Ultrasonic sensor, ultrasonic fingerprint module and manufacturing method therefor, and electronic device

Abstract

Disclosed in the present invention are an ultrasonic sensor, an ultrasonic fingerprint module and a manufacturing method therefor, and an electronic device. The ultrasonic sensor comprises a substrate. The substrate comprises an effective recognition area and a non-effective recognition area. Pad parts are arranged in the non-effective recognition area on the upper surface of the substrate. The effective recognition area and the pad parts are spaced apart by a preset distance in the length direction of the substrate. A first linear distance o between the edge of the effective recognition area parallel to and close to the pad parts and the side edge of the substrate parallel to the edge and close to the pad parts is 0.9-2.5 mm, and a second linear distance g between the edge of the effective recognition area close to one side of the pad parts and the pad parts is 0.8-2.4 mm. The manufacturing method comprises: placing the ultrasonic sensor on a backup support, and press-fitting the ultrasonic sensor and a flexible circuit board by an ACF press-fitting machine to achieve electric connection, wherein the press-fitting pressure is 10-100 N, the press-fitting temperature of an area where an ACF adhesive is located is 110-160°C, and the temperature of the backup support is 50-130°C. The distance between the pad parts and the effective recognition area is shortened, thereby reducing the size of the ultrasonic sensor.

Description

Ultrasonic sensor, ultrasonic fingerprint module, manufacturing method thereof, and electronic device Technical Field

[0001] The present invention relates to the field of fingerprint recognition technology. More specifically, the present invention relates to an ultrasonic sensor, an ultrasonic fingerprint module, a manufacturing method thereof, and an electronic device. Background Art

[0002] Currently, there are multiple fingerprint recognition technologies available, including capacitive, optical, and ultrasonic. Ultrasonic fingerprint recognition is currently the most widely used. As electronic devices become increasingly thinner and lighter, full-screen displays and narrow bezels leave less and less space for optical sensors. However, current optical sensors are relatively large, resulting in larger screen windows, larger overall structural space, and high costs. Technical issues

[0003] The embodiments of the present invention provide an ultrasonic sensor, an ultrasonic fingerprint module, a manufacturing method thereof, and an electronic device, which reduce the size of the ultrasonic sensor while increasing the proportion of the effective recognition area in the ultrasonic sensor, thereby solving the problems of large optical sensor size, large screen windows of electronic devices, large space occupied by the overall structure of the electronic device, and high cost. Technical Solutions

[0004] To this end, the embodiments of the present invention provide the following technical solutions:

[0005] An embodiment of the present invention provides an ultrasonic sensor, comprising a substrate, the substrate including an effective identification area and an ineffective identification area. A pad portion is provided within the ineffective identification area on the upper surface of the substrate. The effective identification area and the pad portion are arranged at a predetermined distance along the length of the substrate. A first straight-line distance o from an edge of the effective identification area parallel to and proximate to the pad portion to a side edge of the substrate parallel to the edge and proximate to the pad portion is 0.9 mm to 2.5 mm. A second straight-line distance g from an edge of the effective identification area proximate to the pad portion to the pad portion is 0.8 mm to 2.4 mm.

[0006] Furthermore, the first straight-line distance o is 1.5 mm, and the second straight-line distance g is 1.2 mm.

[0007] Furthermore, the ultrasonic sensor also includes an acoustic layer, which is arranged on the upper surface of the substrate. The acoustic layer includes a piezoelectric layer, an upper electrode arranged on the upper surface of the piezoelectric layer, and a lower electrode arranged on the lower surface of the piezoelectric layer. The lower electrode is arranged on the upper surface of the substrate, and the area of ​​the substrate where the lower electrode is located is called an effective identification area.

[0008] Furthermore, the pad portion includes a plurality of pads spaced apart along a width direction of the ultrasonic sensor.

[0009] Furthermore, the area of ​​the pad is 8000um 2 -50000um 2 .

[0010] Furthermore, each of the pads includes a plurality of first pads spaced apart along a width direction of the ultrasonic sensor.

[0011] Furthermore, the total area of ​​all the first pads in each of the pads is 8000um 2 -50000um 2 .

[0012] Furthermore, the substrate of the ultrasonic sensor is a silicon-based substrate or a glass substrate.

[0013] An embodiment of the present invention further provides an ultrasonic fingerprint module, comprising the ultrasonic sensor described in the above embodiment and a flexible circuit board, wherein the pad portion of the ultrasonic sensor is electrically connected to the electrical connection area of ​​the flexible circuit board, and the flexible circuit board is used to connect to an external circuit.

[0014] Furthermore, the pad portion of the ultrasonic sensor is electrically connected to the electrical connection area of ​​the flexible circuit board through ACF glue using an ACF lamination process.

[0015] Furthermore, when the pad portion of the ultrasonic sensor and the electrical connection area of ​​the flexible circuit board are pressed together using ACF glue in an ACF pressing process, the pressing pressure is 10N-100N, and the pressing temperature of the area where the ACF glue is located is 110°C-160°C.

[0016] Furthermore, when the pad portion of the ultrasonic sensor and the electrical connection area of ​​the flexible circuit board are pressed together using ACF glue in an ACF pressing process, the pressing pressure is 25N, and the pressing temperature of the area where the ACF glue is located is 148°C.

[0017] Furthermore, when the pad portion of the ultrasonic sensor is pressed with the electrical connection area of ​​the flexible circuit board using ACF glue and an ACF pressing process, the pressure head of the ACF pressing machine completely or partially covers the pad portion in the length direction of the pad portion.

[0018] Furthermore, when the pad portion of the ultrasonic sensor is pressed together with the electrical connection area of ​​the flexible circuit board using ACF glue and an ACF pressing process, the range of a third straight-line distance k from the pressure head of the ACF pressing machine to the edge of the effective identification area of ​​the ultrasonic sensor parallel to and close to the pad portion is: 0.7 mm ≤ k < 2.5 mm.

[0019] Furthermore, the third straight-line distance k is 1.2 mm.

[0020] Furthermore, when the pad portion of the ultrasonic sensor is laminated to the electrical connection area of ​​the flexible circuit board using ACF adhesive using an ACF laminating process, the length n of the projection of the press head of the ACF laminating machine on the ultrasonic sensor is 0.2 mm-1 mm.

[0021] Furthermore, the length n of the projection of the pressing head of the ACF pressing machine on the ultrasonic sensor is 0.3 mm.

[0022] An embodiment of the present invention further provides a method for manufacturing an ultrasonic fingerprint module, wherein the ultrasonic fingerprint module is the ultrasonic fingerprint module described in the above embodiment, and the method comprises:

[0023] The ultrasonic sensor is placed on the back support, and ACF glue is provided between the pad portion of the ultrasonic sensor and the electrical connection area of ​​the flexible circuit board, and the electrical connection is achieved by pressing with an ACF pressing machine.

[0024] The pressing pressure is 10N-100N, the pressing temperature of the area where the ACF glue is located is 110°C-160°C, and the temperature of the backing is 50°C-130°C.

[0025] Furthermore, the pressing pressure of the ACF pressing machine is 25N, the pressing temperature of the area where the ACF glue is located is 148°C, and the temperature of the backing is 120°C.

[0026] Furthermore, when the ACF press is pressing, the pressing head of the ACF press completely or partially covers the pad portion in the length direction of the pad portion.

[0027] Furthermore, when the ACF press is pressed, a third straight line distance k from the press head of the ACF press to an edge of the effective recognition area of ​​the ultrasonic sensor that is parallel to and close to the pad portion is in the range of: 0.7 mm ≤ k < 2.5 mm.

[0028] Furthermore, the third straight-line distance k is 1.2 mm.

[0029] Furthermore, when the ACF pressing machine is pressing, the length n of the projection of the pressing head of the ACF pressing machine on the ultrasonic sensor is 0.2 mm-1 mm.

[0030] Furthermore, when the ACF pressing machine is pressing, the length n of the projection of the pressing head of the ACF pressing machine on the ultrasonic sensor is 0.3 mm.

[0031] An embodiment of the present invention further provides an electronic device, comprising the ultrasonic sensor described in the above embodiment, or the ultrasonic fingerprint module described in the above embodiment, or an ultrasonic fingerprint module manufactured by the method for manufacturing the ultrasonic fingerprint module described in the above embodiment. Beneficial effects

[0032] The beneficial effects of the present invention are: shortening the distance from the pad part to the effective recognition area, reducing the size of the ultrasonic sensor, and at the same time increasing the proportion of the effective recognition area in the ultrasonic sensor, solving the problems of large optical sensor size, large screen window of electronic equipment, large space occupied by the overall structure of the electronic equipment, and high cost, reducing costs and making screen mounting more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of each embodiment. Obviously, the drawings described below are only some embodiments of the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings in the specific description below of the embodiments of the present invention without paying any creative work.

[0034] Figure 1 is a top view of an ultrasonic sensor.

[0035] FIG2 is a side view of an ultrasonic sensor.

[0036] FIG3 is a schematic structural diagram of a pad portion.

[0037] FIG. 4 is a schematic structural diagram of a pad portion according to another embodiment.

[0038] FIG5 is a side view of the ultrasonic fingerprint module.

[0039] FIG6 is a structural diagram of the ACF lamination process.

[0040] FIG7 is a diagram showing the positional relationship between the head and the pad portion of the ACF laminating machine.

[0041] FIG. 8 is a diagram showing the positional relationship between a head and a pad portion of an ACF laminating machine according to another embodiment.

[0042] In the figure, 1. Ultrasonic sensor; 11. Substrate; 111. Effective identification area; 12. Pad portion; 13. Pad; 14. First pad; 15. Acoustic layer; 151. Piezoelectric layer; 152. Upper electrode; 153. Lower electrode; 2. Flexible circuit board; 3. Back support; 4. ACF pressing machine; 41. Press head; 5. FPC platform; 6. ACF glue; 7. Buffer board. Modes for Carrying Out the Invention

[0043] The following, in conjunction with the accompanying drawings, clearly and completely describes the technical solutions of an ultrasonic sensor, an ultrasonic fingerprint module, a method for manufacturing the same, and an electronic device provided by each embodiment of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0044] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, so they cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more features. In the description of the embodiments of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] In the embodiments of the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0046] In the embodiments of the present invention, the word "exemplary" is used to mean "serving as an example, illustration or description". Any embodiment described as "exemplary" in the embodiments of the present invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any person skilled in the art to implement and use the embodiments of the present invention. In the following description, the embodiments of the present invention are listed in detail for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the embodiments of the present invention can be implemented even without using these specific details. In other examples, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the embodiments of the present invention with unnecessary details. Therefore, the embodiments of the present invention are not intended to be limited to the embodiments shown, but should be consistent with the widest scope consistent with the principles and features disclosed in the embodiments of the present invention.

[0047] Example 1:

[0048] Please refer to Figures 1 and 2. Figure 1 is a top view of an ultrasonic sensor, and Figure 2 is a side view of the ultrasonic sensor. This embodiment specifically discloses an ultrasonic sensor. The ultrasonic sensor 1 includes a substrate 11 and an acoustic layer 15. The acoustic layer 15 is disposed on the upper surface of the substrate 11. The acoustic layer 15 includes a piezoelectric layer 151, an upper electrode 152 disposed on the upper surface of the piezoelectric layer 151, and a lower electrode 153 disposed on the lower surface of the piezoelectric layer 151. The lower electrode 153 is an electrode array formed by a plurality of pixel units. The lower electrode 153 is disposed on the upper surface of the substrate 11. The substrate 11 is integrated with a circuit. The area where the lower electrode 153 of the substrate 11 is located is called an active identification area (AA area) 111. Therefore, the substrate 11 includes the active identification area 111 and a non-active identification area (non-AA area). The area of ​​the upper electrode 152 is equal to or larger than the area of ​​the lower electrode 153. Therefore, the acoustic layer 15 can only cover the active identification area 111, or it can completely cover the active identification area 111 and partially cover the non-active identification area. A pad portion 12 is provided within the non-effective identification area on the upper surface of the substrate 11. The effective identification area 111 and the pad portion 12 are arranged at a predetermined distance along the length of the substrate 11. A first straight-line distance o from the edge of the effective identification area 111 of the ultrasonic sensor 1, which is parallel to and close to the pad portion 12, to a side edge of the substrate 11 that is parallel to and close to the pad portion 12 (hereinafter referred to as the fourth side) is 0.9 mm to 2.5 mm, and a second straight-line distance g from the edge of the effective identification area 111 close to the pad portion 12 to the pad portion 12 is 0.8 mm to 2.4 mm. This arrangement shortens the distance from the pad portion 12 to the effective identification area 111, thereby reducing the size of the ultrasonic sensor 1. Specifically, while the distances between the effective identification area 111 and the other three sides of the substrate 11 remain unchanged, the distance between the effective identification area 111 and the fourth side of the substrate 11 is reduced, thereby reducing the size of the substrate 11 and increasing the proportion of the effective identification area 111 in the ultrasonic sensor 1.

[0049] Furthermore, the first straight-line distance o is 1.5 mm and the second straight-line distance g is 1.2 mm, which not only reduces the size of the ultrasonic sensor 1 but also maintains a safe distance between the components, increases the proportion of the effective recognition area 111 in the ultrasonic sensor 1, and ensures the performance of the ultrasonic sensor 1.

[0050] Optionally, referring to FIG3 , the pad portion 12 includes a plurality of pads 13 spaced apart along the width direction of the ultrasonic sensor 1 , and the ultrasonic sensor 1 is electrically connected to other components through the pads 13 . Further, the area of ​​the pad 13 is 8000 μm 2 -50000um 2The size of the pad 13 will directly affect the impedance of the ACF (Anisotropic Conductive Film) after lamination. The larger the pad 13 is, the smaller the ACF lamination impedance is. Therefore, the area of ​​the pad 13 is designed to be 8000um in this application. 2 -50000um 2 , under the premise of reducing the size of the ultrasonic sensor 1, ensure the reliability and stability of the electrical connection with other components and reduce the ACF pressing impedance. For example, the pad 13 is 120um long, 80um wide, and has an area of ​​9600um 2 Or the pad 13 is 300um long, 90um wide, and 27000um in area. 2 Or the pad 13 is 500um long, 100um wide, and has an area of ​​50000um 2 The area of ​​the pad 13 can be flexibly set according to the actual application scenario and electrical connection requirements.

[0051] Optionally, please refer to FIG4 . The pad portion 12 includes a plurality of pads 13 spaced apart along the width direction of the ultrasonic sensor 1. Each pad 13 includes a plurality of first pads 14 spaced apart along the width direction of the ultrasonic sensor 1. Each pad 13 is further divided into a plurality of first pads 14. Compared with the pad portion 12 structure shown in FIG3 , when the pad 13 has the same area and length, the scheme shown in FIG4 increases the overall width occupied by the pad 13 on the substrate 11 due to the spacing between the first pads 14. This increases the width of the entire pad portion 12, further increasing the contact area between the pad portion 12 and other components, making the connection more reliable and stable. Furthermore, the total area of ​​all first pads 14 in each pad 13 is 8000 μm. 2 -50000um 2 The area of ​​the first pads 14 can be flexibly set based on the actual application scenario and electrical connection requirements. Furthermore, each pad 13 includes two or three first pads 14, so that the area of ​​the first pads 14 is not too small, ensuring the actual contact area between the first pads 14 and other components, reducing the ACF pressing resistance, and facilitating processing and production.

[0052] Optionally, the substrate 11 of the ultrasonic sensor 1 is a silicon-based substrate or a glass substrate.

[0053] In a preferred embodiment, the size of the ultrasonic sensor 1 can be reduced to 6 mm in length and width, with the first linear distance o being 1.5 mm and the second linear distance g being 1.2 mm. This ensures a safe distance while shortening the distance from the pad portion 12 to the effective recognition area 111, thereby increasing the proportion of the effective recognition area 111 in the ultrasonic sensor 1.

[0054] Example 2:

[0055] Based on the same inventive concept as the first embodiment, as shown in FIG5 , this embodiment specifically provides an ultrasonic fingerprint module comprising any of the ultrasonic sensors 1 provided in the first embodiment and a flexible printed circuit board (FPC) 2. The pad portion 12 of the ultrasonic sensor 1 is electrically connected to the electrical connection area of ​​the FPC 2, which is used to connect to an external circuit. In this embodiment, the electrical connection area of ​​the FPC 2 also includes a pad. The pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the FPC 2 can be electrically connected using conductive adhesive.

[0056] Optionally, the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 are electrically connected via ACF adhesive 6 using an ACF lamination process. The ultrasonic sensor 1 and the flexible circuit board 2 are bonded together via the ACF adhesive 6, achieving electrical conduction. The ACF adhesive 6 also possesses inherent adhesive properties, bonding the ultrasonic sensor 1 to the flexible circuit board 2. Referring to Figure 6 , during ACF lamination, the ultrasonic sensor 1 is placed on a backing 3, the flexible circuit board 2 is placed on an FPC platform 5, and the electrical connection area of ​​the flexible circuit board 2 is positioned above the pad portion 12 of the ultrasonic sensor 1. ACF adhesive 6 is positioned between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2. The pressure head 41 of the ACF laminating machine 4 presses down from above the electrical connection area of ​​the flexible circuit board 2 to perform high-temperature lamination.

[0057] Optionally, when the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 are pressed together using the ACF glue 6 using the ACF pressing process, the pressing pressure is 10N-100N, and the pressing temperature of the area where the ACF glue 6 is located is 110°C-160°C. During ACF pressing, since the position of the ACF glue 6 and the acoustic layer 15 are on the same substrate 11, the high temperature during pressing will be transmitted to the position of the acoustic layer 15 through both substrate conduction and air conduction. Exceeding a certain range will also cause the acoustic layer 15 to fail. This embodiment effectively reduces the pressing temperature, and even when the size of the ultrasonic sensor 1 is reduced, it can ensure that the acoustic layer 15 will not fail, at least the portion of the acoustic layer 15 corresponding to the effective identification area 111 will not fail, thereby ensuring the image display effect.

[0058] Preferably, when the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 are pressed together through the ACF glue 6 using the ACF pressing process, the pressing pressure is 25N, and the pressing temperature of the area where the ACF glue 6 is located is 148°C, ensuring that the ultrasonic sensor 1 and the flexible circuit board 2 are firmly electrically connected and bonded, while avoiding failure of the acoustic layer 15.

[0059] Optionally, please refer to Figures 7 and 8. When the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 are pressed together using the ACF pressing process through the ACF glue 6, the pressure head 41 of the ACF pressing machine 4 completely covers or partially covers the pad portion 12 in the length direction of the pad portion 12. As long as the ACF glue 6 reaches the preset temperature and pressure, the connection between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 can be stable and reliable, thereby reducing the difficulty of pressing.

[0060] Preferably, when the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 are pressed together using the ACF pressing process through the ACF glue 6, the length n of the projection of the pressure head 41 of the ACF pressing machine 4 on the ultrasonic sensor 1 is 0.2 mm-1 mm, ensuring the area of ​​the ACF glue 6, and further ensuring that the connection between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 is stable and reliable.

[0061] More preferably, when the pad portion 12 of the ultrasonic sensor 1 is laminated to the electrical connection area of ​​the flexible circuit board 2 via the ACF adhesive 6 using an ACF laminating process, the length n of the projection of the press head 41 of the ACF laminating machine 4 on the ultrasonic sensor 1 is 0.3 mm.

[0062] Optionally, when the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 are pressed together using the ACF glue 6 using the ACF pressing process, the range of the third straight-line distance k from the pressure head 41 of the ACF pressing machine 4 to the edge of the effective identification area 111 of the ultrasonic sensor 1 parallel to and close to the pad portion 12 is: 0.7mm≤k<2.5mm, that is, the minimum distance from the pressure head 41 of the ACF pressing machine 4 to the effective identification area 111 of the ultrasonic sensor 1 is 0.7mm, ensuring that the part of the acoustic layer 15 corresponding to the effective identification area 111 does not fail.

[0063] Preferably, the third straight-line distance k is 1.2 mm.

[0064] Example 3:

[0065] This embodiment is based on the same inventive concept as the second embodiment above, and specifically provides a method for manufacturing an ultrasonic fingerprint module. The ultrasonic fingerprint module is the ultrasonic fingerprint module described in the second embodiment above. The method includes:

[0066] The ultrasonic sensor 1 is placed on the backing 3, and ACF glue 6 is applied between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2. The two are then electrically connected using an ACF laminating machine 4. Specifically, referring to FIG6 , the flexible circuit board 2 is placed on the FPC platform 5, with the electrical connection area of ​​the flexible circuit board 2 positioned above the pad portion 12 of the ultrasonic sensor 1. ACF glue 6 is applied between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2. The press head 41 of the ACF laminating machine 4 presses down from above the electrical connection area of ​​the flexible circuit board 2, performing high-temperature lamination. The lamination pressure is 10N-100N, the lamination temperature in the area where the ACF glue 6 is applied is 110°C-160°C, and the temperature of the backing 3 is 50°C-130°C. This effectively reduces the lamination temperature and, even when the size of the ultrasonic sensor 1 is reduced, ensures that the acoustic layer 15 does not fail, at least in the portion corresponding to the effective recognition area 111, thereby maintaining image display quality.

[0067] Optionally, a buffer plate 7 can be placed between the pressure head 41 of the ACF laminating machine 4 and the flexible circuit board 2. This buffer plate 7 serves to cushion any sudden and excessive pressure from the pressure head 41, ensuring a smooth transfer of pressure to the flexible circuit board 2 and ultrasonic sensor 1. Furthermore, since the surface of the flexible circuit board 2 may be uneven, the buffering effect of the buffer plate 7 ensures uniform pressure on the ACF adhesive 6. The buffer plate 7 is made of an elastic material, preferably silicone. During lamination, the buffer plate 7 is placed between the flexible circuit board 2 and the pressure head 41. After lamination, the buffer plate 7 can be removed.

[0068] The temperature at the ACF glue 6 of the embodiment of the present application is the temperature after the pressure head 41 is pressed down and the pressure head 41 and the back support 3 work together. The temperature at the ACF glue 6 and the corresponding temperature of the pressure head 41 and the temperature of the back support 3 have been determined before the production of the ultrasonic fingerprint module. During pressing, only the temperature of the back support 3 and the pressure head 41 is controlled. Before the pressure head 41 is pressed down, the pressure head 41 and the back support 3 are first heated to the corresponding temperature, and then the pressure head 41 is pressed down to apply pressure. During pressing, the back support 3 is kept at a constant temperature, and the pressure head 41 is kept at a constant temperature or pulse heated to ensure that the temperature at the ACF glue 6 reaches the preset temperature. The temperature and pressure are maintained for a period of time to solidify the ACF glue 6, and then the pressure head 41 removes the pressure, removes the ultrasonic sensor 1 and the flexible circuit board 2, and completes the ACF pressing connection.

[0069] Preferably, the pressing pressure of the ACF pressing machine 4 is 25N, the pressing temperature of the area where the ACF glue 6 is located is 148°C, and the temperature of the back support 3 is 120°C, to ensure that the ultrasonic sensor 1 and the flexible circuit board 2 are electrically connected and firmly bonded, and to avoid failure of the acoustic layer 15. Before the pressure head 41 presses down, the back support 3 is first heated to 120°C, the pressure head 41 is heated to 190°C, and then the pressure head 41 is pressed down to apply pressure. During pressing, the back support 3 is kept at a constant temperature of 120°C, and the pressure head 41 is kept at a constant temperature of 190°C or pulse heated to ensure that the temperature of the ACF glue 6 reaches 148°C. The temperature and pressure are maintained for a period of time to solidify the ACF glue 6, and then the pressure head 41 removes the pressure, removes the ultrasonic sensor 1 and the flexible circuit board 2, and completes the ACF pressing connection.

[0070] Optionally, when the ACF laminating machine 4 is laminating, the pressure head 41 of the ACF laminating machine 4 completely covers or partially covers the pad portion 12 in the length direction of the pad portion 12. As long as the ACF glue 6 reaches the preset temperature and pressure, the connection between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 can be stable and reliable, thereby reducing the difficulty of laminating.

[0071] Preferably, when the ACF laminator 4 is laminating, the length n of the projection of the pressure head 41 of the ACF laminator 4 on the ultrasonic sensor 1 is 0.2 mm-1 mm, ensuring the area of ​​the ACF glue 6, and further ensuring that the connection between the pad portion 12 of the ultrasonic sensor 1 and the electrical connection area of ​​the flexible circuit board 2 is stable and reliable.

[0072] More preferably, when the ACF laminating machine 4 is laminating, the length n of the projection of the pressing head 41 of the ACF laminating machine 4 on the ultrasonic sensor 1 is 0.3 mm.

[0073] Optionally, when the ACF laminating machine 4 is laminating, the range of the third straight-line distance k is: 0.7mm≤ k<2.5mm, that is, the minimum distance from the pressure head 41 of the ACF laminating machine 4 to the effective identification area 111 of the ultrasonic sensor 1 is 0.7mm, ensuring that the part of the acoustic layer 15 corresponding to the effective identification area 111 does not fail.

[0074] Preferably, when the ACF laminating machine 4 is laminating, the third straight-line distance k is 1.2 mm.

[0075] Example 4:

[0076] This embodiment is based on the same inventive concept as the second and third embodiments described above, and specifically provides an electronic device comprising any of the ultrasonic sensors 1 provided in the first embodiment, or any of the ultrasonic fingerprint modules provided in the second embodiment, or an ultrasonic fingerprint module manufactured using the manufacturing method of any of the ultrasonic fingerprint modules provided in the third embodiment. The electronic device is an electronic device having a display screen, and may be a laptop computer, a mobile phone, a tablet computer, a desktop computer, a gaming device, an in-vehicle electronic device, a wearable smart device, or the like.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and simple improvements made to the essential contents of the embodiments of the present invention should be included in the scope of protection of the present invention.

Claims

1. An ultrasonic sensor, comprising a substrate (11), the substrate (11) comprising an effective identification area (111) and a non-effective identification area, a pad portion (12) being provided in the non-effective identification area on the upper surface of the substrate (11), the effective identification area (111) and the pad portion (12) being arranged at a predetermined distance along the length direction of the substrate (11), wherein: A first straight-line distance o from an edge of the effective identification area (111) parallel to and close to the pad portion (12) to a side edge of the substrate (11) parallel to the edge and close to the pad portion (12) is 0.9 mm to 2.5 mm, and a second straight-line distance g from an edge of the effective identification area (111) close to the pad portion (12) to the pad portion (12) is 0.8 mm to 2.4 mm.

2. The ultrasonic sensor according to claim 1, wherein The first straight-line distance o is 1.5 mm, and the second straight-line distance g is 1.2 mm.

3. The ultrasonic sensor according to claim 1, wherein The ultrasonic sensor further comprises an acoustic layer (15), wherein the acoustic layer (15) is arranged on the upper surface of the substrate (11), the acoustic layer (15) comprises a piezoelectric layer (151), an upper electrode (152) arranged on the upper surface of the piezoelectric layer (151), and a lower electrode (153) arranged on the lower surface of the piezoelectric layer (151), wherein the lower electrode (153) is arranged on the upper surface of the substrate (11), and the area of the substrate (11) where the lower electrode (153) is located is referred to as an effective identification area (111).

4. The ultrasonic sensor according to claim 1, wherein The pad portion (12) includes a plurality of pads (13) spaced apart along the width direction of the ultrasonic sensor (1).

5. The ultrasonic sensor (1) according to claim 4, wherein The area of the pad (13) is 8000um 2 -50000um 2 . The ultrasonic sensor according to claim 5 , wherein: Each of the soldering pads (13) includes a plurality of first soldering pads (14) spaced apart along the width direction of the ultrasonic sensor (1).

7. The ultrasonic sensor according to claim 6, wherein: The total area of all the first pads (14) in each of the pads (13) is 8000 μm. 2 -50000um 2 .

8. The ultrasonic sensor according to claim 1, wherein The substrate (11) of the ultrasonic sensor (1) is a silicon-based substrate or a glass substrate.

9. An ultrasonic fingerprint module, comprising the ultrasonic sensor (1) and a flexible circuit board (2) according to any one of claims 1 to 8, wherein: The pad portion (12) of the ultrasonic sensor (1) is electrically connected to the electrical connection area of the flexible circuit board (2), and the flexible circuit board (2) is used to connect to an external circuit.

10. The ultrasonic fingerprint module according to claim 9, wherein: The pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2) are electrically connected via ACF glue (6) using an ACF lamination process.

11. The ultrasonic fingerprint module according to claim 10, wherein: When the pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2) are pressed together using an ACF pressing process with an ACF glue (6), the pressing pressure is 10N-100N, and the pressing temperature of the area where the ACF glue (6) is located is 110°C-160°C.

12. The ultrasonic fingerprint module according to claim 10, wherein: When the pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2) are pressed together using an ACF pressing process with an ACF glue (6), the pressing pressure is 25N, and the pressing temperature of the area where the ACF glue (6) is located is 148°C.

13. The ultrasonic fingerprint module according to claim 10, wherein: When the pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2) are pressed together using an ACF pressing process with an ACF glue (6), the pressing head (41) of the ACF pressing machine (4) completely or partially covers the pad portion (12) in the length direction of the pad portion (12).

14. The method for manufacturing an ultrasonic fingerprint module according to claim 10, wherein: When the pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2) are pressed together using an ACF pressing process with an ACF glue (6), a third straight line distance k from a pressing head (41) of an ACF pressing machine (4) to an edge of an effective identification area (111) of the ultrasonic sensor (1) parallel to and close to the pad portion (12) is within the range of 0.7 mm ≤ k < 2.5 mm.

15. The method for manufacturing an ultrasonic fingerprint module according to claim 14, wherein: The third straight-line distance k is 1.2 mm.

16. The ultrasonic fingerprint module according to claim 10, wherein: When the pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2) are pressed together using an ACF pressing process with an ACF glue (6), the length n of the projection of the pressure head (41) of the ACF pressing machine (4) on the ultrasonic sensor (1) is 0.2 mm to 1 mm.

17. The ultrasonic fingerprint module according to claim 16, wherein: The length n of the projection of the pressure head (41) of the ACF pressing machine (4) on the ultrasonic sensor (1) is 0.3 mm.

18. A method for manufacturing an ultrasonic fingerprint module, wherein the ultrasonic fingerprint module is the ultrasonic fingerprint module according to claims 9 to 17, wherein: The method comprises: An ultrasonic sensor (1) is placed on a back support (3), an ACF glue (6) is provided between the pad portion (12) of the ultrasonic sensor (1) and the electrical connection area of the flexible circuit board (2), and an ACF pressing machine (4) is used to press the two to achieve electrical connection. The pressing pressure is 10N-100N, the pressing temperature of the area where the ACF glue (6) is located is 110°C-160°C, and the temperature of the backing (3) is 50°C-130°C.

19. The method for manufacturing an ultrasonic fingerprint module according to claim 18, wherein: The pressing pressure of the ACF pressing machine (4) is 25N, the pressing temperature of the area where the ACF glue (6) is located is 148°C, and the temperature of the backing (3) is 120°C.

20. The method for manufacturing an ultrasonic fingerprint module according to claim 18, wherein: When the ACF pressing machine (4) is pressed, the pressing head (41) of the ACF pressing machine (4) completely covers or partially covers the pad portion (12) in the length direction of the pad portion (12).

21. The method for manufacturing an ultrasonic fingerprint module according to claim 18, wherein: When the ACF pressing machine (4) is pressed, a third straight line distance k from the pressing head (41) of the ACF pressing machine (4) to an edge of the effective identification area (111) of the ultrasonic sensor (1) parallel to and close to the pad portion (12) is in the range of: 0.7 mm ≤ k < 2.5 mm.

22. The method for manufacturing an ultrasonic fingerprint module according to claim 21, wherein: When the ACF pressing machine (4) is pressed, the third straight line distance k is 1.2 mm.

23. The method for manufacturing an ultrasonic fingerprint module according to claim 18, wherein: When the ACF pressing machine (4) is pressed, the length n of the projection of the pressing head (41) of the ACF pressing machine (4) on the ultrasonic sensor (1) is 0.2 mm to 1 mm.

24. The method for manufacturing an ultrasonic fingerprint module according to claim 23, wherein: The length n of the projection of the pressure head (41) of the ACF pressing machine (4) on the ultrasonic sensor (1) is 0.3 mm.

25. An electronic device, wherein: An ultrasonic fingerprint module comprising the ultrasonic sensor (1) according to any one of claims 1 to 8, or the ultrasonic fingerprint module according to any one of claims 9 to 17, or the ultrasonic fingerprint module manufactured by the manufacturing method of the ultrasonic fingerprint module according to any one of claims 18 to 24.

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