CN111801685B - Fingerprint detection device and electronic equipment - Google Patents

Abstract

The present application provides a fingerprint detection device and an electronic device, which can avoid the Newton ring problem. The fingerprint detection device is arranged below the display screen of the electronic device, and the fingerprint detection device includes: a filter layer, the lower surface of the filter layer is silk-screened with supporting ink, and the supporting ink is used to support the filter layer and the upper surface of the optical path layer to maintain a gap; the optical path layer is arranged below the filter layer; a first sensor chip is arranged below the optical path layer; a substrate, the upper surface of the substrate extends downward to form a first groove, at least a part of the first sensor chip is arranged in the first groove and is electrically connected to the substrate; a bracket is arranged above the substrate around the first sensor chip, and is used to support the filter layer; wherein the first sensor chip is used to receive a fingerprint detection signal of a human finger passing through the filter layer and the optical path layer after returning from the human finger above the display screen, so as to detect the fingerprint information of the finger.

Description

Fingerprint detection device and electronic device

Technical Field

The embodiments of the present application relate to the field of fingerprint recognition, and more specifically, to a fingerprint detection device and an electronic device.

Background technique

The under-screen fingerprint recognition solution refers to attaching an optical or ultrasonic fingerprint recognition module to the bottom of the light-emitting layer of the organic light-emitting diode (OLED) screen. That is, both the optical fingerprint recognition module and the ultrasonic fingerprint recognition module need to be tightly bonded to the bottom of the light-emitting layer.

For the under-screen optical fingerprint solution, there is a fingerprint recognition module that includes a collimator for optical path adjustment. The period of the collimator of this fingerprint recognition module must be the same as the period formed by the panel wiring of the screen display to ensure that the collected image has no moiré fringes and does not affect the normal use of the fingerprint function. On the other hand, the filter used is usually filled with optical glue and attached to the surface of the sensor. Once the thickness of the glue covering the sensor surface is uneven, Newton rings will occur, which will affect the normal use of the fingerprint function.

Summary of the invention

The embodiments of the present application provide a fingerprint detection device and an electronic device, which can avoid the Newton ring problem.

In a first aspect, a fingerprint detection device is provided, which is suitable for an electronic device with a display screen, wherein the fingerprint detection device is arranged below the display screen, and comprises: a filter layer, wherein the lower surface of the filter layer is provided with a silk-screened supporting ink; an optical path layer, which is arranged below the filter layer, wherein a gap is provided between the upper surface of the optical path layer and the lower surface of the supporting ink, and the supporting ink is used to support the filter layer, so that a gap is maintained between the upper surface of the optical path layer and the lower surface of the filter layer; a first sensor chip, which is arranged below the optical path layer; a substrate, wherein the upper surface of the substrate extends downward to form a first groove, wherein at least a portion of the first sensor chip is arranged in the first groove and is electrically connected to the substrate; and a bracket, which is arranged above the substrate around the first sensor chip and is used to support the filter layer; wherein the first sensor chip is used to receive a fingerprint detection signal of a human finger passing through the filter layer and the optical path layer after returning from the human finger passing through the upper side of the display screen, and the fingerprint detection signal is used to detect the fingerprint information of the finger.

The fingerprint recognition module of the embodiment of the present application sets the filter layer above the optical path layer. This external filter layer can effectively block the influence of ambient light on the fingerprint recognition process, avoid the decrease in image contrast due to strong light intervention when the user performs fingerprint unlocking, and thus prevent abnormal unlocking problems; and support ink is silk-screened in the middle of the lower surface of the filter layer corresponding to the sensing area of the fingerprint chip, and the middle position of the filter layer is supported by the support ink to prevent Newton ring problems caused by deformation of the filter layer.

In addition, the optical path layer of the fingerprint detection device in the embodiment of the present application is directly arranged on the upper surface of the first sensor chip, and the lower surface of the first sensor chip is fixed on the substrate, which can avoid the need to set up a separate shell for carrying the optical path layer and the first sensor chip, thereby reducing the size (such as thickness) of the fingerprint detection device; and, setting the fingerprint detection device in a groove of the substrate can reduce the thickness of the fingerprint detection device.

Thirdly, the close fit between the layers in the thickness direction ensures that the thickness of the fingerprint detection device is reduced to the greatest extent.

Finally, since the optical path layer is directly arranged on the upper surface of the first sensor chip, the image acquisition field of view of the fingerprint detection device is only affected by the area of the optical path layer and the area of the corresponding first sensor chip. Based on this, the area of the optical path layer and the area of the corresponding first sensor chip can be reasonably designed according to actual needs to meet the needs of different users and different customers (for example, it can meet the needs of a large-area image acquisition field of view).

In some possible implementations, there is a gap between a side wall of the first sensor chip and a side wall of the first groove, and between a side wall of the bracket close to the first sensor chip and a side wall of the first sensor chip.

By designing a certain gap between the side wall of the first sensor chip and the side wall of the first groove, and setting a gap between the side wall of the bracket and the side wall of the first sensor chip, even if there is a difference between the size of the prepared product of the first sensor chip and the designed size of the first sensor chip, or even if there is a difference between the actual size of the first groove and the designed size of the first groove, and there is a difference between the actual size and the designed size of the bracket, it does not affect the installation of the first fingerprint sensor chip in the first groove.

In other words, the gap between the side wall of the first sensor chip and the side wall of the first groove can not only be used as the size tolerance of the first sensor chip and/or as the size tolerance of the first groove, but also can be used as the installation tolerance of the first sensor chip; correspondingly, the gap between the side wall of the bracket and the side wall of the first sensor chip can not only be used as the size tolerance of the first sensor chip and/or as the size tolerance of the bracket, but also can be used as the installation tolerance of the first sensor chip, thereby improving the yield of the fingerprint detection device.

In some possible implementations, the fingerprint detection device also includes: a first gold wire, used to electrically connect the first sensor chip and the conductive layer of the substrate, located between the side wall of the first sensor chip and the side wall of the first groove, and in the gap between the side wall of the bracket close to the first sensor chip and the side wall of the first sensor chip.

In some possible implementations, a width of a gap between a sidewall of the first sensor chip and a sidewall of the support close to the first sensor chip is greater than or equal to a width of a gap between a sidewall of the first sensor chip and a sidewall of the first groove.

In some possible implementations, the width of the gap between the side wall of the first sensor not close to the first gold wire and the side wall of the first groove ranges from 100-400um, for example, can be set to 200um, and the width of the gap between the side wall of the first sensor not close to the first gold wire and the side wall of the bracket close to the first sensor chip ranges from 100-400um, for example, can be set to 270um.

In some possible implementations, one side of the lower surface of the filter layer close to the first gold wire is fixed to the upper surface of the first sensor chip, and the other sides of the lower surface of the filter layer are fixed to the upper surface of the bracket.

For example, the lower surface of the filter layer can be rectangular, then one side of the lower surface of the filter layer is close to the gold wire, and the other three sides are not close to the gold wire. The three sides not close to the gold wire can be fixed on the upper surface of the bracket, and the side close to the gold wire is fixed on the upper surface of the first sensor chip, so as to avoid affecting the installation of the gold wire.

In some possible implementations, one side of the lower surface of the filter layer close to the first gold wire is fixed to the upper surface of the first sensor chip by a first adhesive, and the other sides of the lower surface of the filter layer are fixed to the upper surface of the bracket by a second adhesive.

One side of the lower surface of the filter layer close to the first gold wire is fixed to the upper surface of the first sensor chip by the first backing glue, which can prevent the gold wire protection glue used to fix the gold wire from flowing into the optical path layer.

In some possible implementations, the thickness of the filter layer is less than or equal to 220 um.

Considering the existing technology and mass production, the thickness of the filter layer is usually 110um.

In some possible implementations, the center of the supporting ink coincides with the center of the sensing area of the first sensor chip in the vertical direction.

Since the center position provides more balanced support for the entire filter layer, the position of the silk-screen supporting ink is usually set to coincide with the center of the sensing area of the first sensor chip below.

In some possible implementations, the thickness of the supporting ink is less than or equal to 30 um.

As the thickness of the supporting ink increases, the contrast of the Newton rings gradually decreases. When the distance is 25um, the Newton rings basically disappear. Therefore, the thickness of the supporting ink is usually set to 25um.

In some possible implementations, the area of the supporting ink is less than or equal to 40*40um, for example, can be set to 30um*30um.

Under the premise of not affecting fingerprint recognition, the larger the size of the silk-screen supporting ink, the better the supporting effect on the filter layer, that is, the filter layer is less likely to deform and less likely to produce Newton rings.

In some possible implementations, the reflectivity of the light incident surface of the filter layer to light is less than or equal to 1%.

In some possible implementations, the total thickness of the fingerprint detection device ranges from 0.15 to 0.6 mm.

In some possible implementations, the substrate includes, from top to bottom, a first covering layer, a first conductive layer, a base material layer, a second conductive layer, and a second covering layer, the upper surface of the substrate extends downward in a first region and penetrates the first covering layer and the first conductive layer to form the first groove, the upper surface of the substrate extends downward in a second region connected to the first region and penetrates the first covering layer to form a solder pad of the substrate; the first sensor chip is connected to the solder pad of the substrate through the first gold wire.

By removing the first covering layer and the first conductive layer of the substrate at the first area to form a first groove for accommodating the first fixing glue and the first sensor chip, the thickness of the fingerprint detection device can be reduced.

Secondly, by removing the first covering layer at the second area of the substrate, a substrate pad for electrically connecting the first sensor chip is formed, which can provide an accommodation space for the first gold wire for electrically connecting the first sensor chip and the substrate. Accordingly, the space occupied by the first gold wire above the substrate is reduced, thereby reducing the thickness of the fingerprint detection device.

In some possible implementations, the fingerprint detection device further includes: a first fixing glue, and the lower surface of the first sensor chip is fixed to the first groove by the first fixing glue.

In some possible implementations, the thickness of the first covering layer is equal to the thickness of the second covering layer, and the thickness of the first conductive layer is the same as the thickness of the second conductive layer.

In some possible implementations, the total thickness of the substrate is less than or equal to 150um, the thickness of the first covering layer and the thickness of the second covering layer are both less than or equal to 30um, the thickness of the first conductive layer and the thickness of the second conductive layer are both less than or equal to 20um, and the thickness of the base material is 80um.

In some possible implementations, the thickness of the first sensor chip is less than or equal to 150 um, the maximum arc height of the first gold wire is less than or equal to 60 um, and the thickness of the first fixing glue is less than or equal to 30 um.

In some possible implementations, the outer side of the bracket is shortened by a preset distance relative to the outer side of the first covering film in a direction approaching the first sensor chip.

In some possible implementations, the preset distance has a value range of 100-400 um, for example, can be set to 200 um.

The preset distance can be used not only as the size tolerance of the bracket, but also as the installation tolerance of the bracket, and accordingly, the yield of the fingerprint detection device can be improved.

In some possible implementations, the fingerprint detection device also includes: a second sensor chip, a second fixing glue and a second gold wire; wherein, the upper surface of the substrate extends downward in a third area connected to the second area and penetrates the first covering layer and the first conductive layer to form a second groove, the second sensor chip is fixed in the second groove by the second fixing glue, the second sensor chip is connected to the pad of the substrate by the second gold wire, so that the second sensor chip is connected to the first sensor chip, and the second sensor chip is used to cooperate with the first sensor chip to perform under-screen fingerprint recognition.

By setting up the second sensor chip, the processing task of the first sensor chip can be shared, which is equivalent to replacing a fully functional and thicker sensor chip with a first sensor chip and a second sensor chip that are thinner and set in parallel. Accordingly, the thickness of the fingerprint detection device can be reduced without affecting the fingerprint recognition performance.

In some possible implementations, there is a gap between a sidewall of the second sensor chip and a sidewall of the second groove.

By designing a certain gap between the side wall of the second sensor chip and the side wall of the second groove, even if there is a difference between the size of the manufactured product of the second sensor chip and the designed size of the second sensor chip, or even if there is a difference between the actual size of the second groove and the designed size of the second groove, it does not affect the installation of the second fingerprint sensor chip in the second groove.

In other words, the gap between the side wall of the second sensor chip and the side wall of the second groove can not only be used as the size tolerance of the second sensor chip and/or as the size tolerance of the second groove, but also can be used as the installation tolerance of the second sensor chip. Accordingly, the yield of the fingerprint detection device can be improved.

In some possible implementations, a width of a gap between a side wall of the second sensor chip that is not close to the first gold wire and a side wall of the second groove ranges from 100 to 400 um, for example, may be 200 um.

In some possible implementations, the thickness of the first sensor chip is equal to the thickness of the second sensor chip, the thickness of the first fixing glue is equal to the thickness of the second fixing glue, and the maximum arc height of the first gold wire is equal to the maximum arc height of the second gold wire.

In some possible implementations, the fingerprint detection device further includes: a gold wire protection glue, used to encapsulate the first gold wire and the second gold wire.

The gold wire protection glue can ensure the stability of the electrical connection between the substrate and the first sensor chip, and accordingly, the performance of the fingerprint detection device can be ensured.

In some possible implementations, the height of the gold wire protection glue is less than or equal to 200 um.

In some possible implementations, the thickness of the gold wire protection glue is less than or equal to the sum of the thickness of the optical path layer, the thickness of the first sensor chip, and the thickness of the first fixing glue.

The thickness of the gold wire protection glue is constructed to be less than or equal to the sum of the thickness of the optical path layer, the thickness of the first sensor chip and the thickness of the first fixing glue, which can effectively encapsulate the first gold wire while reducing the thickness of the fingerprint detection device as much as possible.

In some possible implementations, the fingerprint detection device also includes: a foam layer, which is arranged above the bracket around the filter layer, the foam layer is provided with an opening that passes through the foam layer, and the first sensor chip receives the fingerprint detection signal through the opening of the foam layer; the upper surface of the foam layer is flush with the upper surface of the filter layer.

Since the filter layer is arranged above the optical path layer, the height of the upper surface of the bracket may be lower than the height of the upper surface of the filter layer, resulting in inconsistent height of the upper surface of the entire fingerprint detection device. At this time, foam can be arranged to make the upper surface of the fingerprint detection device flat, thereby facilitating the installation of the fingerprint detection device under the display screen.

In some possible implementations, the bracket is a polyethylene terephthalate (PET) adhesive layer used to connect the substrate and the foam layer; or, the lower surface of the bracket is fixed to the upper surface of the substrate by a bracket fixing adhesive, and the upper surface of the bracket is fixed to the foam layer by a bracket fixing adhesive.

In some possible implementations, the thickness of the bracket is less than or equal to 150 um.

In some possible implementations, the display screen includes a transparent cover plate, a display panel, a buffer layer and a copper layer from top to bottom, and the display screen is provided with a window penetrating the buffer layer and the copper layer; the upper surface of the foam is fixed to the surrounding area of the window on the lower surface of the copper layer by a first pressure-sensitive adhesive (PSA), so that the fingerprint recognition module is fixed below the display screen, and the sensing area of the first sensor chip is aligned with the window, so that the first sensor chip receives the fingerprint detection signal.

In some possible implementations, ultraviolet (UV) curing glue is disposed on the outer side of the fingerprint detection device and the outer side of the first PSA to fix the relative position of the fingerprint detection device with respect to the display screen.

In some possible implementations, the display screen includes a transparent cover plate, a display panel, a buffer layer and a copper layer from top to bottom, and the display screen is provided with a window penetrating the buffer layer and the copper layer, and the size of the window of the buffer layer is smaller than the size of the window of the copper layer; the fingerprint detection device is located in the groove of the middle frame of the electronic device, and the upper surface of the foam is fixed to the surrounding area of the window on the lower surface of the buffer layer by foam glue within the window range of the copper layer, so that the fingerprint recognition module is fixed below the display screen, and the sensing area of the first sensor chip is aligned with the window setting of the buffer layer, so that the first sensor chip receives the fingerprint detection signal.

In some possible implementations, the bottom of the fingerprint detection device is disposed in a groove of the middle frame through a second PSA.

In some possible implementations, the optical path layer includes a lens layer and an optical path guiding layer, the microlens is used to converge the light signal returned by the human finger above the display screen to the optical path guiding layer, and the optical path guiding layer guides the light signal converged by the microlens to the first sensor chip.

In some possible implementations, the thickness of the optical path layer is less than or equal to 30 um.

In some possible implementations, the fingerprint detection device further includes: a flexible circuit board, on which a gold finger of the flexible circuit board is formed; and an anisotropic conductive adhesive film, through which the gold finger of the flexible circuit board is electrically connected to the gold finger of the substrate.

By using the anisotropic conductive adhesive film, the gold fingers of the flexible circuit board are pressed onto the gold fingers of the substrate, which is equivalent to configuring flexible circuit boards of different specifications for the fingerprint detection device, making the fingerprint detection device more universal and correspondingly able to meet the needs of different users or customers.

In addition, the fingers electrically connect the substrate and the flexible circuit board, which can not only ensure the insulation between the contact pieces, but also ensure the conductivity between the substrate and the flexible circuit board. In particular, when the fingerprint sensor chip includes multiple chips, the multiple chips on the substrate can be quickly electrically connected to the flexible circuit board through the gold fingers, thereby reducing the complexity of installation and disassembly.

In a second aspect, an electronic device is provided, comprising: a display screen; and a fingerprint detection device, arranged below the display screen, wherein the fingerprint detection device is the fingerprint detection device described in the first aspect or any possible implementation method of the first aspect, and its fingerprint collection area is at least partially located in the display area of the display screen.

In some possible implementations, the display screen includes a transparent cover plate, a display panel, a buffer layer and a copper layer from top to bottom, wherein the display screen is provided with a window penetrating the buffer layer and the copper layer, and the optical path layer of the fingerprint detection device is aligned with the window so that the fingerprint detection device receives a fingerprint detection signal returned by a human finger above the display screen through the window, and the fingerprint detection signal is used to detect fingerprint information of the finger.

In some possible implementations, the edge area of the upper surface of the fingerprint detection device is fixed to the surrounding area of the window on the lower surface of the copper layer through a first PSA, so that the optical path layer of the fingerprint detection device is aligned with the window.

In some possible implementations, the electronic device further includes a middle frame, an upper surface of the middle frame extends downward to form a third groove, and the bottom of the fingerprint detection device is disposed in the third groove through a second PSA.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of an electronic device to which the present application may be applied.

FIG. 2 is a schematic side cross-sectional view of the electronic device shown in FIG. 1 .

3 to 6 and 8 to 9 are schematic structural diagrams of fingerprint recognition devices according to embodiments of the present application.

FIG. 7 is a schematic diagram of the Newton ring phenomenon when the distances between the filter layer and the sensor chip are different according to an embodiment of the present application.

10 and 11 are schematic structural diagrams of electronic devices including fingerprint recognition devices according to embodiments of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

The technical solutions of the embodiments of the present application can be applied to various electronic devices.

For example, portable or mobile computing devices such as smart phones, laptops, tablet computers, gaming devices, and other electronic devices such as electronic databases, cars, bank automated teller machines (ATMs), etc. However, the embodiments of the present application are not limited thereto.

The technical solution of the embodiment of the present application can be used for biometric identification technology. Among them, biometric identification technology includes but is not limited to fingerprint recognition, palm print recognition, iris recognition, face recognition, and liveness recognition. For the sake of convenience, the following description takes fingerprint recognition technology as an example.

The technical solution of the embodiment of the present application can be used for under-screen fingerprint recognition technology and in-screen fingerprint recognition technology.

Under-screen fingerprint recognition technology refers to installing a fingerprint recognition module under the display screen, so as to realize fingerprint recognition operation within the display area of the display screen, and there is no need to set a fingerprint collection area on the front of the electronic device except for the display area. Specifically, the fingerprint recognition module uses the light returned from the top surface of the display component of the electronic device to perform fingerprint sensing and other sensing operations. This returned light carries information about objects (such as fingers) that are in contact or close to the top surface of the display component, and the fingerprint recognition module located below the display component collects and detects this returned light to realize under-screen fingerprint recognition. Among them, the design of the fingerprint recognition module can be to achieve the desired optical imaging by properly configuring the optical elements for collecting and detecting the returned light, thereby detecting the fingerprint information of the finger.

Correspondingly, in-display fingerprint recognition technology refers to installing the fingerprint recognition module or part of the fingerprint recognition module inside the display screen, so as to realize fingerprint recognition operation within the display area of the display screen, without setting up a fingerprint collection area in the area other than the display area on the front of the electronic device.

1 and 2 show schematic diagrams of an electronic device 100 to which the under-screen fingerprint recognition technology can be applied, wherein FIG1 is a schematic front view of the electronic device 100 , and FIG2 is a schematic diagram of a partial cross-sectional structure of the electronic device 100 shown in FIG1 .

As shown in FIG. 1 and FIG. 2 , the electronic device 100 may include a display screen 120 and a fingerprint recognition module 140 .

The display screen 120 may be a self-luminous display screen, which uses a self-luminous display unit as a display pixel. For example, the display screen 120 may be an organic light-emitting diode (OLED) display screen or a micro-light-emitting diode (Micro-LED) display screen. In other alternative embodiments, the display screen 120 may also be a liquid crystal display (LCD) or other passive light-emitting display screens, which is not limited in the present application.

In addition, the display screen 120 may be specifically a touch display screen, which can not only display images, but also detect the user's touch or press operation, thereby providing a human-computer interaction interface for the user. For example, in one embodiment, the electronic device 100 may include a touch sensor, and the touch sensor may be specifically a touch panel (TP), which may be arranged on the surface of the display screen 120, or may be partially integrated or fully integrated into the display screen 120, thereby forming the touch display screen.

The fingerprint recognition module 140 may be an optical fingerprint recognition module, for example, including an optical fingerprint sensor.

Specifically, the fingerprint recognition module 140 may include a sensor chip having an optical sensing array (hereinafter also referred to as an optical fingerprint sensor). The optical sensing array includes a plurality of optical sensing units, each of which may specifically include a light detector or a photoelectric sensor. In other words, the fingerprint recognition module 140 may include a photodetector array (or referred to as a photodetector array, a photoelectric sensor array), which includes a plurality of light detectors distributed in an array.

As shown in FIG. 1 , the fingerprint recognition module 140 may be disposed in a local area below the display screen 120 , so that a fingerprint collection area (or detection area) 130 of the fingerprint recognition module 140 is at least partially located within the display area 102 of the display screen 120 .

Of course, in other alternative embodiments, the fingerprint recognition module 140 may also be disposed at other locations, such as the side of the display screen 120 or the non-light-transmissive area at the edge of the electronic device 100. In this case, the optical signal of at least part of the display area of the display screen 120 may be guided to the fingerprint recognition module 140 through the optical path design, so that the fingerprint collection area 130 is actually located within the display area of the display screen 120.

In some embodiments of the present application, the fingerprint recognition module 140 may include only one sensor chip. In this case, the fingerprint collection area 130 of the fingerprint recognition module 140 is small in area and fixed in position. Therefore, the user needs to press the finger to a specific position of the fingerprint collection area 130 when inputting a fingerprint. Otherwise, the fingerprint recognition module 140 may not be able to collect the fingerprint image, resulting in a poor user experience.

In other embodiments of the present application, the fingerprint recognition module 140 may specifically include a plurality of sensor chips; the plurality of sensor chips may be arranged side by side under the display screen 120 by splicing, and the sensing areas of the plurality of sensor chips together constitute the fingerprint collection area 130 of the fingerprint recognition module 140. That is to say, the fingerprint collection area 130 of the fingerprint recognition module 140 may include a plurality of sub-areas, each of which corresponds to the sensing area of one of the sensor chips, so that the fingerprint collection area 130 of the optical fingerprint module 130 can be extended to the main area of the lower half of the display screen, that is, to the area where the finger is usually pressed, so as to realize the blind fingerprint input operation. Alternatively, when the number of the sensor chips is sufficient, the fingerprint detection area 130 can also be extended to half of the display area or even the entire display area, so as to realize half-screen or full-screen fingerprint detection.

It should be understood that the embodiments of the present application do not limit the specific forms of the multiple sensor chips.

For example, the multiple sensor chips may be independently packaged sensor chips, or may be multiple chips (Die) packaged in the same chip package.

For another example, the plurality of sensor chips may be manufactured on different regions of the same chip through semiconductor technology.

As shown in FIG2 , the area or light sensing range of the optical sensing array of the fingerprint recognition module 140 corresponds to the fingerprint collection area 130 of the fingerprint recognition module 140. The fingerprint collection area 130 of the fingerprint recognition module 140 may be equal to or not equal to the area or light sensing range of the area where the optical sensing array of the fingerprint recognition module 140 is located, and the embodiment of the present application does not specifically limit this.

For example, through the design of a light path for light collimation, the fingerprint collection area 130 of the fingerprint recognition module 140 can be designed to be substantially consistent with the area of the sensing array of the fingerprint recognition module 140 .

For another example, by designing an optical path for converging light or designing an optical path for reflecting light through a macro lens, the area of the fingerprint collection region 130 of the fingerprint recognition module 140 can be made larger than the area of the sensing array of the fingerprint recognition module 140 .

The optical path design of the fingerprint recognition module 140 is exemplarily described below.

Taking the optical path design of the fingerprint recognition module 140 using an optical collimator with a through-hole array with a high aspect ratio as an example, the optical collimator can be specifically a collimator (Collimator) layer made on a semiconductor silicon wafer, which has multiple collimation units or microholes. The collimation unit can be specifically a small hole. Among the reflected light reflected from the finger, the light perpendicularly incident to the collimation unit can pass through and be received by the sensor chip below it, while the light with an incident angle that is too large is attenuated after multiple reflections inside the collimation unit. Therefore, each sensor chip can basically only receive the reflected light reflected from the fingerprint pattern directly above it, which can effectively improve the image resolution and thus improve the fingerprint recognition effect.

Furthermore, when the fingerprint recognition module 140 includes multiple sensor chips, a collimation unit can be configured for one optical sensing unit in the optical sensing array of each sensor chip, and can be fitted above the corresponding optical sensing unit. Of course, the multiple optical sensing units can also share one collimation unit, that is, the one collimation unit has a sufficiently large aperture to cover multiple optical sensing units. Since one collimation unit can correspond to multiple optical sensing units, the correspondence between the spatial period of the display screen 120 and the spatial period of the sensor chip is destroyed. Therefore, even if the spatial structure of the light-emitting display array of the display screen 120 is similar to the spatial structure of the optical sensing array of the sensor chip, it can effectively avoid the fingerprint recognition module 140 from using the light signal passing through the display screen 120 to perform fingerprint imaging to generate moiré fringes, thereby effectively improving the fingerprint recognition effect of the fingerprint recognition module 140.

Taking the optical path design of the fingerprint recognition module 140 using an optical lens as an example, the optical lens may include an optical lens (Lens) layer, which has one or more lens units, such as a lens group composed of one or more aspherical lenses, which is used to converge the reflected light reflected from the finger to the sensing array of the sensor chip below it, so that the sensing array can be imaged based on the reflected light, thereby obtaining a fingerprint image of the finger.

The optical lens layer may also form a pinhole or micro-aperture aperture in the optical path of the lens unit. For example, one or more light shielding sheets may be formed in the optical path of the lens unit, wherein at least one light shielding sheet may form a light-transmitting micro-aperture in the optical axis or optical center area of the lens unit, and the light-transmitting micro-aperture may serve as the pinhole or micro-aperture aperture. The pinhole or micro-aperture aperture may cooperate with the optical lens layer and/or other optical film layers above the optical lens layer to expand the field of view of the fingerprint recognition module 140, so as to improve the fingerprint imaging effect of the fingerprint recognition module 140.

Furthermore, when the fingerprint recognition module 140 includes multiple sensor chips, an optical lens can be configured for each sensor chip to perform fingerprint imaging, or an optical lens can be configured for multiple sensor chips to achieve light convergence and fingerprint imaging. Even when a sensor chip has two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), two or more optical lenses can be configured for the sensor chip to cooperate with the two sensing arrays or multiple sensing arrays for optical imaging, thereby reducing the imaging distance and enhancing the imaging effect.

Taking the optical path design of the fingerprint recognition module 140 using a micro-lens layer as an example, the micro-lens layer may have a micro-lens array formed by a plurality of micro-lenses, which may be formed above the sensing array of the sensor chip by a semiconductor growth process or other processes, and each micro-lens may correspond to one of the sensing units of the sensing array. Other optical film layers, such as a dielectric layer or a passivation layer, may be formed between the micro-lens layer and the sensing unit. More specifically, a light-blocking layer having a plurality of micro-holes may be included between the micro-lens layer and the sensing unit, wherein the micro-holes are formed between the corresponding micro-lenses and the sensing unit. The light-blocking layer may block the optical interference between adjacent micro-lenses and the sensing unit, and allow the light to converge through the micro-lenses into the micro-holes and be transmitted to the sensing unit corresponding to the micro-lens via the micro-holes, so as to perform optical fingerprint imaging.

Optionally, a filter may be disposed above the microlens layer or in the light path between the microlens layer and the sensor chip (hereinafter also referred to as an optical fingerprint sensor).

As an optional embodiment, the filter may be disposed above the microlens layer. For example, the filter may be connected to the microlens layer via a buffer layer. The buffer layer may be a transparent medium layer and may be used to fill the surface of the microlens layer.

Alternatively, the filter may be fixed to the top of the microlens layer by a fixing device, for example, a frame glue or other supporting members are arranged in the non-photosensitive area around the microlens layer to support and fix the filter.

As an optional embodiment, the filter can also be arranged in the optical path between the microlens layer and the sensor chip. For example, the filter can be arranged above the sensor chip. Specifically, the filter can be fixed to the top of the sensor chip by a fixing device. For example, a frame glue or other supporting member is set in the non-photosensitive area of the sensor chip to support and fix the filter. The sensor chip can also be coated by an evaporation process or a sputtering process to form the filter, that is, the filter is integrated with the sensor chip. It can be understood that the filter can also be coated on other optical film layers, which is not limited here.

It should be understood that the above-mentioned several implementation schemes of the optical path guiding structure can be used alone or in combination. For example, a microlens layer can be further provided under the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific stacked structure or optical path may need to be adjusted according to actual needs.

The fingerprint recognition module 140 can be used to collect fingerprint information (such as fingerprint image information) of the user.

Taking the display screen 120 as an example, the display screen 120 can be a display screen with a self-luminous display unit, such as an organic light-emitting diode (OLED) display screen or a micro-light-emitting diode (Micro-LED) display screen. The fingerprint recognition module 140 can use the display unit (i.e., OLED light source) of the OLED display screen located in the fingerprint collection area 130 as an excitation light source for optical fingerprint detection.

When a finger touches, presses or approaches (for ease of description, collectively referred to as pressing in this application) the fingerprint collection area 130, the display screen 120 emits a beam of light to the finger above the fingerprint collection area 130. This beam of light is reflected on the surface of the finger to form reflected light or is scattered inside the finger to form scattered light. In the relevant patent application, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Since the ridges and valleys of the fingerprint have different reflective capabilities for light, the reflected light from the fingerprint ridges and the reflected light from the valleys of the fingerprint have different light intensities. After the reflected light passes through the display screen 120, it is received by the sensor chip in the fingerprint recognition module 140 and converted into a corresponding electrical signal, namely, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby realizing the optical fingerprint recognition function in the electronic device 100.

It can be seen that when the user needs to perform fingerprint unlocking or other fingerprint verification on the electronic device 100, the user only needs to press the finger on the fingerprint collection area 130 located on the display screen 120 to implement the fingerprint feature input operation. Since the collection of fingerprint features can be implemented inside the display area 102 of the display screen 120, the electronic device 100 using the above structure does not need to reserve space on its front to set a fingerprint button (such as the Home button), so a full-screen solution can be adopted. Therefore, the display area 102 of the display screen 120 can be basically extended to the entire front of the electronic device 100.

Of course, in other alternatives, the fingerprint recognition module 140 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection and recognition. In this case, the fingerprint recognition module 140 can be applied not only to self-luminous display screens such as OLED display screens, but also to non-self-luminous display screens, such as liquid crystal display screens or other passive light-emitting display screens.

Taking the application in a liquid crystal display screen having a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display screen, the optical fingerprint system of the electronic device 100 may also include an excitation light source for optical fingerprint detection, and the excitation light source may be specifically an infrared light source or a light source of non-visible light of a specific wavelength, which may be arranged below the backlight module of the liquid crystal display screen or in the edge area below the protective cover of the electronic device 100, and the fingerprint recognition module 140 may be arranged below the edge area of the liquid crystal panel or the protective cover and guided through the optical path so that the fingerprint detection light can reach the fingerprint recognition module 140; or, the fingerprint recognition module 140 may also be arranged below the backlight module, and the backlight module may allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the fingerprint recognition module 140 by opening holes or other optical designs in the film layers such as the diffusion sheet, the brightness enhancement sheet, and the reflective sheet. When the fingerprint recognition module 140 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, the detection principle may be the same.

As shown in FIG. 1 , the electronic device 100 may further include a protective cover 110 .

The cover plate 110 may be specifically a transparent cover plate, such as a glass cover plate or a sapphire cover plate, which is located above the display screen 120 and covers the front of the electronic device 100, and a protective layer may also be provided on the surface of the cover plate 110. Therefore, in the embodiment of the present application, the so-called finger pressing the display screen 120 may actually refer to the finger pressing the cover plate 110 above the display screen 120 or the surface of the protective layer covering the cover plate 110.

As shown in FIG. 1 , a circuit board 150 , such as a flexible printed circuit (FPC), may be further disposed below the fingerprint recognition module 140 .

The fingerprint recognition module 140 can be soldered to the circuit board 150 through the pads, and the circuit board 150 can be used to realize electrical interconnection and signal transmission with other peripheral circuits or other components of the electronic device 100. For example, the fingerprint recognition module 140 can receive a control signal of the processing unit of the electronic device 100 through the circuit board 150, and can also output the fingerprint detection signal from the fingerprint recognition module 140 to the processing unit or control unit of the electronic device 100 through the circuit board 150.

3 to 6 are schematic structural diagrams of a fingerprint detection device 200 according to an embodiment of the present application. The fingerprint detection device 200 is applicable to an electronic device having a display screen, for example, the fingerprint detection device 200 can be applicable to an electronic device 100 as shown in FIG. 1 or FIG. 2 , and the fingerprint detection device 200 can be arranged below the display screen of the electronic device.

It should be noted that, for the convenience of explanation, in the embodiments of the present application, the same figure marks are used to represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

As shown in FIG. 3 , the fingerprint detection device 200 includes: a substrate 210 , an optical path layer 220 , a first sensor chip 230 , a bracket 251 and a filter layer 260 . Specifically, the lower surface of the filter layer 260 is provided with a silk-screened supporting ink 261. For example, the supporting ink 261 can be located in any area of the lower surface of the filter layer 260 corresponding to the sensing area of the first sensor chip 230; the optical path layer 220 is arranged below the filter layer 260, and there is a gap between the upper surface of the optical path layer 220 and the upper surface of the supporting ink 261. At the same time, the supporting ink 261 can also support the filter layer 260 so that a gap is maintained between the lower surface of the filter layer 260 and the upper surface of the optical path layer; the first sensor chip 230 is arranged below the optical path layer 220; the upper surface of the substrate 210 extends downward to form a first groove, at least a portion of the first sensor chip 230 is arranged in the first groove and is electrically connected to the substrate 210; the bracket 251 is arranged above the substrate 210 around the first sensor chip 230 to support the filter layer 260. The first sensor chip 230 is used to receive a fingerprint detection signal that is returned from a human finger above the display screen and passes through the filter layer 260 and the optical path layer 220 , and the fingerprint detection signal is used to detect the fingerprint information of the finger.

The fingerprint recognition module 200 of the embodiment of the present application sets the filter layer 260 above the optical path layer 220. This external filter layer 260 can effectively block the influence of ambient light on the fingerprint recognition process, avoid the image contrast reduction caused by strong light intervention when the user performs fingerprint unlocking, and thus prevent abnormal unlocking problems; and a silk-screened supporting ink 261 is set in the sensing area corresponding to the fingerprint chip on the lower surface of the filter layer 260, and the middle position of the filter layer 260 is supported by the supporting ink 261 to prevent the filter layer 260 from deforming and contacting the optical path layer 220 during the use of the fingerprint recognition module 200, such as when collecting fingerprint information, to generate a Newton ring problem.

In addition, the optical path layer 220 of the fingerprint detection device 200 of the embodiment of the present application is directly arranged on the upper surface of the first sensor chip 230, and the lower surface of the first sensor chip 230 is fixed on the substrate 210, which can avoid the need to set up a separate shell for carrying the optical path layer 220 and the first sensor chip 230, thereby reducing the size (for example, thickness) of the fingerprint detection device 200; and, setting the fingerprint detection device 200 in a groove of the substrate can reduce the thickness of the fingerprint detection device 200.

Thirdly, the close fit between the layers in the thickness direction ensures that the thickness of the fingerprint detection device is reduced to the greatest extent.

Finally, since the optical path layer 220 is directly arranged on the upper surface of the first sensor chip 230, the image acquisition field of view of the fingerprint detection device 200 is only affected by the area of the optical path layer 220 and the corresponding area of the first sensor chip 230. Based on this, the area of the optical path layer 220 and the corresponding area of the first sensor chip 230 can be reasonably designed according to actual needs to meet the needs of different users and different customers (for example, it can meet the needs of a large area image acquisition field of view).

Optionally, as shown in FIG. 3 , the fingerprint recognition module 200 further includes a first gold wire 250 for electrically connecting the first sensor chip 230 and the substrate 210, and the first gold wire 250 is located between the side wall of the first sensor chip and the side wall of the first groove, and in the gap between the side wall of the bracket close to the first sensor chip and the side wall of the first sensor chip.

As shown in Figure 4, the substrate 210 of the embodiment of the present application may include, from top to bottom, a first covering layer 212, a first conductive layer 211, a base layer 213, a second conductive layer 214 and a second covering layer 215. The upper surface of the substrate 210 extends downward in a first area and penetrates the first covering layer 212 and the first conductive layer 211 to form a first groove. The upper surface of the substrate 210 extends downward in a second area connected to the first area and penetrates the first covering layer 212 to form a solder pad 2111 of the substrate 210.

Optionally, in other alternative embodiments, the substrate 210 may include a conductive layer other than the first conductive layer 211 and the second conductive layer 214. Optionally, the first conductive layer 211 or the second conductive layer 214 may be a copper layer or a copper foil layer. Optionally, the first covering layer 212 or the second covering layer 213 may be an insulating layer (e.g., a resin layer).

As shown in Figure 3, the optical path layer 220 is arranged above the first sensor chip 230. The lower surface of the first sensor chip 230 can be fixed to the first groove by the first fixing glue 240. The first sensor chip 230 is connected to the pad 2111 of the substrate 210 through the first gold wire 250. The first sensor chip 230 is used to receive a fingerprint detection signal returned by a human finger above the display screen and guided by the optical path layer 220, and the fingerprint detection signal is used to detect the fingerprint information of the finger.

In other words, the lower surface of the first sensor chip 230 is adhered to the first groove by the first fixing glue 240, so that at least a part of the first sensor chip 230 is set in the first groove and is electrically connected to the substrate 210 through the first gold wire 250; wherein, the first sensor chip 230 can be set below the display screen of the electronic device through the substrate 210, and the first sensor chip 230 is used to receive the fingerprint detection signal returned by the reflection or scattering of the human finger above the display screen, and detect the fingerprint information of the finger based on the fingerprint detection signal to perform fingerprint registration or identification.

It should be understood that the first sensor chip 230 may include multiple chips or one chip. For example, the first sensor chip 230 may include multiple optical fingerprint sensor chips, which are arranged side by side in the first groove to form an optical fingerprint sensor chip assembly. The optical fingerprint sensor chip assembly can be used to simultaneously acquire multiple fingerprint images, which can be used as a fingerprint image for fingerprint registration or identification after being spliced.

For the fingerprint detection device 200, the optical path layer 220 is directly arranged on the upper surface of the first sensor chip 230, and the lower surface of the first sensor chip 230 is fixed on the substrate 210 by the first fixing glue 240, which can avoid setting up a separate shell for carrying the optical path layer 220 and the first sensor chip 230, thereby reducing the size (for example, thickness) of the fingerprint detection device 200.

In addition, by removing the first covering layer 212 and the first conductive layer 211 of the substrate 210 at the first region to form a first groove for accommodating the first fixing glue 240 and the first sensor chip 230 , the thickness of the fingerprint detection device 200 can be reduced.

Secondly, by removing the first covering layer 212 at the second area of the substrate 210, a substrate 210 pad 2111 for electrically connecting the first sensor chip 230 is formed, which can provide an accommodation space for the first gold wire 250 for electrically connecting the first sensor chip 230 and the substrate 210. Accordingly, the space occupied by the first gold wire 250 above the substrate 210 is reduced, thereby reducing the thickness of the fingerprint detection device 200.

Thirdly, in the thickness direction, the various layers are closely matched to ensure that the thickness of the fingerprint detection device 200 is reduced to the greatest extent.

Finally, since the optical path layer 220 is directly arranged on the upper surface of the first sensor chip 230, the image acquisition field of view of the fingerprint detection device 200 is only affected by the area of the optical path layer 220 and the corresponding area of the first sensor chip 230. Based on this, the area of the optical path layer 220 and the corresponding area of the first sensor chip 230 can be reasonably designed according to actual needs to meet the needs of different users and different customers (such as the need for a large-area image acquisition field of view).

In summary, the technical solution of the present application can not only reduce the thickness of the fingerprint detection device 200, but also ensure a sufficiently large image acquisition field of view.

As shown in FIG. 3 and FIG. 4 , in some embodiments of the present application, there is a gap d1 between the sidewall of the first sensor chip 230 and the sidewall of the first groove.

By designing a certain gap d1 between the side wall of the first sensor chip 230 and the side wall of the first groove, even if there is a difference between the size of the prepared product of the first sensor chip 230 and the designed size of the first sensor chip 230, or even if there is a difference between the actual size of the first groove and the designed size of the first groove, it does not affect the installation of the first sensor chip 230 in the first groove.

In other words, the gap d1 between the side wall of the first sensor chip 230 and the side wall of the first groove can be used not only as the dimensional tolerance of the first sensor chip 230 and/or as the dimensional tolerance of the first groove, but also as the installation tolerance of the first sensor chip 230. Accordingly, the yield of the fingerprint detection device 200 can be improved. The dimensional tolerance can be the absolute value of the difference between the maximum limit size allowed and the minimum limit size allowed, or the dimensional tolerance can be the difference between the upper deviation allowed and the lower deviation allowed. Limit deviation = limit size - basic size, upper deviation = maximum limit size - basic size, lower deviation = minimum limit size - basic size. The dimensional tolerance of the first sensor chip 230 can be the amount of variation allowed during the cutting process of the first sensor chip 230. When the basic size is the same, the smaller the dimensional tolerance, the higher the dimensional accuracy. Similarly, the installation tolerance of the first sensor chip 230 may refer to an offset distance between an allowable first extreme installation position and a second extreme installation position, wherein the first extreme installation position may be an allowable installation position closest to the first side wall of the first groove, and the second extreme installation position may be an allowable installation position closest to the second side wall of the first groove, wherein the first side wall is a side wall opposite to the second side wall.

For example, the width d1 of the gap between the sidewall of the first sensor chip 230 and the sidewall of the first groove has a value range of 100-400um, for example, d1=200um. Of course, alternatively, the width of the gap d1 between the sidewall of the first sensor chip 230 and the sidewall of the first groove may also be other values, or belong to another preset value range, and the present application does not make specific restrictions on this. For example, the width of the gap d1 between the sidewall of the first sensor chip 230 and the sidewall of the first groove may also be 100um or 300um. For another example, the width of the gap d1 between the sidewall of the first sensor chip 230 and the sidewall of the first groove may also be within 100um~300un.

It should be noted that the present application does not specifically limit the thickness of each component or layer in the fingerprint detection device 200. As long as the structural relationship between the various components or layers adopts the design scheme of the present application and the thickness of the fingerprint detection device is controlled by a close fit, it falls within the scope of protection of the present application.

For example, the thickness of the substrate 210 in the embodiment of the present application is less than or equal to 150 um, for example, the thickness of the substrate 210 can be set to 130 um. The thickness of the first covering layer 212 and the thickness of the second covering layer can be set to be the same, and the thickness of the first conductive layer 211 and the thickness of the second conductive layer can be set to be the same.

As an example, the thickness of the first covering layer 212 and the thickness of the second covering layer can be set to be less than or equal to 30um, for example, can be set to 20um, the thickness of the first conductive layer 211 and the thickness of the second conductive layer can be set to be less than or equal to 20um, for example, can be set to 13um, and the thickness of the substrate can be set to be less than or equal to 80um, for example, can be set to 64um.

For another example, the thickness of the first sensor chip 230 can be set to be less than or equal to 150um, for example, it can be specifically set to 60um; the thickness of the optical path layer 220 can be less than or equal to 30um, for example, it can be set to 16um or 15.7um; the maximum arc height d6 of the first gold wire 250 can be set to be less than or equal to 60um, for example, it can be set to 40um, and the thickness of the first fixing glue 240 can be set to be less than or equal to 30um, for example, it can be set to 15um.

Of course, the thickness of the first covering layer 212, the thickness of the first conductive layer 211, the thickness of the substrate layer 213, the thickness of the second conductive layer 214, the thickness of the second covering layer 215, the thickness of the first sensor chip 230, the thickness of the first fixing glue 240, or the maximum arc height d6 of the first gold wire 250 may also be other values or within a preset value range, and the present application does not make any specific limitations on this.

It should be understood that the bracket 251 in the embodiment of the present application is disposed on the upper surface of the first covering layer 212 and located outside the first sensor chip 230 , and can also be used to fix the filter layer 260 .

Optionally, the bracket 251 is fixed to the upper surface of the first cover layer 212 and is located outside the first sensor chip 230 by a bracket fixing glue 253. For example, the material of the bracket 251 includes but is not limited to metal, resin, glass fiber composite board and glue layer. For example, the bracket 251 is a polyethylene glycol terephthalate (PET) glue layer. For another example, the bracket 251 can be a bracket formed by a foam material. Optionally, the bracket fixing glue can be a double-sided adhesive.

In other words, the bracket 251 may be disposed above the substrate 210 and located outside or in a surrounding area of the first groove and a pad (for electrically connecting the first sensor chip 230 ) of the substrate 210 .

Optionally, as shown in Figure 3 or Figure 4, the thickness of the bracket 251 (including the bracket fixing glue 253) can be set according to actual applications, for example, it can be set to be less than or equal to 150um, for example, the thickness of the bracket 251 can be set to 70um, that is, the thickness at point C in Figures 3 to 6 can include, from top to bottom: the thickness of the bracket 251 (including the bracket fixing glue 253) (for example, 70um) and the thickness of the substrate 210, wherein the thickness of the substrate 210 includes the thickness of the first covering layer 212 (for example, 20um), the thickness of the first conductive layer 211 (for example, 13um), the thickness of the substrate (for example, 64um), the thickness of the second conductive layer (for example, 13um) and the thickness of the second covering layer (for example, 20um).

As shown in FIG3 , in some embodiments of the present application, the width of the gap d2 formed between the first sensor chip 230 and the bracket 251 is greater than or equal to the width of the gap d1 formed between the sidewall of the first sensor chip 230 and the sidewall of the first groove, and the outer side of the bracket 251 is shortened by a preset distance d3 relative to the outer side of the first cover layer 212 in the direction close to the first sensor chip 230. As an example, the width of the gap d2 formed between the first sensor chip 230 and the bracket 251 can be set to a range of 100-400um, for example, d2 can be 270um, and the preset distance d3 can be set to 100-400um, for example, d3 can be 200um.

In addition, the gap d2 formed by the first sensor chip 230 and the bracket 251 can be used not only as the size tolerance of the bracket 251, but also as the installation tolerance of the bracket 251, and accordingly, the yield of the fingerprint detection device 200 can be improved. Similarly, the preset distance d3 can be used not only as the size tolerance of the bracket 251, but also as the installation tolerance of the bracket 251, and accordingly, the yield of the fingerprint detection device 200 can be improved.

Of course, in other alternative embodiments, the gap d2 formed between the first sensor chip 230 and the bracket 251, the preset distance d3 or the thickness of the bracket 251 can be other specific values or within a preset value range. For example, the thickness of the bracket 251 can also be 80 um.

As shown in FIG3 , in some embodiments of the present application, the fingerprint detection device 200 may further include a gold wire protection glue 252, wherein the gold wire protection glue 252 is used to encapsulate the first gold wire 250. The gold wire protection glue 252 can ensure the stability of the electrical connection between the substrate 210 and the first sensor chip 230, and accordingly, the performance of the fingerprint detection device 200 can be ensured.

In some embodiments of the present application, the thickness of the gold wire protection glue 252 may be greater than or less than or equal to the sum of the thickness of the optical path layer 220, the thickness of the first sensor chip 230, and the thickness of the first fixing glue 240. For example, as shown in FIG3 , the thickness of the gold wire protection glue 252 may be equal to the sum of the maximum arc height of the first gold wire 250, the thickness of the first sensor chip 230, and the thickness of the first fixing glue 240. Optionally, the thickness of the gold wire protection glue 252 may be set according to actual applications, for example, it may be set to be less than or equal to 200um, or other values.

For example, as shown in Figures 3 to 6, the thickness at point B may include, from top to bottom: the maximum arc height of the first gold wire 250 (e.g., 40um), the thickness of the first sensor chip 230 (e.g., 60um), the thickness of the first chip fixing glue 230 (e.g., 15um), the thickness of the substrate (e.g., 64um), the thickness of the second conductive layer (e.g., 13um) and the thickness of the second covering layer (e.g., 20um).

Of course, other parameters can also be designed for the bracket 251 to guide the preparation and installation of the bracket 251. For example, as shown in Figures 3 and 4, in some embodiments of the present application, the width of the gap d4 between the side of the pad 2111 (for electrically connecting the first sensor chip 230) close to the substrate 210 of the first sensor chip 230 and the bracket 251 is greater than the gap d2 between the side of the pad 2111 (for electrically connecting the first sensor chip 230) away from the substrate 210 of the first sensor chip 230 and the bracket 251, so as to reserve sufficient accommodation space for the bracket fixing glue 252. Optionally, the width of the gap d4 between the side of the pad 2111 of the first sensor chip 230 close to the substrate 210 and the bracket 251 can be 300um or other values.

As shown in FIG. 5 and FIG. 6 , in some embodiments of the present application, the fingerprint detection device 200 may further include a second sensor chip 280 , a second fixing glue 281 and a second gold wire 282 .

Among them, the upper surface of the substrate 210 extends downward in a third area connected to the second area and penetrates the first covering layer 212 and the first conductive layer 211 to form a second groove, and the second sensor chip 280 is fixed in the second groove by a second fixing glue 281, and the second sensor chip 280 is connected to the pad 2111 of the substrate 210 by the second gold wire 282, so that the second sensor chip 280 is connected to the first sensor chip 230, and the second sensor chip 280 is used to cooperate with the first sensor chip 230 to perform under-screen fingerprint recognition.

By setting up the second sensor chip 280, the processing task of the first sensor chip 230 can be shared, which is equivalent to replacing a fully functional and thicker sensor chip with a first sensor chip 230 and a second sensor chip 280 that are thinner and set in parallel. Accordingly, the thickness of the fingerprint detection device 200 can be reduced without affecting the fingerprint recognition performance.

In some embodiments of the present application, there is a gap d7 between the sidewall of the second sensor chip 280 and the sidewall of the second groove. Optionally, the width of the gap d7 between the sidewall of the second sensor chip 280 and the sidewall of the second groove is in the range of 100-400um, for example, can be set to 200um.

Optionally, the thickness of the second sensor chip 280 can range from 100 to 400um, and can be set to be equal to the first sensor chip 230, for example, both can be set to 60um; similarly, the maximum arc height of the second gold wire 282 can be set to be less than or equal to 60um, or can be set to be the same as the arc height of the first gold wire 250, for example, can be set to 40um; the thickness of the second fixing glue 281 can be set to be less than or equal to 30um, or can be set to be the same as the first fixing glue 240, for example, both can be set to 15um.

Of course, alternatively, the width of the gap d7 between the side wall of the second sensor chip 280 and the side wall of the second groove, the thickness of the second sensor chip 280, the maximum arc height of the second gold wire 282, or the thickness of the second fixing glue 281 may also be other specific values or within a preset value range, and the embodiments of the present application do not make specific limitations on this.

By designing a certain gap d7 between the side wall of the second sensor chip 280 and the side wall of the second groove, even if there is a difference between the size of the prepared product of the second sensor chip 280 and the designed size of the second sensor chip 280, or even if there is a difference between the actual size of the second groove and the designed size of the second groove, it does not affect the installation of the second sensor chip 280 in the second groove.

In other words, the gap between the side wall of the second sensor chip 280 and the side wall of the second groove can not only be used as the size tolerance of the second sensor chip 280 and/or as the size tolerance of the second groove, but also can be used as the installation tolerance of the second sensor chip 280. Accordingly, the yield of the fingerprint detection device 200 can be improved.

It should be understood that no matter it is the fingerprint detection device including one sensor chip as shown in FIGS. 3 and 4 , or the fingerprint detection device including two sensor chips as shown in FIGS. 5 and 6 , the filter layer 260 is disposed above the optical path layer 220 .

It should be understood that the filter layer 260 of the embodiment of the present application is used to reduce the undesired ambient light in fingerprint sensing to improve the optical sensitivity of the first sensor chip 230 to the received light. For example, the filter layer 260 can be used to filter out light of a specific wavelength, such as near-infrared light and part of red light. For example, human fingers absorb most of the energy of light with a wavelength below 580nm. Based on this, the filter can be designed to filter light with a wavelength from 580nm to infrared to reduce the impact of ambient light on optical detection in fingerprint sensing.

In a specific implementation, the filter layer 260 may include one or more optical filters, which may be configured as, for example, a bandpass filter to allow transmission of light emitted by the OLED screen while blocking other light components such as infrared light in sunlight.

Specifically, as shown in FIGS. 3 to 6 , the filter layer 260 of the embodiment of the present application can be fixed on the upper side of the bracket 251. Specifically, one side of the lower surface of the filter layer 260 close to the first gold wire 250 can be fixed to the upper surface of the first sensor chip 230, while the other sides of the lower surface of the filter layer 260 are fixed to the upper surface of the bracket 251.

For example, as shown in FIG3 , one side of the lower surface of the filter layer 260 close to the first gold wire can be fixed to the upper surface of the first sensor chip 230 by a first adhesive 262, and the other sides of the lower surface of the filter layer 260 can be fixed to the upper surface of the bracket 251 by a second adhesive 263. The thickness of the first adhesive and the second adhesive can be set according to the actual application to ensure that the filter layer 260 is parallel to the optical path layer 220, or the filter layer 260 is parallel to the plane where the sensing area of the upper surface of the first sensor chip 230 is located. For example, according to the size of other parts, the thickness of the first adhesive 262 can be set to be less than or equal to 60, for example, it can be set to 48um, and the thickness of the second adhesive can be set to be less than or equal to 60, for example, it can be set to 20um.

Specifically, assuming that the lower surface of the filter layer 260 is a rectangle, one side of the lower surface of the filter layer 260 is close to the first gold wire 250, and the other three sides are not close to the first gold wire 250. The three sides not close to the gold wire can be fixed on the upper surface of the bracket 251, while the side close to the first gold wire 250 is fixed to the upper surface of the first sensor chip 230, so as to avoid affecting the installation of the first gold wire 250; at the same time, the side of the lower surface of the filter layer 260 close to the first gold wire 250 is fixed to the upper surface of the first sensor chip 230 through the first backing glue 262, and the first backing glue 262 can also prevent the gold wire protective glue used to fix the gold wire from flowing into the optical path layer.

The thickness of the filter layer 260 can be set according to actual applications. For example, the thickness of the filter layer 260 can be set to be less than or equal to 220 um. For example, considering the existing process and mass production, the thickness of the filter layer is usually selected to be 110 um.

Optionally, the supporting ink 261 may be located at any position on the lower surface of the filter layer 260 corresponding to the position of the sensing area of the first sensor chip 230. For example, since the center position provides a more balanced support force for the entire filter layer 260, the position of the silk-screened supporting ink 261 is usually set to coincide with the center of the sensing area of the first sensor chip 230 below, that is, the center of the supporting ink 261 is set to coincide with the center of the sensing area of the first sensor chip 230 in the vertical direction.

It should be understood that the supporting ink 261 is located between the filter layer 260 and the optical path layer 220, and is used to support the filter layer 200, so that a gap is maintained between the filter layer 260 and the optical path layer 220, and at the same time, a gap can also be maintained between the lower surface of the supporting ink 261 and the upper surface of the optical path layer 220. As the thickness of the supporting ink 261 increases, that is, the distance between the upper surface of the optical path layer 220 and the lower surface of the filter layer 260 increases, the contrast of the Newton's ring gradually decreases. FIG. 7 shows several Newton's ring effect diagrams. As shown in FIG. 7, h represents the distance between the filter layer and the upper surface of the optical path layer above the sensor chip. In this embodiment, based on the above-mentioned size setting, when the distance is 25um, the Newton's ring basically disappears. Therefore, the thickness of the supporting ink is usually set to be less than or equal to 30um, for example, it can be set to 25um, that is, the distance between the filter layer 260 and the upper surface of the optical path layer 220 below is 25um, so as to avoid the appearance of Newton's rings. It can be understood that the distance h is not limited to 25um, and it can be adjusted according to actual conditions.

Optionally, the area of the supporting ink can be set according to the actual application. Under the premise of not affecting fingerprint recognition, the larger the size of the silk-screen supporting ink 261, the better the supporting effect on the filter layer 260, that is, the less likely the filter layer is to deform, and the less likely it is to produce Newton rings. However, since the supporting ink 261 will block the returned fingerprint detection signal, the area of the supporting ink should not be too large. For example, the area of the supporting ink 261 can usually be set to be less than or equal to 40*40um, for example, it can be set to a square of 30um*30um.

In the embodiment of the present application, the material of the filter layer 260 can be glass, crystal, resin film, etc., or can also be other materials. In order to ensure that the filter layer 260 can transmit the fingerprint detection signal returned by the finger to the first sensor chip 230 below, and ensure that the first sensor chip 230 can receive enough light signals, thereby ensuring the improvement of the fingerprint recognition effect, the light-incoming surface of the filter layer 260 needs to be coated with an optical inorganic coating or an organic black coating to achieve ultra-low reflection of light, for example, usually set to a reflectivity of <1%.

Optionally, in the embodiment of the present application, there is a gap between the lower surface of the supporting ink 261 and the upper surface of the optical path layer 220, and the gap size d5 can be set according to the actual application and can be adjusted according to the size of other components. For example, as shown in Figures 3 to 6, the thickness at A from top to bottom may include: the thickness of the filter layer 260 (for example, 110um), the thickness of the supporting ink 261 (for example, 25um), the gap d5 between the lower surface of the supporting ink 261 and the upper surface of the optical path layer 220 (for example, 7.3um), the thickness of the optical path layer 220 (for example, 15.7), the thickness of the first sensor chip 230 (for example, 60um), the thickness of the first chip fixing glue 230 (for example, 15um), the thickness of the substrate (for example, 64um), the thickness of the second conductive layer (for example, 13um) and the thickness of the second covering layer (for example, 20um).

It should be understood that, as shown in FIGS. 3 to 6 , the total thickness at A is the total thickness of the fingerprint detection device 200 . According to the description of the above embodiments, the total thickness of the fingerprint detection device 200 can be set within the range of 0.15-0.6 mm.

The optical path layer 220 of the embodiment of the present application may include a lens layer 221 and an optical path guide layer 222, wherein the lens layer 221 is used to converge the optical signal returned by the human finger above the display screen to the optical path guide layer 222, and the optical path guide layer 222 guides the optical signal converged by the lens layer 221 to the first sensor chip 230.

Considering that the filter layer 260 of the fingerprint detection device 200 is arranged above the optical path layer 220, it is possible that the height of the upper surface of the bracket 251 is less than the height of the upper surface of the filter layer 260. For example, as shown in Figures 3 to 6, the height of the upper surface of the entire fingerprint detection device is inconsistent. At this time, foam can be provided to make the upper surface of the fingerprint detection device 200 flat, thereby facilitating the installation of the fingerprint detection device 200 below the display screen. Specifically, the fingerprint detection device may further include: a foam layer, which is arranged above the bracket 251 around the filter layer 260, the foam layer is provided with an opening that passes through the foam layer, and the first sensor chip 230 receives the fingerprint detection signal through the opening of the foam layer; the upper surface of the foam layer is flush with the upper surface of the filter layer 260, so that the upper surface of the fingerprint detection device 200 is flat.

Optionally, the arc height position of the first gold wire 250 may be designed to be embedded in the foam layer; or, a foam layer may be disposed above the first gold wire 250 according to the arc height position thereof.

It should be noted that when the fingerprint detection device 200 is installed in an electronic device, it can be connected to the main board of the electronic device through an additional flexible circuit board. For example, as shown in FIG8 , the substrate 210 can also include a gold finger 2122 of the substrate 210, and the gold finger 2122 of the substrate 210 is used to connect to the flexible circuit board. Accordingly, the substrate 210 is connected to the main board of the electronic device through the flexible circuit board.

FIG9 is a schematic structural diagram of a fingerprint detection device 200 provided with a flexible circuit board according to an embodiment of the present application. As shown in FIG9 , in some embodiments of the present application, the fingerprint detection device 200 may further include a flexible circuit board 290 and an Anisotropic Conductive Film (ACF) 292, wherein the flexible circuit board 290 is formed with a gold finger 291 of the flexible circuit board 290; the gold finger 291 of the flexible circuit board 290 is electrically connected to the gold finger 2122 of the substrate 210 through the anisotropic conductive film 292.

Through the anisotropic conductive adhesive film 292, the gold finger 291 of the flexible circuit board 290 can be pressed onto the gold finger 2122 of the substrate 210, which is equivalent to configuring flexible circuit boards of different specifications for the fingerprint detection device 200, so that the fingerprint detection device 200 is more versatile and can meet the needs of different users or customers accordingly.

As shown in FIG9 , in some embodiments of the present application, the fingerprint detection device 200 may further include a protective glue 293 of the anisotropic conductive film 292, and the protective glue 293 may be located at both ends of the anisotropic conductive film 292 to protect the anisotropic conductive film 292, and further protect the gold finger 291 of the flexible circuit board 290 and the gold finger 2122 of the substrate 210. As shown in FIG9 , in some embodiments of the present application, the fingerprint detection device 200 may further include an image processor 296, and the image processor 296 is disposed at one end of the flexible circuit board 290. For example, the image processor 296 may be a microprocessor (MCU) for receiving a fingerprint detection signal (such as a fingerprint image) sent from the first sensor chip 230 through the flexible circuit board 290, and performing simple processing on the fingerprint detection signal. As shown in FIG9 , in some embodiments of the present application, the fingerprint detection device 200 may further include at least one capacitor 295 disposed at one end of the flexible circuit board 290, and the at least one capacitor 295 is used to optimize (e.g., filter) the fingerprint detection signal collected by the first sensor chip 230. Optionally, each chip in the first sensor chip 230 corresponds to one or more capacitors. As shown in FIG9 , in some embodiments of the present application, the fingerprint detection device 200 may further include a connector 294 disposed at one end of the flexible circuit board 290, and the connector 294 may be used to connect to an external device or other components of the electronic device (e.g., a motherboard), thereby realizing communication with the external device or other components of the electronic device. For example, the connector 294 may be used to connect to the processor of the electronic device, so that the processor of the electronic device receives the fingerprint detection signal processed by the image processor 296, and performs fingerprint recognition based on the processed fingerprint detection signal.

It should be understood that FIGS. 3 to 9 are merely examples of embodiments of the present application and should not be construed as limiting the present application.

For example, in FIG. 3 to FIG. 6 , the lens layer 221 is used as a device for converging light signals in the optical path layer 220. Alternatively, the lens layer 221 may also use an optical collimator. The relevant description of the optical collimator may refer to the relevant description of the optical path design of the fingerprint detection device 130 in the foregoing content.

For another example, the lens layer 221 may have a microlens array formed by a plurality of microlenses, the optical path guiding layer 222 may be a light blocking layer, the light blocking layer having a plurality of microholes and arranged below the microlens layer 221, and the microholes correspond one to one with the microlenses, and one or more optical sensing units in the first sensor chip 230 correspond to a microlens in the lens layer 221. Optionally, the optical path layer 220 may further include other optical film layers, such as a dielectric layer or a passivation layer.

The fingerprint detection device 200 according to the embodiment of the present application is introduced above in conjunction with FIG. 3 to FIG. 9 . The electronic device equipped with the fingerprint detection device 200 is described below.

FIG. 10 is a schematic structural diagram of an electronic device 300 equipped with the fingerprint detection device 200 shown in FIG. 4 according to an embodiment of the present application.

As shown in FIG. 10 , the electronic device 300 includes a display screen, a middle frame 360 located below the display screen, a battery 370 located below the middle frame 360, and a battery pull-out adhesive 380 located below the battery, wherein the display screen includes a transparent cover plate 310, a display panel 320, a cushion layer 330, and a copper layer 340 from top to bottom, and the display screen is provided with a window penetrating the buffer layer 330 and the copper layer 340. In other words, the buffer layer 330 may be provided with a first window 331 penetrating the buffer layer 330, and the copper layer 340 may be provided with a second window 341 penetrating the copper layer 340. Optionally, the display screen may be an OLED organic light-emitting panel made of low-temperature polysilicon technology (LTPS), which is ultra-thin, light, and low in power consumption, and can be used to provide a clearer image. The middle frame 360 may be used to carry or support various devices or components in the electronic device 300. The devices or components include but are not limited to batteries, cameras, antennas, main boards and the display screen.

The buffer layer 330 may also be referred to as a screen print layer or an embossed layer, and the screen print layer may carry graphics, which may be used as logos such as trademark patterns. The buffer layer 330 may be a black sheet layer or a printed layer for shielding light. For example, the buffer layer 330 may be a layer structure formed by a foam material. The copper layer 340 may also be referred to as a heat dissipation layer (used to reduce the temperature of the display screen) or an anti-radiation layer. The buffer layer 330 and the copper layer 340 may be combined to form a rear panel of the display screen, or the copper layer 340 may be referred to as a rear panel of the display screen.

The specific functions and structures of the fingerprint detection device 200 may be understood by referring to the reference numerals in FIG. 5 and FIG. 6 .

In other words, the fingerprint detection device 200 includes a substrate 210, an optical path layer 220, a filter layer 260, a first sensor chip 230, a first fixing glue 240, a bracket 251 and a first gold wire 250. The substrate 210 includes a first covering layer 212, a first conductive layer 211, a substrate layer 212, a second conductive layer 214 and a second covering layer 215 from top to bottom. Optionally, the optical path layer 220 includes a lens layer 221 and an optical path guide layer 222 thereunder. Optionally, the fingerprint detection device 200 may further include a gold wire protection glue 252. The fingerprint detection device 200 may further include a foam layer 270 to make the surface of the fingerprint detection device 200 flush. Optionally, the fingerprint detection device 200 may further include a second sensor chip 280, a second fixing glue 281 and a second gold wire 282.

Based on the above structure, the installation scheme of the fingerprint detection device 200 is described in detail here. As shown in FIG10 , the foam 270 on the upper surface of the fingerprint detection device 200 is fixed to the surrounding area of the openings (i.e., the first openings 331 and the second openings 341) on the lower surface of the copper layer 340 through the first PSA 391, so that the first sensor chip 230 is aligned with the openings, and the first sensor chip is used to receive the fingerprint detection signal returned by the human finger above the display screen and guided by the optical path layer through the openings, and the fingerprint detection signal is used to detect the fingerprint information of the finger.

Taking the display screen as an OLED screen as an example, the display screen can be a soft screen or a hard screen. When a finger is placed on the illuminated OLED screen, the finger will reflect the light emitted by the OLED screen, and this reflected light will penetrate the OLED screen until it reaches the bottom of the OLED screen. The optical path layer located below the OLED screen can be used to filter out the infrared signal component in the leaked light. Since the fingerprint is a diffuse reflector, the light signal formed by reflection or diffusion of the finger will exist in all directions. The fingerprint detection device 200 collects the light signal leaked from the top of the OLED screen, and images the fingerprint image based on the received light signal.

For the fingerprint detection device 200, the optical path layer 220 is directly arranged on the upper surface of the first sensor chip 230, and the lower surface of the first sensor chip 230 is fixed on the substrate 210 by the first fixing glue 240, which can avoid setting up a separate shell for carrying the optical path layer 220 and the first sensor chip 230, thereby reducing the size (for example, thickness) of the fingerprint detection device 200.

In addition, by using the foam on the upper surface of the substrate 210 through the first PSA, the fingerprint detection device 200 is attached to the copper layer 340 of the display screen. Compared with directly attaching the fingerprint detection device 200 to the display panel (i.e., the OLED layer) of the display screen, it is not only possible to avoid affecting the performance of the display screen after attaching the fingerprint detection device 200 to the display screen, but also to reduce the difficulty of installing the fingerprint detection device 200. Accordingly, it is possible to reduce the installation complexity of the fingerprint detection device 200 and improve the yield of the electronic device 300. In addition, attaching the fingerprint detection device 200 to the copper layer 340 of the display screen can also avoid damaging the display screen during the disassembly of the fingerprint detection device 200. Accordingly, it is possible to reduce the disassembly complexity of the fingerprint detection device 200 and improve the yield of the electronic device 300. In addition, when the display screen is pressed or the electronic device falls or collides, the buffer layer 330 and the copper layer 340 exist between the display panel 320 and the fingerprint detection device 200, so as to avoid the display panel 320 and the fingerprint detection device 200 being squeezed and affecting the performance of the display panel 320 and the fingerprint detection device 200.

In addition, compared with directly attaching the fingerprint detection device 200 to the display panel 320 of the display screen, attaching the fingerprint detection device 200 to the copper layer 340 of the display screen can also avoid the size of the window being too large. Accordingly, it can reduce the visibility of the fingerprint detection device 200 when the user views it from the front of the display screen, thereby beautifying the appearance of the electronic device 300.

As shown in FIG. 10 , in some embodiments of the present application, UV curing glue 392 is disposed on the outer side of the foam layer 270 , part of the outer side of the bracket 251 , and the outer side of the first PSA 391 to fix the fingerprint detection device 200 relative to the display screen.

The UV curing adhesive 392 can not only fix the fingerprint detection device 200 relative to the display screen, but also reduce the difficulty of installing the fingerprint detection device 200 by utilizing the characteristics of the UV curing adhesive 392 .

It should be understood that FIG. 10 is merely an example of attaching the fingerprint detection device 200 to the display screen of an electronic device and should not be construed as a limitation to the present application.

For example, in FIG10 , the middle frame 360 is formed with a third window below the fingerprint detection device 200. In other words, the fingerprint detection device 200 is attached to the copper layer 340 of the display screen by hanging. For example, there is a gap between the fingerprint detection device 200 and the display screen. However, the above scheme is only one implementation method. In another implementation method, the upper surface of the middle frame extends downward to form a third groove, and the bottom of the fingerprint detection device 200 contacts the middle frame. In other words, the fingerprint detection device 200 is still attached to the copper layer 340 of the display screen by hanging, but there is no gap between the fingerprint detection device 200 and the display screen. In other words, the third groove is only used to provide a housing position for the fingerprint detection device 200, and is not used to fix the fingerprint detection device 200.

The fingerprint detection device 200 is designed through a stacked structure so that the components fit tightly together in the thickness direction (that is, the components fit tightly together in the thickness direction without reserving any gap). Based on the current thickness of the middle frame, even if the buffer layer 330 and the copper layer 340 in the display screen are retained, a gap of at least 200 um can be reserved between the bottom of the fingerprint detection device 200 and the battery 370, which is sufficient to set the fingerprint detection device 200 between the display screen and the battery 370.

Accordingly, compared with setting the fingerprint recognition device 200 at other positions outside the battery 370, setting the fingerprint detection device 200 between the display screen and the battery 370 not only does not require adjusting the original internal structure of the electronic device 300, but also can improve the utilization rate of the internal space of the electronic device 300. For example, the volume of the battery 370 can be increased, and the saved space can be used to accommodate the battery 370 with an increased volume. Accordingly, the service life and user experience of the electronic device 300 can be increased without increasing the volume of the electronic device 300.

The above description is made in conjunction with FIG. 10 to describe the solution of installing the fingerprint detection module 200 on the copper layer 340 of the display screen, but the embodiments of the present application are not limited thereto. For example, in other alternative embodiments, the fingerprint detection device 200 can also be installed and fixed on the middle frame 380 .

FIG11 is another schematic structural diagram of an electronic device 300 according to an embodiment of the present application, in which the fingerprint detection device 200 shown in FIG5 and FIG6 is installed. The specific functions and structures of the fingerprint detection device 200 can be understood with reference to the reference numerals in FIG5 and FIG6, and the functions and structures of the various components in the electronic device 300 can be understood with reference to FIG10. To avoid repetition, they will not be described again here.

As shown in FIG11 , the upper surface of the middle frame 380 extends downward to form a third groove, and the bottom of the fingerprint detection device 200 is disposed in the third groove through the second PSA 393. In other words, the third groove is only used to provide a storage position for the fingerprint detection device 200, and is also used to fix the fingerprint detection device 200.

As shown in Figure 11, in some embodiments of the present application, there is a gap between the fingerprint detection device 200 and the side wall of the third groove. The gap formed between the fingerprint detection device and the side wall of the third groove can be used as the size tolerance or installation tolerance of the fingerprint detection device 200, and can also be used as the size tolerance of the third groove.

As shown in FIG. 11 , in some embodiments of the present application, the buffer layer 330 may be provided with a first window 331 penetrating the buffer layer 330, and the copper layer 340 may be provided with a second window 341 penetrating the copper layer 340, wherein the size of the first window 331 is smaller than the size of the second window 341, so that the buffer layer 220 and the fingerprint detection device 200 form a buffer space. Optionally, as shown in FIG. 11 , the buffer space may be provided with a buffer material 396, and the buffer material 396 includes but is not limited to foam. In other words, the upper surface of the fingerprint detection device 200 is pressed against the buffer layer 330 through the buffer material 396. For example, the foam 270 on the upper surface of the fingerprint detection device 200 is pressed against the buffer layer 330 through the buffer material 396. The buffer material 396 can not only be used to prevent the fingerprint detection device 200 from touching the display screen and affecting the detection performance of the fingerprint detection device 200, but also can be sealed and dust-proof to ensure the detection performance of the fingerprint detection device 200 and improve the service life of the fingerprint detection device 200. In addition, the buffer material 396 can also reduce the visibility of the fingerprint detection device 200 when the user views it from the front of the display screen, thereby beautifying the appearance of the electronic device 300. In addition, by arranging the buffer material 396 in the buffer space, the internal space of the electronic device 300 can be reasonably utilized, thereby reducing the thickness of the electronic device and improving the user experience.

It should be understood that FIG. 10 and FIG. 11 are merely examples of the present application and should not be construed as limiting the present application.

For example, in other alternative embodiments, the fingerprint detection device can also be attached to the display screen and the middle frame at the same time. For another example, in order to maximize the use of the internal space of the electronic device, the fingerprint detection device 300 can also be attached and fixed to the side of the groove of the middle frame 380.

It should be understood that the specific examples in the embodiments of the present application are only intended to help those skilled in the art better understand the embodiments of the present application, rather than to limit the scope of the embodiments of the present application.

It should be understood that the terms used in the embodiments of the present application and the appended claims are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. For example, the singular forms "a", "above", and "said" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

Those of ordinary skill in the art will appreciate that the elements of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

In the several embodiments provided in the present application, it should be understood that the disclosed systems and devices can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the elements is only a logical function division. There may be other division methods in actual implementation, such as multiple elements or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or elements, or it can be an electrical, mechanical or other form of connection.

The functional elements mentioned above can be integrated or physically exist separately. Each functional element can be implemented in the form of hardware or in the form of a software functional unit. If it is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the prior art that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, RandomAccess Memory), a disk or an optical disk.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims (35)

1. A fingerprint detection device, characterized in that it is suitable for an electronic device with a display screen, and the fingerprint detection device is arranged below the display screen, comprising: A filter layer, wherein the lower surface of the filter layer is provided with a silk-screen supporting ink; An optical path layer is arranged below the optical filter layer, and a gap is provided between the upper surface of the optical path layer and the lower surface of the supporting ink, and the supporting ink is used to support the optical filter layer so that a gap is maintained between the upper surface of the optical path layer and the lower surface of the optical filter layer; A first sensor chip is arranged below the optical path layer, the optical path layer is arranged on the upper surface of the first sensor chip, and the center of the supporting ink coincides with the center of the sensing area of the first sensor chip in the vertical direction; A substrate, wherein an upper surface of the substrate extends downward to form a first groove, and at least a portion of the first sensor chip is disposed in the first groove and is electrically connected to the substrate; A bracket, arranged above the substrate around the first sensor chip, and used for supporting the filter layer; The first sensor chip is used to receive a fingerprint detection signal from a human finger passing through the filter layer and the optical path layer after returning from the human finger above the display screen, and the fingerprint detection signal is used to detect fingerprint information of the finger; The fingerprint detection device further includes: a first gold wire, which is used to electrically connect the first sensor chip and the conductive layer of the substrate, and is located between the side wall of the first sensor chip and the side wall of the first groove, and in a gap between the side wall of the bracket close to the first sensor chip and the side wall of the first sensor chip, one side of the lower surface of the filter layer close to the first gold wire is fixed to the upper surface of the first sensor chip, and the other sides of the lower surface of the filter layer are fixed to the upper surface of the bracket; The substrate includes, from top to bottom, a first covering layer, a first conductive layer, a base material layer, a second conductive layer, and a second covering layer. The upper surface of the substrate extends downward in a first region and penetrates the first covering layer and the first conductive layer to form the first groove. The upper surface of the substrate extends downward in a second region connected to the first region and penetrates the first covering layer to form a soldering pad of the substrate. The first sensor chip is connected to the soldering pad of the substrate through the first gold wire. 2. The fingerprint detection device according to claim 1, characterized in that there is a gap between the side wall of the first sensor chip and the side wall of the first groove, and between the side wall of the bracket close to the first sensor chip and the side wall of the first sensor chip. A width of a gap between a side wall of the support close to the first sensor chip and a side wall of the first sensor chip is greater than or equal to a width of a gap between a side wall of the first sensor chip and a side wall of the first groove. 3. The fingerprint detection device according to claim 1 is characterized in that one side of the lower surface of the filter layer close to the first gold wire is fixed to the upper surface of the first sensor chip by a first adhesive, and the other sides of the lower surface of the filter layer are fixed to the upper surface of the bracket by a second adhesive. 4. The fingerprint detection device according to any one of claims 1 to 3 is characterized in that the width of the gap between the side wall of the first sensor not close to the first gold wire and the side wall of the first groove is in the range of 100-400um, and the gap between the side wall of the first sensor not close to the first gold wire and the side wall of the bracket close to the first sensor chip is in the range of 100-400um. 5. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the thickness of the filter layer is less than or equal to 220 um. 6. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the thickness of the supporting ink is less than or equal to 30 um. 7. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the area of the supporting ink is less than or equal to 40*40um. 8. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the reflectivity of the light incident surface of the filter layer to light is less than or equal to 1%. 9. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the total thickness of the fingerprint detection device ranges from 0.15 to 0.6 mm. 10. The fingerprint detection device according to any one of claims 1 to 3, further comprising: A first fixing glue, wherein the lower surface of the first sensor chip is fixed to the first groove by the first fixing glue. 11. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the thickness of the first covering layer is equal to the thickness of the second covering layer, and the thickness of the first conductive layer is the same as the thickness of the second conductive layer. 12. The fingerprint detection device according to claim 11, characterized in that the total thickness of the substrate is less than or equal to 150 um, the thickness of the first covering layer and the thickness of the second covering layer are both less than or equal to 30 um, The thickness of the first conductive layer and the thickness of the second conductive layer are both less than or equal to 20 um, and the thickness of the substrate is less than or equal to 80 um. 13. The fingerprint detection device according to claim 10, characterized in that the thickness of the first sensor chip is less than or equal to 150um, the maximum arc height of the first gold wire is less than or equal to 60um, and the thickness of the first fixing glue is less than or equal to 30um. 14. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the outer side of the bracket is shortened by a preset distance relative to the outer side of the first covering layer in a direction approaching the first sensor chip. 15. The fingerprint detection device according to claim 14, characterized in that the preset distance has a value range of 100-400 um. 16. The fingerprint detection device according to any one of claims 1 to 3, further comprising: a second sensor chip, a second fixing glue and a second gold wire; The upper surface of the substrate extends downward in a third area connected to the second area and penetrates the first covering layer and the first conductive layer to form a second groove. The second sensor chip is fixed in the second groove by the second fixing glue, and the second sensor chip is connected to the pad of the substrate by the second gold wire, so that the second sensor chip is connected to the first sensor chip, and the second sensor chip is used to cooperate with the first sensor chip to perform under-screen fingerprint recognition. 17 . The fingerprint detection device according to claim 16 , wherein there is a gap between a side wall of the second sensor chip and a side wall of the second groove. 18. The fingerprint detection device according to claim 17, characterized in that a width of a gap between a side wall of the second sensor chip not close to the first gold wire and a side wall of the second groove is 100-400 um. 19. The fingerprint detection device according to claim 16 is characterized in that the lower surface of the first sensor chip is fixed to the first groove by a first fixing glue, the thickness of the first sensor chip is equal to the thickness of the second sensor chip, the thickness of the first fixing glue is equal to the thickness of the second fixing glue, and the maximum arc height of the first gold wire is equal to the maximum arc height of the second gold wire. 20. The fingerprint detection device according to claim 16, further comprising: The gold wire protection glue is used to encapsulate the first gold wire and the second gold wire. 21. The fingerprint detection device according to claim 20, characterized in that the height of the gold wire protection glue is less than or equal to 200um. 22. The fingerprint detection device according to any one of claims 1 to 3, further comprising: A foam layer, surrounding the filter layer and arranged above the bracket, the foam layer is provided with an opening penetrating the foam layer, and the first sensor chip receives the fingerprint detection signal through the opening of the foam layer; The upper surface of the foam layer is flush with the upper surface of the filter layer. 23. The fingerprint detection device according to claim 22, characterized in that the bracket is a polyethylene terephthalate (PET) adhesive layer, used to connect the substrate and the foam layer; or The lower surface of the bracket is fixed to the upper surface of the substrate by bracket fixing glue, and the upper surface of the bracket is fixed to the foam layer by bracket fixing glue. 24. The fingerprint detection device according to claim 22, characterized in that the thickness of the bracket is less than or equal to 150 um. 25. The fingerprint detection device according to claim 22, characterized in that the display screen comprises a transparent cover plate, a display panel, a buffer layer and a copper layer from top to bottom, and the display screen is provided with a window penetrating the buffer layer and the copper layer; The upper surface of the foam is fixed to the surrounding area of the window on the lower surface of the copper layer by a first pressure-sensitive adhesive, so that the fingerprint detection device is fixed below the display screen. The sensing area of the first sensor chip is aligned with the window, so that the first sensor chip receives the fingerprint detection signal. 26. The fingerprint detection device according to claim 25, characterized in that ultraviolet curing adhesive is provided on the outer side of the fingerprint detection device and the outer side of the first pressure-sensitive adhesive to fix the relative position of the fingerprint detection device with respect to the display screen. 27. The fingerprint detection device according to claim 22, characterized in that the display screen comprises a transparent cover plate, a display panel, a buffer layer and a copper layer from top to bottom, the display screen is provided with a window penetrating the buffer layer and the copper layer, and the size of the window of the buffer layer is smaller than the size of the window of the copper layer; The fingerprint detection device is located in a groove of the middle frame of the electronic device. The upper surface of the foam is fixed to the surrounding area of the window on the lower surface of the buffer layer by foam glue within the window range of the copper layer, so that the fingerprint detection device is fixed below the display screen. The sensing area of the first sensor chip is aligned with the window of the buffer layer, so that the first sensor chip receives the fingerprint detection signal. 28. The fingerprint detection device according to claim 27, characterized in that the bottom of the fingerprint detection device is arranged in the groove of the middle frame through a second pressure-sensitive adhesive. 29. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the optical path layer comprises a lens layer and an optical path guide layer, The lens layer is used to converge the optical signal returned by the human finger above the display screen to the optical path guiding layer, and the optical path guiding layer guides the optical signal converged by the lens layer to the first sensor chip. 30. The fingerprint detection device according to claim 29, characterized in that the thickness of the optical path layer is less than or equal to 30 um. 31. The fingerprint detection device according to any one of claims 1 to 3, further comprising: A flexible circuit board, wherein the flexible circuit board is formed with a gold finger of the flexible circuit board; Anisotropic conductive adhesive film, the gold fingers of the flexible circuit board are electrically connected to the gold fingers of the substrate through the anisotropic conductive adhesive film. 32. An electronic device, comprising: Display screen; A fingerprint detection device is arranged below the display screen. The fingerprint detection device is a fingerprint detection device as described in any one of claims 1 to 31, and its fingerprint collection area is at least partially located in the display area of the display screen. 33. The electronic device according to claim 32 is characterized in that the display screen includes a transparent cover plate, a display panel, a buffer layer and a copper layer from top to bottom, wherein the display screen is provided with a window penetrating the buffer layer and the copper layer, and the optical path layer of the fingerprint detection device is aligned with the window so that the fingerprint detection device receives a fingerprint detection signal returned by a human finger above the display screen through the window, and the fingerprint detection signal is used to detect the fingerprint information of the finger. 34. The electronic device according to claim 33 is characterized in that the edge area of the upper surface of the fingerprint detection device is fixed to the surrounding area of the window on the lower surface of the copper layer by a first pressure-sensitive adhesive so that the optical path layer of the fingerprint detection device is aligned with the window. 35. The electronic device according to claim 33 is characterized in that the electronic device further comprises a middle frame, the upper surface of the middle frame extends downward to form a third groove, and the bottom of the fingerprint detection device is arranged in the third groove through a second pressure-sensitive adhesive.