Ultrasonic wave fingerprint identification module and manufacturing method thereof

Abstract

The invention relates to the technical field of fingerprint identification, and provides an ultrasonic wave fingerprint identification module and a manufacturing method thereof, and the method comprises the steps: providing a mother glass substrate; forming a first metal wire layer on the substrate, wherein the first metal wire layer is provided with a plurality of first wires extending along a first direction, and a first contact area and a second contact area which are integrally formed; forming a piezoelectric layer in a partial region of the first metal wire layer to enable the first contact region and the second contact region to be exposed; forming a second metal wire layer on the piezoelectric layer, wherein the second metal wire layer comprises a plurality of second wires which extend along a second direction and are electrically connected to the second contact area; and forming a protective layer on the second metal wire layer. The first contact area and the second contact area are respectively used for connecting the algorithm chip and the power supply control chip. According to the invention, the structure can be simplified, the process precision requirement can be reduced, and the module can be lightened and thinned and the stability can be improved.

Description

Technical Field

[0001] This application relates to the field of fingerprint recognition technology, and in particular to an ultrasonic fingerprint recognition module and its manufacturing method. Background Technology

[0002] Current ultrasonic fingerprint recognition modules can generally be divided into two types. The first type is as follows: Figure 1 The diagram shows a cross-sectional view of an ultrasonic fingerprint recognition module based on a TFT array substrate, as described in related technologies. The basic structure of this ultrasonic fingerprint recognition module, from bottom to top, includes a TFT array substrate 11, a piezoelectric layer 12, an electrode layer 13, and a protective layer 14. The TFT array substrate 11 is typically fabricated using the traditional LTPS process, with common materials such as silicon nitride (SiN), silicon oxide (SiO), molybdenum / aluminum / molybdenum trilayer metal (MoAlMo), indium tin oxide (ITO), amorphous silicon (a-Si), and molybdenum-tungsten alloy (MoW). Multiple coating and photolithography processes are required to form the sensing pixel circuitry. Sensing wires are positioned below the piezoelectric layer 12 in both the X and Y directions and are isolated by an intermediate insulating layer. Furthermore, the module also includes a flexible printed circuit board (FPC) 15 and an algorithm chip (Algorithm IC) 16 mounted on it, connected to the contacts in the sensing area via wires to achieve signal acquisition and digital processing of the fingerprint image. Although the overall structural design can achieve high-resolution sensing, the process is complex, there are many types of materials, and the requirements for wire alignment and insulation thickness are extremely high, resulting in low yield and high cost.

[0003] The second type is as follows Figure 2 The diagram shows a cross-sectional view of an ultrasonic fingerprint recognition module based on a wafer substrate, as described in related technologies. The basic structure of this ultrasonic fingerprint recognition module mainly consists of a wafer substrate 21, a piezoelectric layer 22, an electrode layer 23, and a protective layer 24. The wafer substrate 21 is fabricated through processes such as film deposition, photolithography, and ion implantation, using materials such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), or gallium nitride (GaN). In this structure, the sensing pixel circuit is also located below the piezoelectric layer 22, and the X / Y conductors are also integrated into the wafer substrate 21. The circuit layout is dense, requiring high alignment, and the overall structure is not conducive to achieving a thinner and lighter design. Furthermore, the module also includes a flexible printed circuit board (FPC) 25 and a power / switch IC 26 mounted on it. This chip provides sensing drive voltage, switches scanning channels, and works with the main chip to achieve complete fingerprint sensing and signal processing.

[0004] Both of the aforementioned structures share common drawbacks, including numerous manufacturing steps, stringent requirements for conductor width and spacing, and the need for high-precision alignment of insulation layers and multi-layer patterns, leading to reduced yield and increased costs. Furthermore, the design of the contact area is not easily simplified, often requiring through-holes or additional layers for connection. Therefore, the industry still has a need for improved technologies that are simpler in structure, easier to manufacture, lower in cost, and conducive to module thinning. Summary of the Invention

[0005] In view of this, in order to solve the problems that current ultrasonic fingerprint recognition modules generally have, such as complex structure, high process precision requirements, difficulty in simplifying contact design, and limited module thickness, the main purpose of this application is to provide an ultrasonic fingerprint recognition module and its manufacturing method, so as to improve manufacturing efficiency and achieve module thinning.

[0006] To achieve the above objectives, this application provides an ultrasonic fingerprint recognition module, comprising a substrate, a first metal wire layer, a piezoelectric layer, a second metal wire layer, and a protective layer. The substrate is made of plain glass and has an upper surface. The first metal wire layer is disposed on the upper surface and includes a plurality of first wires extending along a first direction, a first contact area, and a second contact area. The first contact areas are electrically connected to the plurality of first wires, and the second contact areas are adjacent to the first contact areas. The piezoelectric layer is disposed in a portion of the first metal wire layer, exposing the first and second contact areas. The second metal wire layer is disposed on the piezoelectric layer and includes a plurality of second wires extending along a second direction perpendicular to the first direction, and the plurality of second wires are electrically connected to the second contact areas. The protective layer covers the second metal wire layer. The first and second contact areas include a plurality of contacts for electrically connecting an algorithm chip and a power control chip, respectively, and are integrally formed from the first metal wire layer.

[0007] According to embodiments of this application, the thickness of the aforementioned substrate is between 50 micrometers and 150 micrometers.

[0008] According to embodiments of this application, the aforementioned first and second metal conductor layers are MoAlMo or Cu / Ti metal materials.

[0009] According to an embodiment of this application, the aforementioned ultrasonic fingerprint recognition module further includes an ITO conductive film, which is disposed on the surface of the first metal wire layer and has a thickness between 0.05 micrometers and 0.1 micrometers.

[0010] According to embodiments of this application, the thicknesses of the aforementioned first metal conductor layer and second metal conductor layer are both between 0.5 micrometers and 1 micrometer.

[0011] According to embodiments of this application, the thickness of the aforementioned piezoelectric layer is between 5 micrometers and 15 micrometers.

[0012] According to an embodiment of this application, the aforementioned protective layer is a polymer coating with a thickness between 5 micrometers and 20 micrometers.

[0013] In addition, this application also provides a method for manufacturing an ultrasonic fingerprint recognition module, which includes the following steps:

[0014] S10. Provide a substrate, which is made of plain glass and has an upper surface;

[0015] S20. A first metal wire layer is formed on the upper surface of the substrate. The first metal wire layer includes a plurality of first wires extending along a first direction and a first contact area and a second contact area. The first contact area is electrically connected to the plurality of first wires, and the second contact area is adjacent to the first contact area.

[0016] S30. A piezoelectric layer is formed in a portion of the first metal conductor layer, so that the first contact area and the second contact area remain exposed;

[0017] S40. A second metal conductor layer is formed on the piezoelectric layer, the second metal conductor layer including a plurality of second conductors extending along a second direction perpendicular to the first direction, and the plurality of second conductors are electrically connected to an exposed second contact area; and

[0018] S50. A protective layer is formed on the second metal conductor layer to cover the second metal conductor layer;

[0019] In step S20, the first contact area and the second contact area include multiple contacts for electrically connecting the algorithm chip and the power control chip, respectively, and are integrally formed when forming the first metal wire layer.

[0020] According to an embodiment of this application, the aforementioned step S10 includes thinning the substrate so that the thickness of the substrate is between 50 micrometers and 150 micrometers.

[0021] According to an embodiment of this application, the aforementioned step S20 includes depositing MoAlMo or Cu / Ti metal material by PVD sputtering to form a first metal wire layer, wherein the thickness of the first metal wire layer is between 0.5 micrometers and 1 micrometer.

[0022] According to an embodiment of this application, the aforementioned step S20 includes forming an ITO film on the surface of the first metal conductor layer, the thickness of which is between 0.05 micrometers and 0.1 micrometers.

[0023] According to an embodiment of this application, the aforementioned step S40 includes depositing MoAlMo or Cu / Ti metal material by PVD sputtering to form a second metal wire layer, the thickness of which is between 0.5 micrometers and 1 micrometer.

[0024] According to an embodiment of this application, the aforementioned step S30 involves coating or printing a piezoelectric material onto a first metal wire layer to form a piezoelectric layer, the thickness of which is between 5 micrometers and 15 micrometers.

[0025] According to an embodiment of this application, the aforementioned step S50 includes coating or printing a polymer material onto a second metal wire layer to form a protective layer, the thickness of which is between 5 micrometers and 20 micrometers.

[0026] Compared with prior art, the embodiments of this application have the following advantages:

[0027] (1) This application can overcome the problem that the conductor layer needs to be stacked in multiple layers and connected by through holes in the related technology. The contact area can be integrally formed, which simplifies the contact design and improves the accuracy.

[0028] (2) This application uses a plain glass substrate and a simplified material structure, requiring fewer types of metals and fewer process steps, which helps to reduce costs and improve yield.

[0029] (3) The wire width and spacing specifications of the conductive layer in this application are loose, which can reduce the alignment accuracy requirements of the yellow light and improve the process tolerance.

[0030] (4) The stacked design of the piezoelectric layer and the conductive layer in this application is conducive to the thinning of the module and the improvement of sensing stability, and is suitable for a variety of fingerprint recognition application scenarios.

[0031] The following detailed description through specific embodiments will make it easier to understand the purpose, technical content, features, and effects achieved by this application. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of an ultrasonic fingerprint recognition module based on a TFT array substrate in related technologies.

[0033] Figure 2 This is a cross-sectional view of an ultrasonic fingerprint recognition module based on a wafer substrate in related technologies.

[0034] Figure 3 This is a cross-sectional view of an ultrasonic fingerprint recognition module provided in an embodiment of this application.

[0035] Figure 4 This is a flowchart illustrating a method for manufacturing an ultrasonic fingerprint recognition module according to an embodiment of this application.

[0036] Figure 5 This is a schematic diagram of the configuration of the first metal conductor layer in an embodiment of this application.

[0037] Figure 6 and Figure 7 This is a schematic diagram of an embodiment of the present application in which an ITO conductive film is disposed on a first metal wire layer.

[0038] Figure 8 This is a schematic diagram of the piezoelectric layer coated on the first metal conductor layer in an embodiment of this application.

[0039] Figure 9 This is a schematic diagram of the second metal wire layer disposed on the piezoelectric layer in an embodiment of this application.

[0040] Figure 10 This is a schematic diagram of a protective layer disposed on the second metal conductor layer in an embodiment of this application.

[0041] Figure 11 This is a schematic diagram illustrating the integration of the ultrasonic fingerprint recognition module with the algorithm chip and power control chip in an embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 11: TFT array substrate;

[0044] 12: Piezoelectric layer;

[0045] 13: Electrode layer;

[0046] 14: Protective layer;

[0047] 15: Flexible circuit board;

[0048] 16: Algorithm chip;

[0049] 21: Wafer substrate;

[0050] 22: Piezoelectric layer;

[0051] 23: Electrode layer;

[0052] 24: Protective layer;

[0053] 25: Flexible circuit board;

[0054] 26: Power control chip;

[0055] 100: Ultrasonic fingerprint recognition module;

[0056] 110:Substrate;

[0057] 120: First metallic conductor layer;

[0058] 121a: Molybdenum layer;

[0059] 121b: Aluminum layer;

[0060] 121c: molybdenum layer;

[0061] 121d: Titanium layer;

[0062] 121e: Copper layer;

[0063] 122: First conductor;

[0064] 123: First contact area;

[0065] 125: Second contact area;

[0066] 124: ITO conductive film

[0067] 130: Piezoelectric layer;

[0068] 140: Second metallic conductor layer;

[0069] 142: Second conductor;

[0070] 150: Protective layer;

[0071] 160: Algorithm chip;

[0072] 170: Flexible circuit board;

[0073] 180: Power control chip;

[0074] S10, S20, S30, S40, S50: Steps. Detailed Implementation

[0075] The embodiments of this application will be further explained below with reference to the accompanying drawings. Wherever possible, the same reference numerals represent the same or similar components in the drawings and description. In the drawings, shapes and thicknesses may be exaggerated for simplicity and convenience. It is understood that elements not specifically shown in the drawings or described in the description are forms known to those skilled in the art. Those skilled in the art can make various changes and modifications based on the content of this application.

[0076] The technical solutions used in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of this application, and are therefore only examples. Unless otherwise specified, they should not be used to limit the scope of protection of this application. In the description of the specification, many specific details are provided to give the reader a more complete understanding of this application; however, this application may still be implemented even if some or all of the specific details are omitted. Furthermore, well-known steps or elements are not described in the details to avoid unnecessarily limiting this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0077] As described in previous works, most current ultrasonic fingerprint recognition modules use TFT substrates or wafers as substrates. This not only results in complex structures but also relies on multi-layer stacking and insulating layer isolation for wire design, requiring high precision in process alignment. This can easily lead to increased costs and unstable yields, and also limits the module's thickness and application flexibility. To address these technical problems, the basic idea of ​​this application is to provide an ultrasonic fingerprint recognition module and its fabrication method. By utilizing a plain glass substrate combined with simplified metal wires and a piezoelectric stacking structure, a single-layer contact integral molding design is introduced. This not only reduces process steps and material types but also improves module stability, thereby effectively improving manufacturing efficiency, module thinning capabilities, and overall process yield.

[0078] Please refer to Figure 3 and combined Figure 5 and Figures 8 to 11 This will be explained together. Figure 3 A cross-sectional view of the ultrasonic fingerprint recognition module 100 provided in an embodiment of this application; Figure 5 A schematic diagram of the configuration of the first metal conductor layer 120; Figure 8 This is a schematic diagram of the piezoelectric layer 130 coated on the first metal conductor layer 120 in an embodiment of this application; Figure 9 This is a schematic diagram of the second metal conductor layer 140 disposed on the piezoelectric layer 130 in an embodiment of this application; Figure 10 This is a schematic diagram of the protective layer 150 disposed on the second metal conductor layer 140 in an embodiment of this application; Figure 11 This is a schematic diagram of the integration of the ultrasonic fingerprint recognition module 100 with the algorithm chip 160 and the power control chip 180 in an embodiment of this application. In this embodiment, the ultrasonic fingerprint recognition module 100 includes a substrate 110, a first metal wire layer 120, a piezoelectric layer 130, a second metal wire layer 140, and a protective layer 150.

[0079] The substrate 110 is a piece of plain glass, which can be made of glass materials with high thermal stability and low coefficient of thermal expansion, such as borosilicate glass. The thickness can be controlled to 50 micrometers to 150 micrometers after chemical or mechanical thinning, which helps to make the module thinner and improve the ultrasonic penetration efficiency.

[0080] A first metal conductive layer 120 is disposed on the upper surface of the substrate 110, and includes a plurality of first conductive lines 122 extending along a first direction (e.g., the X-axis direction), as well as a first contact area 123 and a second contact area 125 (see...). Figure 5The first contact area 123 is electrically connected to the first conductor 122, and the second contact area 125 is adjacent to the first contact area 123. The pattern of the first conductor 22 is designed according to application requirements and can present straight lines, grids, serpentine lines, or other variable line shapes. The first contact area 123 and the second contact area 125 are disposed at the edge or corner of the module to facilitate the packaging and signal connection of external chips such as algorithm chip 160 and power control chip 180 through COG or FPC. The contact pattern can be adjusted according to the product size to be compatible with different packaging structures. The first metal conductor layer 120 can be made of metal materials such as MoAlMo or Cu / Ti, with a thickness ranging from 0.5 micrometers to 1 micrometer, and can be formed by sputtering and photolithography. The first contact area 123 and the second contact area 125 are integrally formed from the first metal conductor layer 120.

[0081] A piezoelectric layer 130 is disposed in a portion of the first metal conductor layer 120, exposing the first contact area 123 and the second contact area 125 (see...). Figure 8 To ensure the conductive contacts remain exposed, the piezoelectric layer 130 is not fully coated, but selectively coated on the sensing area, which refers to the overlapping area between the piezoelectric layer 130 and the first and second metal conductive layers 120. The piezoelectric layer 130 can be made of polymer materials such as PVDF, PVDF-HFP, and P(VDF-TrFE), or a ceramic dispersion with a piezoelectric effect. Coating methods include spin coating, precision screen printing, and droplet printing, with the thickness controlled between 5 and 15 micrometers, balancing sensing sensitivity and flexibility.

[0082] The second metal conductor layer 140 is disposed on the piezoelectric layer 130 and includes a plurality of second conductors 142 extending along a second direction (e.g., the Y-axis direction) (see Figure 9 The second direction is perpendicular to the extension direction of the first wire 122. The first wire 122 and the second wire 142 together form a sensing electrode arranged alternately in the transverse and longitudinal directions. The second metal wire layer 140 may be made of the same or different material as the first metal wire layer 120, and its thickness is between 0.5 micrometers and 1 micrometer. The second wire 142 extends from the edge region of the piezoelectric layer 130 to the exposed second contact region 125 to achieve electrical connection.

[0083] The protective layer 150 is disposed on the second metal conductor layer 140 (see...). Figure 10 This serves as a protective layer for the overall module surface. The protective layer 150 can be a polymer coating with a thickness preferably between 5 and 20 micrometers, such as polyimide (PI) or polymethyl methacrylate (PMMA), or it can be a laminated polymer membrane to provide protection functions such as waterproofing, scratch resistance, and environmental isolation.

[0084] The sensing signal can be transmitted to the corresponding second contact area 125 via the interlaced second wires 142 disposed on the piezoelectric layer 130, and then connected to the power control chip 180 through the second contact area 125 to realize the transmission and reception of the sensing signal and drive control. The first contact area 123 can be connected to the algorithm chip (Algorithm IC) 160 disposed on the top of the module via the first wire 122. The algorithm chip 160 is directly disposed on the substrate 110 and is electrically integrated with the sensing signal line (see...). Figure 11 In addition, the module also includes a power control chip (Power / Switch IC) 180 disposed on the flexible circuit board (FPC) 170. The power control chip 180 is electrically connected to the second contact area 125 to provide the module with the required drive voltage, scan control and power management functions, further realizing the integration of the overall module's signal sensing, processing and output functions.

[0085] Next, please refer to the following: Figure 4 This document describes the manufacturing process of the ultrasonic fingerprint recognition module 100 according to an embodiment of this application. The method includes the following steps:

[0086] As in step S10, a substrate 110 is provided, which is made of plain glass and has an upper surface. In this embodiment, since commercially available plain glass has a thickness of 0.5 mm to 0.55 mm, this step includes thinning the substrate 110 so that the thickness of the substrate 110 is between 50 micrometers and 150 micrometers.

[0087] As in step S20, a first metal wire layer 120 is formed on the upper surface of the substrate 110. The first metal wire layer 120 includes a plurality of first wires 122 extending along a first direction, as well as a first contact area 123 and a second contact area 125. The first contact area 123 is electrically connected to the first wires 122, and the second contact area 125 is adjacent to the first contact area 123.

[0088] As in step S30, a piezoelectric layer 130 is formed in a portion of the first metal conductor layer 120, and the first contact area 123 and the second contact area 125 are kept exposed.

[0089] As in step S40, a second metal wire layer 140 is formed on the piezoelectric layer 130. The second metal wire layer 140 includes a plurality of second wires 142 extending along a second direction perpendicular to the first direction, and the second wires 142 are electrically connected to the exposed second contact area 125.

[0090] As in step S50, a protective layer 150 is formed on the second metal wire layer 140 to cover the second metal wire layer 140.

[0091] In this application, the first contact area 123 and the second contact area 125 are integrally formed during the formation of the first metal conductor layer 120, eliminating the need for subsequent through-hole processes. Furthermore, the overall process of this application is simplified, avoiding traditional multi-layer through-hole and insulation layer stacking, making the process easier to implement.

[0092] Further explanation. For example... Figure 5 As shown, the first metal conductive layer 120 is formed on the substrate 110. A metal layer can be deposited using PVD sputtering, followed by photolithography and etching to form the desired pattern. The material of the first metal conductive layer 120 can be MoAlMo, Cu / Ti alloy, or other materials with good conductivity and adhesion. The first conductive lines 122 are arranged along a first direction, and the line spacing can vary from 20 / 20 micrometers to 100 / 100 micrometers, offering high process flexibility and suitability for various resolution designs. For example, at 500ppi, the line width / spacing is 40 / 40 micrometers; for higher resolutions, it can be designed to be as low as 20 / 20 micrometers. The first contact area 123 and the second contact area 125 are located at one end of the first metal conductive layer 120, and multiple contacts are reserved for electrical connection with the algorithm chip 160, the power control chip 180, and the flexible printed circuit board (FPC) 170.

[0093] Additionally, please refer to Figure 6 This is a schematic diagram illustrating the fabrication of the first metal conductive layer 120 using a MoAlMo structure in an embodiment of this application. The first metal conductive layer 120 is formed on a plain glass substrate 110 by sequentially forming a molybdenum layer 121a, an aluminum layer 121b, and a molybdenum layer 121c, forming a three-layer metal stack structure. An ITO conductive thin film 124 is then formed on the top layer. The molybdenum layers 121a and 121c provide excellent conductivity and adhesion, while the aluminum layer 121b offers both conductivity and cost control benefits. This metal stack structure has a uniform thickness, with the overall thickness of the first conductive layer 120 controlled between 0.5 micrometers and 1 micrometer, suitable for the uniform film deposition requirements of large-area sensing arrays. This metal stack structure possesses high conductivity, good adhesion, and resistive stability, and is commonly used in precision sensing element processes.

[0094] Please refer to Figure 7 This is a schematic diagram illustrating the fabrication of the first metal conductive layer 120 using a Cu / Ti structure in an embodiment of this application. The process involves sequentially depositing a titanium (Ti) layer 121d and a copper (Cu) layer 121e on a plain glass substrate 110. The titanium layer 121d serves as an adhesion layer for the copper conductive lines and prevents diffusion, while the copper layer 121e provides a highly conductive and low-resistance path. Similarly, an ITO conductive thin film 124 is formed on the top layer to enhance stability and protect the metal layers from oxidation. The overall thickness of this metal stack structure is controlled within 0.5 micrometers to 1 micrometer, exhibiting excellent conductivity and low material cost.

[0095] An ITO conductive film 124 is disposed on the first metal conductor layer 120. ITO has high surface conductivity and oxidation resistance, which can meet the product's requirements for conductivity stability and durability. The ITO conductive film 124 can be formed by sputtering, with the thickness controlled between 0.05 micrometers and 0.1 micrometers. This fabrication method is a recommended structure in the embodiments of this application, suitable for ultrasonic fingerprint modules with high conductivity requirements and symmetrical structural designs.

[0096] Figure 6 and Figure 7 Both fabrication methods shown can be applied to the processes of the first metal conductive layer 120 and the second metal conductive layer 140 in this application. Depending on product application requirements, conductive layer design, and cost considerations, a MoAlMo or Cu / Ti structure can be selected. Both can be used in conjunction with ITO conductive thin film processes to achieve compatibility with the required conductive patterns and subsequent coating processes.

[0097] like Figure 8 As shown, the piezoelectric layer 130 can be made of organic piezoelectric materials such as polyvinylidene fluoride (PVDF), or it can be combined with copolymers to improve mechanical elasticity and sensing sensitivity. The coating method can be spin coating, printing, microdroplet coating, or other suitable methods, and the thickness of the piezoelectric layer 130 is controlled between 5 micrometers and 15 micrometers. The piezoelectric layer 130 is only coated on the sensing area, with the first contact area 123 and the second contact area 125 left exposed to ensure smooth electrical connection with the algorithm chip 160 and the second metal conductor layer 140, respectively.

[0098] like Figure 9 As shown, the second conductor 142 of the second metal conductor layer 140 extends along a second direction perpendicular to the first conductor 122 to form an interlaced sensing grid. The second conductor 142 can be made of the same material as the first conductor 122 (e.g., MoAlMo or Cu / Ti), or it can be made of a different material. The second conductor 142 can extend to the edge of the piezoelectric layer 130 and electrically connect to the second contact area 125 located below it and kept exposed, to complete the electrical integration of the second metal conductor layer 140 and the first metal conductor layer 120. The alignment and pattern of the conductors can be adjusted according to application requirements, and the line width / spacing design is flexible, which is beneficial for optimizing the module resolution and sensitivity. This design omits multi-layer insulation and perforation steps, making the sensing array structure more stable and easier to mass-produce. The sensing signal is read out via a matrix, and after calculation by the algorithm chip 160, an accurate fingerprint image can be obtained.

[0099] like Figure 10As shown, after the second metal conductor layer 140 is completed, a protective layer 150 is applied to it. The protective layer 150 can be made of flexible polymer materials such as polyimide, acrylic, or silicone resin, and can be formed by coating or printing to form a polymer coating. Alternatively, a pre-fabricated polymer film can be adhered to the surface of the second metal conductor layer 140. The thickness of the polymer film is typically between 15 and 25 micrometers, while the thickness of the polymer coating can be controlled between 5 and 20 micrometers to balance the protective effect required for fingerprint sensing with the penetration requirements of ultrasonic signals, and to effectively prevent damage to the conductor structure from environmental moisture or foreign objects.

[0100] like Figure 11 As shown, after completing the protective layer 150, the module and chip can be further integrated and packaged. The algorithm chip 160 can be directly disposed on the substrate 110 and bonded to the contact formed by the first contact area 123 by soldering to receive the signal output by the sensing area. The second contact area 125 extends and connects through the second wire 142 disposed on the second metal wire layer 140, and is electrically connected to the power control chip 180 on the flexible circuit board 170 to provide module drive voltage and scan control signal. Through this packaging design, the functions of sensing signal reading, algorithm processing and power supply control can be effectively integrated, simplifying the module structure and improving system stability and process yield.

[0101] In summary, the ultrasonic fingerprint recognition module and its fabrication method provided in this application, based on a bare glass substrate and incorporating a simplified stacked structure of metal conductive layers and piezoelectric layers, not only simplifies the overall process steps but also effectively reduces dependence on material selection, photomask alignment accuracy, and advanced process conditions. Furthermore, through the integrated molding design of the first and second contact areas and the staggered conductive wire configuration, this application achieves high sensing stability and a thinner module, contributing to improved manufacturing yield and system integration flexibility. Overall, this application possesses advantages such as simple structure, user-friendly process, and high stability, exhibiting high practicality and industrial application potential, and is particularly suitable for fingerprint recognition modules in next-generation wearable devices, mobile terminals, and biometric systems.

[0102] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. Therefore, all equivalent variations or modifications made in accordance with the features and spirit described in the claims of this application should be included within the scope of the claims of this application.

Claims

1. An ultrasonic fingerprint recognition module, characterized in that, The ultrasonic fingerprint recognition module includes: The substrate is made of plain glass and has an upper surface; A first metal conductor layer is disposed on the upper surface, the first metal conductor layer comprising: Multiple first conductors extending along a first direction; The first contact area is electrically connected to the plurality of first wires; and The second contact area is adjacent to the first contact area; A piezoelectric layer is disposed in a portion of the first metal conductor layer, exposing the first contact area and the second contact area; A second metal conductor layer is disposed on the piezoelectric layer, and the second metal conductor layer includes: A plurality of second conductors extending along a second direction perpendicular to the first direction, and the plurality of second conductors being electrically connected to the second contact area; and A protective layer covering the second metal conductor layer; The first contact area and the second contact area include multiple contacts for electrically connecting the algorithm chip and the power control chip, respectively, and are integrally formed from the first metal wire layer.

2. The ultrasonic fingerprint recognition module as described in claim 1, characterized in that, The thickness of the substrate is between 50 micrometers and 150 micrometers.

3. The ultrasonic fingerprint recognition module as described in claim 1, characterized in that, The first metal conductor layer and the second metal conductor layer are MoAlMo or Cu / Ti metal materials.

4. The ultrasonic fingerprint recognition module as described in claim 1, characterized in that, The ultrasonic fingerprint recognition module also includes an ITO conductive film, which is disposed on the surface of the first metal wire layer, and the thickness of the ITO conductive film is between 0.05 micrometers and 0.1 micrometers.

5. The ultrasonic fingerprint recognition module as described in claim 1, characterized in that, The thickness of both the first metal conductor layer and the second metal conductor layer is between 0.5 micrometers and 1 micrometer.

6. The ultrasonic fingerprint recognition module as described in claim 1, characterized in that, The thickness of the piezoelectric layer is between 5 micrometers and 15 micrometers.

7. The ultrasonic fingerprint recognition module as described in claim 1, characterized in that, The protective layer is a polymer coating with a thickness between 5 micrometers and 20 micrometers.

8. A method for manufacturing an ultrasonic fingerprint recognition module, characterized in that, Includes the following steps: S10. Provide a substrate, the substrate being made of plain glass and having an upper surface; S20. A first metal wire layer is formed on the upper surface, the first metal wire layer comprising: Multiple first conductors extending along a first direction; The first contact area is electrically connected to the plurality of first wires; and The second contact area is adjacent to the first contact area; S30. A piezoelectric layer is formed in a portion of the first metal conductor layer, so that the first contact area and the second contact area remain exposed; S40. A second metal wire layer is formed on the piezoelectric layer, the second metal wire layer including a plurality of second wires extending along a second direction perpendicular to the first direction, and the plurality of second wires are electrically connected to the exposed second contact area; and S50. A protective layer is formed on the second metal wire layer to cover the second metal wire layer; in step S20, the first contact area and the second contact area include multiple contacts for electrically connecting the algorithm chip and the power control chip, respectively, and are integrally formed when the first metal wire layer is formed.

9. The method for manufacturing the ultrasonic fingerprint recognition module as described in claim 8, characterized in that, Step S10 includes thinning the substrate to a thickness between 50 micrometers and 150 micrometers.

10. The method for manufacturing the ultrasonic fingerprint recognition module as described in claim 8, characterized in that, Step S20 includes depositing MoAlMo or Cu / Ti metal material by PVD sputtering to form the first metal wire layer, the thickness of which is between 0.5 micrometers and 1 micrometer.

11. The method for manufacturing the ultrasonic fingerprint recognition module as described in claim 8, characterized in that, Step S20 includes forming an ITO conductive film on the surface of the first metal conductor layer, wherein the thickness of the ITO conductive film is between 0.05 micrometers and 0.1 micrometers.

12. The method for manufacturing the ultrasonic fingerprint recognition module as described in claim 8, characterized in that, Step S40 includes depositing MoAlMo or Cu / Ti metal material by PVD sputtering to form the second metal wire layer, the thickness of which is between 0.5 micrometers and 1 micrometer.

13. The method for manufacturing the ultrasonic fingerprint recognition module as described in claim 8, characterized in that, Step S30 involves coating or printing a piezoelectric material onto the first metal wire layer to form the piezoelectric layer, the thickness of which is between 5 micrometers and 15 micrometers.

14. The method for manufacturing the ultrasonic fingerprint recognition module as described in claim 8, characterized in that, Step S50 includes coating or printing a polymer material onto the second metal wire layer to form the protective layer, the thickness of which is between 5 micrometers and 20 micrometers.

Images