Patent Publication Number: US-2020302139-A1

Title: Fingerprint identification device, fingerprint identification method, and method for manufacturing the fingerprint identification device

Description:
FIELD OF INVENTION 
     The present disclosure relates to the field of display technologies, and more particularly to a fingerprint identification device, a fingerprint identification method, and a method for manufacturing the fingerprint identification device. 
     BACKGROUND OF INVENTION 
     With development of technologies, fingerprint identification devices are being used more and more widely in various electronic devices. For example, if a current smartphone including a fingerprint identification device is provided, a user can perform functions such as unlocking the smartphone and paying for bill for a fingerprint identification through the fingerprint identification device. 
     At present, fingerprint identification devices of electronic devices usually use push-type fingerprint sensors, for example, mobile terminals such as APPLE&#39;IPHONE 5S, IPHONE 6, and IPHONE 6S. With the development of technologies, fingerprint identification technologies have further appeared in a new trend, such as applications to full screens and in-cell display screens, etc. Current fingerprint identification devices have certain defects and cannot meet higher requirements. 
     Therefore, there is a need to provide a fingerprint identification device, a fingerprint identification method, and a method for manufacturing the fingerprint identification device to solve issues of the prior art. 
     SUMMARY OF INVENTION 
     To solve the above technical problem, the present disclosure provides a fingerprint identification device including a fingerprint identification unit, a control circuit unit, and a connection component. The fingerprint identification unit includes at least one thermosensitive wire layer and is configured to sense a fingerprint of a user&#39;s finger through the at least one thermosensitive wire layer. The control circuit unit is disposed at one side of the fingerprint identification unit and is electrically connected to the fingerprint identification unit. The connection component is connected to the fingerprint identification unit and the control circuit unit. The at least one thermosensitive wire layer includes a first thermosensitive wire layer and a second thermosensitive wire layer, the first thermosensitive wire layer includes a plurality of longitudinal thermosensitive wires, the second thermosensitive wire layer includes a plurality of transverse thermosensitive wires, and the longitudinal thermosensitive wires and the transverse thermosensitive wires intersect to define a plurality of sensing regions. Two ends of each of the longitudinal thermosensitive wires and two ends of each of the transverse thermosensitive wires are electrically connected to the control circuit unit. 
     In an embodiment of the present disclosure, a material of the longitudinal thermosensitive wires and a material of the transverse thermosensitive wires are selected from the group consisting of at least one of copper, silver, nickel, platinum, a cobalt base alloy, a nickel base alloy, and a ferrous alloy. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a substrate and an insulating layer, the first thermosensitive wire layer and the second thermosensitive wire layer are disposed on the substrate, and the insulating layer is disposed at an intersection of the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a protective layer disposed on the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     The present disclosure further provides a fingerprint identification device including a fingerprint identification unit, a control circuit unit, and a connection component. The fingerprint identification unit includes at least one thermosensitive wire layer and is configured to sense a fingerprint of a user&#39;s finger through the at least one thermosensitive wire layer. The control circuit unit is disposed at one side of the fingerprint identification unit and is electrically connected to the fingerprint identification unit. The connection component is connected to the fingerprint identification unit and the control circuit unit. 
     In an embodiment of the present disclosure, the at least one thermosensitive wire layer includes a first thermosensitive wire layer and a second thermosensitive wire layer, the first thermosensitive wire layer includes a plurality of longitudinal thermosensitive wires, the second thermosensitive wire layer includes a plurality of transverse thermosensitive wires, and the longitudinal thermosensitive wires and the transverse thermosensitive wires intersect to define a plurality of sensing regions. 
     In an embodiment of the present disclosure, two ends of each of the longitudinal thermosensitive wires and two ends of each of the transverse thermosensitive wires are electrically connected to the control circuit unit. 
     In an embodiment of the present disclosure, a material of the longitudinal thermosensitive wires and a material of the transverse thermosensitive wires are selected from the group consisting of at least one of copper, silver, nickel, platinum, a cobalt base alloy, a nickel base alloy, and a ferrous alloy. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a substrate and an insulating layer, the first thermosensitive wire layer and the second thermosensitive wire layer are disposed on the substrate, and the insulating layer is disposed at an intersection of the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a protective layer disposed on the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     The present disclosure further provides a fingerprint identification method applied to the fingerprint identification device. The fingerprint identification method includes sensing the fingerprint of the user&#39;s finger using the at least one thermosensitive wire layer, when the at least one thermosensitive wire layer senses the fingerprint of the user&#39;s finger, using the at least one thermosensitive wire layer to sense a temperature change and feedback, to the control circuit unit, a resistance change, using the control circuit unit to determine a fingerprint pattern of the user&#39;s finger according to an amount of the resistance change and collect the fingerprint pattern, matching the fingerprint pattern with a preset fingerprint pattern, and if the fingerprint pattern and the preset fingerprint pattern match, it is determined that an identification of the fingerprint pattern is successful. 
     In an embodiment of the present disclosure, the at least one thermosensitive wire layer includes a first thermosensitive wire layer and a second thermosensitive wire layer, the first thermosensitive wire layer includes a plurality of longitudinal thermosensitive wires, the second thermosensitive wire layer includes a plurality of transverse thermosensitive wires, and the longitudinal thermosensitive wires and the transverse thermosensitive wires intersect to define a plurality of sensing regions. 
     In an embodiment of the present disclosure, two ends of each of the longitudinal thermosensitive wires and two ends of each of the transverse thermosensitive wires are electrically connected to the control circuit unit. 
     In an embodiment of the present disclosure, a material of the longitudinal thermosensitive wires and a material of the transverse thermosensitive wires are selected from the group consisting of at least one of copper, silver, nickel, platinum, a cobalt base alloy, a nickel base alloy, and a ferrous alloy. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a substrate and an insulating layer, the first thermosensitive wire layer and the second thermosensitive wire layer are disposed on the substrate, and the insulating layer is disposed at an intersection of the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a protective layer disposed on the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     The present disclosure further provides a method for manufacturing a fingerprint identification device. The method for manufacturing the fingerprint identification device includes providing a fingerprint identification unit, wherein the fingerprint identification unit includes at least one thermosensitive wire layer and is configured to sense a fingerprint of a user&#39;s finger through the at least one thermosensitive wire layer, forming a control circuit unit at one side of the fingerprint identification unit, wherein the control circuit unit is electrically connected to the fingerprint identification unit, and forming a connection component, wherein the connection component connects the fingerprint identification unit and the control circuit unit. 
     In an embodiment of the present disclosure, the at least one thermosensitive wire layer includes a first thermosensitive wire layer and a second thermosensitive wire layer, the first thermosensitive wire layer includes a plurality of longitudinal thermosensitive wires, the second thermosensitive wire layer includes a plurality of transverse thermosensitive wires, and the longitudinal thermosensitive wires and the transverse thermosensitive wires intersect to define a plurality of sensing regions. 
     In an embodiment of the present disclosure, a material of the longitudinal thermosensitive wires and a material of the transverse thermosensitive wires are selected from the group consisting of at least one of copper, silver, nickel, platinum, a cobalt base alloy, a nickel base alloy, and a ferrous alloy. 
     In an embodiment of the present disclosure, the fingerprint identification unit further includes a substrate and an insulating layer, the first thermosensitive wire layer and the second thermosensitive wire layer are disposed on the substrate, and the insulating layer is disposed at an intersection of the longitudinal thermosensitive wires and the transverse thermosensitive wires. 
     Compared with the prior art, in order to solve the above technical problem, the fingerprint identification device, the fingerprint identification method, and the method for manufacturing the fingerprint identification device of the embodiments of the present disclosure can realize fingerprint identification through at least one thermosensitive wire layer and can intuitively feedback sensitivity and precision of fingerprint graphics and fingerprint identification. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic structural diagram of a fingerprint identification device according to an embodiment of the present disclosure. 
         FIG. 2  is a schematic structural diagram of a fingerprint identification unit according to an embodiment of the present disclosure. 
         FIG. 3  is a schematic structural diagram of a fingerprint identification unit according to an embodiment of the present disclosure. 
         FIG. 4  is a schematic diagram illustrating a resistance of at least one thermosensitive wire layer changes with temperature according to an embodiment of the present disclosure. 
         FIG. 5  is a block diagram of a fingerprint identification method according to an embodiment of the present disclosure. 
         FIG. 6  is a block diagram of a method for manufacturing a fingerprint identification device according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following description of the various embodiments is provided to illustrate the specific embodiments with reference to the accompanying drawings. 
     In order to make the above description of the present disclosure and other objects, features, and advantages of the present disclosure more comprehensible, preferred embodiments are described below, and are described in detail below with reference to the accompanying drawings. Furthermore, directional terms described by the present disclosure, such as up, down, top, bottom, front, back, left, right, inner, outer, side, surrounding, center, horizontal, vertical, longitudinal, axial, radial, uppermost or lowermost, etc., are only directions by referring to the accompanying drawings, and thus the used terms are used only for the purpose of describing embodiments of the present disclosure and are not intended to be limiting of the present disclosure. 
     In the drawings, units with similar structures are labeled with the same reference number. 
     Referring to  FIGS. 1 and 2 , a fingerprint identification device  10  of an embodiment of the present disclosure includes a fingerprint identification unit  100 , a control circuit unit  200 , and a connection component  300 . The fingerprint identification unit  100  includes at least one thermosensitive wire layer  110  and is configured to sense a fingerprint of a user&#39;s finger through the at least one thermosensitive wire layer  110 . The control circuit unit  200  is disposed at one side of the fingerprint identification unit  100  and is electrically connected to the fingerprint identification unit  100 . The connection component  300  is connected to the fingerprint identification unit  100  and the control circuit unit  200 . 
     Because the fingerprint identification device  10  of the embodiment of the present disclosure performs fingerprint identification through at least one thermosensitive wire layer  110 , the fingerprint identification device  10  can intuitively feedback sensitivity and precision of fingerprint graphics and fingerprint identification. 
     In details, an electronic device includes the fingerprint identification device  10 . 
     In details, the control circuit unit  200  is, for example, an integrated circuit (IC) unit configured to process fingerprint identification related signals and/or messages. 
     Referring to  FIGS. 1 to 3 , in details, the at least one thermosensitive wire layer  110  includes a first thermosensitive wire layer  112  and a second thermosensitive wire layer  114 . The first thermosensitive wire layer  112  includes a plurality of longitudinal thermosensitive wires  113 , the second thermosensitive wire layer  114  includes a plurality of transverse thermosensitive wires  115 . The longitudinal thermosensitive wires  113  and the transverse thermosensitive wires  115  intersect to define a plurality of sensing regions  116 . 
     In details, two ends of each of the longitudinal thermosensitive wires  113  and two ends of each of the transverse thermosensitive wires  115  are electrically connected to the control circuit unit  200 . A material of the longitudinal thermosensitive wires  113  and a material of the transverse thermosensitive wires  115  are selected from the group consisting of at least one of copper, silver, nickel, platinum, a cobalt base alloy, a nickel base alloy, and a ferrous alloy. 
     In details, the fingerprint identification unit  100  further includes a substrate  120  and an insulating layer  130 . The first thermosensitive wire layer  112  and the second thermosensitive wire layer  114  are disposed on the substrate  120 . The insulating layer  130  is disposed at an intersection of the longitudinal thermosensitive wires  113  and the transverse thermosensitive wires  115 . The fingerprint identification unit  100  further includes a protective layer  140  disposed on the longitudinal thermosensitive wires  113  and the transverse thermosensitive wires  115 . 
     Referring to  FIGS. 1 to 4 , in details, a resistance of the at least one thermosensitive wire layer  110  changes significantly with temperature. Because the at least one thermosensitive wire layer  110  changes with temperature, as illustrated in  FIG. 4 , as a temperature of the at least one thermosensitive wire layer  110  rises, the resistance of the at least one thermosensitive wire layer  110  decreases. With this property, when a finger touches a surface of the fingerprint identification device  10 , there is a temperature difference at a contact surface of the fingerprint identification device  10  due to presence of a fingerprint peak and a fingerprint valley, thereby causing a resistance change of the at least one thermosensitive wire layer  110 . According to a resistance signal, the control circuit unit  200  in  FIG. 1  converts into a graphic message. A thermistor can sense a temperature change of 0.001 K at the lowest, and the test sensitivity is high. A position of a grid line defined by the first thermosensitive wire layer  112  and the second thermosensitive wire layer  114  realizes positioning of a temperature change point. 
     Referring to  FIG. 5 , an embodiment of the present disclosure further provides a fingerprint identification method  500  applied to the fingerprint identification device  10 . The fingerprint identification method  500  includes: at a block  510 , sensing the fingerprint of the user&#39;s finger using the at least one thermosensitive wire layer  110 , at a block  520 , when the at least one thermosensitive wire layer  110  senses the fingerprint of the user&#39;s finger, using the at least one thermosensitive wire layer  110  to sense a temperature change and feedback, to the control circuit unit  200 , a resistance change, at a block  530 , using the control circuit unit  200  to determine a fingerprint pattern of the user&#39;s finger according to an amount of the resistance change and collect the fingerprint pattern, at a block  540 , matching the fingerprint pattern with a preset fingerprint pattern, and at a block  550 , if the fingerprint pattern and the preset fingerprint pattern match, it is determined that an identification of the fingerprint pattern is successful. 
     In details, the user&#39;s finger touches a screen surface of the electronic device, and the at least one thermosensitive wire layer  110  senses a temperature change, and a resistance of the at least one thermosensitive wire layer  110  changes, and the resistance change fed back by the at least one thermosensitive wire layer  110  is processed by the control circuit unit  200 . The control circuit unit  200  performs graphical deformation and correlates with current fingerprint patterns to implement unlocking or password service of the electronic device. 
     Referring to  FIG. 1  and  FIG. 6 , an embodiment of the present disclosure further provides a method  600  for manufacturing the fingerprint identification device  10 . The method  600  for manufacturing the fingerprint identification device  10  includes: at a block  610 , providing the fingerprint identification unit  100 , wherein the fingerprint identification unit  100  includes the at least one thermosensitive wire layer  110  and is configured to sense a fingerprint of a user&#39;s finger through the at least one thermosensitive wire layer  110 , at a block  620 , forming the control circuit unit  200  at one side of the fingerprint identification unit  100 , wherein the control circuit unit  200  is electrically connected to the fingerprint identification unit  100 , and at a block  630 , forming the connection component  300 , wherein the connection component  300  connects the fingerprint identification unit  100  and the control circuit unit  200 . 
     In details, referring to  FIG. 2  and  FIG. 3 , in the embodiment of the present disclosure, the first thermosensitive wire layer  112  and the second thermosensitive wire layer  114  are formed on the substrate  120 . The insulating layer  130  is disposed at an intersection of the first thermosensitive wire layer  112  and the second thermosensitive wire layer  114  for insulation protection. 
     In details, first, the first thermosensitive wire layer  112  is formed on the substrate  120 , and a wire shape thereof is formed by a process such as plating, exposure, etching, or the like. Thereafter, the insulating layer  130  is formed, and if an inorganic insulating film is used, a pattern can be formed by a process such as plating, exposure, etching, or the like. If an organic insulating film is used, the organic insulating film can be molded by exposure. Thereafter, the second thermosensitive wire layer  114  is formed, and a wire pattern thereof is formed by a process such as plating, exposure, etching, or the like. Thereafter, the protective layer  140  is formed, and an inorganic insulating film or an organic insulating film can also be used. 
     In details, the substrate  120  may be a glass substrate, a ceramic substrate, a polyimide (PI) substrate, a polyethylene terephthalate (PET) substrate, or a cycloolefin polymer (COP) substrate or the like. The substrate  120  may have transparent material or non-transparent material. The substrate  120  having transparent material can be placed on a surface of a display screen of an electronic device, or the display screen itself can be used as the substrate  120 . 
     The above process can be used as a general process, but is not limited to the above process. It is also possible to produce a film pattern of the same performance by processes such as embossing, letterpress printing, and laser etching. 
     The embodiment of the present disclosure provides a fingerprint identification device that can be used independently or combined with a display screen of an electronic device to adapt to a full-screen design. 
     In the embodiment of the present disclosure, a fingerprint coordinate map is established by using a thermosensitive material, and a fingerprint position and shape are sensed by different temperatures of contact with the finger, thereby implementing the fingerprint identification technology. 
     Because the fingerprint identification device, the fingerprint identification method, and the method for manufacturing the fingerprint identification device of the embodiment of the present disclosure, fingerprint identification can realize fingerprint identification through at least one thermosensitive wire layer and can intuitively feedback sensitivity and precision of fingerprint graphics and fingerprint identification. In addition, the manufacturing process thereof is simple, materials used thereof are easy to obtain, and the process operation thereof is convenient. The fingerprint identification device can be attached to a target product (for example, an electronic device) as an external product, or can be made as a process layer inside the target product. 
     Although the present disclosure is described via one or more embodiments, those of ordinary skill in the art can come up with equivalent variations and modifications based upon the understanding of the specification and the accompanying drawings. The present disclosure includes all such modifications and variations, and is only limited by the scope of the appended claims. In particular, as to the various functions performed by the components described above, the terms used to describe the components are intended to correspond to any component performing the specific functions (e.g., which are functionally equivalent) of the components (unless otherwise indicated), even those which are structurally different from the disclosed structure for performing the functions in the exemplary embodiments in the specification shown herein. In addition, although a particular feature in the specification is disclosed in only one of many embodiments, this feature may be combined with one or more features in other embodiments which are desirable and advantageous to a given or particular application. Moreover, the terms “include”, “have”, “consist of”, or variations thereof used in the detailed description or the claims are intended to be used in a manner similar to the term “comprising”. 
     In summary, although the preferable embodiments of the present disclosure have been disclosed above. It should be noted that those of ordinary skill in the art can make a variety of improvements and substitutions on the premise of not deviating from the technical principle of the present disclosure, and these improvements and substitutions should be encompassed within the protection scope of the present disclosure.