CN210038816U

CN210038816U - Optical fingerprint device and electronic equipment

Info

Publication number: CN210038816U
Application number: CN201920859217.6U
Authority: CN
Inventors: 吴宝全; 张建湘; 刘辰锦
Original assignee: Shenzhen Huiding Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2020-02-07
Anticipated expiration: 2029-06-05

Abstract

The embodiment of the application provides an optical fingerprint device and electronic equipment, and the thickness of the optical fingerprint device can be thinned. The optical fingerprint device is arranged below the OLED display screen and comprises a circuit board, a rewiring layer and a fingerprint chip; the circuit board is arranged below the fingerprint chip; the rewiring layer is arranged between the circuit board and the fingerprint chip and comprises a first bonding pad; the fingerprint chip comprises a second bonding pad, a conductive through hole structure, a driving circuit and a plurality of optical sensing units distributed in an array manner, wherein the optical sensing units are used for receiving optical signals which are formed by fingers irradiating the upper part of the OLED display screen by light rays and penetrate through the OLED display screen, and converting the optical signals into corresponding electric signals; the multiple optical sensing units are electrically connected to the second bonding pad through the driving circuit, the second bonding pad is arranged on the upper surface of the fingerprint chip, the conductive through hole structure is arranged inside the fingerprint chip and communicated with the first bonding pad and the second bonding pad, and the rewiring layer is electrically connected with the circuit board.

Description

Optical fingerprint device and electronic equipment

Technical Field

The embodiments of the present application relate to the field of electronics, and more particularly, to an optical fingerprint device and an electronic apparatus.

Background

Along with the progress of scientific technology and the gradual increase of user demands, the integration level of electronic equipment is higher and higher. In order to meet the trend, various components and devices used in electronic devices are also moving toward higher integration, smaller size and higher standardization.

The optical fingerprint device, which is an important component of an electronic device with an optical fingerprint recognition function, is greatly limited in thickness due to the packaging manner thereof, so that it is difficult to reduce the volume thereof. Therefore, how to reduce the thickness of the optical fingerprint device brings a larger design space of the whole structure for electronic equipment manufacturers, which is a technical problem to be solved urgently.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an optical fingerprint device and electronic equipment, and the thickness of the optical fingerprint device can be thinned.

In a first aspect, an optical fingerprint device is provided, which is applied to an electronic device having an organic light emitting diode OLED display screen, and is characterized in that the optical fingerprint device is arranged below the OLED display screen, and the optical fingerprint device includes a circuit board, a redistribution layer, and a fingerprint chip; wherein the content of the first and second substances,

the circuit board is arranged below the fingerprint chip;

the rewiring layer is arranged between the circuit board and the fingerprint chip and comprises a first bonding pad;

the fingerprint chip comprises a second bonding pad, a conductive through hole structure, a driving circuit and a plurality of optical sensing units distributed in an array manner,

the optical sensing unit is used for receiving optical signals which are formed by fingers irradiating the upper part of the OLED display screen by light rays and penetrate through the OLED display screen, and converting the optical signals into corresponding electric signals; the multiple optical sensing units are electrically connected to the second bonding pad through the driving circuit, the second bonding pad is arranged on the upper surface of the fingerprint chip, the conductive through hole structure is arranged inside the fingerprint chip and communicated with the first bonding pad and the second bonding pad, and the rewiring layer is electrically connected with the circuit board so as to transmit the electric signals converted by the multiple optical sensing units to the circuit board.

In the optical fingerprint device of this application embodiment, set up in the inside electrically conductive through-hole structure intercommunication of fingerprint chip and be located the second pad of fingerprint chip upper surface and be located the first pad of fingerprint chip below to can avoid setting up the encapsulation bonding wire of connecting fingerprint chip upper surface pad and fingerprint chip lower surface pad in fingerprint chip outside, overcome the influence of the line arc height of encapsulation bonding wire to optical fingerprint device thickness, the fingerprint chip can accomplish thinly, and then can promote optical fingerprint device's performance.

In some possible implementations, the plurality of optical sensing units are disposed on a device layer of the fingerprint chip.

In some possible implementations, the optical fingerprint device further includes:

and the electric connection layer is arranged between the redistribution layer and the circuit board, and the redistribution layer is electrically connected with the circuit board through the electric connection layer.

In some possible implementations, the electrical connection layer is a metal layer or an Anisotropic Conductive Film (ACF) layer.

In some possible implementations, the metal layer includes at least one of:

copper layer, tin layer, gold layer, alloy layer.

In some possible implementation manners, an included angle between the side wall of the conductive through hole structure and the lower surface of the fingerprint chip ranges from 45 degrees to 90 degrees.

In some possible implementations, a cross section of the conductive via structure perpendicular to the lower surface of the fingerprint chip is rectangular or inverted trapezoid.

In some possible implementations, the conductive via structure is electrically isolated from the fingerprint chip by a first insulating layer.

In some possible implementations, the redistribution layer is electrically isolated from the fingerprint chip by a second insulating layer, and the first pad penetrates through the second insulating layer to be electrically connected to the conductive via structure.

In some possible implementations, a height by which the first pad protrudes beyond the second insulating layer is less than or equal to 5 μm.

the fingerprint sensor comprises a fingerprint chip, at least one light blocking layer and a microlens array, wherein the at least one light blocking layer is arranged above the fingerprint chip, the microlens array is arranged above the at least one light blocking layer, the microlens array comprises a plurality of microlens units, the curvatures of the microlens units are the same in different directions, the light blocking layer comprises a plurality of light passing small holes, the microlens array is used for converging optical signals in a specific direction to the plurality of light passing small holes and converging optical signals in a non-specific direction to a light blocking area of the light blocking layer, and the optical signals in the specific direction are transmitted to the optical sensing unit through the plurality of light passing small holes.

the fingerprint sensor comprises a specific waveband filter layer, a transparent optical adhesive layer and a color filter layer, wherein the specific waveband filter layer, the transparent optical adhesive layer and the color filter layer are arranged between a micro-lens array and a fingerprint chip.

In some possible implementations, the specific-band filter layer is disposed above the upper surface of the fingerprint chip, the transparent optical adhesive layer is disposed above the specific-band filter layer, the color filter layer is disposed above the transparent optical adhesive layer, and the microlens array is disposed above the color filter layer.

In some possible implementations, a distance between a lower surface of the microlens array and an upper surface of the color filter layer ranges from 1 μm to 6 μm.

In some possible implementations, the specific-waveband filter layer is disposed above the upper surface of the fingerprint chip, the color filter layer is disposed above the specific-waveband filter layer, the transparent optical adhesive layer is disposed above the color filter layer, and the microlens array is disposed above the transparent optical adhesive layer.

In some possible implementations, a distance between a lower surface of the microlens array and an upper surface of the transparent optical adhesive layer ranges from 1 μm to 6 μm.

In some possible implementations, the light blocking layer is disposed inside the transparent optical adhesive layer, and/or the light blocking layer is disposed on an upper surface of the transparent optical adhesive layer, and/or the light blocking layer is disposed on a lower surface of the transparent optical adhesive layer.

In some possible implementations, the specific waveband filter layer is configured to filter out optical signals in a non-target waveband, and transmit the optical signals in a target waveband, where the target waveband is in a range from 400nm to 650 nm.

In some possible implementations, the specific-wavelength-band filter layer has a thickness ranging from 1 μm to 10 μm.

In some possible implementations, the band-specific filter layer covers at least the plurality of optical sensing units.

In some possible implementations, the band-specific filter layer includes multiple layers of silicon oxide and/or titanium oxide.

In some possible implementations, the color filter layer includes at least two of the following filter regions in the same plane:

red filter area, green filter area, blue filter area, white filter area, yellow filter area.

In some possible implementations, areas occupied by filter regions of different colors in the color filter layer are the same or different.

In some possible implementations, a projected area of at least one of the microlens array, the at least one light blocking layer, the specific-wavelength filter layer, the transparent optical adhesive layer, and the color filter layer on the upper surface of the fingerprint chip is larger than an area of the plurality of optical sensing units on the upper surface of the fingerprint chip.

In some possible implementation manners, the refractive index of the transparent optical adhesive layer ranges from 1.3 to 1.7, and the light transmittance of the transparent optical adhesive layer is greater than or equal to 95%.

In some possible implementations, a ratio of a projected area of the microlens unit on the upper surface of the fingerprint chip to an area of the optical sensing unit on the upper surface of the fingerprint chip is greater than or equal to 0.6.

In some possible implementations, the plurality of microlens units and the plurality of optical sensing units correspond to each other one by one, and geometric centers of the microlens units and the corresponding optical sensing units overlap in a vertical direction of the upper surface of the fingerprint chip.

In some possible implementations, a light blocking ratio of the light blocking area of the light blocking layer is greater than or equal to 95%.

In some possible implementation manners, a dotted adhesive layer is arranged around the fingerprint chip to fix the fingerprint chip on the circuit board and protect the fingerprint chip.

In some possible implementations, the circuit board includes a substrate and a circuit layer disposed on a surface of the substrate, and the redistribution layer is electrically connected to the circuit layer in the circuit board.

In some possible implementations, the optical fingerprint device has a thickness in a range from 150 μm to 400 μm.

In a second aspect, an electronic device is provided, which includes an OLED display screen and the optical fingerprint device of the first aspect or any possible implementation manner of the first aspect, where the optical fingerprint device is disposed below the OLED display screen.

In some possible implementations, the electronic device further includes a middle frame, and the optical fingerprint device is fixed on the middle frame.

Drawings

Fig. 1 is a schematic structural diagram of an electronic device to which the embodiment of the present application is applied.

Fig. 2 is a schematic structural diagram of an optical fingerprint device according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of another optical fingerprint device provided in an embodiment of the present application.

Fig. 4 is a schematic structural diagram of an electronic device provided in an embodiment of the present application.

Detailed Description

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

As the smart terminal moves into the full-screen era, the fingerprint acquisition area on the front side of the electronic device is squeezed by the full-screen, and therefore the Under-screen (or Under-screen) fingerprint identification technology is receiving more and more attention. Fingerprint identification technology is installed in the display screen below with fingerprint identification device (for example fingerprint identification module) under the screen to realize carrying out the fingerprint identification operation in the display area inside of display screen, need not set up the fingerprint collection region in the positive region except that the display area of electronic equipment.

The underscreen fingerprint identification technology may include underscreen optical fingerprint identification technology, underscreen ultrasonic fingerprint identification technology, or other types of underscreen fingerprint identification technology.

Taking the example of an off-screen optical fingerprinting technique, the off-screen optical fingerprinting technique uses light returning from the top surface of the device display assembly for fingerprint sensing and other sensing operations. The returning light carries information of an object (e.g., a finger) in contact with the top surface, and a specific optical sensor module located below the display screen is implemented by capturing and detecting the returning light. The design of the particular optical sensor module may be such that the desired optical imaging is achieved by appropriately configuring the optical elements used to capture and detect the returned light.

It should be understood that the technical solutions of the embodiments of the present application may be applied to various electronic devices, and more particularly, may be applied to an electronic device having a display screen. For example, portable or mobile computing devices such as smart phones, notebook computers, tablet computers, and game devices, and other electronic devices such as electronic databases, automobiles, and Automatic Teller Machines (ATMs), but the present application is not limited thereto.

It should also be understood that, the technical solution of the embodiment of the present application may perform other fingerprint identification besides fingerprint identification, for example, living body identification, and the like, which is also not limited in the embodiment of the present application.

It should be noted that, for convenience of description, like reference numerals denote like parts in the embodiments of the present application, and a detailed description of the like parts is omitted in different embodiments for the sake of brevity.

It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the underscreen fingerprint identification device shown in the drawings are merely illustrative and should not be construed as limiting the present application in any way.

Fig. 1 is a schematic structural diagram of an electronic device to which the embodiment of the present invention is applicable, where the electronic device 1 includes a display screen 10 and an underscreen fingerprint identification device 20, where the underscreen fingerprint identification device 20 is disposed in a local area below the display screen 10. The device 20 comprises an optical fingerprint sensor having a light detecting array 400 with a plurality of pixel units 401, and the area where the light detecting array 400 is located or the sensing area thereof is the fingerprint detection area 103 of the device 20. As shown in fig. 1, the fingerprint detection area 103 is located in the display area of the display screen 10. In an alternative embodiment, the underscreen fingerprint identification device 20 may be disposed at other positions, such as the side of the display screen 10 or the edge non-light-transmitting area of the electronic device 1, and the light signal of at least a part of the display area of the display screen 10 is guided to the underscreen fingerprint identification device 20 through the light path design, so that the fingerprint detection area 103 is actually located in the display area of the display screen 10.

It should be understood that the area of the fingerprint detection area 103 may be different from the area of the sensing array of the under-screen fingerprint identification device 20, for example, the area of the fingerprint detection area 103 of the under-screen fingerprint identification device 20 may be larger than the area of the sensing array of the under-screen fingerprint identification device 20 by the optical path design such as lens imaging, reflective folded optical path design, or other optical path design such as light converging or reflecting. In other alternative implementations, the fingerprint sensing area 103 of the underscreen fingerprint identification device 20 may also be designed to substantially coincide with the area of the sensing array of the underscreen fingerprint identification device 20 if optical path guidance is performed using, for example, light collimation.

Therefore, when the user needs to unlock or verify other fingerprints of the electronic device, the user only needs to press a finger on the fingerprint detection area 103 of the display screen 10, so as to realize fingerprint input. Because fingerprint detection can be realized under the screen, the electronic device 1 adopting the above structure does not need a special reserved space on the front surface thereof to set a fingerprint key (such as a Home key), so that a full-screen scheme can be adopted, that is, the display area of the display screen 10 can be basically expanded to the front surface of the whole electronic device 1.

As an alternative implementation, as shown in fig. 1, the underscreen fingerprint identification device 20 includes an optical assembly 30 and a light detection portion 40, where the light detection portion 40 includes the light detection array 400 and a reading circuit and other auxiliary circuits electrically connected to the light detection array, which may be fabricated on a chip (Die) through a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor, and the sensing array is specifically a Photo detector (Photo detector) array including a plurality of Photo detectors distributed in an array, and the Photo detectors may serve as the pixel units as described above; the optical assembly 30 may be disposed above the sensing array of the light detecting portion 40.

In a specific implementation, the optical assembly 30 may be packaged with the same optical fingerprint component as the light detection portion 40. For example, the optical component 30 may be packaged in the same optical fingerprint chip as the light detection portion 40, or the optical component 30 may be disposed outside the chip where the light detection portion 40 is located, for example, the optical component 30 is attached above the chip, or some components of the optical component 30 are integrated in the chip.

It should be understood that in a specific implementation, the electronic device 1 further includes a transparent protective cover 130, which may be a glass cover or a sapphire cover, positioned above the display screen 10 and covering the front surface of the electronic device 1. Because, in the present embodiment, the pressing of the finger on the display screen 10 actually means pressing on the cover plate above the display screen 10 or the surface of the protective layer covering the cover plate.

On the other hand, in some embodiments, the off-screen fingerprint identification device 20 may include only one optical fingerprint sensor, where the area of the fingerprint detection area 103 of the off-screen fingerprint identification device 20 is small and the location is fixed, so that the user needs to press a finger to a specific location of the fingerprint detection area 103 when performing fingerprint input, otherwise the off-screen fingerprint identification device 20 may not acquire a fingerprint image and the user experience is poor. In other alternative embodiments, the underscreen fingerprint identification device 20 may specifically include a plurality of optical fingerprint sensors; the plurality of optical fingerprint sensors can be arranged below the display screen 10 side by side in a splicing mode, and sensing areas of the plurality of optical fingerprint sensors jointly form a fingerprint detection area 103 of the fingerprint identification device 20 under the screen. That is, the fingerprint detection area 103 of the under-screen fingerprint identification apparatus 20 may include a plurality of sub-areas, each of which corresponds to a sensing area of one of the optical fingerprint sensors, so that the fingerprint detection area 103 of the optical fingerprint module 130 may be extended to a main area of the lower half portion of the display screen, that is, to a region that a finger presses conventionally, thereby implementing a blind-touch fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 may also be extended to half or even the entire display area, thereby enabling half-screen or full-screen fingerprint detection.

It should be understood that a circuit board 150, such as a Flexible Printed Circuit (FPC), may also be disposed under the underscreen fingerprint recognition device 20. The underscreen fingerprint identification device 20 can be adhered to the circuit board 150 by a back adhesive, and is electrically connected to the circuit board 150 by soldering a pad and a metal wire. The optical fingerprint recognition device 20 can be electrically interconnected and signal-transmitted with other peripheral circuits or other components of the electronic apparatus 1 through the circuit board 150. For example, the underscreen fingerprint identification apparatus 20 may receive a control signal of a processing unit of the electronic device 1 through the circuit board 150, and may also output a fingerprint detection signal from the underscreen fingerprint identification apparatus 20 to the processing unit or the control unit of the electronic device 1 through the circuit board 150, or the like.

It should be noted that, optical fingerprint device in this application embodiment also can be called optical fingerprint identification module, fingerprint identification device, fingerprint identification module, fingerprint collection device etc. but above-mentioned term mutual replacement.

It should be noted that, when the display screen 10 is a display screen having a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking an OLED display screen as an example, the under-screen fingerprint identification device 20 may utilize the display unit (i.e., OLED light source) of the OLED display screen 10 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. The display screen 10 emits a beam of light toward the target finger 140 above the fingerprint detection area 103, which is reflected at the surface of the finger 140 to form reflected light or scattered light by the interior of the finger 140, which is collectively referred to as reflected light for ease of description in the related patent application. Because ridges (ridges) and valleys (vally) of a fingerprint have different light reflection capacities, reflected light from the ridges and the valleys of the fingerprint have different light intensities, and the reflected light is received by the light detection array 400 in the underscreen fingerprint identification device 20 and converted into corresponding electric signals, i.e., fingerprint detection signals, after passing through the optical assembly 30; fingerprint image data can be obtained based on the fingerprint detection signal, and fingerprint matching verification can be further performed, so that an optical fingerprint identification function is realized in the electronic device 1.

When the display screen 10 is a display screen without a self-luminous display unit, for example, a liquid crystal display screen or other passive luminous display screens, a backlight module is required to be used as a light source of the display screen 10. Taking an application to a liquid crystal display screen having a backlight module and a liquid crystal panel as an example, in order to support fingerprint detection under the liquid crystal display screen, as shown in fig. 1, the display screen 10 includes a liquid crystal panel 110 and a backlight module 120, the backlight module is configured to send an optical signal to the liquid crystal panel, and the liquid crystal panel 110 includes a liquid crystal layer and a control circuit, and is configured to control deflection of liquid crystal so as to transmit the optical signal. The electronic device 1 may further include an excitation light source 160 for optical fingerprint detection, the under-screen fingerprint identification apparatus 20 is disposed below the backlight module 120, when the finger 140 presses the fingerprint detection area 103, the excitation light source 160 emits excitation light 111 to the target finger 140 above the fingerprint detection area 103, the excitation light 111 is reflected on the surface of the finger 140 to form a first reflected light 151 of the fingerprint ridge 141 and a second reflected light 152 of the fingerprint valley 142, and the first reflected light 151 and the second reflected light 152 are received by the light detection array 400 in the under-screen fingerprint identification apparatus 20 and converted into fingerprint detection signals after passing through the liquid crystal panel 110 and the backlight module 120 and the optical assembly 30.

In some embodiments, the light detecting portion 40 is packaged in an optical fingerprint chip, and the light detecting portion 40 is electrically connected to the circuit board 150 by package bonding wires 41. However, in current industry packaging, the height of the wire loop of the packaging bonding wire 41 is generally more than 50 μm to ensure sufficient clearance between the wire loop and the chip, otherwise, the wire loop may contact with the circuit metal on the surface of the optical fingerprint chip to cause electrical failure (short circuit), the height of the wire loop of the packaging bonding wire 41 may affect the arrangement of the optical component 30, and the thickness of the under-screen fingerprint identification device 20 is undoubtedly increased.

Based on the above problem, this application provides a new bonding wire packaging mode, can avoid setting up the encapsulation bonding wire of the upper surface pad of connecting the fingerprint chip and the lower surface pad of fingerprint chip in fingerprint chip outside, overcomes the influence of the line arc height of encapsulation bonding wire to optics fingerprint device thickness, and the fingerprint chip can accomplish thinly to reduce the thickness of optics fingerprint device, and then can promote the performance of optics fingerprint device.

The optical fingerprint device 200 and the electronic apparatus 400 according to the embodiment of the present application are described in detail below with reference to fig. 2 to 4. It should be noted that, for convenience of description, the same reference numerals are used to designate the same components in the embodiments of the present application, and detailed description of the same components is omitted in different embodiments for the sake of brevity.

Fig. 2 is a schematic structural diagram of an optical fingerprint device 200 according to an embodiment of the present application.

As shown in fig. 2, the optical fingerprint device 200 is applied to an electronic device having an OLED display screen 10, the optical fingerprint device 200 is arranged below the OLED display screen 10, and the optical fingerprint device 200 includes a circuit board 210, a redistribution layer 220, and a fingerprint chip 230.

Wherein, the circuit board 210 is disposed below the fingerprint chip 230; the redistribution layer 220 is disposed between the circuit board 210 and the fingerprint chip 230, and the redistribution layer 220 includes a first pad 221; the fingerprint chip 230 includes a second pad 231, a conductive via structure 232, a driving circuit 235 and a plurality of optical sensing units 233 distributed in an array.

Specifically, the optical sensing unit 233 is configured to receive an optical signal formed by a finger that irradiates light onto the OLED display screen 10 and passes through the OLED display screen 10, and convert the optical signal into a corresponding electrical signal; the plurality of optical sensing units 233 are electrically connected to the second pads 231 through the driving circuit 235, the second pads 231 are disposed on the upper surface of the fingerprint chip 230, the conductive via structures 232 are disposed inside the fingerprint chip 230 and communicate with the first pads 221 and the second pads 231, and the redistribution layer 220 is electrically connected to the circuit board 210 to transmit the electrical signals converted by the plurality of optical sensing units 233 to the circuit board 210.

It should be noted that the second pads 231 are not disposed to protrude the upper surface of the fingerprint chip 230, that is, the second pads 231 are not disposed to increase the thickness of the fingerprint chip 230.

Optionally, the plurality of optical sensing units 233 are disposed on a device layer of the fingerprint chip 230.

It should be noted that, in the fingerprint chip 230, the plurality of optical sensing units 233 and the driving circuit 235 may be electrically connected through an internal interconnection line, and the driving circuit 235 is electrically connected to the second pad 231, that is, the plurality of optical sensing units 233 are electrically connected to the second pad 231 through the driving circuit 235, and the plurality of optical sensing units 233 are finally interconnected with an external module or unit of the fingerprint chip 230 through the second pad 231. Specifically, the conductive via structure 232 is connected to the first pad 221 and the second pad 231, and the redistribution layer 220 is electrically connected to the circuit board 210 to transmit the electrical signal converted by the plurality of optical sensing units 233 to the circuit board 210.

It should be understood that, in the embodiment of the present application, the plurality of optical sensing units 233 distributed in an array may also be referred to as a photoelectric conversion pixel area array.

It should be noted that the circuit board 210 may be electrically connected to a module or unit outside the optical fingerprint apparatus 200, for example, the circuit board 210 may be electrically connected to a processor or a memory of the electronic device, and the embodiment of the present application is not limited thereto.

Optionally, in this embodiment, the thickness of the optical fingerprint device 200 is in a range from 150 μm to 400 μm.

Alternatively, the redistribution layer 220 may include a plurality of pads within the first pad 221, and other pads except the first pad 221 may correspond to modules or devices other than some of the optical fingerprint devices 200.

The chip itself of the fingerprint chip 230 may be formed of a Silicon material, that is, the conductive Via structure 232 may be prepared by a Through Silicon Via (TSV) technology. For example, a via structure is prepared on the fingerprint chip 230 through TSV, and then the via structure is filled with metal such as copper, aluminum, tin, etc., so as to form the conductive via structure 232.

Optionally, an included angle between the sidewall of the conductive via structure 232 and the lower surface of the fingerprint chip 230 ranges from 45 degrees to 90 degrees.

In other words, the cross section of the conductive via structure 232 perpendicular to the lower surface of the fingerprint chip 230 is rectangular or inverted trapezoid. That is, the conductive via structure 232 may be formed by filling a metal such as copper, aluminum, tin, etc. in a vertical via structure, or the conductive via structure 232 may be formed by filling a metal such as copper, aluminum, tin, etc. in an inclined via structure.

Optionally, the conductive via structure 232 is electrically isolated from the fingerprint chip 230 by a first insulating layer 234.

It should be understood that the first insulating layer 234 is disposed to prevent the conductive via structure 232 from being electrically connected to the fingerprint chip 230, which may result in leakage current.

In the embodiment of the present application, the material of the first insulating layer 234 is not limited. Meanwhile, the thickness of the first insulating layer 234 is not limited in the embodiment of the present application.

Alternatively, the off-screen fingerprint identification device 20 in FIG. 1 may be the optical fingerprint device 200 described above. Optionally, the second pad 231 is electrically connected to the plurality of optical sensing units 233 through the driving circuit.

Optionally, the redistribution layer 220 is electrically isolated from the fingerprint chip 230 by a second insulating layer 240, and the first pad 221 penetrates through the second insulating layer 240 to be electrically connected to the conductive via structure 232.

Optionally, the height of the first pad 221 protruding from the second insulating layer 240 is less than or equal to 5 μm.

For example, the thickness of the redistribution layer 220 under the second insulating layer 240 is less than or equal to 5 μm.

It should be understood that the second insulating layer 240 may prevent the redistribution layer 220 from being electrically connected to the fingerprint chip 230, thereby causing electrical leakage.

Note that, in the case where electrical isolation is satisfied, the thinner the thickness of the second insulating layer 240 is, the better.

Optionally, as shown in fig. 2, the optical fingerprint device 200 further includes:

an electrical connection layer 250, wherein the electrical connection layer 250 is disposed between the redistribution layer 220 and the circuit board 210, and the redistribution layer 220 is electrically connected to the circuit board 210 through the electrical connection layer 250.

Optionally, the electrical connection layer 250 is a metal layer or an Anisotropic Conductive Film (ACF) layer.

In the case where the electrical connection layer 250 is a metal layer, the metal layer includes at least one of: copper layer, tin layer, gold layer, alloy layer. That is, the metal layer may be a single metal layer or a stack of multiple metal layers.

Optionally, the circuit board 210 includes a substrate 211 and a circuit layer 212, the circuit layer 212 is disposed on a surface of the substrate 211, and the redistribution layer 220 is electrically connected to the circuit layer 212 in the circuit board 210.

For example, as shown in fig. 2, the redistribution layer 220 is electrically connected to the circuit layer 212 in the circuit board 210 through the electrical connection layer 250.

Optionally, in this embodiment of the present application, the optical fingerprint device 200 further includes:

a microlens array 260 and at least one light blocking layer 270.

Specifically, as shown in fig. 2, the at least one light blocking layer 270 is disposed above the fingerprint chip 230, the microlens array 260 is disposed above the at least one light blocking layer 270, the microlens array 260 includes a plurality of microlens units, curvatures of the microlens units are the same in different directions, the light blocking layer 270 includes a plurality of light passing apertures, and the microlens array 260 is configured to converge an optical signal in a specific direction to the plurality of light passing apertures and converge an optical signal in a non-specific direction to a light blocking area of the light blocking layer 270, where the optical signal in the specific direction is transmitted to the optical sensing unit 233 through the plurality of light passing apertures.

It should be noted that the microlens units in the microlens array 260 can be various lenses with a converging function. Optionally, the focusing point of the microlens unit may be located within the light passing aperture. The material of the micro lens may be an organic material, such as resin.

The light-passing small hole is used for passing the light converged by the micro lens unit. Alternatively, the light-passing aperture is cylindrical, i.e., the light-passing aperture may be an aperture in the light-blocking layer 270. Alternatively, the light passing aperture may be larger than 100nm in diameter to pass the light required for imaging. The diameter of the light passing hole is also smaller than a predetermined value to ensure that the light blocking layer 270 blocks unwanted light. That is, the parameter setting of the light passing aperture is such that the light signal required for imaging the optical fingerprint device 200 is maximally transmitted to the optical sensing unit 233, while the undesired light is maximally blocked. For example, the light passing aperture may be configured to maximize the transmission of light signals incident substantially vertically downward or obliquely downward on the corresponding area above the optical fingerprint device 200 to the optical sensing unit 233, while maximizing the blocking of other light signals.

By the arrangement of the microlens array 260, the light blocking layer 270, the light passing aperture and the optical sensing unit 233, the light signal from above the microlens unit is converged to the light passing aperture, and transmitted to the optical sensing unit 233 through the light passing aperture. In this way, the optical sensing unit 233 can detect the optical signal from the corresponding region above the microlens unit, and can further acquire the pixel value according to the light intensity of the optical signal.

Optionally, a ratio of a projected area of the microlens units in the microlens array 260 on the upper surface of the fingerprint chip 230 to an area of the optical sensing unit 233 on the upper surface of the fingerprint chip 230 is greater than or equal to 0.6.

In other words, the ratio of the projected area of the microlens units in the microlens array 260 on the upper surface of the fingerprint chip 230 to the area of the optical sensing unit 233 on the upper surface of the fingerprint chip 230 is greater than or equal to 60%.

Optionally, the plurality of microlens units correspond to the plurality of optical sensing units one to one, and a geometric center of the microlens unit overlaps a geometric center of the corresponding optical sensing unit in a vertical direction of the upper surface of the fingerprint chip.

Optionally, a light blocking ratio of a light blocking area of the light blocking layer is greater than or equal to 95%.

It should be noted that the microlens units in the microlens array 260 can increase the incident angle of the central field of view, and increase the light convergence, so as to increase the amount of signals detected by the optical sensing unit, and further improve the imaging quality. Meanwhile, the interference of large-angle incident light of adjacent areas can be reduced to the maximum extent by the microlens units in the microlens array 260, so that the problem of crosstalk between the adjacent units is reduced, and the imaging quality is improved.

a specific wavelength filter layer 280, a transparent optical adhesive layer 290 and a color filter layer 300, wherein the specific wavelength filter layer 280, the transparent optical adhesive layer 290 and the color filter layer 300 are disposed between the microlens array 260 and the fingerprint chip 230.

Optionally, as shown in fig. 2, the specific wavelength band filter layer 280 is disposed above the upper surface of the fingerprint chip 230, the transparent optical adhesive layer 290 is disposed above the specific wavelength band filter layer 280, the color filter layer 300 is disposed above the transparent optical adhesive layer 290, and the microlens array 260 is disposed above the color filter layer 300.

In the case where the microlens array 260 is disposed above the color filter layer 300, the distance between the lower surface of the microlens array 260 and the upper surface of the color filter layer 300 ranges from 1 μm to 6 μm.

Optionally, as shown in fig. 3, the specific wavelength band filter layer 280 is disposed above the upper surface of the fingerprint chip 230, the color filter layer 300 is disposed above the specific wavelength band filter layer 280, the transparent optical adhesive layer 290 is disposed above the color filter layer 300, and the microlens array 260 is disposed above the transparent optical adhesive layer 290.

When the microlens array 260 is disposed above the transparent optical adhesive layer 290, a distance between a lower surface of the microlens array 260 and an upper surface of the transparent optical adhesive layer 290 ranges from 1 μm to 6 μm.

Optionally, the light-blocking layer 270 is disposed inside the transparent optical adhesive layer 290, and/or the light-blocking layer 270 is disposed on the upper surface of the transparent optical adhesive layer 290, and/or the light-blocking layer 270 is disposed on the lower surface of the transparent optical adhesive layer 290.

For example, the optical fingerprint device 200 includes a light blocking layer a, a light blocking layer B, and a light blocking layer C, where the light blocking layer a is disposed on the upper surface of the transparent optical adhesive layer 290, the light blocking layer B is disposed inside the transparent optical adhesive layer 290, and the light blocking layer C is disposed on the lower surface of the transparent optical adhesive layer 290.

For another example, the optical fingerprint device 200 includes a light blocking layer a, a light blocking layer B, and a light blocking layer C, where the light blocking layer a and the light blocking layer B are disposed inside the transparent optical adhesive layer 290, and the light blocking layer C is disposed on the lower surface of the transparent optical adhesive layer 290.

For another example, the optical fingerprint device 200 includes a light blocking layer a, a light blocking layer B, and a light blocking layer C, where the light blocking layer a is disposed on the upper surface of the transparent optical adhesive layer 290, and the light blocking layer B and the light blocking layer C are disposed inside the transparent optical adhesive layer 290.

For another example, the optical fingerprint device 200 includes a light blocking layer a, a light blocking layer B, and a light blocking layer C, which are all disposed inside the transparent optical adhesive layer 290.

In the case of multiple light-blocking layers, the light-passing holes in different light-blocking layers cooperate with each other, so that the light signal incident on the corresponding area above the optical fingerprint device 200 in a substantially vertical downward or inclined downward direction is maximally transmitted to the optical sensing unit 233, and the other light signals are maximally blocked.

It should be noted that necessary adhesive layers are present among the microlens array 260, the light blocking layer 270, the specific wavelength band filter layer 280, the transparent optical adhesive layer 290, and the color filter layer 300, and at the same time, the adhesive layers may be thin enough not to greatly affect the thickness of the optical fingerprint device 200.

Optionally, the specific wavelength band filter layer 280 is configured to filter optical signals in a non-target wavelength band, and transmit the optical signals in a target wavelength band, where the target wavelength band is 400nm to 650 nm.

Optionally, the thickness of the specific waveband filter layer 280 ranges from 1 μm to 10 μm.

Optionally, the specific waveband filter layer 280 covers at least the plurality of optical sensing units 233.

Optionally, the specific wavelength band filter layer 280 includes multiple layers of silicon oxide and/or titanium oxide. That is, the band-specific filter layer 280 may include a stack of multiple layers of silicon oxide and/or titanium oxide.

Optionally, the color filter layer 300 includes at least two kinds of filter regions in the same plane: red filter area, green filter area, blue filter area, white filter area, yellow filter area.

It should be noted that the filter regions of different colors may correspond to corresponding pixels in the optical sensing unit, so as to improve the optical imaging quality.

Alternatively, the distribution of the filter regions of the respective colors in the color filter layer 300 may be determined based on the distribution of the pixels in the photo sensor unit.

Optionally, the areas occupied by the filter regions of different colors in the color filter layer 300 are the same or different.

Optionally, a projected area of at least one of the microlens array 260, the at least one light blocking layer 270, the specific wavelength band filter layer 280, the transparent optical adhesive layer 290, and the color filter layer 300 on the upper surface of the fingerprint chip 230 is larger than an area of the plurality of optical sensing units 233 on the upper surface of the fingerprint chip 230.

For example, as shown in fig. 2 and 3, the projected areas of the microlens array 260, the at least one light blocking layer 270, the band-specific filter layer 280, the transparent optical adhesive layer 290, and the color filter layer 300 on the upper surface of the fingerprint chip 230 are larger than the areas of the plurality of optical sensing units 233 on the upper surface of the fingerprint chip 230.

Optionally, the refractive index of the transparent optical adhesive layer 290 ranges from 1.3 to 1.7, and the light transmittance of the transparent optical adhesive layer 290 is greater than or equal to 95%.

Optionally, in this embodiment, as shown in fig. 2 and 3, a glue layer 310 is disposed around the fingerprint chip 230 to fix the fingerprint chip 230 on the circuit board 210 and protect the fingerprint chip 230.

Of course, the adhesive dispensing layer 310 may fix at least one of the at least one light blocking layer 270, the specific wavelength band filter layer 280, the transparent optical adhesive layer 290, and the color filter layer 300. For example, as shown in fig. 2, the dot adhesive layer 310 may also fix the specific wavelength band filter layer 280 and the transparent optical adhesive layer 290.

In the optical fingerprint device of this application embodiment, second pad and a plurality of optical sensing unit in the fingerprint chip set up the upper surface at the fingerprint chip, set up in the inside electrically conductive through-hole structure intercommunication of fingerprint chip and be located the second pad of fingerprint chip upper surface and be located the first pad of fingerprint chip below, thereby can avoid setting up the encapsulation bonding wire of connecting fingerprint chip upper surface pad and fingerprint chip lower surface pad in fingerprint chip outside, overcome the influence of the line arc height of encapsulation bonding wire to optical fingerprint device thickness, the fingerprint chip can accomplish thinly, and then can promote optical fingerprint device's performance.

An electronic device 400 is further provided, as shown in fig. 4, the electronic device 400 may include an OLED display screen 10 and the optical fingerprint device 200 according to the embodiment of the present application, where the optical fingerprint device 200 is disposed below the OLED display screen 10.

The electronic device 400 may be any electronic device having a display screen.

The OLED display screen 10 may adopt the display screen described above, and for the description of the display screen, reference may be made to the description of the display screen in the above description, and for brevity, no further description is given here.

Optionally, the electronic device 400 further includes a middle frame, and the optical fingerprint device 200 is fixed on the middle frame.

It should be understood that the specific examples in the embodiments of the present application are for the purpose of promoting a better understanding of the embodiments of the present application and are not intended to limit the scope of the embodiments of the present application.

It is to be understood that the terminology used in the embodiments of the present application and the appended claims is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application. For example, as used in the examples of this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Those of ordinary skill in the art will appreciate that the elements of the examples described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the components and steps of the examples have been described above generally in terms of their functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in the present application, it should be understood that the disclosed system and apparatus may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may also be an electric, mechanical or other form of connection.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiments of the present application.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially or partially contributed by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An optical fingerprint device is applied to electronic equipment with an Organic Light Emitting Diode (OLED) display screen, and is characterized in that the optical fingerprint device is arranged below the OLED display screen and comprises a circuit board, a rewiring layer and a fingerprint chip; wherein the content of the first and second substances,

the circuit board is arranged below the fingerprint chip;

2. The optical fingerprint device of claim 1, wherein the plurality of optical sensing units are disposed on a device layer of the fingerprint chip.

3. The optical fingerprint device of claim 1, further comprising:

4. The optical fingerprint device of claim 3, wherein the electrical connection layer is a metal layer or an ACF layer.

5. The optical fingerprint device of claim 4, wherein the metal layer comprises at least one of:

copper layer, tin layer, gold layer, alloy layer.

6. The optical fingerprint device according to any one of claims 1 to 5, wherein an angle between the sidewall of the conductive via structure and the lower surface of the fingerprint chip is in a range of 45 degrees to 90 degrees.

7. The optical fingerprint device according to any one of claims 1 to 5, wherein the cross section of the conductive via structure perpendicular to the lower surface of the fingerprint chip is rectangular or inverted trapezoid.

8. The optical fingerprint device of any one of claims 1 to 5, wherein the conductive via structure is electrically isolated from the fingerprint chip by a first insulating layer.

9. The optical fingerprint device of any one of claims 1 to 5, wherein the redistribution layer is electrically isolated from the fingerprint chip by a second insulating layer, and the first pad extends through the second insulating layer to electrically connect to the conductive via structure.

10. The optical fingerprint device of claim 9, wherein the height of the first pad protruding beyond the second insulating layer is less than or equal to 5 μ ι η.

11. The optical fingerprint device of any one of claims 1 to 5, further comprising:

12. The optical fingerprint device of claim 11, further comprising:

13. The optical fingerprint device of claim 12,

the specific wave band filter layer set up in the top of the upper surface of fingerprint chip, transparent optical cement layer set up in the top of specific wave band filter layer, the colored filter layer set up in the top of transparent optical cement layer, the microlens array set up in the top of colored filter layer.

14. The optical fingerprint device of claim 13, wherein a distance between a lower surface of the microlens array and an upper surface of the color filter layer is in a range from 1 μm to 6 μm.

15. The optical fingerprint device of claim 12,

the specific wave band filter layer set up in the top of the upper surface of fingerprint chip, the colored filter layer set up in the top of specific wave band filter layer, transparent optical adhesive layer set up in the top of colored filter layer, the microlens array set up in the top of transparent optical adhesive layer.

16. The optical fingerprint device of claim 15, wherein the distance between the lower surface of the microlens array and the upper surface of the transparent optical adhesive layer is in the range of 1 μm to 6 μm.

17. The optical fingerprint device according to claim 12, wherein the light blocking layer is disposed inside the transparent optical adhesive layer, and/or the light blocking layer is disposed on the upper surface of the transparent optical adhesive layer, and/or the light blocking layer is disposed on the lower surface of the transparent optical adhesive layer.

18. The optical fingerprint device of claim 12, wherein the band-specific filter is configured to filter out non-target band optical signals and pass target band optical signals, and the target band range is 400nm to 650 nm.

19. The optical fingerprint device of claim 12, wherein the band-specific optical filter has a thickness in a range from 1 μm to 10 μm.

20. The optical fingerprint device of claim 12, wherein the band-specific filter layer covers at least the plurality of optical sensing units.

21. The optical fingerprint device of claim 12, wherein the band-specific filter layer comprises multiple layers of silicon oxide and/or titanium oxide.

22. The optical fingerprint device of claim 12, wherein the color filter layer comprises at least two of the following planar filter regions:

23. The optical fingerprint device of claim 22, wherein filter regions of different colors in the color filter layer occupy the same or different areas.

24. The optical fingerprint device of claim 12, wherein a projected area of at least one of the microlens array, the at least one light blocking layer, the band-specific filter layer, the transparent optical adhesive layer, and the color filter layer on the top surface of the fingerprint chip is larger than an area of the plurality of optical sensing units on the top surface of the fingerprint chip.

25. The optical fingerprint device of claim 12, wherein the refractive index of the transparent optical adhesive layer is in a range of 1.3-1.7, and the light transmittance of the transparent optical adhesive layer is greater than or equal to 95%.

26. The optical fingerprint device of claim 11, wherein a ratio of a projected area of the microlens unit on the upper surface of the fingerprint chip to an area of the optical sensing unit on the upper surface of the fingerprint chip is greater than or equal to 0.6.

27. The optical fingerprint device of claim 11, wherein the plurality of microlens units and the plurality of optical sensing units are in one-to-one correspondence, and the geometric centers of the microlens units and the corresponding optical sensing units overlap in a vertical direction of the upper surface of the fingerprint chip.

28. The optical fingerprint device of claim 11, wherein the light blocking area of the light blocking layer has a light blocking ratio greater than or equal to 95%.

29. The optical fingerprint device according to any one of claims 1 to 5,

a spot glue layer is arranged on the periphery of the fingerprint chip to fix the fingerprint chip on the circuit board and protect the fingerprint chip.

30. The optical fingerprint device according to any one of claims 1 to 5, wherein the circuit board comprises a substrate and a wiring layer, the wiring layer is disposed on a surface of the substrate, and the redistribution layer is electrically connected to the wiring layer in the circuit board.

31. The optical fingerprint device of any one of claims 1 to 5, wherein the optical fingerprint device has a thickness in the range of 150 μm to 400 μm.

32. An electronic device comprising an Organic Light Emitting Diode (OLED) display screen and the optical fingerprint device of any one of claims 1 to 31, the optical fingerprint device being disposed below the OLED display screen.

33. The electronic device of claim 32, further comprising a bezel, wherein the optical fingerprint device is secured to the bezel.