic waves emitted by the piezoelectric material layer to be accurately focused on the target fingerprint, increasing the signal reflected by the fingerprint, thereby improving contrast and signal-to-noise ratio.

[0076] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An ultrasonic fingerprint recognition module, characterized in that: include: A base substrate, a receiving electrode layer located on the base substrate, a microlens array structure located on a side of the receiving electrode layer facing away from the base substrate, a piezoelectric material layer located on a side of the microlens array structure facing away from the base substrate, and an emitting electrode layer located on a side of the piezoelectric material layer facing away from the base substrate; wherein the piezoelectric material layer is arranged according to the morphology of the microlens array structure, and the emitting electrode layer is arranged according to the morphology of the piezoelectric material layer; The microlens array structure includes a plurality of microlenses arranged in an array. The surface of the substrate facing away from the microlenses is a touch surface. The touch surface has a plurality of ultrasonic focusing points corresponding one-to-one with the microlenses. The distance between any point on the surface of the microlenses facing away from the substrate and the corresponding ultrasonic focusing point is equal.

2. The ultrasonic fingerprint recognition module according to claim 1, characterized in that: The distance between any point on the surface of the microlens away from the substrate and the corresponding ultrasound focal point, the aperture of the microlens, and the arch height of the microlens satisfy the following relationship: Wherein, R is the distance between any point on the surface of the microlens away from the substrate and the corresponding ultrasonic focusing point, D is the aperture of the microlens, and H is the arch height of the microlens.

3. The ultrasonic fingerprint recognition module according to claim 1 or 2, characterized in that: It also includes a reflective layer located on a side of the emitting electrode layer away from the substrate.

4. The ultrasonic fingerprint recognition module according to claim 1 or 2, characterized in that: The invention also includes a first buffer layer located between the receiving electrode layer and the microlens array.

5. The ultrasonic fingerprint recognition module according to claim 1 or 2, characterized in that: The receiving electrode layer includes a plurality of receiving electrodes corresponding to the microlens array, the piezoelectric material layer is a structure arranged on the entire surface, the emitting electrode layer is a structure arranged on the entire surface, or the emitting electrode layer includes a plurality of emitting electrodes corresponding to the receiving electrodes.

6. The ultrasonic fingerprint recognition module according to claim 5, characterized in that: It also includes a fingerprint recognition circuit layer located between the base substrate and the receiving electrode layer, the fingerprint recognition circuit layer includes a plurality of fingerprint recognition circuits corresponding one to one with the receiving electrodes, and the fingerprint recognition circuits are electrically connected to the corresponding receiving electrodes.

7. The ultrasonic fingerprint recognition module according to claim 1 or 2, characterized in that: The material of the microlens array includes photosensitive resin.

8. The ultrasonic fingerprint recognition module according to claim 1 or 2, characterized in that: The material of the piezoelectric material layer includes polyvinylidene fluoride, polyvinylidene fluoride trifluoroethylene, polyvinyl chloride, polycarbonate, polyvinylidene fluoride, polymethyl methacrylate or polytetrafluoroethylene.

9. A display panel, characterized in that: It comprises a display module and an ultrasonic fingerprint recognition module according to any one of claims 1-8.

10. A display device, characterized in that: The display panel according to claim 9 is included.

11. A method for manufacturing an ultrasonic fingerprint recognition module, characterized in that: Used to manufacture the ultrasonic fingerprint recognition module according to any one of claims 1 to 8, the manufacturing method comprising: forming a receiving electrode layer on the base substrate; forming a microlens array structure on a side of the receiving electrode layer facing away from the base substrate; forming a piezoelectric material layer on a side of the microlens array structure facing away from the substrate; An emitting electrode layer is formed on a side of the piezoelectric material layer facing away from the base substrate; wherein the piezoelectric material layer is arranged according to the morphology of the microlens array structure, and the emitting electrode layer is arranged according to the morphology of the piezoelectric material layer.

12. The manufacturing method according to claim 11, characterized in that: A microlens array structure is formed on a side of the receiving electrode layer facing away from the substrate, specifically comprising: forming a photosensitive resin layer on the receiving electrode layer; exposing and developing the photosensitive resin layer to form a patterned microlens pattern; The structure formed with the microlens pattern is placed on a heating platform, and the microlens array structure is formed through a thermal reflow process.

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