WO2018045740A1

WO2018045740A1 - Fingerprint recognition module and terminal

Info

Publication number: WO2018045740A1
Application number: PCT/CN2017/077909
Authority: WO
Inventors: 姜佳欣
Original assignee: 中兴通讯股份有限公司
Priority date: 2016-09-12
Filing date: 2017-03-23
Publication date: 2018-03-15
Also published as: CN107818284A; CN107818284B

Abstract

Provided are a fingerprint recognition module and terminal. The fingerprint recognition module comprises a fingerprint recognition component and a pressure measurement component located beneath the fingerprint recognition component; the pressure measurement component comprises a flexible insulating substrate and a pressure-sensitive ink block and copper wire printed on said flexible insulating substrate; the pressure-sensitive ink block and copper wire are connected to one another. The present disclosure combines fingerprint recognition and touch-control pressure, improving the sensitivity of measuring pressure by means of a pressure measurement component, reducing the packaging volume of a fingerprint recognition module, and increases the reliability of the pressure measurement component.

Description

Fingerprint identification module and terminal

Technical field

This document relates to, but is not limited to, the field of touch technology, and in particular, to a fingerprint recognition module and a terminal.

Background technique

With the popularity of smart devices, people's lives are becoming more and more convenient, and the personal information and property security issues that follow are becoming more and more prominent. Because fingerprints have lifetime invariance, uniqueness and convenience, fingerprint recognition has become the most reliable identification scheme at present. A fingerprint recognition module is installed on more and more smart devices. With the development of semiconductor packaging technology, the size of the fingerprint recognition module is becoming smaller, and the fingerprint recognition module can be embedded in the smart device as a verification end for unlocking and paying, thereby improving the security of the smart device.

The sensitivity and algorithm of the fingerprint recognition module are improving, and the running speed is getting faster and faster, which leads to more and more false triggering. More and more false triggering operations may increase the power consumption of the device. Too many attempts cause the device to lock; but when the false trigger is successfully unlocked, false triggering may also result in enabling apps or features that the user does not need to use.

In summary, although the fingerprint recognition technology improves the security of the smart device and facilitates some operations of the user, the false triggering also affects the user experience.

Summary of invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

The present disclosure provides a fingerprint identification module and a terminal, which can be applied to a fingerprint recognition module for pressure detection.

According to an aspect of the present disclosure, a fingerprint identification module includes a fingerprint recognition module and a pressure detection module located under the fingerprint recognition module;

The pressure detecting module includes a flexible insulating substrate and a pressure sensitive ink block and a copper trace printed on the flexible insulating substrate; wherein the pressure sensitive ink block is connected to the copper trace.

Optionally, a differential bridge is formed between the pressure sensitive ink blocks; a first diagonal end of the differential bridge The bridge power supply is connected, and the second diagonal output is used to detect the measured voltage of the touch pressure.

Optionally, the printing area of a single of the pressure sensitive ink blocks is 2 to 5 square millimeters.

Optionally, the ink printing thickness of the pressure sensitive ink block is from 10 nanometers to 30 nanometers.

Optionally, the pressure sensitive ink blocks are arranged in a matrix, and the row spacing is 3 to 5 mm, and the column spacing is 1 mm to 3 mm.

Optionally, the relative resistance error between the pressure sensitive ink blocks is less than or equal to 5%.

Optionally, the pressure sensitive ink block is printed on both sides of the flexible insulating substrate.

Optionally, the flexible insulating substrate is made of polyimide, polyester, polyethylene or polyethylene naphthalate.

Optionally, the pressure sensitive ink material used in the pressure sensitive ink block comprises: high density polyethylene and a graphite semiconductor composite.

Optionally, the fingerprint identification module comprises: a fingerprint recognition sensor and a flexible circuit board; the flexible circuit board is located under the fingerprint recognition sensor.

Optionally, the fingerprint recognition sensor comprises one of the following: a capacitive sensor, an optical sensor, and a radio frequency sensor.

Optionally, a reinforcing piece for reinforcing the strength of the fingerprint identification module is disposed between the fingerprint identification module and the pressure detecting module.

According to an aspect of the present disclosure, a terminal includes a main control module and the above-described fingerprint recognition module;

The main control module is configured to: when the touch pressure value detected by the pressure detecting module in the fingerprint identification module is greater than a preset threshold, control a fingerprint identification module in the fingerprint identification module to collect a fingerprint, and The fingerprint is matched with the preset fingerprint. When the collected fingerprint matches the preset fingerprint successfully, the control operation is performed.

Optionally, the main control module is further configured to perform different control operations according to the pressure level to which the touch pressure value belongs when the collected fingerprint is successfully matched with the preset fingerprint.

Compared with the related art, the technical solution provided by the present disclosure includes: a fingerprint identification module and a pressure detecting module located under the fingerprint identification module; wherein the pressure detecting module comprises a flexible insulating substrate And a pressure sensitive ink block and a copper trace printed on the flexible insulating substrate; wherein the pressure sensitive ink block is connected to the copper trace. The fingerprint identification module and the terminal provided by the disclosure not only have high pressure sensing sensitivity by using the sensing ink block as the pressure detecting device of the pressure detecting module, but also have relatively high reliability because the mechanical structure is not involved. At the same time, because the space occupied by the sensing ink block is small, the packaging volume of the fingerprint recognition module is effectively reduced, and the assembly of the module is facilitated. In addition, the present disclosure can not only perform identity recognition according to the collected fingerprint image, but also perform different operations according to the magnitude of the user's pressing force, thereby realizing the differentiation and diversification of the function of the fingerprint recognition module, and bringing a richer experience to the user. Expand the application areas of smart terminals.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

1 is a structural block diagram of a fingerprint identification module according to an embodiment of the present invention;

2 is a cross-sectional view of a fingerprint recognition module in accordance with an embodiment of the present invention;

3 is a top plan view of a fingerprint recognition module according to an embodiment of the present invention;

4 is a schematic structural view of a pressure detecting module according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a terminal according to an embodiment of the present invention; FIG.

FIG. 6 is a flowchart of operations of a terminal according to an embodiment of the present invention.

Detailed

Embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

The fingerprint identification module provided by the present disclosure combines fingerprint recognition and touch pressure, improves the pressure detecting component, has high pressure sensing sensitivity, and can also effectively reduce the packaging volume of the fingerprint recognition module and improve The reliability of the pressure sensing component. Referring to FIG. 1 , the present disclosure provides a fingerprint identification module including a fingerprint recognition module 1 and a pressure detection module 2 located below the fingerprint recognition module 1 .

Wherein, for the fingerprint recognition module 1, referring to FIGS. 2 and 3, a fingerprint recognition sensor 1 and a flexible circuit board (FPC) 12 are included. The flexible circuit board 12 and the fingerprint recognition sensor 11 are packaged together by Surface Mount Technology (SMT). Among them, flexible circuit board 12 is located in the lower layer of the fingerprint recognition sensor 11, and is configured to send the fingerprint signal collected by the fingerprint recognition sensor 11 to the main control module of the terminal. Optionally, in FIG. 3, a portion of the flexible circuit board 12 outside the button area is provided with a device area 13 connected to the main control module of the terminal through the FPC connector 14.

The fingerprint recognition sensor 11 may be a capacitive, optical, radio frequency or other principle based sensor;

The principle of a capacitive sensor is to integrate a semiconductor array pixel electrode on a substrate such that the substrate corresponds to one plate of the capacitor. When the finger is attached to the substrate, it forms a plate of capacitance with the pixel electrode. The silicon crystal element forms an electric field with the conductive subcutaneous electrolyte. Since the surface of the finger is uneven, the actual distance between the bump and the pixel at the pit is different, and the capacitance value is also different. In this way, according to the capacitance values formed by the "ridge" and the "valley" of the finger fingerprint and the pixel electrode, the image of the fingerprint is processed to realize the collection of the fingerprint data of the finger. However, since the surface of the capacitive sensor is easily damaged by using a silicon material, the service life is lowered. Further, the fingerprint image is formed by the unevenness between the valley and the ridge of the fingerprint, resulting in a low recognition rate of a difficult finger such as a dirty finger or a wet finger.

The optical sensor uses the principle of light refraction and reflection. The light is emitted from the bottom to the prism and is emitted by the prism. The angle of the emitted light is refracted on the uneven line of the finger surface of the finger and the light reflected back and forth will not be bright. same. The optical device of a complementary metal oxide semiconductor (CMOS) or a charge-coupled device (CCD) collects picture information of different brightness levels to complete fingerprint collection.

The RF sensor is divided into two types: radio wave detection and ultrasonic detection. The principle is similar to that of detecting the submarine material. It is based on the signal reflection of a specific frequency to detect the shape of the fingerprint. Ultrasonic waves have the ability to penetrate materials and produce echoes of different sizes depending on the material (the degree of absorption, penetration and reflection is different when the ultrasonic waves reach different material surfaces). Therefore, by using the difference between the skin and the air for the acoustic impedance, the position of the fingerprint ridge and the valley can be distinguished, and the fingerprint information is collected.

In order to protect the detecting device in the fingerprint recognition module 1 from being damaged by an external force, optionally, the reinforcing sheet 3 is disposed under the fingerprint recognition module 1 and is set to enhance the strength of the fingerprint recognition module 1. The reinforcing sheet 3 is adhered to the back surface of the flexible circuit board 12 by means of hot melt adhesive. Enhancement sheet 3 The lower layer is provided with a pressure detecting module 2.

The pressure detecting module 2 is located on the lower layer of the reinforcing sheet 3, and is attached to the back surface of the reinforcing sheet 3 by an adhesive such as double-sided tape, foam rubber or water glue. The pressure detecting module 2 is a flexible circuit board slightly larger than the fingerprint recognition module 1 to detect the touch pressure of each area of the fingerprint recognition module 1. The pressure detecting module 2 can be connected to the flexible circuit board 12 in the fingerprint identification module 1 by hot pressing or welding, or can be connected to the main control module of the terminal through an FPC connector by setting an FPC connector, for example, in FIG. The flexible circuit board is provided with a device area 21 (including a device such as an amplifier, an analog-to-digital converter, and a micro control unit), and is connected to the main control module through the FPC connector 22.

Optionally, the flexible circuit board of the pressure detecting module 2 uses a flexible insulating material as a substrate, and the flexible insulating substrate is printed with a pressure sensitive ink block 23 and a copper trace (not shown), and the pressure sensitive ink block 23 passes through the gold. A finger (not shown) is connected to the copper trace. The flexible insulating substrate may be a polymer such as polycarbamide, polyester (PET), polyethylene (PE) or polyethylene naphthalate (PEN). The pressure sensitive ink block may be composed of a high density polyethylene (density of 0.940 to 0.976 g/cm3), a graphite semiconductor composite or the like. In addition, the surface of the flexible circuit board is covered with an electromagnetic shielding film for shielding the external device from interference with the pressure detecting module.

For the pressure sensitive ink block 23 on the pressure detecting module 2, in one embodiment of the invention, the touch pressure value is detected by using the arrangement form of the differential bridge. Alternatively, as shown in FIG. 4, each of the four pressure sensitive ink blocks 23 constitutes a differential bridge. A pressure sensitive ink block 23 is disposed on each of the bridge arms. One diagonal end of the differential bridge is connected to the bridge power supply, and the other diagonal end outputs a measurement voltage U for detecting the touch pressure value. When the pressure acts on the fingerprint recognition module 1, the fingerprint recognition module 1 will elastically deform, so that the resistance value of the pressure sensitive ink block changes, and the small change of the resistance value is converted into the change of the measurement voltage U through the differential bridge. Then, the amplifier through the device area 21 is amplified into a processable signal, which is converted into a digital signal by an analog-to-digital converter, and then sent to the micro-control unit MCU for arithmetic processing, and then sent to the terminal control module of the terminal after the processing is completed.

Because the differential bridge has high sensitivity and small nonlinear error, it has the effect of compensating for the same symbol. Therefore, the optional pressure-sensitive ink block is arranged on both sides of the flexible insulating substrate, which is beneficial to suppress temperature drift. For example, in FIG. 4, eight pressure-sensitive ink blocks are actually disposed, and four of the front and back sides are respectively disposed opposite each other (the reverse side is not shown).

The arrangement of the pressure sensitive ink block can be flexibly arranged according to the pressure distribution and the required sensitivity. Optionally, the pressure sensitive ink blocks are arranged in a matrix manner to facilitate construction of the differential bridge. The layout specifications of the matrix will be described by taking four pressure sensitive ink blocks as an example. Specifically, the four pressure-sensitive ink blocks are arranged in a rectangular shape, and the longitudinal direction (column) pitch is between 3 mm (mm) and 5 mm, and most preferably 4 mm. The width direction (row) spacing is between 1 mm and 3 mm, preferably 2 mm.

In order to ensure the accuracy and sensitivity of the bridge, the resistance of each of the pressure sensitive ink blocks is required to be uniform, and the relative error of the resistance values does not exceed 5%. Since the pressure sensitive ink block is related to the resistivity, printing area, ink thickness and other parameters of the pressure sensitive ink material, the specific resistance value needs to refer to the impedance matching of the subsequent processing circuit. The number and size of the pressure sensitive ink blocks on the pressure sensing module can be varied according to the shape of the fingerprint recognition module 1 to meet the pressure sensitivity requirements. Preferably, in the embodiment of Figure 4, the printed area of the monolithic pressure-sensitive ink may vary between 5 mm2 - ²² mm, the shape may be rectangular, circular, triangular symmetrical shape, optionally 2mm * 2mm Square; for ink thickness between 10 nm and 30 nm, for example, ink thickness is 20 nm.

The fingerprint identification module provided by the present disclosure not only has high pressure sensing sensitivity by using the pressure sensitive ink block as the detecting device of the pressure detecting module, but also ensures the pressure because the structural member is smallly modified and does not involve mechanical structure. The high reliability of the detection module and the small space occupied by the pressure sensitive ink block can effectively reduce the packaging volume of the fingerprint module and improve the space utilization of the terminal.

The present disclosure also provides a terminal, as shown in FIG. 5, including a main control module and the above-mentioned fingerprint identification module;

The main control module is configured to: when the touch pressure value detected by the pressure detecting module in the fingerprint recognition module is greater than a preset threshold, the fingerprint recognition module in the fingerprint recognition module controls the fingerprint collection, and matches the collected fingerprint with the preset fingerprint. When the collected fingerprint matches the preset fingerprint successfully, the control operation is performed.

Optionally, as shown in FIG. 6 , when the fingerprint module is pressed by the human hand, the fingerprint recognition module 1 generates a slight deformation, the resistance value of the pressure sensitive ink on the pressure detecting module 2 changes, and the voltage of the differential bridge balance point changes accordingly. Through the processing of the amplifier, the analog-to-digital converter and the MCU of the device region 21, the pressure value of the pressing force is obtained. The main control module compares the touch pressure value obtained by the pressure sensing module 2 with a preset pressure threshold; if the preset pressure threshold is reached, the fingerprint recognition module 1 collects a fingerprint image.

Optionally, the collected fingerprint image is compared with the fingerprint in the pre-existing fingerprint database; if the collected fingerprint is successfully matched with the preset fingerprint, the pressure level of the touch pressure is obtained, and different operations are performed according to the corresponding pressure level. . The operation type user can set it in the terminal. For pressure level users can also set their own. For example, it is set to two levels: light pressure is regarded as non-active contact, and equipment unlocking is not performed; heavy pressure is regarded as active contact, and operations such as unlocking the device, opening the secondary menu, and entering a specific application can be performed. Of course, it can be divided into multiple levels, corresponding to different operations, such as starting a music player, starting a camera, etc., and the invention is not limited.

Based on the above, the terminal provided by the present disclosure can not only collect fingerprint images for identity recognition, but also perform different operations according to the magnitude of the pressing force, such as unlocking the device, opening the secondary menu, entering a specific application, and the like. Therefore, the differentiation and diversification of the use of the fingerprint recognition module by the present disclosure can increase the diversity of applications, broaden the application range of the intelligent terminal, and bring a rich user experience.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Orientations of "post", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. The positional relationship is based on the orientation or positional relationship shown in the drawings, and is merely for the convenience of the description of the present invention and the simplified description, and is not intended to indicate or imply that the device or component referred to has a specific orientation, and is constructed and operated in a specific orientation. Therefore, it should not be construed as limiting the invention. Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" or "second" may include one or more of the described features either explicitly or implicitly. In the description of the present invention, the meaning of "a plurality" is two or more unless specifically and specifically defined otherwise.

In the description of the present invention, it should be noted that the terms "installation", "connected", and "connected" are to be understood broadly, and may be fixed or detachable, for example, unless otherwise explicitly defined and defined. Connected, or integrally connected; may be mechanically connected, may be electrically connected or may communicate with each other; may be directly connected, or may be indirectly connected through an intermediate medium, may be internal communication of two elements or interaction of two elements relationship. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the present invention. The spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct related hardware, such as a processor, which may be stored in a computer readable storage medium, such as a read only memory, disk or optical disk. Wait. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the foregoing embodiment may be implemented in the form of hardware, for example, by implementing an integrated circuit to implement its corresponding function, or may be implemented in the form of a software function module, for example, being executed by a processor and stored in a memory. Programs/instructions to implement their respective functions. The invention is not limited to any specific form of combination of hardware and software.

The embodiments disclosed in the present application are as described above, but the descriptions are only for the purpose of understanding the present application, and are not intended to limit the present application, such as the specific implementation method in the embodiments of the present invention. Any modifications and changes in the form and details of the embodiments may be made by those skilled in the art without departing from the spirit and scope of the disclosure. The scope defined by the appended claims shall prevail.

Industrial applicability

The above technical solution realizes the combination of fingerprint recognition and touch pressure, improves the sensitivity of pressure detection by the pressure detecting component, reduces the packaging volume of the fingerprint recognition module, and improves the reliability of the pressure detecting component.

Claims

A fingerprint identification module includes: a fingerprint identification module and a pressure detecting module located under the fingerprint identification module; wherein

The pressure detecting module includes: a flexible insulating substrate; and a pressure sensitive ink block and a copper trace printed on the flexible insulating substrate;

Wherein, the pressure sensitive ink block is connected to the copper trace.
The fingerprint recognition module of claim 1 , wherein the pressure sensitive ink blocks form a differential bridge; the first diagonal end of the differential bridge is connected to a bridge power supply, and the second diagonal end is output A measurement voltage used to detect the touch pressure.
The fingerprint recognition module according to claim 2, wherein a single printed ink block has a printing area of 2 to 5 mm 2 .
The fingerprint recognition module according to claim 2, wherein the ink-sensitive printing ink block has an ink printing thickness of 10 nm to 30 nm.
The fingerprint recognition module according to claim 2, wherein the pressure sensitive ink blocks are arranged in a matrix, and the line pitch is 3 to 5 mm, and the column pitch is 1 mm to 3 mm.
The fingerprint recognition module of claim 2, wherein the relative resistance error between the pressure sensitive ink blocks is less than or equal to 5%.
The fingerprint recognition module according to any one of claims 1 to 6, wherein the pressure sensitive ink block is printed on both front and back sides of the flexible insulating substrate.
The fingerprint recognition module according to any one of claims 1 to 6, wherein the flexible insulating substrate is made of polyimide, polyester, polyethylene or polyethylene naphthalate.
The fingerprint recognition module according to any one of claims 1 to 6, wherein the pressure sensitive ink material used in the pressure sensitive ink block comprises: high density polyethylene and a graphite semiconductor composite.
The fingerprint identification module according to any one of claims 1 to 6, wherein the fingerprint identification module comprises: a fingerprint recognition sensor and a flexible circuit board; the flexible circuit board is located under the fingerprint recognition sensor.
The fingerprint recognition module of claim 10, wherein the fingerprint recognition sensor Includes one of the following: capacitive sensors, optical sensors, and RF sensors.
The fingerprint recognition module according to any one of claims 1 to 6, wherein a reinforcing sheet is disposed between the fingerprint recognition module and the pressure detecting module.
A terminal comprising a main control module and the fingerprint recognition module according to any one of claims 1 to 12;

The main control module is configured to: when the touch pressure value detected by the pressure detecting module in the fingerprint identification module is greater than a preset threshold, control the fingerprint recognition module in the fingerprint identification module to collect fingerprints, and collect the collected fingerprints The fingerprint is matched with the preset fingerprint. When the collected fingerprint matches the preset fingerprint successfully, the control operation is performed.
The terminal according to claim 13, wherein the main control module is further configured to perform a corresponding control operation according to the pressure level to which the touch pressure value belongs when the acquired fingerprint matches the preset fingerprint.