WO2020243926A1

WO2020243926A1 - Optical fingerprint apparatus and electronic device

Info

Publication number: WO2020243926A1
Application number: PCT/CN2019/090171
Authority: WO
Inventors: 吴宝全; 张建湘; 刘辰锦
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2020-12-10
Also published as: CN110770745B; CN110770745A

Abstract

An optical fingerprint apparatus (200) and an electronic device, being able to reduce the thickness of the optical fingerprint apparatus (200). The optical fingerprint apparatus (200) is arranged below an OLED display screen (10), and comprises a circuit board (210), a rewiring layer (220) and a fingerprint chip (230). The circuit board (210) is arranged below the fingerprint chip (230); the rewiring layer (220) is arranged between the circuit board (210) and the fingerprint chip (230), and the rewiring layer (220) comprises a first pad (221); the fingerprint chip (230) comprises a second pad (231), a conductive through-hole structure (232), a drive circuit (235) and a plurality of optical sensing units (233) distributed in an array; the optical sensing units (233) are used for receiving an optical signal which is formed by light irradiating a finger above the OLED display screen (10) and passes through the OLED display screen (10), and converting the optical signal into a corresponding electrical signal; the plurality of optical sensing units (233) are electrically connected to the second pad (231) by means of the drive circuit (235); the second pad (231) is arranged on an upper surface of the fingerprint chip (230); the conductive through-hole structure (232) is provided inside the fingerprint chip (230) and in communication with the first pad (221) and the second pad (231); and the rewiring layer (220) is electrically connected to the circuit board (210).

Description

Optical fingerprint device and electronic equipment

Technical field

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

Background technique

With the advancement of science and technology and the gradual increase in user needs, the integration of electronic devices is getting higher and higher. In order to adapt to this development trend, various components and devices used in electronic equipment are also facing a shift towards higher integration, smaller size, and higher standardization.

As an important part of electronic equipment with optical fingerprint recognition function, optical fingerprint device is affected by its packaging method, its thickness is greatly restricted, and it is difficult to reduce its volume. Therefore, how to reduce the thickness of the optical fingerprint device and bring more room for the design of the whole machine structure to electronic equipment manufacturers is a technical problem to be solved urgently.

Summary of the invention

The embodiments of the present application provide an optical fingerprint device and electronic equipment, which can reduce the thickness of the optical fingerprint device.

In a first aspect, an optical fingerprint device is provided, which is applied to an electronic device with an organic light-emitting diode OLED display screen, wherein the optical fingerprint device is configured to be arranged under the OLED display screen, and the optical fingerprint The device includes a circuit board, a rewiring layer, and a fingerprint chip; among them,

The circuit board is arranged under the fingerprint chip;

The rewiring layer is arranged between the circuit board and the fingerprint chip, and the rewiring layer includes a first pad;

The fingerprint chip includes a second pad, a conductive via structure, a driving circuit, and a plurality of optical sensing units distributed in an array, wherein:

The optical sensing unit is used to receive the light signal formed by the finger above the OLED display screen and pass through the OLED display screen, and convert the light signal into a corresponding electrical signal; The optical sensing unit is electrically connected to the second pad through the drive circuit, the second pad is disposed on the upper surface of the fingerprint chip, and the conductive via structure is disposed inside the fingerprint chip and communicates with The first pad and the second pad, the redistribution layer is electrically connected to the circuit board, so as to transmit the electrical signals obtained by the conversion of the plurality of optical sensing units to the circuit board.

In the optical fingerprint device of the embodiment of the present application, the conductive through-hole structure provided inside the fingerprint chip communicates with the second pad located on the upper surface of the fingerprint chip and the first pad located below the fingerprint chip, thereby avoiding installation outside the fingerprint chip The package wire connecting the upper surface pad of the fingerprint chip and the lower surface pad of the fingerprint chip overcomes the influence of the arc height of the package wire on the thickness of the optical fingerprint device. The fingerprint chip can be made thinner, thereby improving the optical fingerprint device performance.

In some possible implementation manners, the multiple optical sensing units are disposed on the device layer of the fingerprint chip.

In some possible implementation manners, the optical fingerprint device further includes:

The electrical connection layer, wherein the electrical connection layer is disposed between the rewiring layer and the circuit board, and the rewiring layer is electrically connected to the circuit board through the electrical connection layer.

In some possible implementation manners, the electrical connection layer is a metal layer or an anisotropic conductive film (ACF) layer.

In some possible implementation manners, the metal layer includes at least one of the following:

Copper layer, tin layer, gold layer, alloy layer.

In some possible implementation manners, the angle between the sidewall of the conductive via structure and the bottom surface of the fingerprint chip ranges from 45 degrees to 90 degrees.

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

In some possible implementation manners, the conductive via structure and the fingerprint chip are electrically isolated 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 the second insulating layer to communicate with the conductive via structure. Electric connection.

In some possible implementation manners, the height of the first pad protruding from the second insulating layer is less than or equal to 5 μm.

A microlens array and at least one light blocking layer, wherein the at least one light blocking layer is disposed above the fingerprint chip, the microlens array is disposed above the at least one light blocking layer, and the The microlens array includes a plurality of microlens units, the curvatures of the microlens units are the same in different directions, the light blocking layer includes a plurality of light-passing holes, and the microlens array is used to converge light signals in a specific direction To the plurality of light-passing holes, and converge non-specific direction optical signals to the light-blocking area of the light-blocking layer, wherein the specific direction optical signal is transmitted to the light-blocking area through the plurality of light-passing holes Optical sensing unit.

A specific wavelength filter layer, a transparent optical adhesive layer and a color filter layer, wherein the specific wavelength filter layer, the transparent optical adhesive layer, and the color filter layer are disposed on the microlens array and the fingerprint Between chips.

In some possible implementations, the specific wavelength filter layer is disposed above the upper surface of the fingerprint chip, the transparent optical adhesive layer is disposed above the specific wavelength filter layer, and the color filter layer is The layer is arranged above the transparent optical glue layer, and the micro lens array is arranged above the color filter layer.

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

In some possible implementations, the specific wavelength filter layer is disposed above the upper surface of the fingerprint chip, the color filter layer is disposed above the specific wavelength filter layer, and the transparent optical adhesive The layer is arranged above the color filter layer, and the micro lens array is arranged above the transparent optical glue layer.

In some possible implementation manners, the distance between the lower surface of the microlens array and the 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 the upper surface of the transparent optical adhesive layer, and/or the The light blocking layer is arranged on the lower surface of the transparent optical adhesive layer.

In some possible implementation manners, the specific wavelength band filter layer is used to filter out non-target wavelength band optical signals and transmit optical signals in the target wavelength band, and the target wavelength band ranges from 400 nm to 650 nm.

In some possible implementations, the thickness of the specific wavelength filter layer ranges from 1 μm to 10 μm.

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

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

In some possible implementation manners, the color filter layer includes the following at least two filter regions on the same plane:

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

In some possible implementation manners, the area occupied by the filter regions of different colors in the color filter layer is the same or different.

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

In some possible implementations, 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, the ratio of the projection area of the micro lens unit on the upper surface of the fingerprint chip to the 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 correspond to the plurality of optical sensing units one-to-one, and the geometric center of the microlens unit and the geometric center of the corresponding optical sensing unit are in the The upper surface of the fingerprint chip overlaps in the vertical direction.

In some possible implementation manners, the light blocking rate of the light blocking area of the light blocking layer is greater than or equal to 95%.

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

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

In some possible implementation manners, the thickness of the optical fingerprint device ranges from 150 μm to 400 μm.

In a second aspect, an electronic device is provided, including an OLED display screen and the first aspect or the optical fingerprint device in any possible implementation manner of the first aspect, the optical fingerprint device being disposed under 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.

Description of the drawings

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

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

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

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

Detailed ways

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

As smart terminals enter the era of full-screen, the fingerprint collection area on the front of electronic devices is squeezed by the full-screen, so under-display (under-screen) fingerprint recognition technology has attracted more and more attention. Under-screen fingerprint recognition technology refers to the installation of under-screen fingerprint recognition devices (such as fingerprint recognition modules) below the display screen, so as to realize fingerprint recognition operations inside the display area of the display screen, without the need for the front of the electronic device except for the display area Set the fingerprint collection area in the area.

The under-screen fingerprint identification technology may include under-screen optical fingerprint identification technology, under-screen ultrasonic fingerprint identification technology, or other types of under-screen fingerprint identification technology.

Taking the under-screen optical fingerprint recognition technology as an example, the under-screen optical fingerprint recognition technology uses light returned from the top surface of the device display component to perform fingerprint sensing and other sensing operations. The returned light carries information of an object (for example, a finger) in contact with the top surface, and a specific optical sensor module located below the display screen is realized by capturing and detecting the returned light. The design of the specific optical sensor module may be to achieve desired optical imaging by appropriately configuring optical elements for capturing and detecting returned light.

It should be understood that the technical solutions of the embodiments of the present application can be applied to various electronic devices, and more specifically, can be applied to electronic devices with display screens. For example, portable or mobile computing devices such as smart phones, laptops, tablet computers, and gaming devices, as well as other electronic devices such as electronic databases, automobiles, and automated teller machines (ATM) in banks, but the embodiments of this application are not limited to this .

It should also be understood that, in addition to fingerprint recognition, the technical solutions of the embodiments of the present application can also perform other fingerprint recognition, such as living body recognition, which is not limited in the embodiments of the present application.

It should be noted that, for ease of description, in the embodiments of the present application, the same reference numerals denote the same components, and for brevity, detailed descriptions of the same components are omitted in different embodiments.

It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width, etc. of the fingerprint identification device under the screen are only exemplary descriptions, and are not applicable to this application. Constitute any limitation.

Figure 1 is a schematic structural diagram of an electronic device to which the embodiments of the application can be applied. The electronic device 1 includes a display screen 10 and an under-screen fingerprint identification device 20, wherein the under-screen fingerprint identification device 20 is provided in the The partial area below the display screen 10. The under-screen fingerprint recognition device 20 includes an optical fingerprint sensor. The optical fingerprint sensor has a light detection array 400 with a plurality of pixel units 401, and the area where the light detection array 400 is located or its sensing area is the under-screen fingerprint recognition device 20 of the fingerprint detection area 103. 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 under-screen fingerprint identification device 20 can also be arranged in other positions, such as the side of the display screen 10 or the non-transparent area of the edge of the electronic device 1, and the optical path design is used to The light signal of at least a part of the display area of the display screen 10 is guided to the under-screen fingerprint identification device 20 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 recognition device 20, for example, through a light path design such as lens imaging, a reflective folding light path design, or other light converging or reflecting light paths. The design can make the area of the fingerprint detection area 103 of the fingerprint identification device 20 under the screen larger than the area of the sensing array of the fingerprint identification device 20 under the screen. In other alternative implementations, if the light path is guided by, for example, light collimation, the fingerprint detection area 103 of the under-screen fingerprint identification device 20 can also be designed to be substantially equal to the area of the sensing array of the under-screen fingerprint identification device 20. Consistent.

Therefore, when the user needs to unlock the electronic device or perform other fingerprint verification, he only needs to press his finger on the fingerprint detection area 103 located in the display screen 10 to realize fingerprint input. Since fingerprint detection can be implemented under the screen, the electronic device 1 adopting the above structure does not need to reserve space on the front side for the fingerprint button (such as the Home button), so that a full screen solution can be adopted, that is, the display area of the display screen 10 It can be basically extended to the front of the entire electronic device 1.

As an optional implementation, as shown in FIG. 1, the under-screen fingerprint identification device 20 includes an optical assembly 30 and a light detection part 40, and the light detection part 40 includes the light detection array 400 and the light The reading circuit and other auxiliary circuits that detect the electrical connection of the array can be fabricated on a chip (Die) by a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor. The sensing array is specifically a photodetector (Photodetector) The array includes a plurality of photodetectors distributed in an array, and the photodetectors can be used as the above-mentioned pixel unit; the optical component 30 can be arranged above the sensing array of the photodetection part 40.

In terms of specific implementation, the optical assembly 30 and the light detecting part 40 may be packaged in the same optical fingerprint component. For example, the optical component 30 and the light detecting part 40 may be packaged in the same optical fingerprint chip, or the optical component 30 may be arranged outside the chip where the light detecting part 40 is located, for example, the optical component 30 is attached above the chip, or some components of the optical assembly 30 are integrated into the chip.

It should be understood that, in specific implementation, the electronic device 1 further includes a transparent protective cover 130. The cover may be a glass cover or a sapphire cover, which is located above the display screen 10 and covers the The front of the electronic device 1. Because, in the embodiment of the present application, the so-called finger pressing on the display screen 10 actually refers to pressing the cover plate above the display screen 10 or covering the surface of the protective layer of the cover plate.

On the other hand, in some embodiments, the under-screen fingerprint recognition device 20 may include only one optical fingerprint sensor. At this time, the fingerprint detection area 103 of the under-screen fingerprint recognition device 20 has a small area and a fixed position, so the user When performing fingerprint input, it is necessary to press the finger to a specific position of the fingerprint detection area 103, otherwise the fingerprint recognition device 20 under the screen may not be able to collect fingerprint images, which may result in poor user experience. In other alternative embodiments, the under-screen fingerprint identification device 20 may specifically include multiple optical fingerprint sensors; the multiple optical fingerprint sensors may be arranged side by side under the display screen 10 in a splicing manner, and the multiple The sensing areas of the two optical fingerprint sensors collectively constitute the fingerprint detection area 103 of the under-screen fingerprint identification device 20. In other words, the fingerprint detection area 103 of the under-screen fingerprint identification device 20 may include multiple sub-areas, and each sub-area corresponds to the sensing area of one of the optical fingerprint sensors, so that the fingerprint of the optical fingerprint module 130 The detection area 103 can be extended to the main area of the lower half of the display screen, that is, to the area where the finger is habitually pressed, so as to realize the blind fingerprint input operation. Alternatively, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing 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 provided under the fingerprint identification device 20 under the screen. The under-screen fingerprint recognition device 20 can be adhered to the circuit board 150 through adhesive, and is electrically connected to the circuit board 150 through bonding pads and metal wires. The optical fingerprint recognition device 20 can realize electrical interconnection and signal transmission with other peripheral circuits or other components of the electronic device 1 through the circuit board 150. For example, the under-screen fingerprint recognition device 20 can receive the control signal of the processing unit of the electronic device 1 through the circuit board 150, and can also output the fingerprint detection signal from the under-screen fingerprint recognition device 20 to the electronic device 1 through the circuit board 150. Unit or control unit, etc.

It should be noted that the optical fingerprint device in the embodiments of the present application may also be referred to as an optical fingerprint recognition module, a fingerprint recognition device, a fingerprint recognition module, a fingerprint module, a fingerprint acquisition device, etc., and the above terms can be replaced with each other.

It should be noted that when the display screen 10 is a display screen with a self-luminous display unit, such as an Organic Light-Emitting Diode (OLED) display or a Micro Light-Emitting Diode (Micro-LED) ) Display screen. Taking an OLED display screen as an example, the under-screen fingerprint identification device 20 may use the display unit (ie, 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 to the target finger 140 above the fingerprint detection area 103, and the light is reflected on the surface of the finger 140 to form reflected light or scattered inside the finger 140 to form scattered light. In related patent applications For ease of description, the above reflected light and scattered light are collectively referred to as reflected light. Since the ridge and valley of the fingerprint have different light reflection capabilities, the reflected light from the fingerprint ridge and the reflected light from the fingerprint ridge have different light intensities. After the reflected light passes through the optical component 30, it is screened. The light detection array 400 in the lower fingerprint identification device 20 receives and converts it into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, so that The electronic device 1 realizes the optical fingerprint recognition function.

When the display screen 10 is a display screen without a self-luminous display unit, such as a liquid crystal display screen or other passive light-emitting display screens, a backlight module needs to be used as the light source of the display screen 10. Taking a liquid crystal display with a backlight module and a liquid crystal panel as an example, in order to support fingerprint detection under the liquid crystal display, as shown in FIG. 1, the display 10 includes a liquid crystal panel 110 and a backlight module 120. The backlight module is used to send a light signal to the liquid crystal panel, and the liquid crystal panel 110 includes a liquid crystal layer and a control circuit for controlling the deflection of the liquid crystal to transmit the light signal. The electronic device 1 may also include an excitation light source 160 for optical fingerprint detection. The under-screen fingerprint identification device 20 is arranged under the backlight module 120. When the finger 140 is pressed against the fingerprint detection area 103, the The light source 160 emits excitation light 111 to the target finger 140 above the fingerprint detection area 103, and the excitation light 111 is reflected on the surface of the finger 140 to form the first reflected light 151 of the fingerprint ridge 141 and the second reflected light 152 of the fingerprint ridge 142 , The first reflected light 151 and the second reflected light 152 need to pass through the liquid crystal panel 110 and the backlight module 120, and then pass through the optical assembly 30, and are received by the light detection array 400 in the under-screen fingerprint identification device 20 and converted into fingerprints Heartbeat.

In some embodiments, the light detecting part 40 is packaged in an optical fingerprint chip, and the light detecting part 40 is electrically connected to the circuit board 150 through a packaging wire 41. However, in the current packaging industry, the height of the wire arc of the package bonding wire 41 should generally be more than 50μm to ensure that there is a sufficient gap between the wire arc and the chip, otherwise it may cause the bonding wire to contact the circuit metal on the surface of the optical fingerprint chip and cause electrical properties. Failure (short circuit), the arc height of the package bonding wire 41 will affect the arrangement of the optical component 30, and will undoubtedly increase the thickness of the under-screen fingerprint identification device 20.

Based on the above-mentioned problems, the present application proposes a new wire bonding packaging method, which can avoid arranging packaging wires connecting the upper surface pads of the fingerprint chip and the lower surface pads of the fingerprint chip outside the fingerprint chip, and overcomes the packaging wire bonding wires. The arc height affects the thickness of the optical fingerprint device, and the fingerprint chip can be made thinner, thereby reducing the thickness of the optical fingerprint device, thereby improving the performance of the optical fingerprint device.

The optical fingerprint device 200 and the electronic device 400 of the embodiment of the present application will be described in detail below with reference to FIGS. 2 to 4. It should be noted that, for ease of description, in the embodiments of the present application, the same reference numerals are used to denote the same components, and for brevity, detailed descriptions of the same components are omitted in different embodiments.

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 configured to be disposed under the OLED display screen 10, and the optical fingerprint device 200 includes a circuit The board 210, the redistribution layer 220, and the fingerprint chip 230.

The circuit board 210 is arranged under the fingerprint chip 230; the redistribution layer 220 is arranged 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 used to receive the optical signal formed by the finger above the OLED display screen 10 and passing through the OLED display screen 10, and convert the optical signal into a corresponding electrical signal. Signal; the plurality of optical sensing units 233 are electrically connected to the second pad 231 through the drive circuit 235, the second pad 231 is provided on the upper surface of the fingerprint chip 230, the conductive via The structure 232 is disposed inside the fingerprint chip 230 and communicates with the first pad 221 and the second pad 231. The redistribution layer 220 is electrically connected to the circuit board 210 to connect the plurality of optical The electrical signal converted by the sensing unit 233 is transmitted to the circuit board 210.

It should be noted that the arrangement of the second pad 231 does not protrude from the upper surface of the fingerprint chip 230, that is, the arrangement of the second pad 231 does not increase the thickness of the fingerprint chip 230.

Optionally, the plurality of optical sensing units 233 are arranged on the 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 internal interconnections, and the driving circuit 235 may be 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 connected to the fingerprint chip 230 through the second pad 231. The external modules or units are interconnected. Specifically, the conductive via structure 232 communicates with the first pad 221 and the second pad 231, and the redistribution layer 220 is electrically connected to the circuit board 210 to induce the plurality of optical sensors The electrical signal converted by the unit 233 is transmitted to the circuit board 210.

It should be understood that, in this embodiment of the present application, the multiple optical sensing units 233 distributed in an array can 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 modules or units other than the optical fingerprint device 200, for example, the circuit board 210 may be electrically connected to the processor or memory of the electronic device, etc., in the present application The embodiment does not limit this.

Optionally, in the embodiment of the present application, the thickness of the optical fingerprint device 200 ranges from 150 μm to 400 μm.

Optionally, the rewiring layer 220 may include multiple pads including the first pad 221, and other pads except the first pad 221 may correspond to some of the optical fingerprint devices Modules or devices other than 200.

The chip itself of the fingerprint chip 230 may be formed of silicon material, that is, the conductive via structure 232 may be fabricated by through silicon via (TSV) technology. For example, a through-hole structure is prepared on the fingerprint chip 230 by TSV, and then metals such as copper, aluminum, tin, etc. are filled in the through-hole structure to form a conductive through-hole structure 232.

Optionally, the 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 bottom surface of the fingerprint chip 230 is rectangular or inverted trapezoid. That is, the conductive via structure 232 may be formed by filling copper, aluminum, tin and other metals in a vertical via structure, and the conductive via structure 232 may also be formed by filling copper, aluminum, or tin in an inclined via structure. Wait for the metal to form.

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

It should be understood that the arrangement of the first insulating layer 234 can prevent the conductive via structure 232 from being electrically connected to the fingerprint chip 230, thereby causing electric leakage.

It should be noted that the embodiment of the present application does not limit the material of the first insulating layer 234. Meanwhile, the embodiment of the present application does not limit the thickness of the first insulating layer 234.

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

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 arrangement of the second insulating layer 240 can prevent the rewiring layer 220 from being electrically connected to the fingerprint chip 230, thereby causing leakage.

It should be noted that, in the case of satisfying electrical isolation, the thickness of the second insulating layer 240 is as thin as possible.

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

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

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 the following: a copper layer, a tin layer, a gold layer, and an alloy layer. That is, the metal layer can be a layer of metal or a stack of multiple layers of metal.

Optionally, the circuit board 210 includes a substrate 211 and a circuit layer 212, the circuit layer 212 is disposed on the surface of the substrate 211, and the redistribution layer 220 is the same as the circuit layer 212 in the circuit board 210 Electric connection.

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

The micro lens 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, and the The microlens array 260 includes a plurality of microlens units whose curvatures are the same in different directions, the light blocking layer 270 includes a plurality of light passing holes, and the microlens array 260 is used to The optical signal is concentrated to the plurality of light-passing holes, and the non-specific direction optical signal is concentrated to the light-blocking area of the light-blocking layer 270, wherein the specific direction optical signal passes through the plurality of light-passing holes To the optical sensing unit 233.

It should be noted that the micro lens unit in the micro lens array 260 may be various lenses with a converging function. Optionally, the focal point of the micro lens unit may be located in the light-passing hole. The material of the micro lens may be an organic material, such as resin.

The light-transmitting aperture is used for condensing light through the micro lens unit. Optionally, the light passing hole is cylindrical, that is, the light passing hole may be a small hole in the light blocking layer 270. Optionally, the diameter of the light-passing hole may be greater than 100 nm, so as to transmit required light for imaging. The diameter of the light-passing hole should also be smaller than a predetermined value to ensure that the light blocking layer 270 can block unwanted light. That is to say, the parameter setting of the light-passing hole is as far as possible so that the optical signal required for imaging of the optical fingerprint device 200 is transmitted to the optical sensing unit 233 as much as possible, and unnecessary light is blocked as much as possible. . For example, the parameters of the light-passing hole can be set to maximize the transmission of the optical signal incident downward or obliquely downward to the optical sensing unit 233 in the corresponding area above the optical fingerprint device 200, and maximize Block other light signals.

Through the arrangement of the microlens array 260, the light-blocking layer 270, the light-passing hole and the optical sensing unit 233, the light signal from above the micro-lens unit is condensed to the light-passing hole and transmitted to the optical sensing unit through the light-passing hole 233. In this way, the optical sensing unit 233 can detect the light signal from the corresponding area above the microlens unit, and then can obtain the pixel value according to the light intensity of the light signal.

Optionally, the ratio of the projection area of the micro lens unit on the upper surface of the fingerprint chip 230 in the micro lens array 260 to the 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 micro lens unit in the micro lens 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 the geometric center of the microlens unit and the geometric center of the corresponding optical sensing unit are on the fingerprint chip The surfaces overlap in the vertical direction.

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

It should be noted that the microlens unit in the microlens array 260 can increase the incident angle of the central field of view and increase the inflow of light, thereby increasing the amount of signal detected by the optical sensing unit, thereby improving the imaging quality. At the same time, the microlens unit in the microlens array 260 can minimize the interference of large-angle incident light from adjacent areas, thereby reducing the problem of crosstalk between adjacent units, thereby improving imaging quality.

The specific wavelength filter layer 280, the transparent optical adhesive layer 290 and the 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 on the micro Between the lens array 260 and the fingerprint chip 230.

Optionally, as shown in FIG. 2, the specific wavelength filter layer 280 is disposed above the upper surface of the fingerprint chip 230, and the transparent optical adhesive layer 290 is disposed above the specific wavelength filter layer 280 The color filter layer 300 is disposed above the transparent optical glue layer 290, and the micro lens array 260 is disposed above the color filter layer 300.

In the case where the micro lens array 260 is disposed above the color filter layer 300, the distance between the lower surface of the micro lens 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 filter layer 280 is disposed above the upper surface of the fingerprint chip 230, and the color filter layer 300 is disposed above the specific wavelength filter layer 280 The transparent optical glue layer 290 is disposed above the color filter layer 300, and the micro lens array 260 is disposed above the transparent optical glue layer 290.

When the micro lens array 260 is disposed above the transparent optical adhesive layer 290, the distance between the lower surface of the micro lens array 260 and the 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 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. The light blocking layer A is disposed on the upper surface of the transparent optical adhesive layer 290, and the light blocking layer B is disposed inside the transparent optical adhesive layer 290. 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. The light-blocking layer A and the light-blocking layer B are arranged inside the transparent optical glue layer 290, and the light-blocking layer C is arranged on the transparent optical glue. The bottom surface of 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. 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 on the transparent layer. Inside the 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. The light-blocking layer A, the light-blocking layer B, and the light-blocking layer C 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 corresponding area above the optical fingerprint device 200 is substantially vertically downward or obliquely downwardly incident optical signals Maximum transmission to the optical sensing unit 233, and maximum blocking of other optical signals.

It should be noted that the microlens array 260, the light blocking layer 270, the specific wavelength filter layer 280, the transparent optical glue layer 290, and the color filter layer 300 are required to exist between each layer. At the same time, these adhesive layers can be sufficiently thin and do not have a major impact on the thickness of the optical fingerprint device 200.

Optionally, the specific waveband filter layer 280 is used to filter out optical signals in non-target wavebands and transmit optical signals in the target waveband, and the target waveband ranges from 400 nm to 650 nm.

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

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

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

Optionally, the color filter layer 300 includes the following at least two filter areas on the same plane: a red filter area, a green filter area, a blue filter area, a white filter area, and a yellow filter area.

It should be noted that the filter regions of different colors can correspond to corresponding pixels in the optical sensing unit, thereby improving the optical imaging quality.

Optionally, the distribution of the filter regions of each color in the color filter layer 300 may be determined based on the pixel distribution in the optical sensing unit.

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

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

For example, as shown in FIGS. 2 and 3, the microlens array 260, the at least one light blocking layer 270, the specific wavelength filter layer 280, the transparent optical glue layer 290, and the color filter The projection area of the layer 300 on the upper surface of the fingerprint chip 230 is larger than the area 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 the embodiment of the present application, as shown in FIG. 2 and FIG. 3, a dot glue layer 310 is provided 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 dispensing layer 310 can also fix at least one of the at least one light blocking layer 270, the specific wavelength filter layer 280, the transparent optical adhesive layer 290, and the color filter layer 300 . For example, as shown in FIG. 2, the dispensing layer 310 may also fix the specific wavelength filter layer 280 and the transparent optical adhesive layer 290.

In the optical fingerprint device of the embodiment of the present application, the second pad and the plurality of optical sensing units in the fingerprint chip are arranged on the upper surface of the fingerprint chip, and the conductive via structure arranged inside the fingerprint chip communicates with the second pad on the upper surface of the fingerprint chip. The second pad and the first pad located below the fingerprint chip can avoid setting the package bonding wire connecting the top surface pad of the fingerprint chip and the bottom surface pad of the fingerprint chip outside the fingerprint chip, and overcome the arc height of the package bonding wire. Due to the thickness of the optical fingerprint device, the fingerprint chip can be made thinner, which in turn can improve the performance of the optical fingerprint device.

The embodiment of the present application also provides an electronic device 400. As shown in FIG. 4, the electronic device 400 may include an OLED display screen 10 and the optical fingerprint device 200 of the foregoing embodiment of the present application, wherein the optical fingerprint device 200 is configured to Below the OLED display screen 10.

The electronic device 400 can be any electronic device with a display screen.

The OLED display screen 10 may adopt the display screen described above, and the related description of the display screen may refer to the description of the display screen in the above description. For the sake of brevity, details are not repeated 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 only intended to help those skilled in the art to better understand the embodiments of the present application, rather than limiting 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 of "a", "above" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

A person of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments disclosed herein, the units can be implemented by electronic hardware, computer software, or a combination of both, in order to clearly illustrate the interchangeability of hardware and software. In the above description, the composition and steps of each example have been described generally in terms of function. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

In the several embodiments provided in this application, it should be understood that the disclosed system and device may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may also be electrical, mechanical or other forms of connection.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the objectives of the solutions of the embodiments of the present application.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or software functional unit.

If the integrated unit 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 this application is essentially or the part that contributes to the existing technology, 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 It includes several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program code .

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Anyone familiar with the technical field can easily think of various equivalents within the technical scope disclosed in this application. Modifications or replacements, these modifications or replacements shall be covered within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

An optical fingerprint device applied to an electronic device with an organic light-emitting diode OLED display screen. The optical fingerprint device is characterized in that the optical fingerprint device is used to be arranged under the OLED display screen, and the optical fingerprint device includes a circuit board, a heavy Wiring layer, fingerprint chip; among them,

The circuit board is arranged under the fingerprint chip;

The rewiring layer is arranged between the circuit board and the fingerprint chip, and the rewiring layer includes a first pad;

The fingerprint chip includes a second pad, a conductive via structure, a driving circuit, and a plurality of optical sensing units distributed in an array, wherein:

The optical sensing unit is used to receive the light signal formed by the finger above the OLED display screen and pass through the OLED display screen, and convert the light signal into a corresponding electrical signal; The optical sensing unit is electrically connected to the second pad through the drive circuit, the second pad is disposed on the upper surface of the fingerprint chip, and the conductive via structure is disposed inside the fingerprint chip and communicates with The first pad and the second pad, the redistribution layer is electrically connected to the circuit board, so as to transmit the electrical signals obtained by the conversion of the plurality of optical sensing units to the circuit board.
The optical fingerprint device according to claim 1, wherein the plurality of optical sensing units are arranged on a device layer of the fingerprint chip.
The optical fingerprint device according to claim 1 or 2, wherein the optical fingerprint device further comprises:

The electrical connection layer, wherein the electrical connection layer is disposed between the rewiring layer and the circuit board, and the rewiring layer is electrically connected to the circuit board through the electrical connection layer.
The optical fingerprint device according to claim 3, wherein the electrical connection layer is a metal layer or an anisotropic conductive adhesive ACF layer.
The optical fingerprint device according to claim 4, wherein the metal layer comprises at least one of the following:

Copper layer, tin layer, gold layer, alloy layer.
The optical fingerprint device according to any one of claims 1 to 5, wherein the angle between the sidewall of the conductive via structure and the lower surface of the fingerprint chip ranges from 45 degrees to 90 degrees .
The optical fingerprint device according to any one of claims 1 to 6, 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 according to any one of claims 1 to 7, wherein the conductive via structure and the fingerprint chip are electrically isolated by a first insulating layer.
The optical fingerprint device according to any one of claims 1 to 8, wherein the rewiring layer is electrically isolated from the fingerprint chip by a second insulating layer, and the first pad penetrates the The second insulating layer is electrically connected with the conductive via structure.
The optical fingerprint device according to claim 9, wherein the height of the first pad protruding from the second insulating layer is less than or equal to 5 μm.
The optical fingerprint device according to any one of claims 1 to 10, wherein the optical fingerprint device further comprises:

A microlens array and at least one light blocking layer, wherein the at least one light blocking layer is disposed above the fingerprint chip, the microlens array is disposed above the at least one light blocking layer, and the The microlens array includes a plurality of microlens units, the curvatures of the microlens units are the same in different directions, the light blocking layer includes a plurality of light-passing holes, and the microlens array is used to converge light signals in a specific direction To the plurality of light-passing holes, and converge non-specific direction optical signals to the light-blocking area of the light-blocking layer, wherein the specific direction optical signal is transmitted to the light-blocking area through the plurality of light-passing holes Optical sensing unit.
The optical fingerprint device of claim 11, wherein the optical fingerprint device further comprises:

A specific wavelength filter layer, a transparent optical adhesive layer and a color filter layer, wherein the specific wavelength filter layer, the transparent optical adhesive layer, and the color filter layer are disposed on the microlens array and the fingerprint Between chips.
The optical fingerprint device of claim 12, wherein:

The specific wavelength filter layer is disposed above the upper surface of the fingerprint chip, the transparent optical adhesive layer is disposed above the specific wavelength filter layer, and the color filter layer is disposed above the transparent optical adhesive Above the layer, the micro lens array is arranged above the color filter layer.
The optical fingerprint device according to claim 13, wherein the distance between the lower surface of the microlens array and the upper surface of the color filter layer ranges from 1 μm to 6 μm.
The optical fingerprint device of claim 12, wherein:

The specific wavelength filter layer is disposed above the upper surface of the fingerprint chip, the color filter layer is disposed above the specific wavelength filter layer, and the transparent optical adhesive layer is disposed on the color filter Above the layer, the micro lens array is arranged above the transparent optical glue layer.
The optical fingerprint device according to 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.
The optical fingerprint device according to any one of claims 12 to 16, wherein the light blocking layer is disposed inside the transparent optical adhesive layer, and/or the light blocking layer is disposed on the transparent The upper surface of the optical adhesive layer, and/or the light blocking layer is disposed on the lower surface of the transparent optical adhesive layer.
The optical fingerprint device according to any one of claims 12 to 17, wherein the specific wavelength band filter layer is used to filter out the optical signal of the non-target wavelength band, and the optical signal of the target wavelength band is transmitted through the target wavelength band. The wavelength range is 400nm～650nm.
The optical fingerprint device according to any one of claims 12 to 18, wherein the specific wavelength band filter layer has a thickness ranging from 1 μm to 10 μm.
The optical fingerprint device according to any one of claims 12 to 19, wherein the specific wavelength filter layer at least covers the plurality of optical sensing units.
The optical fingerprint device according to any one of claims 12 to 20, wherein the specific wavelength filter layer comprises multiple layers of silicon oxide and/or titanium oxide.
The optical fingerprint device according to any one of claims 12 to 21, wherein the color filter layer comprises the following at least two kinds of filter regions on the same plane:

Red filter area, green filter area, blue filter area, white filter area, yellow filter area.
The optical fingerprint device according to claim 22, wherein the area occupied by the filter regions of different colors in the color filter layer is the same or different.
The optical fingerprint device according to any one of claims 12 to 23, wherein the microlens array, the at least one light blocking layer, the specific wavelength filter layer, and the transparent optical adhesive layer The projected area of at least one of the color filter layers on the upper surface of the fingerprint chip is larger than the area of the plurality of optical sensing units on the upper surface of the fingerprint chip.
The optical fingerprint device according to any one of claims 12 to 24, wherein the refractive index of the transparent optical adhesive layer is in the range of 1.3 to 1.7, and the light transmittance of the transparent optical adhesive layer is greater than or equal to 95%.
The optical fingerprint device according to any one of claims 11 to 25, wherein the projection area of the micro lens unit on the upper surface of the fingerprint chip and the optical sensor unit on the fingerprint chip The surface area ratio is greater than or equal to 0.6.
The optical fingerprint device according to any one of claims 11 to 26, wherein the plurality of micro lens units corresponds to the plurality of optical sensing units one-to-one, and the geometric center of the micro lens unit corresponds to the same The geometric centers of the corresponding optical sensing units overlap in the vertical direction of the upper surface of the fingerprint chip.
The optical fingerprint device according to any one of claims 11 to 27, wherein the light blocking rate of the light blocking area of the light blocking layer is greater than or equal to 95%.
The optical fingerprint device according to any one of claims 1 to 28, wherein:

A glue layer is arranged around the fingerprint chip to fix the fingerprint chip on the circuit board and protect the fingerprint chip.
The optical fingerprint device according to any one of claims 1 to 29, wherein the circuit board comprises a substrate and a circuit layer, the circuit layer is disposed on the surface of the substrate, and the redistribution layer is connected to the The circuit layers in the circuit board are electrically connected.
The optical fingerprint device according to any one of claims 1 to 30, wherein the thickness of the optical fingerprint device ranges from 150 μm to 400 μm.
An electronic device, characterized by comprising an organic light emitting diode OLED display screen and the optical fingerprint device according to any one of claims 1 to 31, the optical fingerprint device being arranged under the OLED display screen.
The electronic device according to claim 32, wherein the electronic device further comprises a middle frame, and the optical fingerprint device is fixed on the middle frame.