Fingerprint module and electronic device

Abstract

The application provides a fingerprint module and an electronic device. The fingerprint module comprises an ultrasonic sensor and a circuit board; the ultrasonic sensor comprises a first electrode layer, an acoustic layer and a first electrical connection area, the first electrode layer is electrically connected to a first side of the acoustic layer along a thickness direction, the first electrode layer is electrically connected to the first electrical connection area, and the acoustic layer is used for emitting an ultrasonic signal and receiving an ultrasonic signal reflected back by an external structure; a second electrode layer of the circuit board is electrically connected to a second side of the acoustic layer along the thickness direction through a first conductive adhesive layer, the second electrode layer is electrically connected to a second electrical connection area, the first electrical connection area is electrically connected to the second electrical connection area through a second conductive adhesive layer, and the first electrode layer and the second electrode layer are used for providing a voltage for the acoustic layer to emit and receive the ultrasonic signal; the ultrasonic sensor is used for processing the received ultrasonic signal into an electrical signal and sending the electrical signal to a processing unit, so that the processing unit performs fingerprint identification based on the electrical signal.

Description

Technical Field

[0001] This application relates to the field of fingerprint module technology, and more particularly to a fingerprint module and electronic device. Background Technology

[0002] With the development of the consumer electronics industry, including but not limited to the trend of full-screen displays in mobile communication devices, consumer demand for under-display fingerprint recognition technology is constantly increasing. There are two main publicly disclosed under-display fingerprint recognition solutions: optical and ultrasonic. The performance of optical fingerprint modules is significantly affected by the screen's light transmittance. With the increasing complexity of internal wiring in displays and the development of flexible screen solutions, the screen's optical transmittance has decreased, rendering optical fingerprint solutions inadequate for application requirements. Ultrasonic fingerprint modules, however, do not depend on the screen's optical transmittance, making them a better alternative. However, ultrasonic fingerprint modules are more complex to manufacture, making them difficult to meet application needs. Summary of the Invention

[0003] To address the aforementioned problems, embodiments of this application provide a fingerprint module and electronic device, which at least partially solve the problems mentioned above.

[0004] According to a first aspect of this application, a fingerprint module is provided, comprising:

[0005] An ultrasonic sensor includes: a first electrode layer, an acoustic layer, and a first electrical connection region. The first electrode layer is electrically connected to a first side of the acoustic layer along its thickness direction, and the first electrode layer is electrically connected to the first electrical connection region. The acoustic layer is used to emit ultrasonic signals and receive ultrasonic signals reflected back by an external structure.

[0006] The circuit board includes: a second electrode layer and a second electrical connection region. The second electrode layer is electrically connected to a second side of the acoustic layer along the thickness direction through a first conductive adhesive layer. The second electrode layer is electrically connected to the second electrical connection region. The first electrical connection region is electrically connected to the second electrical connection region through the second conductive adhesive layer. The first electrode layer and the second electrode layer are used to provide the acoustic layer with voltage for transmitting and receiving ultrasonic signals.

[0007] The ultrasonic sensor is electrically connected to the processing unit outside the fingerprint module through the first electrical connection area, the second conductive adhesive layer, and the second electrical connection area. The ultrasonic sensor is used to process the received ultrasonic signal into an electrical signal and send the electrical signal to the processing unit through the circuit board so that the processing unit can perform fingerprint recognition based on the electrical signal.

[0008] In some optional embodiments, the circuit board further includes a circuit board substrate and a first conductive layer, the first conductive layer being disposed on a first side of the circuit board substrate along the thickness direction, the first side of the circuit board substrate along the thickness direction further including a second conductive layer, the second electrode layer being located on the second conductive layer, and the second electrical connection region being located on the first conductive layer.

[0009] In some optional embodiments, the circuit board further includes a third conductive layer disposed on a second side of the circuit board substrate along the thickness direction; at least a portion of the first vertical projection of the third conductive layer toward the circuit board substrate along the thickness direction overlaps with the first conductive layer and does not overlap with the second electrical connection area.

[0010] In some alternative embodiments, the circuit board substrate includes a bent section that is raised relative to the second conductive layer, and the third conductive layer is disposed on the bent section.

[0011] In some optional embodiments, the circuit board further includes a circuit board substrate and a first conductive layer, the first conductive layer being disposed on a first side of the circuit board substrate along the thickness direction, the first side of the circuit board substrate along the thickness direction further including a void.

[0012] The white area, the second electrode layer is located on the blank area, and the second electrical connection area is located on the first conductive layer.

[0013] In some optional embodiments, the circuit board further includes a third conductive layer disposed on a second side of the circuit board substrate along the thickness direction; at least a portion of the first vertical projection of the third conductive layer toward the circuit board substrate along the thickness direction overlaps with the first conductive layer and does not overlap with the second electrical connection area.

[0014] In some alternative embodiments, the circuit board substrate includes a curved section that is raised relative to the blank area, and the third conductive layer is disposed on the curved section.

[0015] In some optional embodiments, along the thickness direction of the acoustic layer, the second vertical projection of the acoustic layer toward the first conductive adhesive layer is located within the first conductive adhesive layer; the gap d1 between the edge of the second vertical projection and the edge of the first conductive adhesive layer satisfies: d1≥0.2mm.

[0016] In some alternative embodiments, the ultrasonic sensor further includes a sensor substrate, on which the first electrode layer is formed; a first side of the acoustic layer along the thickness direction is attached to the first electrode layer, and the first electrode layer is located within the outer contour of the acoustic layer.

[0017] In some optional embodiments, the ultrasonic sensor further includes a sensor substrate, wherein the distance H between the side of the sensor substrate away from the circuit board and the side of the circuit board away from the sensor substrate along the thickness direction of the acoustic layer satisfies: H < 0.3 mm.

[0018] According to a second aspect of the embodiments of this application, an electronic device is provided, including: a processing unit, a screen, and a fingerprint module as provided in any of the first aspects; the electronic device further includes an adhesive layer, through which the fingerprint module is adhered to the back of the screen.

[0019] In some optional embodiments, the screen is a non-foldable screen, the screen includes a screen substrate and a buffer layer, the buffer layer is mounted on the screen substrate, the buffer layer is used to buffer the screen; the buffer layer has a first opening, the adhesive layer is located in the first opening and is bonded to the screen substrate, and the fingerprint module is bonded to the screen substrate through the adhesive layer.

[0020] In some optional embodiments, the electronic device further includes a first light-shielding structure and a first fixing structure, wherein the first light-shielding structure is used to cover the gap formed between the edge of the adhesive layer and the edge of the first opening, and the first fixing structure is used to fix the edge of the ultrasonic sensor to the adhesive layer; or, the electronic device further includes a second fixing structure, the second fixing structure being used to fix the edge of the ultrasonic sensor to the screen substrate.

[0021] In some alternative embodiments, the screen is a foldable screen, the screen includes a support piece for supporting the screen; the fingerprint module is bonded to the support piece via the adhesive layer.

[0022] In some alternative embodiments, the electronic device further includes a third fixing structure for fixing the edge of the ultrasonic sensor to the adhesive layer; or, the electronic device further includes a fourth fixing structure for fixing the edge of the ultrasonic sensor to the support sheet.

[0023] In summary, the fingerprint module in this embodiment of the application uses a first electrode layer and a second electrode layer to provide voltage for transmitting and receiving ultrasonic signals to the acoustic layer of the ultrasonic sensor. These layers are placed on the ultrasonic sensor and the circuit board, respectively. The first electrode layer and the second electrode layer are electrically connected by a first conductive adhesive layer, and the first electrical connection area and the second electrical connection area are electrically connected by a second conductive adhesive layer. Therefore, when manufacturing the fingerprint module, it is not necessary to fabricate the second electrode layer on the ultrasonic sensor chip. Instead, the second electrode layer can be fabricated on the circuit board. Fabricating the second electrode layer on the circuit board is more convenient and simpler than fabricating it on the ultrasonic sensor chip, thereby reducing the complexity of manufacturing the ultrasonic fingerprint module and making it easier to meet application requirements. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 A schematic diagram of an exemplary fingerprint module according to this application is shown.

[0026] Figure 2A A schematic diagram of an exemplary ultrasonic sensor according to this application is shown.

[0027] Figure 2B A schematic diagram of an exemplary matrix distribution of a plurality of sub-electrodes according to this application is shown.

[0028] Figure 2C A schematic diagram of the first electrical connection region being created by method 1 of this application is shown.

[0029] Figure 2D A schematic diagram of the first electrical connection region being created using method 2 of this application is shown.

[0030] Figure 3A A schematic diagram of the first pad of an exemplary ultrasonic sensor according to this application is shown.

[0031] Figure 3B It shows Figure 3A Enlarged schematic diagram of point Q in the middle.

[0032] Figure 4 A schematic diagram of an exemplary circuit board according to this application is shown.

[0033] Figure 5A schematic diagram of an exemplary double-sided flexible copper-clad laminate according to this application is shown.

[0034] Figure 6 A schematic diagram of another exemplary circuit board according to this application is shown.

[0035] Figure 7 A schematic diagram of an exemplary electronic device according to this application is shown.

[0036] Figure 8 A schematic diagram of another exemplary electronic device according to this application is shown.

[0037] Figure 9 A schematic diagram of an exemplary double-sided tape according to this application is shown.

[0038] Figure 10A A schematic diagram of a fingerprint module and a non-foldable screen according to this application is shown.

[0039] Figure 10B Another schematic diagram of a fingerprint module and a non-foldable screen according to this application is shown.

[0040] Figure 11A A schematic diagram of the fingerprint module of this application with another non-foldable screen is shown.

[0041] Figure 11B Another schematic diagram of the fingerprint module of this application with another non-foldable screen is shown.

[0042] Figure 12A A schematic diagram of a fingerprint module and a foldable screen according to this application is shown.

[0043] Figure 12B Another schematic diagram of a fingerprint module and a foldable screen according to this application is shown.

[0044] Figure 13A A schematic diagram of the fingerprint module of this application with another foldable screen is shown.

[0045] Figure 13B Another schematic diagram of the fingerprint module of this application with another type of foldable screen is shown. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0047] The specific implementation of the fingerprint module and electronic device according to embodiments of this application is described below with reference to the accompanying drawings. It should be noted that, for illustrative purposes, the structures in the following drawings are not necessarily drawn to scale.

[0048] In order to at least partially improve the problems existing in the prior art, a fingerprint module is provided according to a first aspect of this application. Figure 1 A schematic diagram of an exemplary fingerprint module according to this application is shown. (Refer to...) Figure 1 As shown, the fingerprint module 100 includes: an ultrasonic sensor 110 and a circuit board 120; the ultrasonic sensor 110 includes: a first electrode layer 111, an acoustic layer 112, and a first electrical connection area 113, the first electrode layer 111 is electrically connected to a first side of the acoustic layer 112 along the thickness direction, the first electrode layer 112 is electrically connected to the first electrical connection area 113, and the acoustic layer 112 is used to emit ultrasonic signals and receive ultrasonic signals reflected back by external structures; the circuit board 120 includes: a second electrode layer 121 and a second electrical connection area 122, the second electrode layer 121 is electrically connected to a second side of the acoustic layer 112 along the thickness direction through a first conductive adhesive layer 130, the second electrode layer 121 is electrically connected to the second electrical connection area 122, and the first electrical connection area 113 is electrically connected to the second electrical connection area 122 through a second conductive adhesive layer 140.

[0049] Region 122, the first electrode layer 111 and the second electrode layer 121 are used to provide voltage for the acoustic layer 112 to transmit and receive ultrasonic signals; the ultrasonic sensor 110 is electrically connected to the processing unit 210 outside the fingerprint module 100 through the first electrical connection region 113, the second conductive adhesive layer 140 and the second electrical connection region 122. The ultrasonic sensor 110 is used to process the received ultrasonic signals into electrical signals and send the electrical signals to the processing unit 210 through the circuit board 120 so that the processing unit 210 can perform fingerprint recognition based on the electrical signals.

[0050] In the fingerprint module 100 of this application embodiment, a first electrode layer 111 and a second electrode layer 121, which provide voltage for transmitting and receiving ultrasonic signals to the acoustic layer 112 of the ultrasonic sensor 110, are respectively placed on the ultrasonic sensor 110 and the circuit board 120. The first electrode layer 111 and the second electrode layer 121 are electrically connected by a first conductive adhesive layer 130, and the first electrical connection area 113 and the second electrical connection area 122 are electrically connected by a second conductive adhesive layer 140. Therefore, when manufacturing the fingerprint module 100, it is not necessary to fabricate the second electrode layer 121 on the ultrasonic sensor 110 chip, but the second electrode layer 121 can be fabricated on the circuit board 120. Fabricating the second electrode layer 121 on the circuit board 120 is more convenient and simpler than fabricating the second electrode layer 121 on the ultrasonic sensor 110 chip, thereby improving the complexity of manufacturing the ultrasonic fingerprint module and making it easier to meet application requirements.

[0051] Furthermore, when fabricating the second electrode layer 121 on the circuit board 120, it is easier to fabricate the second electrode layer 121 with a uniform thickness, thereby better ensuring the fabrication efficiency of the fingerprint module 100 and making it easier to ensure the performance of the fingerprint module 100.

[0052] The fingerprint module 100 and electronic device 200 of this application are described in detail below. It should be understood that the following description is not intended to limit this application.

[0053] Optionally, the fingerprint module 100 can be installed on an electronic device 200 during use. This application does not limit the type of electronic device 200; the electronic device 200 can be, but is not limited to, a mobile phone, a tablet, or other electronic devices requiring fingerprint recognition functionality. The processing unit can be any external processing unit to the fingerprint module 100. Optionally, the processing unit can be the processing unit 210 within the electronic device 200. The electronic device 200 of this application will be described in detail below, and will not be repeated here.

[0054] In this application, the acoustic layer 112 is used to transmit ultrasonic signals and receive ultrasonic signals reflected back by an external structure. Optionally, the external structure can be a user's finger (see reference). Figure 8 (In the example shown, the finger is indicated by the symbol 300). For example, in one application scenario, the fingerprint module 100 is used for under-display fingerprint recognition. The user touches a specific area of ​​the screen with their finger 300. The acoustic layer 112 of the ultrasonic sensor 110 of the fingerprint module 100 emits an ultrasonic signal. The user's finger 300 reflects at least a portion of the ultrasonic signal, and the acoustic layer 112 receives the ultrasonic signal reflected back by the user's finger 300.

[0055] In this application, the ultrasonic sensor 110 can process the received ultrasonic signal into an electrical signal. Optionally, the ultrasonic sensor 110 may include a sensor substrate 114, on which an ultrasonic signal processing circuit is formed, which can process the received ultrasonic signal into an electrical signal. The ultrasonic signal processing circuit can adopt any existing technical solution or other innovative technical solutions, and this application does not limit it. After the ultrasonic sensor 110 processes the received ultrasonic signal into an electrical signal, the electrical signal can be sent to the processing unit 210 outside the fingerprint module 100 through the circuit board 120, so that the processing unit 210 can perform fingerprint recognition based on the electrical signal.

[0056] Optionally, the sensor substrate 114 can be a silicon-based substrate or a substrate of other materials, and this application does not impose any limitations on it. For the sake of illustrating this embodiment, the sensor substrate 114 will be used as an example of a silicon-based substrate in the following description.

[0057] In this application, the circuit board 120 can be used for wiring. For example, the circuit board 120 can be provided with electrical connection lines. The second electrical connection area 112 can be electrically connected to the processing unit outside the fingerprint module 100 through the electrical connection lines. Based on this, the ultrasonic sensor 110 can be electrically connected to the processing unit outside the fingerprint module 100 through the first electrical connection area 113, the second conductive adhesive layer 140, and the second electrical connection area 122. After the ultrasonic sensor 110 processes the received ultrasonic signal into an electrical signal, it can send the electrical signal to the processing unit 210 outside the fingerprint module 100 through the circuit board 120, so that the processing unit 210 can perform fingerprint processing based on the electrical signal.

[0058] Identification.

[0059] Optionally, the total thickness of the ultrasonic sensor 110 in this application can be within the following range: 80µm to 200µm. The total thickness of the ultrasonic sensor 110 can be the total thickness of the ultrasonic sensor 110 along the thickness direction of the acoustic layer 112. The total thickness of the ultrasonic sensor 110 meeting the above range can better match the performance of the fingerprint module 100 and better match the structural requirements of the electronic device 200 to which the fingerprint module 100 is applied.

[0060] Optionally, the ultrasonic sensor 110 includes a CMOS ultrasonic sensor. Compared to TFT ultrasonic sensors, CMOS ultrasonic sensors offer superior pixel integration, stability, and driving performance. Furthermore, CMOS ultrasonic sensors are manufactured using CMOS technology, allowing for smaller and thinner dimensions that do not occupy excessive space. Therefore, they can simultaneously meet the performance and space requirements of mobile terminals.

[0061] Optionally, the acoustic layer 112 in this application includes a piezoelectric material. By applying a voltage to the piezoelectric material of the acoustic layer 112, and based on the piezoelectric effect of the material, the acoustic layer 112 can emit ultrasonic signals and receive ultrasonic signals reflected back from external structures. Optionally, the piezoelectric material of the acoustic layer 112 can be a film layer, for example, formed using a coating process. This application does not limit the piezoelectric material; for example, the piezoelectric material can include PVDF (Polyvinylidene fluoride) material, including but not limited to PVDF and its copolymers. Therefore, the acoustic layer 112 in this application includes a PVDF material layer, which can effectively meet the requirements of emitting ultrasonic signals and receiving ultrasonic signals reflected back from external structures.

[0062] In this application, the first electrode layer 111 is electrically connected to a first side of the acoustic layer 112 along its thickness direction, and the second electrode layer 121 is electrically connected to a second side of the acoustic layer 112 along its thickness direction via a first conductive adhesive layer 130. The first electrode layer 111 and the second electrode layer 121 can provide the acoustic layer 112 with a voltage (which can be an AC voltage) for transmitting and receiving ultrasonic signals. Specifically, the first electrode layer 111 and the second electrode layer 121 can be an anode layer and a cathode layer, respectively. For example, in some optional embodiments, the first electrode layer 111 can be the anode layer of the acoustic layer 112, and the second electrode layer 121 can be the cathode layer of the acoustic layer 112. Optionally, the voltage value connected to the first electrode layer 111 is different from the voltage value connected to the second electrode layer 121, thereby forming a voltage difference between the first electrode layer 111 and the second electrode layer 121. This voltage difference can be used as the voltage for the acoustic layer 112 to transmit and receive ultrasonic signals, thus realizing the function of the acoustic layer 112.

[0063] Optionally, the first electrode layer 111 serves as the anode layer of the acoustic layer 112, and is electrically connected to the first electrical connection region 113 and grounded through the first electrical connection region 113; the second electrode layer 121 serves as the cathode layer of the acoustic layer 112, and is electrically connected to the second electrical connection region 122 and connected to an external voltage through the second electrical connection region 122, thereby forming a voltage difference between the first electrode layer 111 and the second electrode layer 121, thereby providing the acoustic layer 112 with a voltage for transmitting and receiving ultrasonic signals.

[0064] In some other alternative embodiments, the second electrode layer 121 may serve as the anode layer of the acoustic layer 112, while the first electrode layer 111 may serve as the cathode layer of the acoustic layer 112. This application does not impose any limitations on this.

[0065] In this application, the first electrode layer 111 is disposed on the ultrasonic sensor 110, and the second electrode layer 121 is disposed on the circuit board 120. The first electrode layer 111 is electrically connected to the second electrode layer 121 through the first conductive adhesive layer 130. Therefore, when manufacturing the fingerprint module 100, it is not necessary to manufacture the second electrode layer 121 on the ultrasonic sensor 110 chip, but the second electrode layer 121 can be manufactured on the circuit board 120. Manufacturing the second electrode layer 121 on the circuit board 120 is more convenient and simpler than manufacturing the second electrode layer 121 on the ultrasonic sensor 110 chip, thereby improving the complexity of manufacturing the ultrasonic fingerprint module and making it easier to meet application requirements.

[0066] In some alternative embodiments, refer to Figure 1 and Figure 2A As shown, the ultrasonic sensor 110 of the fingerprint module 100 further includes a sensor substrate 114, a first electrode layer 111 formed on the sensor substrate 114; an acoustic layer 112 is attached to the first electrode layer 111 along a first side in the thickness direction, and the first electrode layer 111 is located within the outer contour of the acoustic layer 112. In this application, the base...

[0067] With this structure, the function of the acoustic layer 112 can be guaranteed, and the first electrode layer 111 can form a stable electrical connection with the acoustic layer 112.

[0068] Optionally, the first electrode layer 111 in this application may not be a single unit, but may include multiple sub-electrodes 1111 (the shape, size, number, and spacing between them are not limited in this application), and the multiple sub-electrodes 1111 are distributed in a matrix to form the first electrode layer 111 (for example, see reference). Figure 2B To understand, the dashed box P illustrates an example of multiple sub-electrodes 1111 arranged in a matrix (the dashed box P can be considered the outer contour of the first electrode layer 111). Each sub-electrode 1111 is equivalent to a "pixel." After the acoustic layer 112 receives the ultrasonic signal reflected back by an external structure (e.g., a finger), the voltage signal converted on each sub-electrode 1111 will be different depending on the intensity of the ultrasonic signal. The ultrasonic signal processing circuit of the ultrasonic sensor 100 calculates the voltage signal of each sub-electrode 1111 using an algorithm and sends each voltage signal to the processing unit 210. The processing unit 210 then processes the voltage signals and outputs a fingerprint image for fingerprint recognition. For example, each sub-electrode 1111 can be a metal electrode, such as a copper or silver metal electrode.

[0069] For example, when manufacturing the ultrasonic sensor of the fingerprint module 100, a metal layer (comprising multiple metal electrodes arranged in a matrix, i.e., the aforementioned sub-electrodes 1111) can be first formed in a region of the sensor substrate 114 of the ultrasonic sensor 110 as the first electrode layer 111. Then, an acoustic layer 112 is formed on the first electrode layer 111, such that a first side of the acoustic layer 112 along its thickness direction can adhere to the first electrode layer 114 and form an electrical connection. The outer contour of the acoustic layer 112 can be larger than the outer contour of the first electrode layer 111 (the first electrode layer 111 comprises multiple sub-electrodes 1111 arranged in a matrix, so the outer contour of the first electrode layer 111 can be the outer contour of the smallest circumscribed rectangle of the multiple sub-electrodes 1111). This can be combined with... Figure 2B (The dashed box P is for illustrative purposes only and is not intended to limit the scope of this application.) The first electrode layer 111 is positioned slightly larger than the outer contour of the acoustic layer 112. For example, if the acoustic layer 112 is a PVDF material layer, PVDF material can be coated onto the first electrode layer 111 using a coating process to form the acoustic layer 112. It should be understood that this is merely an example and not intended to limit the scope of the embodiments of this application. In some other alternative embodiments, the first electrode layer 111 may also be a single unit, as long as the requirements are met.

[0070] Optionally, refer to Figure 3A As shown, the ultrasonic sensor 110 in this application has a recognition area AA and a non-recognition area NAA. The recognition area AA is the region on the ultrasonic sensor 110 that can be used for fingerprint recognition. At least a portion of the acoustic layer 112 may be located within the recognition area AA. Optionally, the recognition area AA may include the outer contour region of the first electrode layer 111 (for example, the recognition area AA may have the same position and size as the outer contour region of the first electrode layer 111, for example, combined with...). Figure 2B and Figure 3A As shown, the outer contour area of ​​the first electrode layer 111 is the area outlined by the dashed box P, and the recognition area AA is also outlined by the dashed box. Both are in the same position and size (this should be understood as an example for ease of understanding only and not as a limitation of this application), because fingerprint recognition can be performed within the outer contour area of ​​the first electrode layer 111; the non-recognition area NAA is the area on the ultrasonic sensor 110 that cannot be used for fingerprint recognition, which includes the area other than the recognition area AA (see reference). Figure 3A The area outside the dashed frame of the identification area AA can be considered as the non-identification area NAA. The non-identification area NAA can be used to carry other components of the ultrasonic sensor 110, such as the first electrical connection area 113. The size of the identification area AA is not specifically limited in this application, as long as it meets the requirements.

[0071] In this application, the first conductive adhesive layer 130 can be any conductive adhesive layer structure, such as conductive adhesive. In some optional embodiments, the first conductive adhesive layer 130 includes ACA (Anisotropic Conductive Adhesive) conductive adhesive. ACA conductive adhesive, also known as ACA anisotropic conductive adhesive, is a conductive adhesive with unidirectional (vertical conduction, parallel non-conductivity) conductivity and bonding and fixing functions. Through the ACA conductive adhesive (i.e., the first conductive adhesive layer 130), the second side of the acoustic layer 112 along the thickness direction can achieve a reliable electrical connection with the second electrode layer 121 of the circuit board 120, and the two can achieve electrical connection by pressing, which is very convenient and simplifies the complexity of the fingerprint module 100 manufacturing process, making it easier to meet application requirements.

[0072] In some optional embodiments, along the thickness direction of the acoustic layer 112, the second vertical projection of the acoustic layer 112 toward the first conductive adhesive layer 130 is located within the first conductive adhesive layer 130; the gap d1 between the edge of the second vertical projection and the edge of the first conductive adhesive layer 130 satisfies: d1≥0.2mm.

[0073] Specifically, along the thickness direction of the acoustic layer 112, the second vertical projection of the acoustic layer 112 toward the first conductive adhesive layer 130 is located within the first conductive adhesive layer 130. At this time, the outer contour of the first conductive adhesive layer 130 is larger than the outer contour of the acoustic layer 112, and d1 satisfies the above range (i.e., d1≥0.2mm). Based on this structure, this application can effectively meet the bonding requirements between the acoustic layer 112 and the first conductive adhesive layer 130, and it is more convenient to bond the second side of the acoustic layer 112 along the thickness direction to the first conductive adhesive layer 130 as a whole, so as to realize that the second side of the acoustic layer 112 along the thickness direction and the second electrode layer 121 are electrically connected through the first conductive adhesive layer 130.

[0074] In this application, the second conductive adhesive layer 140 can be any conductive adhesive layer structure, such as conductive adhesive. In some optional embodiments, the second conductive adhesive layer 140 includes an ACF (Anisotropic Conductive Film) conductive film. An ACF conductive film, also known as anisotropic conductive film, is a conductive film with unidirectional (vertically conductive, horizontally non-conductive) conductivity and adhesive bonding function. Through the ACF conductive film (i.e., the second conductive adhesive layer 140), the first electrical connection area 113 of the ultrasonic sensor 110 can achieve a reliable electrical connection with the second electrical connection area 122 of the circuit board 120, and the two can be electrically connected by pressing, which is very convenient and simplifies the manufacturing process of the fingerprint module 100, making it easier to meet application requirements.

[0075] Optionally, when the second conductive adhesive layer 140 in this application is an ACF conductive film, the thickness of the ACF conductive film after being pressed together by the first electrical connection region 113 and the second electrical connection region 122 satisfies the following range: 3µm to 10µm. Within this range, it can better meet the requirements for thinner and lighter fingerprint module 100.

[0076] Optionally, after the first electrical connection region 113 and the second electrical connection region 122 are electrically connected by the second conductive adhesive layer 140 (e.g., ACF conductive film), a protective adhesive 150 can be added to the outside of the second conductive adhesive layer 140 to protect the second conductive adhesive layer 140. For details, please refer to... Figure 1 , Figure 10B , Figure 11B , Figure 12B , Figure 13B As shown.

[0077] Optionally, the circuit board 120 can be an FPC (Flexible Printed Circuit) circuit board. FPC circuit boards have good flexibility and strength, and can meet the circuit routing requirements of the fingerprint module 100, and can adapt to the structural requirements of the fingerprint module 100 within the electronic device 200.

[0078] In this application, a second electrode layer 121 can be fabricated on the circuit board 120. The second electrode layer 121 can be a metal layer, such as a copper layer or a silver layer.

[0079] When fabricating the second electrode layer 121 on the circuit board 120, it is easier to fabricate the second electrode layer 121 with uniform thickness, thereby better ensuring the fabrication efficiency of the fingerprint module 100 and making it easier to ensure the performance of the fingerprint module 100.

[0080] Optionally, taking the second electrode layer 121 as a copper layer as an example, copper can be plated on the surface of the copper layer and OSP (Organic Solderability Preservatives) protection treatment can be applied to improve the oxidation resistance, thermal shock resistance, and moisture resistance of the second electrode layer 121. This application does not limit the thickness of the second electrode layer 121. For example, in some optional embodiments, taking the second electrode layer 121 as a copper layer as an example, the total thickness of the second electrode layer 121 and the copper plating and OSP film thereon can be between 6 μm and 50 μm.

[0081] Optionally, the first electrical connection region 113 in this application is formed on the sensor substrate 114 of the ultrasonic sensor 110, and may be the gold finger region of the ultrasonic sensor 110. The second electrical connection region 122 in this application is formed on the circuit board 120 (e.g., an FPC circuit board), and may be the gold finger region on the circuit board 120. Optionally, referring to... Figure 1 , Figure 3A , Figure 3B As shown, the ultrasonic sensor 110 may further include a pin pad area 115, which is electrically connected to the first electrical connection area 113. Optionally, the pin pad area 115 includes pads for multiple pins of the ultrasonic sensor 110 (hereinafter referred to as pin pad 1151), which are electrically connected to the first electrical connection area 113. The first electrical connection area 113 is then connected to the pin pad area 115 via a second conductive adhesive layer.

[0082] 140 is electrically connected to the second electrical connection area 122. The second electrical connection area 122 can be electrically connected to the external processing unit 210 through an electrical connection line (which can be laid on the circuit board 120), thereby meeting the requirement that the ultrasonic sensor 110 is electrically connected to the external processing unit 210 through the first electrical connection area 113, the second conductive adhesive layer 140 and the second electrical connection area 122.

[0083] In some alternative embodiments, refer to Figure 1 and Figure 3A As shown, the first electrical connection area 113 includes N first pads 1131, and the second electrical connection area 122 includes N second pads (not shown in the figure). Each of the N first pads 1131 is electrically connected to one second pad through a second conductive adhesive layer 140. Different first pads 1131 are electrically connected to different second pads through the second conductive adhesive layer 140, where N ≥ 2 and is an integer. This application achieves the purpose of electrically connecting the first electrical connection area 113 to the second electrical connection area 122 through the second conductive adhesive layer 140 using this structure.

[0084] Furthermore, taking the second conductive adhesive layer 140 as an ACF conductive film as an example, when a whole piece of ACF conductive film is adhered to the second electrical connection area 122, the N first pads 1131 of the first electrical connection area 113 of the ultrasonic sensor 110 can be aligned with the N second pads of the second electrical connection area 122 of the circuit board 120 (or the N second pads of the second electrical connection area 122 of the circuit board 120 can be aligned with the N first pads 1131 of the first electrical connection area 113 of the ultrasonic sensor 110), and then they are pressed together to bond them. The N first pads 1131 and the N second pads are in one-to-one correspondence. Due to the unidirectional conductivity of the ACF conductive film, it can be ensured that each of the N first pads 1131 forms electrical conduction with only one second pad at its corresponding position. Different first pads 1131 and different second pads form electrical connections through the second conductive adhesive layer 140, and there will be no electrical connection error.

[0085] Optionally, refer to Figure 3A and Figure 3B It is understood that the pin pad area 115 may include N pin pads 1151, each of the N pin pads 1151 being electrically connected to a first pad 1131, and different pin pads 1151 being electrically connected to different first pads 1131. This satisfies the requirement that the ultrasonic sensor 110 be electrically connected to the external processing unit 210 through the first electrical connection area 113, the second conductive adhesive layer 140, and the second electrical connection area 122.

[0086] Optionally, a passivation layer 116 can generally be formed on the sensor substrate 114 of the ultrasonic sensor 110 (see reference). Figure 2C and Figure 2D (As shown). Optionally, the first electrical connection area 113 (e.g., including N first pads 1131) can be fabricated in this application using either method 1 or method 2, specifically:

[0087] Method 1: Refer to Figure 2C For example, an RDL (ReDistribution Layer) circuit can be fabricated on the surface of the passivation layer 116 of the sensor substrate 114 of the ultrasonic sensor 110 using an RDL (ReDistribution Layer) process. One end of the RDL circuit is electrically connected to the pin pad 1151 of the pin pad area 115 of the ultrasonic sensor 110 that needs to output a line, and the RDL circuit can form the first pad 1131 of the first electrical connection area 113.

[0088] Method 2: Refer to Figure 2DFor example, during the chip design of the ultrasonic sensor 110, an area for forming N first pads 1131 for forming the first electrical connection area 113 can be pre-added below the pin pads 1151 of the pin pad area 115 of the ultrasonic sensor 110 (which can be understood as appropriately designing the pin pads 1151 to be larger), and a window is opened on the surface of the passivation layer 116 of the sensor substrate 114 of the ultrasonic sensor 110 to expose the area. Then, a conductive layer of appropriate thickness is set on the area (the way of setting the conductive layer is not limited here, for example, it can be achieved by plating an Au layer, etc.) to form the first pads 1131 of the first electrical connection area 113.

[0089] Both methods can be used to create a first electrical connection region 113 including N first pads 1131, and the choice can be made as needed; this application does not impose any restrictions on this method. Of course, other methods can also be used to create a first electrical connection region 113 including N first pads 1131, and this application does not impose any restrictions on these methods either.

[0090] Alternatively, a second electrical connection area 122 (e.g., including N second pads) can be fabricated on the circuit board 120, which can also be done with reference to the aforementioned methods 1 and 2. The implementation process and principle are quite similar, so they will not be described in detail here.

[0091] In some alternative embodiments, refer to Figure 3A and Figure 3B As shown, each pair of adjacent first pads 1131 in the N first pads

[0092] The distance d2 between the center lines of pad 1131 satisfies: 50µm ≤ d2 ≤ 200µm. (Refer to...) Figure 3A and Figure 3B As shown, the first pad 1131 in this example is approximately rectangular in shape, and the centerline of the first pad 1131 is the line connecting the midpoints of the top and bottom sides of the rectangle. In this application, the distance d2 between the centerlines of every two adjacent first pads 1131 in the N first pads 1131 satisfies the above-mentioned value range, which can meet the signal transmission performance of the fingerprint module and has good heat dissipation. When using ACF conductive adhesive film as the second conductive adhesive layer 140, it can better ensure the consistent curing effect of ACF adhesive and the uniform bursting of conductive particles in ACF adhesive.

[0093] Optionally, the distance between the centerlines of any two adjacent second pads in the N second pads satisfies a range of 50µm to 200µm, to accommodate the requirement that the N first pads 1131 and the N second pads are electrically connected via a second conductive adhesive layer 140 (e.g., ACF conductive film). It should be understood that although the second pads are not shown in the figure, they can be combined with... Figure 3A and Figure 3B To understand.

[0094] Optionally, refer to Figure 3A and Figure 3B As shown, the width W of the electrical connection area between the first pad 1131 and the pin pad 1151 satisfies: W ≥ 0.03 mm. Optionally, the length L of the electrical connection area between the first pad 1131 and the pin pad 1151 satisfies: L ≥ 0.01 mm. Optionally, the distance T between the bottom edge of the electrical connection area between the first pad 1131 and the pin pad 1151 and the bottom edge of the sensor substrate 114 satisfies: T ≥ 0.01 mm. These value ranges can better ensure the stability of the electrical connection between the first pad 1131 and the pin pad 1151, meet the signal transmission performance requirements of the fingerprint module, and provide good heat dissipation capabilities.

[0095] In some optional embodiments, a conductive plating layer is provided on the surface of the first pad 1131, and / or, a conductive plating layer is provided on the surface of the second pad. Optionally, the conductive plating layer can be fabricated as a conductive thin film. The reason for additionally providing a conductive plating layer on the first pad 1131 and / or the second pad in this application is that during the fabrication of the first pad 1131 / second pad, under the influence of certain manufacturing processes, the first pad 1131 / second pad will have a certain degree of depression (for example, a depression of 1um to 2um). Therefore, the additional provision of a conductive plating layer on the first pad 1131 and / or the second pad in this application is beneficial for protecting the first pad 1131 and / or the second pad, and can raise the depression on the first pad 1131 and / or the second pad, so as to better meet the needs of the first pad 1131 and the second pad being electrically connected through the second conductive adhesive layer 140 (e.g., ACF conductive film).

[0096] This application does not limit the material of the conductive plating layer, as long as it meets the requirements. Optionally, the conductive plating layer includes at least one of ITO (Indium Tin Oxides), Ti plating (i.e., titanium plating), Ni plating (i.e., nickel plating), Ag plating (i.e., silver plating), and Au plating (i.e., gold plating). These types of conductive plating layers can conduct electricity well and better meet the process requirements of the first pad 1131 and the second pad being electrically connected through the second conductive adhesive layer 140 (e.g., ACF conductive film).

[0097] In some alternative embodiments, refer to Figure 4As shown, the circuit board 120 also includes a circuit board substrate 123 and a first conductive layer 124. The first conductive layer 124 is disposed on a first side of the circuit board substrate 123 along the thickness direction. The first side of the circuit board substrate 123 along the thickness direction also includes a second conductive layer 125. A second electrode layer 121 is located on the second conductive layer 125, and a second electrical connection area 122 is located on the first conductive layer 124. With this structure, the second electrode layer 121 and the second electrical connection area 122 of the circuit board 120 can both be located on the same side of the circuit board substrate 123. Thus, even if the second side of the circuit board substrate 123 along the thickness direction is not provided with a conductive layer, it will not affect the circuit connection between the circuit board 120 and the ultrasonic sensor 110, thereby facilitating the reduction of the thickness of the fingerprint module 100 and meeting the requirements for a thinner and lighter fingerprint module 100.

[0098] This application does not limit the structure of the first conductive layer 124 and the second conductive layer 125, nor does it limit the material of the circuit board substrate 123, but rather takes into account actual needs. For example, the material of the circuit board substrate 123 may be PI material.

[0099] Optionally, taking circuit board 120 as an example, which includes an FPC circuit board, the FPC circuit board may be fabricated based on a double-sided flexible copper clad laminate (FCCL). For example, Figure 5 A schematic diagram of an exemplary double-sided flexible copper-clad laminate according to this application is shown, with reference to... Figure 5 As shown, the double-sided flexible copper-clad laminate may include a first copper foil layer 1271, a first copper plating layer 1273, a substrate layer 1270, a second copper foil layer 1272, and a second copper plating layer 1274, which are stacked sequentially along the thickness direction.

[0100] Furthermore, the double-sided flexible copper-clad laminate may include a first cover film layer 1275 and a second cover film layer 1276 for protection, with the first cover film layer 1275 located above the first copper plating layer 1273 and the second cover film layer 1276 located below the second copper plating layer 1274. Optionally, the substrate layer 1270 may be made of PI material.

[0101] Optionally, refer to Figure 4As shown, in this application, the substrate layer 1270 of the double-sided flexible copper-clad laminate can be used as the circuit board substrate 123. The first portion of the combination layer of the first copper foil layer 1271 and the first copper plating layer 1273 on the first side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction is used as the first conductive layer 124 (a portion of the first cover film layer 1275 can also be removed). The second portion of the combination layer of the first copper foil layer and the first copper plating layer on the first side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction is used as the second conductive layer 125 (a portion of the first cover film layer 1275 can also be removed). Furthermore, the electrical... At least a portion of the combined layer of the second copper foil layer 1272, the second copper plating layer 1274, and the second cover film layer 1276 on the second side of the circuit board substrate 123 (i.e., the conductive layer is not provided in at least a portion of the area on the second side of the circuit board substrate 123 along the thickness direction (of course, it can be completely removed, i.e., no conductive layer is provided on the second side of the circuit board substrate 123 along the thickness direction)); then a second electrode layer 121 (e.g., a silver layer or a copper layer) is formed on the second conductive layer 125, and a second electrical connection area 122 (e.g., including N second pads) is formed on the first conductive layer 124. With this structure, even if the circuit board substrate 123 of the circuit board 120 is not provided with a conductive layer on the second side of the thickness direction, the circuit connection between the circuit board 120 and the ultrasonic sensor 110 is not affected. Obviously, the thickness of the circuit board 120 (e.g., the circuit board of an FPC) can be reduced, thereby facilitating the reduction of the thickness of the fingerprint module 100 and meeting the demand for a thinner and lighter fingerprint module 100.

[0102] Optionally, on the first side of the circuit board 120 along the thickness direction, a certain distance may exist between the second conductive layer 125 and the first conductive layer 124. Optionally, a portion of the combined layer between the first and second portions of the aforementioned first copper foil layer and first copper plating layer can be removed to expose a portion of the circuit board substrate 123 (i.e., the substrate layer 1270), thereby creating a distance between the second conductive layer 125 and the first conductive layer 124 (which can be combined). Figure 4 (For clarification, please refer to the diagram).

[0103] In some alternative embodiments, refer to Figure 4As shown, the circuit board 120 also includes a third conductive layer 126, which is disposed on the second side of the circuit board substrate 123 along the thickness direction. At least a portion of the first vertical projection of the third conductive layer 126 toward the circuit board substrate 123 along the thickness direction overlaps with the first conductive layer 124, but does not overlap with the second electrical connection area 122. With this structure, the third conductive layer 126 can be used for wiring, allowing the circuit board 120 to route traces through both the first conductive layer 124 and the third conductive layer 126, thus meeting the double-sided routing requirements of the fingerprint module 100 when routing traces to the outside.

[0104] This application does not limit the structure of the third conductive layer 126, but rather adapts to meet actual needs. Optionally, taking the example in the aforementioned embodiment, "at least a portion of the combined layer of the second copper foil layer 1272, the second copper plating layer 1274, and the second cover film layer 1276 on the second side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction can be removed," that is, in this application, a portion of the combined layer of the second copper foil layer 1272, the second copper plating layer 1274, and the second cover film layer 1276 on the second side of the circuit board substrate 123 (i.e., the substrate layer) along the thickness direction can be retained, and this retained portion can be used as the third conductive layer 126. Along the thickness direction of the circuit board substrate 123, at least a portion of the first vertical projection of the third conductive layer 126 toward the circuit board substrate 123 overlaps with the first conductive layer 124, but does not overlap with the second electrical connection area 122. With such a structure, the double-sided routing requirement of the fingerprint module 100 when sending out external wiring can obviously be met, and the thickness of the circuit board (e.g., FPC circuit board) will not be too large.

[0105] Optionally, refer to Figure 1 and Figure 4 As shown, the circuit board 120 in this embodiment of the present application can be divided into three sub-regions: a chip bonding area, a lamination area, and a wiring area. The chip bonding area may include a second electrode layer 121, a second conductive layer 125, and the circuit board substrate 123 below it. The acoustic layer 112 of the ultrasonic sensor 110 (e.g., a PVDF piezoelectric material layer) can be electrically connected to the second electrode layer 121 via a first conductive adhesive layer 130 (e.g., ACA conductive adhesive). The lamination area may include a second electrical connection area 122 and the first conductive layer 125 below it.

[0106] The circuit board substrate 123 below layer 124 and the first electrical connection area 113 of the ultrasonic sensor 110 can be electrically connected to the second electrical connection area 122 by pressing it onto the second conductive adhesive layer 140 (e.g., an ACF conductive film). The outgoing area can include the third conductive layer 126 and the circuit board substrate 123 above it, and the first conductive layer 124 above it. The fingerprint module 100 can achieve double-sided routing when outgoing wires through this outgoing area. It should be understood that such division is only for the purpose of explaining the embodiments of this application and is not intended to limit the application in any way.

[0107] In some alternative embodiments, refer to Figure 1 and Figure 4 As shown, the circuit board substrate 123 includes a bent section 1231, which is protruding relative to the second conductive layer 125, and a third conductive layer 126 is disposed on the bent section 1231.

[0108] Because the curved section 1231 of the circuit board substrate 123 is convex relative to the second conductive layer 125, the third conductive layer 126 is disposed on the curved section 1231, so that the third conductive layer 126 does not additionally increase the thickness of the fingerprint module 100 (see reference). Figure 1 and Figure 4 As shown, along the thickness direction of the circuit board substrate 123, the third conductive layer 126 is located above the second conductive layer 125 (without adding extra thickness to the fingerprint module 100), thereby meeting the requirement of double-sided wiring while better adapting to the requirement of a thinner and lighter fingerprint module 100.

[0109] In some alternative embodiments, refer to Figure 6 As shown, the circuit board 120 also includes a circuit board substrate 123 and a first conductive layer 124. The first conductive layer 124 is disposed on a first side of the circuit board substrate 123 along the thickness direction. The first side of the circuit board substrate 123 along the thickness direction also includes a blank area 127. A second electrode layer 121 is located on the blank area 127, and a second electrical connection area 122 is located on the first conductive layer 124. With this structure, the second electrode layer 121 and the second electrical connection area 122 of the circuit board 120 can both be located on the same side of the circuit board substrate 123. Thus, even if the second side of the circuit board substrate 123 along the thickness direction is not provided with a conductive layer, it will not affect the circuit connection between the circuit board 120 and the ultrasonic sensor 110, thereby facilitating the reduction of the thickness of the fingerprint module 100 and meeting the requirements for a thinner and lighter fingerprint module 100.

[0110] This application does not limit the structure of the first conductive layer 124, nor does it limit the material of the circuit board substrate 123, but rather takes into account actual needs. For example, the material of the circuit board substrate 123 may be PI material.

[0111] Optionally, taking circuit board 120 as an example, which includes an FPC circuit board, the FPC circuit board may be fabricated based on a double-sided flexible copper clad laminate (FCCL). For example, refer to Figure 5 As shown, the double-sided flexible copper-clad laminate may include a first copper foil layer 1271, a first immersion copper layer 1273, a substrate layer 1270, a second copper foil layer 1272, and a second immersion copper layer 1274, stacked sequentially along the thickness direction. Furthermore, the double-sided flexible copper-clad laminate may include a first cover film layer 1275 and a second cover film layer 1276 for protection, with the first cover film layer 1275 located above the first immersion copper layer 1273 and the second cover film layer 1276 located below the second immersion copper layer 1274. Optionally, the substrate layer 1270 may be made of PI material.

[0112] Optionally, refer to Figure 6 As shown, in this application, the substrate layer of the double-sided flexible copper-clad laminate can be used as the circuit board substrate 123. The first portion of the combination layer of the first copper foil layer and the first copper plating layer on the first side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction is used as the first conductive layer 124 (or a portion of the first cover film layer 1275 can be removed). Then, the second portion of the combination layer of the first copper foil layer 1271 and the first copper plating layer 1273 on the first side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction is removed, so that the circuit board substrate 123 (i.e., the substrate layer 1270) below the second portion is exposed to form a blank area 127. Furthermore, at least a portion of the combined layer of the second copper foil layer 1272, the second copper plating layer 1274, and the second cover film layer 1276 on the second side of the circuit board substrate 123 (i.e., the conductive layer is not provided in at least a portion of the area on the second side of the circuit board substrate 123 along the thickness direction (of course, it can be completely removed, i.e., no conductive layer is provided on the second side of the circuit board substrate 123 along the thickness direction) can be removed; then a second electrode layer 121 (e.g., a silver layer or a copper layer) can be formed on the blank area 127, and a second electrical connection area 122 (e.g., including N second pads) can be formed on the first conductive layer 124. With such a structure, even if the circuit board substrate 123 of the circuit board 120 is not provided with a conductive layer on the second side of the thickness direction, the circuit connection between the circuit board 120 and the ultrasonic sensor 110 is not affected. Obviously, the thickness of the circuit board 120 (e.g., the circuit board of an FPC) can be reduced, thereby facilitating the reduction of the thickness of the fingerprint module 100 and meeting the demand for a thinner and lighter fingerprint module 100.

[0113] Optionally, on the first side of the circuit board 120 along the thickness direction, there may be a certain distance between the second electrode layer 121 and the first conductive layer 124 (which can be combined). Figure 6 (For clarification, please refer to the diagram).

[0114] In some alternative embodiments, refer to Figure 6 As shown, the circuit board 120 also includes a third conductive layer 126, which is disposed on the second side of the circuit board substrate 123 along the thickness direction. At least a portion of the first vertical projection of the third conductive layer 126 toward the circuit board substrate 123 along the thickness direction overlaps with the first conductive layer 124, but does not overlap with the second electrical connection area 122. With this structure, the third conductive layer 126 can be used for wiring, allowing the circuit board 120 to route traces through both the first conductive layer 124 and the third conductive layer 126, thus meeting the double-sided routing requirements of the fingerprint module 100 when routing traces to the outside.

[0115] This application does not limit the structure of the third conductive layer 126, but rather adapts to meet actual needs. Optionally, taking the example in the aforementioned embodiment, "at least a portion of the combined layer of the second copper foil layer 1272, the second copper plating layer 1274, and the second cover film layer 1276 on the second side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction can be removed," that is, in this application, a portion of the combined layer of the second copper foil layer 1272, the second copper plating layer 1274, and the second cover film layer 1276 on the second side of the circuit board substrate 123 (i.e., the substrate layer 1270) along the thickness direction can be retained, and this retained portion can be used as the third conductive layer 126. Along the thickness direction of the circuit board substrate 123, at least a portion of the first vertical projection of the third conductive layer 126 toward the circuit board substrate 123 overlaps with the first conductive layer 124, but does not overlap with the second electrical connection area 122. With such a structure, the double-sided routing requirement of the fingerprint module 100 when sending out external wiring can obviously be met, and the thickness of the circuit board 120 (e.g., an FPC circuit board) will not be too large.

[0116] Optionally, refer to Figure 6As shown, the circuit board 120 in this embodiment of the present application can be divided into three sub-regions: a chip bonding area, a lamination area, and a wiring area. The chip bonding area may include the second electrode layer 121 and the portion of the circuit board substrate 123 below it (it is easy to understand that this portion of the circuit board substrate 123 forms the aforementioned blank area 127). The acoustic layer 112 of the ultrasonic sensor 110 (e.g., a PVDF piezoelectric material layer) can be electrically connected to the second electrode layer 121 through the first conductive adhesive layer 130 (e.g., ACA conductive adhesive). The pressing area may include a second electrical connection area 122, a first conductive layer 124 below it, and a circuit board substrate 123 below it. The first electrical connection area 113 of the ultrasonic sensor 110 can be pressed onto the second conductive adhesive layer 140 (e.g., an ACF conductive film) to form an electrical connection with the second electrical connection area 122. The wire exit area may include a third conductive layer 126, a circuit board substrate 123 above it, and a first conductive layer 124 above it. The fingerprint module 100 can achieve double-sided wiring when exiting to the outside through this wire exit area. It should be understood that such division is only for the purpose of explaining the embodiments of this application and is not intended to limit the application in any way.

[0117] In some alternative embodiments, refer to Figure 6 As shown, the circuit board substrate 123 includes a bent section 1231, which is raised relative to the blank area 127, and a third conductive layer 126 is disposed on the bent section 1231.

[0118] Because the curved section 1231 of the circuit board substrate 123 is convex relative to the blank area 127, the third conductive layer 126 is disposed on the curved section 1231, so that the third conductive layer 126 does not additionally increase the thickness of the fingerprint module 100 (see reference). Figure 6 As shown, along the thickness direction of the circuit board substrate 123, the third conductive layer 126 is located above the blank area 127 (without adding extra thickness to the fingerprint module 100), thereby meeting the requirement of double-sided wiring while better adapting to the requirement of a thinner and lighter fingerprint module 100.

[0119] In some optional embodiments, the fingerprint module 100 may further include a reinforcing structure (not shown in the figure). The reinforcing structure may be disposed on a first side and / or a second side of the circuit board substrate 123 of the circuit board 120 along the thickness direction, for reinforcing the strength of the second conductive adhesive layer 140 between the first electrical connection area 113 and the second electrical connection area 122. This application, through the reinforcing structure, can strengthen the strength of the second conductive adhesive layer 140, improving the stability of the electrical connection formed by the bonding of the first electrical connection area 113 and the second electrical connection area 122 through the second conductive adhesive layer 140. Optionally, the reinforcing structure may include a reinforcing plate disposed on a first side and / or a second side of the circuit board substrate 123 of the circuit board 120 along the thickness direction. Optionally, the reinforcing plate may be a metal plate, such as a reinforcing steel plate, a reinforcing copper plate, etc.

[0120] In some optional embodiments, along the thickness direction of the acoustic layer 112, the distance H between the side of the sensor substrate 114 away from the circuit board 120 and the side of the circuit board 120 away from the sensor substrate 114 satisfies: H < 0.3 mm. The distance H in this application can be considered as the thickness of the fingerprint module 100, which satisfies the above-mentioned value range, thus meeting the requirements for a thinner and lighter fingerprint module 100 and matching its performance requirements.

[0121] It is understood that the above embodiments are merely examples of fingerprint module 100 in the embodiments of this application, and are not any limitation on fingerprint module 100 in the embodiments of this application.

[0122] The electronic device provided in the second aspect of this application will now be described in detail. Figure 7 A schematic diagram of an exemplary electronic device 200 according to this application is shown. The electronic device 200 includes a processing unit 210 and a fingerprint module 100 provided in the first aspect of this application. Specifically, the processing unit 210 can be the "processing unit outside the fingerprint module" in the aforementioned fingerprint module embodiments, which is capable of receiving electrical signals generated from ultrasonic signals received by the ultrasonic sensor 110 of the fingerprint module 100 and performing fingerprint recognition based on these electrical signals. The processing unit 210 may include at least one chip capable of data processing, such as a CPU, GPU, MCU, DSP, FPGA, etc.

[0123] Optionally, when performing fingerprint recognition based on the electrical signal, the processing unit 210 in this application can process the electrical signal through an image processing circuit and / or an image processing algorithm to generate a fingerprint image, and perform fingerprint recognition based on the fingerprint image.

[0124] This application does not limit the type of electronic device 200. The electronic device 200 may include, but is not limited to, mobile phones, PADs, etc., or other electronic devices that require fingerprint recognition function, such as fingerprint locks.

[0125] This application does not limit the placement of the fingerprint module 100 on the electronic device 200; it can be placed in any suitable location as needed. Optionally, the electronic device 200 may include a screen 220, with the fingerprint module 100 located below the screen 220. By placing the fingerprint module 100 below the screen 220, this application can realize under-display fingerprint recognition functionality. For example, under-display fingerprint recognition can be used for under-display fingerprint unlocking and under-display fingerprint payment functions of the electronic device 200 (including but not limited to mobile phones).

[0126] The screen 220 in this application can be any type of screen, including but not limited to LCD screens, LED screens, OLED screens, etc. The screen 220 can be a non-foldable screen or a non-foldable screen; this application does not impose any restrictions.

[0127] It is understandable that screen 220 includes a front and a back. The front of screen 220 is the side used to display the image. For under-display fingerprint recognition, refer to... Figure 8 As shown, the user can use their finger 300 to register a fingerprint in a specific area on the front of the screen 220; while the back of the screen 220 is the side opposite to the front of the screen 220 and generally does not display an image (for example, if the electronic device 200 is a mobile phone, then the back of the screen 220 is often located inside the phone's casing).

[0128] This application does not limit the installation method of the fingerprint module 100 below the screen 220. For example, in some optional embodiments, refer to... Figure 8 As shown, the electronic device 200 also includes an adhesive layer 230, through which the fingerprint module 100 is adhered to the back of the screen 220. In this application, the adhesive layer 230 ensures that the fingerprint module 100 is adhered to the back of the screen 220, maintaining the installation stability of the fingerprint module 100 on the electronic device 200 and facilitating the use of the fingerprint module 100's functions by the electronic device 200.

[0129] In this application, the adhesive layer 230 can be selected from any adhesive structure. Optionally, the adhesive layer 230 may include double-sided adhesive. Double-sided adhesive can achieve the function of bonding the fingerprint module 100 to the back of the screen 220, and some types of double-sided adhesive can also serve as a buffer and insulation for the fingerprint module 100 and the screen 220 when needed.

[0130] The adhesive layer 230 can be made of any type of double-sided adhesive, and this application does not impose any restrictions. For example, Figure 9A schematic diagram of an exemplary double-sided tape according to this application is shown, with reference to... Figure 9 As shown, in some optional embodiments, the double-sided adhesive (i.e., adhesive layer 230) may include a first double-sided adhesive layer 231, a metal foil layer 232, and a second double-sided adhesive layer 233. The first double-sided adhesive layer 231 is bonded to a first side of the metal foil layer 232 along its thickness direction, and the second double-sided adhesive layer 233 is bonded to the metal foil layer 232 along its thickness direction.

[0131] The second side facing upwards. When using this double-sided adhesive, the side of the first double-sided adhesive layer 231 away from the metal foil layer 232 can be bonded to the back of the screen 220 (i.e., the first double-sided adhesive layer 231 can be a screen-facing double-sided adhesive layer), while the fingerprint module 100 is bonded to the side of the second double-sided adhesive layer 233 away from the metal foil layer 232, thereby allowing the fingerprint module 100 to be bonded to the back of the screen 220 via the double-sided adhesive (i.e., adhesive layer 230). The metal foil layer 232 is located between the first double-sided adhesive layer 231 and the second double-sided adhesive layer 233, which can improve the structural stability of the double-sided adhesive to a certain extent. For example, the metal foil layer 232 can be a copper foil layer, or it can be other metal foil layers that meet the requirements. Optionally, both the first double-sided adhesive layer 231 and the second double-sided adhesive layer 233 can be made by coating adhesive on both sides of the double-sided adhesive substrate, and the double-sided adhesive substrate can include polymer materials, including but not limited to acrylic materials.

[0132] In some alternative embodiments, refer to Figure 10B , Figure 11B , Figure 12B , Figure 13B As shown, the side of the circuit board 120 of the fingerprint module 100 away from the ultrasonic sensor 110 contacts the adhesive layer 230, so that the fingerprint module 100 is bonded to the back of the screen 220 through the adhesive layer 230. This application, through this structure, can effectively bond the fingerprint module 100 to the back of the screen 220 through the adhesive layer 230. Furthermore, according to the principle of coherent superposition of ultrasonic waves and acoustic simulation, the stacking performance of this structure is superior and does not affect the function of the fingerprint module 100. Specifically, the side of the circuit board 120 away from the ultrasonic sensor 110 contacts the adhesive layer 230, thereby bonding the circuit board 120 to the adhesive layer 230, so that the fingerprint module 100 is bonded to the back of the screen 220 through the adhesive layer 230.

[0133] Alternatively, in some other embodiments, the ultrasonic sensor 110 of the fingerprint module 100 contacts the adhesive layer 230, so that the fingerprint module 100 is bonded to the back of the screen 220 through the adhesive layer 230. This application, with such a structure, can also effectively bond the fingerprint module 100 to the back of the screen 220 through the adhesive layer 230. Furthermore, according to the principle of coherent superposition of ultrasonic waves and acoustic simulation, the stacking performance using this structure is superior and does not affect the function of the fingerprint module 100. Specifically, the ultrasonic sensor 110 contacts the adhesive layer 230, thereby bonding the ultrasonic sensor 110 to the adhesive layer 230, so that the fingerprint module 100 is bonded to the back of the screen 220 through the adhesive layer 230.

[0134] It should be understood that both of these optional methods (i.e., the side of the circuit board 120 of the fingerprint module 100 away from the ultrasonic sensor 110 contacts the adhesive layer 230, and the ultrasonic sensor 110 of the fingerprint module 100 contacts the adhesive layer 230) can both achieve the function of attaching the fingerprint module 100 to the back of the screen 220, and neither affects the function of the fingerprint module 100. Therefore, these two methods can be selected as needed to attach the fingerprint module 100 to the back of the screen 220.

[0135] In some alternative implementations, refer to Figure 10A and Figure 10B , Figure 11A and Figure 11B As shown, for the non-foldable screen 220 of the electronic device 200, the screen 220 includes a screen substrate 221 and a buffer layer 222. The buffer layer 222 is mounted on the screen substrate 221 and is used to buffer the screen 220. The buffer layer 222 has a first opening 2221. The adhesive layer 230 is located in the first opening 2221 and is bonded to the screen substrate 221. The fingerprint module 100 is bonded to the screen substrate 221 through the adhesive layer 230.

[0136] Specifically, the buffer layer 222 and the screen substrate 221 can form the back side of the screen 220. The buffer layer 222 cushions the screen 220 (non-folding screen), as the characteristics of a non-folding screen necessitate the cushioning effect of the buffer layer 222 to reduce the impact on the screen 220. The buffer layer 222 can generally be made of an elastic structure. It should be understood that different structures can be selected for the buffer layer 222 for different screens 220, and this application does not impose any limitations. For example, in some embodiments, the buffer layer 222 may include foam, etc.

[0137] Optionally, the buffer layer 222 can be the same color or similar to the first double-sided adhesive layer 231 of the aforementioned adhesive layer 230, so that the electronic device 200 has a better appearance and more aesthetically pleasing display when the first opening 2221 is made in the buffer layer 222. Alternatively, the aforementioned first double-sided adhesive layer 231 (i.e., the screen-attached double-sided adhesive layer) can be black, so that the adhesive layer 230 can provide light-blocking, which can effectively improve the problem of poor screen display caused by the first opening 2221 in the buffer layer 222.

[0138] In this application, a first opening 2221 is formed on the buffer layer 222 used to buffer the screen 220. A portion of the screen substrate 221 is exposed through the first opening 2221. An adhesive layer 230 (e.g., double-sided tape) is bonded to the screen substrate 221 exposed through the first opening 2221. This can reduce the obstruction and absorption effect of the buffer layer 222 on the ultrasonic signals transmitted and received by the ultrasonic sensor 110 of the fingerprint module 100, thereby improving the performance of the fingerprint module 100 and meeting the application requirements of the fingerprint module 100 in an electronic device 200 with a non-folding screen.

[0139] The size and shape of the first opening 2221 may be as required, and this application does not impose any restrictions on them. (See reference...) Figure 10A and Figure 10B , Figure 11A and Figure 11B As shown, the outer contour of the first opening 2221 is larger than the outer contour of the adhesive layer 230, and also larger than the outer contour of the ultrasonic sensor 110 of the fingerprint module 100. Figure 10A and Figure 11A The example shown has the first opening 2221 in the shape of a rounded rectangle, but this is only an example. It can also be made into regular shapes such as rectangles, circles, regular polygons, or irregular shapes.

[0140] In some optional embodiments, the screen 220 of the electronic device 200 is a non-folding screen. The electronic device 200 also includes a first light-shielding structure 240 and a first fixing structure 251, wherein the first light-shielding structure 240 is used to cover the gap formed between the edge of the adhesive layer 230 and the edge of the first opening 2221, and the first fixing structure 251 is used to fix the edge of the ultrasonic sensor 110 to the adhesive layer 230.

[0141] For example, in some exemplary embodiments, reference is made to... Figure 10A and Figure 10BAs shown, in the electronic device 200, the screen 220 is a non-folding screen, the gap d3 between the edge of the adhesive layer 230 and the edge of the first opening 2221 is ≥0.1mm, and along the thickness direction of the acoustic layer 112, the third vertical projection of the ultrasonic sensor 110 toward the adhesive layer 230 is located inside the adhesive layer 230, and the gap d4 between the edge of the third vertical projection and the edge of the adhesive layer 230 is ≥0.5mm. The electronic device 200 also includes a first light-shielding structure 240 and a first fixing structure 251, wherein the first light-shielding structure 240 is used to cover the gap formed between the edge of the adhesive layer 230 and the edge of the first opening 2221, and the first fixing structure 251 is used to fix the edge of the ultrasonic sensor 110 to the adhesive layer 230.

[0142] Specifically, when the gap d3 between the edge of the adhesive layer 230 and the edge of the first opening 2221 is ≥0.1mm, the outer contour of the adhesive layer 230 does not exceed the outer contour of the first opening 2221 (which can be combined with...). Figure 10A and Figure 10B (For understanding purposes only), a portion of the screen substrate 221 of the screen 220 (non-folding screen) can be exposed from the gap formed between the edge of the adhesive layer 230 and the edge of the first opening 2221. The screen 220 may experience light leakage. Therefore, based on this structure, this application addresses this by using a first light-shielding structure 240 to cover the gap formed between the edge of the adhesive layer 230 and the edge of the first opening 2221, thereby improving the adverse effects of light leakage on the display effect of the screen 220 and the appearance of the electronic device 200. Along the thickness direction of the acoustic layer 112, the third vertical projection of the ultrasonic sensor 110 toward the adhesive layer 230 is located within the adhesive layer 230. When the edge of the third vertical projection is... When the gap d4 between the edges of the adhesive layer 230 is ≥0.5mm, the outer contour of the adhesive layer 230 exceeds the outer contour of the ultrasonic sensor 110 by too much. Therefore, based on this structure, this application can, on the other hand, fix the edge of the ultrasonic sensor 110 to the adhesive layer 230 through the first fixing structure 251, thereby improving the stability of the fingerprint module 100 installed on the electronic device 200. Furthermore, because the edge of the ultrasonic sensor 110 is fixed to the adhesive layer 230 by the first fixing structure 251 in this structure, it is easier to remove the fingerprint module 100 from the electronic device 200, and it is less likely to damage the screen 220. It also facilitates the rework and installation of the fingerprint module 100 on the electronic device 200.

[0143] Optionally, the first light-shielding structure 240 can adopt any suitable light-shielding structure, as long as it meets the requirements. For example, the first light-shielding structure 240 may include a light-shielding adhesive. The light-shielding adhesive can be applied to the gap formed between the edge of the adhesive layer 230 and the edge of the first opening 2221, so that the cured light-shielding adhesive covers the gap, thereby achieving the light-shielding function. Optionally, the curing shrinkage rate of the light-shielding adhesive is less than 3%. When the curing shrinkage rate of the light-shielding adhesive is too large, it is easy to exert a pulling force on the screen 220, resulting in poor display effect of the screen 220. In this application, a light-shielding adhesive with a curing shrinkage rate of less than 3% is selected as the first light-shielding structure 240, which can better avoid the problem of poor display effect of the screen 220 caused by the light-shielding adhesive pulling the screen 220. This application does not limit the type of light-shielding adhesive in any way, as long as it meets the requirements. For example, the light-shielding adhesive can be a UV-cured adhesive (e.g., UV-cured adhesive).

[0144] The adhesive is at least one of the following: UV-cured adhesive (i.e., UV-cured adhesive that requires ultraviolet light irradiation), UV-cured adhesive and moisture-cured adhesive, and low-temperature curing adhesive (e.g., low temperature means less than 100°C).

[0145] Optionally, the first fixing structure 251 can be any suitable fixing structure, as long as it meets the requirements. For example, the first fixing structure 251 may include a fixing adhesive, which can be applied to the edge of the ultrasonic sensor 110 and the adhesive layer 230 to fix the edge of the ultrasonic sensor 110 to the adhesive layer 230. Optionally, the curing shrinkage rate of the fixing adhesive is less than 3%. If the curing shrinkage rate of the fixing adhesive is too large, it can easily create a pulling force on the screen 220, resulting in poor display effect of the screen 220. In this application, a fixing adhesive with a curing shrinkage rate of less than 3% is selected as the first fixing structure 251, which can better avoid the problem of poor display effect of the screen 220 caused by the fixing adhesive pulling the screen 220. This application does not limit the type of fixing adhesive, as long as it meets the requirements. For example, the fixing adhesive can be at least one of the following: UV-curing adhesive (e.g., UV glue, i.e., shadowless glue, which needs to be cured by ultraviolet light), UV and moisture-curing adhesive, and low-temperature curing adhesive (e.g., low temperature means less than 100°C).

[0146] Therefore, in some embodiments of this application, the fingerprint module 100 can be installed between screens 220 (non-folding screens) by applying two layers of adhesive (i.e., the aforementioned light-shielding adhesive (i.e., the first light-shielding structure 240) and fixing adhesive (i.e., the first fixing structure 251)), which takes into account both the needs of light shielding and module fixing.

[0147] Alternatively, in some other optional embodiments, the screen 220 of the electronic device 200 is a non-folding screen, and the electronic device 200 further includes a second fixing structure 252 for fixing the edge of the ultrasonic sensor 110 to the screen substrate 221.

[0148] For example, in some exemplary embodiments, reference is made to... Figure 11A and Figure 11B As shown, in the electronic device 200, the screen 220 is a non-foldable screen. Along the thickness direction of the acoustic layer 112, the fourth vertical projection of the ultrasonic sensor 110 toward the screen substrate 221 is located in the first opening 2221. The gap d5 between the edge of the fourth vertical projection and the edge of the first opening 2221 is ≥0.5mm, and the edge of the adhesive layer 230 does not exceed the edge of the adhesive surface on the fingerprint module 100 that is bonded to the adhesive layer 230. The electronic device 200 also includes a second fixing structure 252, which is used to fix the edge of the ultrasonic sensor 110 to the screen substrate 221.

[0149] Specifically, along the thickness direction of the acoustic layer 112, the fourth vertical projection of the ultrasonic sensor 110 toward the screen substrate 221 is located within the first opening 2221, the gap d5 between the edge of the fourth vertical projection and the edge of the first opening 2221 is ≥0.5mm, and the edge of the adhesive layer 230 does not extend beyond the edge of the adhesive surface on the fingerprint module 100 that forms an adhesive bond with the adhesive layer 230 (the adhesive surface on the fingerprint module 100 can be a surface on the circuit board 120 (e.g.)). Figure 11B The circuit board 120 is an FPC circuit board, and the bonding surface is either the surface of the circuit board substrate 123 away from the ultrasonic sensor 110, or it can be the surface of the ultrasonic sensor 110 (for example, the surface of the ultrasonic sensor 110 away from the circuit board 120). In this case, no separate light-shielding structure is set in this application. Instead, the edge of the ultrasonic sensor 110 is directly fixed to the screen substrate 221 by the second fixing structure 252. Based on this structure, on the one hand, the edge of the ultrasonic sensor 110 can be fixed to the screen substrate 221 by the second fixing structure 252, which improves the stability of the fingerprint module 100 installed on the electronic device 200; on the other hand, the second fixing structure 252 can also improve screen light leakage to a certain extent, achieve the effect of light shielding, and improve the adverse effects of screen light leakage on the display effect of the screen 220 and the appearance of the electronic device 200; furthermore, since no separate light-shielding structure is set, the manufacturing process of the electronic device 200 is also simplified.

[0150] Optionally, the second fixing structure 252 can be any suitable fixing structure, as long as it meets the requirements. For example, the second fixing structure 252 may include a fixing adhesive, which can be applied to the edge of the ultrasonic sensor 110 and the screen substrate 221 (for example, the fixing adhesive can be applied to the edge of the first opening 2221) to fix the edge of the ultrasonic sensor 110 to the screen substrate 221. Optionally, the curing shrinkage rate of the fixing adhesive is less than 3%. If the curing shrinkage rate of the fixing adhesive is too large, it can easily create a tensile force on the screen 220, resulting in poor display performance of the screen 220. In this application, the fixing adhesive...

[0151] Using a fixative with a shrinkage rate of less than 3% as the second fixing structure 252 can effectively avoid the problem of poor display effect of the screen 220 caused by the fixative pulling on the screen 220. This application does not limit the type of fixative, as long as it meets the requirements. For example, the fixative can be at least one of the following: UV-curing adhesive (e.g., UV glue, i.e., shadowless glue, which needs to be cured by ultraviolet light), UV and moisture-curing adhesive, and low-temperature curing adhesive (e.g., low temperature means below 100°C).

[0152] Therefore, in some embodiments of this application, the fingerprint module 100 can be installed between screens 220 (non-folding screens) by applying adhesive once (i.e., the aforementioned fixing adhesive (i.e., the second fixing structure 252)), which takes into account both the needs of light shielding and module fixing.

[0153] In some alternative implementations, for the screen 220 of the electronic device 200 to be a foldable screen, refer to Figure 12A and Figure 12B , Figure 13A and Figure 13B As shown, the screen 220 includes a support piece 223 for supporting the screen 220; the fingerprint module 100 is bonded to the support piece 223 by an adhesive layer 230.

[0154] Specifically, the support piece 223 can form the back of the screen 220. The support piece 223 supports the screen 220 (folding screen), and the characteristics of the folding screen make it necessary for the support piece 223 to improve stability. Folding screens generally do not require a separate buffer layer, so there is no problem of the buffer layer affecting the ultrasonic signals transmitted and received by the ultrasonic sensor 110 of the fingerprint module 100. The support piece 223 can generally be made of a material with plasticity and a certain strength, such as metal. For example, in some optional embodiments, the support piece 223 can be a supporting steel sheet, or in other embodiments it can be a supporting copper sheet, etc. This application does not impose specific limitations here. Of course, other suitable materials can also be used for the support piece 223 when necessary.

[0155] In this application, by bonding the fingerprint module 100 to the support piece 223 for supporting the screen 220 via the adhesive layer 230, the fingerprint module 100 can be bonded to the back of the screen 220 without affecting the function of the fingerprint module 100 in sending and receiving ultrasonic signals. This improves the usability of the fingerprint module 100 and meets the application requirements of the fingerprint module 100 in electronic devices 200 with foldable screens.

[0156] In some alternative embodiments, the screen 220 of the electronic device 200 is a non-folding screen, and the electronic device 200 also includes a third fixing structure 253 for fixing the edge of the ultrasonic sensor 110 to the adhesive layer 230.

[0157] For example, in some exemplary embodiments, reference is made to... Figure 12A and Figure 12B As shown, in the electronic device 200, the screen 220 is a folding screen. Along the thickness direction of the acoustic layer 112, the third vertical projection of the ultrasonic sensor 110 toward the adhesive layer 230 is located inside the adhesive layer 230. The gap d4 between the edge of the third vertical projection and the edge of the adhesive layer 230 is ≥0.5mm. The electronic device 200 also includes a third fixing structure 253, which is used to fix the edge of the ultrasonic sensor 110 to the adhesive layer 230.

[0158] Specifically, along the thickness direction of the acoustic layer 112, the third vertical projection of the ultrasonic sensor 110 toward the adhesive layer 230 is located within the adhesive layer 230, and the gap d4 between the edge of the third vertical projection and the edge of the adhesive layer 230 is ≥0.5mm. At this time, the outer contour of the adhesive layer 230 extends too far beyond the outer contour of the ultrasonic sensor 110. Therefore, based on this structure, on the one hand, the edge of the ultrasonic sensor 110 can be fixed to the adhesive layer 230 by the third fixing structure 253, which improves the stability of the fingerprint module 100 installed on the electronic device 200; on the other hand, since the edge of the ultrasonic sensor 110 is fixed to the adhesive layer 230 by the third fixing structure 253 in this structure, it is easier to remove the fingerprint module 100 from the electronic device 200, and it is less likely to damage the screen 220. It also facilitates the rework and installation of the fingerprint module 100 of the electronic device 200.

[0159] Optionally, the third fixing structure 253 can be any suitable fixing structure, as long as it meets the requirements. For example, the third fixing structure 253 may include a fixing adhesive, which can be applied to the edge of the ultrasonic sensor 110 and the adhesive layer 230 to fix the edge of the ultrasonic sensor 110 to the adhesive layer 230. Optionally, the fixing adhesive...

[0160] The curing shrinkage rate is less than 3%. Excessive curing shrinkage of the fixative can easily create tensile force on the screen 220, resulting in poor display quality. This application selects a fixative with a curing shrinkage rate of less than 3% as the third fixing structure 253, which can effectively avoid the problem of poor display quality caused by the fixative pulling on the screen 220. This application does not impose any limitations on the type of fixative; any type that meets the requirements is acceptable. For example, the fixative can be at least one of the following: UV-curing adhesives (e.g., UV adhesives, i.e., shadowless adhesives, which require ultraviolet light irradiation for curing), UV- and moisture-curing adhesives, and low-temperature curing adhesives (e.g., low temperature refers to below 100°C).

[0161] Therefore, in some embodiments of this application, the fingerprint module 100 can be installed between the screens 220 (folding screen) by applying adhesive once (i.e., the aforementioned fixing adhesive (i.e., the third fixing structure 253)), which takes into account both the needs of light shielding and module fixing.

[0162] Alternatively, in some other optional embodiments, the screen 220 of the electronic device 200 is a foldable screen, and the electronic device 200 also includes a fourth fixing structure 254 for fixing the edge of the ultrasonic sensor 110 to the support piece 223.

[0163] For example, in some exemplary embodiments, reference is made to... Figure 13A and Figure 13B As shown, in the electronic device 200, the screen 220 is a folding screen, the edge of the adhesive layer 230 does not exceed the edge of the adhesive surface on the fingerprint module 100 that is bonded to the adhesive layer 230, and the electronic device 200 also includes a fourth fixing structure 254, which is used to fix the edge of the ultrasonic sensor 110 to the support piece 223.

[0164] Specifically, the edge of the adhesive layer 230 does not extend beyond the edge of the adhesive surface on the fingerprint module 100 that forms an adhesive bond with the adhesive layer 230 (the adhesive surface on the fingerprint module 100 can be a surface on the circuit board 120 (e.g.)). Figure 13B The circuit board 120 is an FPC circuit board, and the bonding surface is the surface of the circuit board substrate 123 away from the ultrasonic sensor 110, or it can be the surface of the ultrasonic sensor 110 (for example, the surface of the ultrasonic sensor 110 away from the circuit board 120). In this application, the edge of the ultrasonic sensor 110 can be fixed to the support piece 223 by the fourth fixing structure 254, thereby improving the stability of the fingerprint module 100 installed on the electronic device 200.

[0165] Optionally, the fourth fixing structure 254 can adopt any suitable fixing structure, as long as it meets the requirements. For example, the fourth fixing structure 254 may include a fixing adhesive, which can be applied to the edge of the ultrasonic sensor 110 and the support plate 223 to fix the edge of the ultrasonic sensor 110 to the support plate 223, thereby achieving the function of fixing the edge of the ultrasonic sensor 110 to the support plate 223. Optionally, the curing shrinkage rate of the fixing adhesive is less than 3%. When the curing shrinkage rate of the fixing adhesive is too large, it is easy to create a pulling force on the screen 220, resulting in poor display effect of the screen 220. In this application, a fixing adhesive with a curing shrinkage rate of less than 3% is selected as the fourth fixing structure 254, which can better avoid the problem of poor display effect of the screen 220 caused by the fixing adhesive pulling the screen 220. This application does not limit the type of fixing adhesive, as long as it meets the requirements. For example, the fixing adhesive can be at least one of UV-curing adhesives (such as UV glue, i.e., shadowless glue, which requires ultraviolet light irradiation for curing), UV and moisture-curing adhesives, and low-temperature curing adhesives (e.g., low temperature means less than 100°C).

[0166] Therefore, in some embodiments of this application, the fingerprint module 100 can be installed between the screens 220 (folding screen) by applying adhesive once (i.e., the aforementioned fixing adhesive (i.e., the fourth fixing structure 254)), which takes into account both the needs of light shielding and module fixing.

[0167] In some alternative embodiments, refer to Figure 8 As shown, the electronic device 200 also includes a battery 260, and the vertical projection of the fingerprint module 100 along the thickness direction of the electronic device 200 does not overlap with the battery 260. The battery 260 in this application can power the electronic device 200 and can be a primary or secondary battery, including but not limited to lead-acid batteries, lithium-ion batteries, sodium-ion batteries, etc. Through this structure, the fingerprint module 100 and the battery 260 of the electronic device 200 do not overlap, making the fingerprint module 100 less susceptible to adverse effects from the battery 260 (such as battery compression, heat generation during battery use, etc.), thereby better meeting the functional and usage requirements of the fingerprint module 100. Furthermore, this structure can effectively reduce the weight of the electronic device.

[0168] 200mm thickness.

[0169] For example, in one instance, taking an electronic device 200 as a mobile phone, the fingerprint module 100 can pass through the mid-frame of the phone and be placed in the non-battery area of ​​the phone, and be electrically connected to the main control circuit board of the phone (e.g., the processing unit 210 can be disposed on the main control circuit board) via an electrical connection cable, and the fingerprint module 100 does not overlap with the battery 260.

[0170] It is understood that the above embodiments are merely examples of fingerprint modules and electronic devices in this application, and are not intended to limit the fingerprint modules and electronic devices in this application.

[0171] It should be noted that the term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc., mentioned in this application are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0172] It should be noted that the terms "a" and "a plurality of" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0173] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A fingerprint module, characterized in that, include: An ultrasonic sensor includes: a first electrode layer, an acoustic layer, and a first electrical connection region. The first electrode layer is electrically connected to a first side of the acoustic layer along its thickness direction, and the first electrode layer is electrically connected to the first electrical connection region. The acoustic layer is used to emit ultrasonic signals and receive ultrasonic signals reflected back by an external structure. A circuit board includes: a circuit board substrate, a second electrode layer, and a second electrical connection region. The second electrode layer and the second electrical connection region are located on the same side of the circuit board substrate, on a first side of the circuit board along the thickness direction, and there is a certain distance between the second electrode layer and the second electrical connection region. The second electrode layer is electrically connected to the second side of the acoustic layer along the thickness direction through a first conductive adhesive layer. The second electrode layer is also electrically connected to the second electrical connection region. The first electrical connection region is electrically connected to the second electrical connection region through a second conductive adhesive layer. The first electrode layer and the second electrode layer are used to provide voltage to the acoustic layer for transmitting and receiving ultrasonic signals. The ultrasonic sensor is electrically connected to the processing unit outside the fingerprint module through the first electrical connection area, the second conductive adhesive layer, and the second electrical connection area. The ultrasonic sensor is used to process the received ultrasonic signal into an electrical signal and send the electrical signal to the processing unit through the circuit board so that the processing unit can perform fingerprint recognition based on the electrical signal.

2. The fingerprint module according to claim 1, characterized in that, The circuit board further includes a first conductive layer disposed on a first side of the circuit board substrate along the thickness direction. The first side of the circuit board substrate along the thickness direction also includes a second conductive layer, a second electrode layer located on the second conductive layer, and a second electrical connection area located on the first conductive layer.

3. The fingerprint module according to claim 2, characterized in that, The circuit board further includes a third conductive layer, which is disposed on a second side of the circuit board substrate along the thickness direction. Along the thickness direction of the circuit board substrate, at least a portion of the first vertical projection of the third conductive layer toward the circuit board substrate overlaps with the first conductive layer, but does not overlap with the second electrical connection area.

4. The fingerprint module according to claim 3, characterized in that, The circuit board substrate includes a bent section, which is convex relative to the second conductive layer, and the third conductive layer is disposed on the bent section.

5. The fingerprint module according to claim 1, characterized in that, The circuit board further includes a first conductive layer disposed on a first side of the circuit board substrate along the thickness direction. The first side of the circuit board substrate along the thickness direction also includes a blank area. The second electrode layer is located on the blank area, and the second electrical connection area is located on the first conductive layer.

6. The fingerprint module according to claim 2, characterized in that, The circuit board further includes a third conductive layer, which is disposed on a second side of the circuit board substrate along the thickness direction. Along the thickness direction of the circuit board substrate, at least a portion of the first vertical projection of the third conductive layer toward the circuit board substrate overlaps with the first conductive layer, but does not overlap with the second electrical connection area.

7. The fingerprint module according to claim 5, characterized in that, The circuit board substrate includes a curved section that is raised relative to the blank area; the circuit board also includes a third conductive layer disposed on a second side of the circuit board substrate along the thickness direction and on the curved section.

8. The fingerprint module according to claim 1, characterized in that, Along the thickness direction of the acoustic layer, the second vertical projection of the acoustic layer toward the first conductive adhesive layer is located within the first conductive adhesive layer; The gap d1 between the edge of the second vertical projection and the edge of the first conductive adhesive layer satisfies: d1≥0.2mm.

9. The fingerprint module according to claim 1, characterized in that, The ultrasonic sensor further includes a sensor substrate, and the first electrode layer is formed on the sensor substrate; The acoustic layer is attached to the first electrode layer on a first side along the thickness direction, and the first electrode layer is located within the outer contour of the acoustic layer.

10. The fingerprint module according to claim 1, characterized in that, The ultrasonic sensor further includes a sensor substrate, and along the thickness direction of the acoustic layer, the distance H between the side of the sensor substrate away from the circuit board and the side of the circuit board away from the sensor substrate satisfies: H < 0.3 mm.

11. The fingerprint module according to any one of claims 1-10, characterized in that, The fingerprint module satisfies at least one of the following conditions: The circuit board includes an FPC circuit board; the acoustic layer includes a piezoelectric material; the first conductive adhesive layer includes ACA conductive adhesive; the second conductive adhesive layer includes an ACF conductive adhesive film; and the ultrasonic sensor includes a CMOS ultrasonic sensor.

12. An electronic device, characterized in that, include: The processing unit, the screen, and the fingerprint module as described in any one of claims 1-11; The electronic device also includes an adhesive layer, through which the fingerprint module is adhered to the back of the screen.

13. The electronic device according to claim 12, characterized in that, The screen is a non-foldable screen, and the screen includes a screen substrate and a buffer layer. The buffer layer is installed on the screen substrate and is used to buffer the screen. The buffer layer has a first opening, the adhesive layer is located in the first opening and is bonded to the screen substrate, and the fingerprint module is bonded to the screen substrate through the adhesive layer.

14. The electronic device according to claim 13, characterized in that, The electronic device further includes a first light-shielding structure and a first fixing structure, wherein the first light-shielding structure is used to cover the gap formed between the edge of the adhesive layer and the edge of the first opening, and the first fixing structure is used to fix the edge of the ultrasonic sensor to the adhesive layer. or, The electronic device further includes a second fixing structure for fixing the edge of the ultrasonic sensor to the screen substrate.

15. The electronic device according to claim 12, characterized in that, The screen is a foldable screen, and the screen includes a support piece for supporting the screen. The fingerprint module is bonded to the support sheet via the adhesive layer.

16. The electronic device according to claim 15, characterized in that, The electronic device further includes a third fixing structure for fixing the edge of the ultrasonic sensor to the adhesive layer; or, The electronic device further includes a fourth fixing structure for fixing the edge of the ultrasonic sensor to the support plate.

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