WO2018143655A1 - Fingerprint sensor - Google Patents

Abstract

A fingerprint sensor according to an embodiment comprises: a piezoelectric layer; a first substrate which is disposed on the piezoelectric layer; a first electrode pattern between the piezoelectric layer and the first substrate; a first conductive member between the first electrode pattern and the piezoelectric layer; a second substrate which is disposed below the piezoelectric layer; a second electrode pattern between the piezoelectric layer and the second substrate; and a second conductive member between the second electrode pattern and the piezoelectric layer, wherein the sizes of the first substrate and the second substrate are different from each other.

Description

Fingerprint sensor

An embodiment relates to a fingerprint sensor,

The fingerprint sensor is a sensor that detects a human fingerprint, and is widely used to determine whether a door lock or the like has recently been widely applied, as well as whether to turn on or off the power of an electronic device. It is becoming.

The fingerprint sensor may be classified into an ultrasonic method, an infrared method, and a capacitive method according to its operation principle. For example, the ultrasonic method uses the acoustic impedance difference between each valley and the floor when an ultrasonic signal of a certain frequency emitted from a plurality of piezoelectric sensors is reflected from the valley and the valley of the fingerprint. Fingerprints are detected by measuring them using a plurality of piezoelectric sensors, which are the sources of ultrasonic waves. Especially, the advantage of the ultrasonic method is that the ultrasonic waves are generated in a pulse form beyond the function of simple fingerprint recognition, and the Doppler effect by the echo wave is generated. Since it has a function to grasp the flow of blood inside the finger by detecting, it can have the advantage of determining whether or not a fake fingerprint using it.

Such a fingerprint sensor may arrange a piezoelectric layer including a piezoelectric material on a substrate, for example, a cover substrate, and arrange electrodes on both sides of the piezoelectric layer to recognize a fingerprint according to ultrasonic generation.

Such a fingerprint sensor may be disposed on top and bottom of the piezoelectric layer, and may be connected to an ASIC by connecting an upper electrode and a lower electrode to a printed circuit board, respectively.

However, in order to connect the upper electrode or the lower electrode to the printed circuit board, a process of forming a via hole in the piezoelectric layer is required, which lowers the process efficiency.

Therefore, there is a need for a fingerprint sensor having a new structure that can solve such problems.

Embodiments are intended to provide a fingerprint sensor that can be easily manufactured and has improved reliability.

Fingerprint sensor according to the embodiment, the piezoelectric layer; A first substrate disposed on the piezoelectric layer; A first electrode pattern between the piezoelectric layer and the first substrate; A first conductive member between the first electrode pattern and the piezoelectric layer; A second substrate disposed under the piezoelectric layer; A second electrode pattern between the piezoelectric layer and the second substrate; And a second conductive member between the second electrode pattern and the piezoelectric layer, wherein the size of the first substrate and the second substrate is different.

The fingerprint sensor according to the embodiment may omit a process of forming a via hole or the like in the piezoelectric layer to connect the first electrode on the first substrate to the application specific integrated circuit. In detail, the first substrate and the second substrate include a flexible printed circuit board on which electrodes are disposed, and since the first substrate is bent and directly connected to the custom circuit, the piezoelectric layer forms holes and the like, The process of connecting a custom integrated circuit can be omitted.

1 is a diagram illustrating a perspective view of a fingerprint sensor according to an embodiment.

2 is a diagram illustrating a perspective view of a piezoelectric member of a fingerprint sensor according to an embodiment.

3 is a plan view illustrating a fingerprint sensor according to an embodiment.

4 is a cross-sectional view illustrating an operation principle of a fingerprint sensor according to an embodiment.

5 is a sectional view of a fingerprint sensor according to an embodiment.

FIG. 6 is a cross-sectional view illustrating a bending of a first substrate in a fingerprint sensor according to an embodiment. FIG.

7 illustrates a perspective view of a piezoelectric member of a fingerprint sensor according to another exemplary embodiment.

FIG. 8 is an enlarged perspective view of region A of FIG. 7.

FIG. 9 is an enlarged plan view of region A of FIG. 7.

10 is a plan view illustrating a fingerprint sensor according to another exemplary embodiment.

FIG. 11 is a cross-sectional view taken along the line BB ′ of FIG. 10.

FIG. 12 is an enlarged plan view of region C of FIG. 10.

FIG. 13 is an enlarged plan view of the region D of FIG. 10.

14 to 16 are views for explaining a manufacturing process of the piezoelectric member of the fingerprint sensor according to another embodiment.

17 illustrates a cross-sectional view of a display panel to which a fingerprint sensor according to an embodiment is applied.

18 to 21 illustrate various embodiments to which the fingerprint sensor according to the embodiments is applied.

In the description of embodiments, each layer, region, pattern, or structure may be “on” or “under” the substrate, each layer, region, pad, or pattern. Substrate formed in ”includes all formed directly or through another layer. Criteria for the top / bottom or bottom / bottom of each layer will be described with reference to the drawings.

In addition, when a part is "connected" with another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with the other member in between. In addition, when any part "includes" any component, this means that it is possible to further include other components, not to exclude other components unless otherwise stated.

In the drawings, the thickness or size of each layer (film), region, pattern, or structure may be modified for clarity and convenience of description, and thus do not necessarily reflect the actual size.

Hereinafter, a fingerprint sensor according to an embodiment will be described with reference to the drawings.

Referring to FIG. 1, the fingerprint sensor according to the embodiment may include a cover substrate 100, a substrate, a piezoelectric member 400, and an electrode.

The cover substrate 100 may be rigid or flexible. Preferably, the cover substrate 1000 may be flexible to be bent or foldable.

For example, the cover substrate 100 may include plastic. In detail, the cover substrate 1000 may include reinforced or soft plastic such as polyimide (PI), polyethylene terephthalate (PET), propylene glycol (PPG) polycarbonate (PC), or sapphire. It may include.

In addition, the cover substrate 100 may include a light isotropic film. For example, the cover substrate 100 may include a cyclic olefin copolymer (COC), a cyclic olefin polymer (COP), an isotropic polycarbonate (PC), or an isotropic polymethyl methacrylate (PMMA). .

Sapphire is a material that can be used as a cover substrate because of its excellent electrical properties such as permittivity, which can dramatically increase the touch response speed, and can easily implement spatial touch such as hovering and high surface strength. Here, hovering refers to a technique of recognizing coordinates even at a distance far from the display.

A deco layer having a color may be further disposed on the cover substrate. For example, a decoration layer for implementing such a color may be further disposed in one region of the cover substrate to match the color of the cover substrate with the color of the peripheral component or package of the fingerprint sensor disposed in the region of the cover substrate. .

The substrate may be disposed below the cover substrate 100. The substrate may include a first substrate 210 and a second substrate 220. In detail, the substrate 210 may include the first substrate 210 disposed below the cover substrate 100 and the second substrate 220 disposed below the first substrate 210. have.

The first substrate 210 and the second substrate 220 may include plastic. For example, the first substrate 210 and the second substrate 220 may include a resin material such as polyimide (PI). For example, the first substrate 210 and the second substrate 220 may include a printed circuit board. For example, the first substrate 210 and the second substrate 220 may include a flexible printed circuit board (FPCB).

The thickness of the first substrate 210 and the second substrate 220 may be about 30 μm or less.

The first substrate 210 and the second substrate 220 may be disposed in different widths. In detail, the width of the first substrate 210 may be greater than the width of the second substrate 220.

The width and position of the first base 210 will be described in detail below.

The piezoelectric member 400 may be disposed below the cover substrate 100. In detail, the piezoelectric member 400 may be disposed under the first substrate 210. In detail, the piezoelectric member 400 may be disposed between the first substrate 210 and the second substrate 220.

The piezoelectric member 400 may include various piezoelectric materials. For example, the piezoelectric member 400 may include single crystal ceramics, polycrystalline ceramics, a polymer material, a thin film material, or a composite material in which a polycrystalline material and a polymer material are composited.

The piezoelectric material of the single crystal ceramics may include α-AlPO 4, α-SiO 2, LiTiO 3, LiNbO 3, SrxBayNb 2 O 3, Pb5-Ge 3 O 11, Tb 2 (MnO 4) 3, Li 2 B 4 O 7, CdS, ZnO, Bi12SiO20 or Bi12GeO20.

In addition, the piezoelectric material of the polycrystalline ceramics may include PZT-based, PT-based, PZT-Complex Perovskite-based, or BaTiO3.

In addition, the piezoelectric material of the polymer material may include PVDF, P (VDF-TrFe), P (VDFTeFE), or TGS.

In addition, the piezoelectric material of the thin film material may include ZnO, CdS or AlN.

In addition, the piezoelectric material of the composite material may include PZT-PVDF, PZT-Silicon Rubber, PZT-Epoxy, PZT-foaming polymer or PZT-foaming urethane.

The piezoelectric member 400 according to the embodiment may include a piezoelectric material of polycrystalline ceramics. For example, the piezoelectric member 400 according to the embodiment may include a PZT-based, PT-based, PZT-Complex Perovskite-based, or BaTiO 3.

Referring to FIG. 2, the piezoelectric member 400 may include a plurality of pillars. In detail, the piezoelectric member 400 may include a plurality of piezoelectric pillars 410.

The piezoelectric pillars 410 may be spaced apart from each other. That is, the piezoelectric pillars 410 may be disposed without contacting each other.

The piezoelectric pillars 410 may be arranged to have rows and columns. For example, the piezoelectric pillars 410 may extend in a plurality of row directions and a plurality of column directions.

 For example, the piezoelectric pillars 410 may be spaced apart at intervals of about 50 μm or less. In addition, a resin material 420 may be disposed between the piezoelectric pillars 410. That is, the resin material 420 may be disposed to surround the piezoelectric pillars 410. That is, the piezoelectric pillars 410 may be supported by the resin material 420.

Referring to FIG. 3, an effective area AA and an invalid area UA may be defined in a fingerprint sensor according to an exemplary embodiment.

The effective area AA may be an area for fingerprint recognition. In addition, the invalid area UA disposed around the effective area AA may be an area where fingerprint recognition is not performed.

In detail, when a finger approaches or contacts the effective area AA, a fingerprint may be recognized by ultrasonic waves transmitted and received in the effective area. The driving principle of the fingerprint sensor will be described in detail below.

The electrode may be disposed on one surface of the substrate. In detail, the electrode may include a first electrode 310 and a second electrode 320.

The first electrode 310 may be disposed on one surface of the first substrate 210. In detail, the first electrode 310 may be disposed between the first substrate 210 and the piezoelectric member 400.

In addition, the second electrode 320 may be disposed on one surface of the second substrate 220. In detail, the second electrode 320 may be disposed between the second substrate 220 and the piezoelectric member 400.

The first electrode 310 and the second electrode 320 may be disposed on an area corresponding to the effective area of the piezoelectric member 400.

The first electrode 310 and the second electrode 320 may include a conductive material.

For example, the first electrode 310 and the second electrode 320 may be indium tin oxide, indium zinc oxide, copper oxide, or tin oxide. ), Metal oxides such as zinc oxide and titanium oxide.

Alternatively, the first electrode 310 and the second electrode 320 may include nanowires, photosensitive nanowire films, carbon nanotubes (CNT), graphene, conductive polymers, or mixtures thereof. .

Alternatively, the first electrode 310 and the second electrode 320 may include various metals. For example, the sensing electrode 200 is chromium (Cr), nickel (Ni), copper (Cu), aluminum (Al), silver (Ag), molybdenum (Mo). Gold (Au), titanium (Ti) and their alloys may include at least one metal.

Alternatively, the first electrode 310 and the second electrode 320 may be formed in a mesh shape. In detail, at least one of the first electrode 310 and the second electrode 320 may include a plurality of sub-electrodes, and the sub-electrodes may be disposed to cross each other in a mesh shape.

In detail, the first electrode 310 and the second electrode 320 are mesh openings OA between the mesh line LA and the mesh line LA by a plurality of sub-electrodes that cross each other in a mesh shape. It may include.

The line width of the mesh line LA may be about 0.1 μm to about 10 μm. A mesh line having a line width of less than about 0.1 μm may be impossible in the manufacturing process. When the mesh line LA exceeds about 10 μm, the touch electrode pattern may be visually recognized from the outside, thereby reducing visibility. In detail, the line width of the mesh line LA may be about 1 μm to about 5 μm. In more detail, the line width of the mesh line LA may be about 1.5 μm to about 3 μm.

In addition, the thickness of the mesh line LA may be about 100 nm to about 1000 nm. When the thickness of the mesh line is less than about 100 nm, the electrode resistance may be increased to reduce the electrical characteristics. When the thickness of the mesh line is greater than about 1000 nm, the overall thickness of the fingerprint sensor may be thick and the process efficiency may be reduced. In detail, the thickness of the mesh line LA may be about 150 nm to about 500 nm. In more detail, the thickness of the mesh line LA may be about 180 nm to about 200 nm.

In addition, the mesh opening may be formed in various shapes. For example, the mesh opening OA may have various shapes such as a polygonal shape or a circular shape of a square, diamond, pentagon, and hexagon. In addition, the mesh opening may be formed in a regular shape or a random shape.

Since the first electrode 310 and the second electrode 320 have a mesh shape, the pattern of the electrode may be made invisible on the display area as an example of an effective area. That is, even if the electrode is made of metal, the pattern can be made invisible. Further, even when the electrode is applied to a large size fingerprint sensor device, the resistance of the fingerprint sensor device can be lowered.

The first electrode 310 may be disposed extending in the first direction. In detail, the first electrode 310 may include a plurality of first electrode patterns 311 extending and extending in a first direction.

In addition, the second electrode 320 may extend in a second direction. In detail, the second electrode 320 may include a plurality of second electrode patterns 321 extending in the second direction different from the first direction.

The line width LW1 of the first electrode pattern 311 and the line width LW2 of the second electrode pattern 321 may be about 20 μm to about 70 μm. In detail, line widths of the first electrode pattern 311 and the second electrode pattern 321 may be about 30 μm to about 50 μm.

When the line widths of the first electrode pattern 311 and the second electrode pattern 321 are less than about 20 μm, energy transmitted to the piezoelectric member may be reduced, and thus output may be lowered to lower fingerprint sensing sensitivity. . In addition, when the line widths of the first electrode pattern 311 and the second electrode pattern 321 exceed about 70 μm, the resolution of the piezoelectric member may decrease.

In addition, the first electrode patterns 311 may be spaced apart from each other, and the separation distance d1 of the first electrode patterns 311 may be about 40 μm to 100 μm.

In addition, the second electrode patterns 321 may be spaced apart from each other, and the separation distance d2 of the second electrode patterns 321 may be about 40 μm to 100 μm.

When the first electrode patterns 311 and the second electrode pattern 321 are spaced apart by less than about 40 μm, fingerprint sensing sensitivity may be lowered, and when the thickness exceeds about 100 μm, the resolution of the piezoelectric member may be reduced. Can be lowered.

The first electrode pattern 311 and the second electrode pattern 312 may extend in a direction crossing each other. That is, the first electrode pattern 311 and the second electrode pattern 312 extend in the first direction and the second direction to cross each other, and the first electrode pattern 311 and the second electrode pattern ( A plurality of node regions N intersected by 312 may be formed.

In FIG. 2, the first electrode pattern 311 and the second electrode pattern 321 are formed as a bar pattern. However, the embodiment is not limited thereto, and the first electrode pattern 311 and The second electrode pattern 321 may be formed in a pattern having various shapes such as a polygon or a circle such as a quadrangle, diamond, pentagon, and hexagon.

Widths of the first electrode pattern 311 and the second electrode pattern 321 may be equal to or less than a width of the piezoelectric pillar 410. In detail, the width of the node region N may be equal to or less than the width of the piezoelectric pillar 410.

In addition, each node region N may be disposed at a position overlapping with the piezoelectric pillar 410. That is, the position of the node region N and the position of the piezoelectric pillar 410 may overlap. That is, the piezoelectric pillar 410 may be disposed in the region of the piezoelectric member 400 corresponding to the node region N. FIG.

In the node region N, a signal may be transmitted or received by an object approaching or contacting the piezoelectric member 400. In detail, the node region N may transmit and receive an ultrasonic signal. That is, the node area N may be a sensor that recognizes a fingerprint according to the approach or contact of a finger.

At least one node region N may be formed on the piezoelectric member 400. In detail, a plurality of node regions N may be formed on the piezoelectric member 400. For example, the node area N may be formed at a resolution of about 400 dpi to about 500 dpi with respect to the piezoelectric substrate.

Accordingly, the spacing of the node regions N may be about 100 μm or less. For example, the node area N may include node areas adjacent to each other, and the node areas may be spaced at intervals of about 100 μm or less.

For example, at least one of the first interval of the first electrodes 310 and the second interval of the second electrodes 320 forming the node region N may be about 100 μm or less, in detail, about 70 Or less, more specifically, about 50 μm or less apart.

When the spacing of the node regions N exceeds about 50 μm, the resolution of the node regions N may be degraded. Accordingly, an ultrasonic signal transmitted and received in the node regions N may be weak so that a fingerprint may be accurately corrected. It may not be recognized and the reliability of the fingerprint sensor may be degraded.

The node region N may simultaneously play a role of transmitting and receiving an ultrasonic signal. In detail, when a finger touches or approaches, an ultrasonic signal may be transmitted in the direction of the finger in the node region N, and the ultrasonic signals reflected from the finger may be received in the node region N again. The fingerprint sensor according to the embodiment may recognize the fingerprint of the finger due to the signal difference between the transmission and the reception.

4 is a view for explaining the driving of the fingerprint sensor according to the contact or approach of the finger.

Referring to FIG. 4, a voltage having a resonant frequency of an ultrasonic band is applied to the first electrode 310 and the second electrode 320 disposed on one surface and the other surface of the piezoelectric member 400 by an external control unit. An ultrasonic signal may be generated at 400. In detail, when a voltage is applied to the piezoelectric member 400, the piezoelectric pillars 410 of the piezoelectric member 400 may be deformed, that is, vibrate, and generate an ultrasonic signal by the vibration.

When the finger or the like does not touch or approach the ultrasonic signal, the node N of the piezoelectric member 400 due to a difference in acoustic impedance between the air and the node N of the piezoelectric member 400 from which the ultrasonic signal is emitted. Most of the ultrasonic signals transmitted from the plurality of ultrasonic signals do not pass through the interface between the piezoelectric sensor 200 and the air and are returned to the piezoelectric member 400.

On the other hand, when the finger touches or approaches as shown in FIG. 4, a part of the ultrasonic signals transmitted from the node N of the piezoelectric member 400 penetrates the interface between the skin of the finger and the piezoelectric member 400 and proceeds inside the finger. Accordingly, the strength of the reflected signal is lowered, so that the fingerprint pattern can be detected therefrom.

Although it is difficult to check with the naked eye, the fingerprint of a finger may have a pattern in which numerous valleys and floors are repeated, and the height difference may be repeated as the valleys and floors are repeated. Therefore, as illustrated in FIG. 4, the piezoelectric member 400 may not directly contact the skin in the valley 710 of the fingerprint, and the piezoelectric member 400 may directly contact the skin in the floor 620 of the fingerprint. .

Accordingly, the ultrasonic signal transmitted from the node N of the piezoelectric member 400 corresponding to the valley 710 of the fingerprint emits only a very small signal to the outside and almost most of the ultrasonic signal is reflected therein so that the node ( N), and the ultrasonic signal emitted from the node N of the piezoelectric member 400 corresponding to the floor 720 of the fingerprint, a considerable amount passes through the finger boundary, is reflected and received back to the node N The intensity of the ultrasonic signal is relatively reduced.

Accordingly, the fingerprint pattern of the finger may be detected by measuring the intensity or the reflection coefficient of the reflected signal from which the ultrasonic signal generated from the acoustic impedance difference along the valley 710 and the floor 720 of the fingerprint at each node N is received. Can be.

1 and 5, a conductive member may be further disposed between the electrode and the piezoelectric member 400. In detail, a first conductive member 510 may be disposed between the first electrode 310 and the piezoelectric member 400. In addition, a second conductive member 520 may be disposed between the second electrode 320 and the piezoelectric member 400.

The first conductive member 510 and the second conductive member 520 may be disposed on an area corresponding to the effective area of the piezoelectric member 400.

The first conductive member 510 and the second conductive member 520 may include a conductive film. The first conductive member 510 and the second conductive member 520 may include conductive particles. For example, the first conductive member 510 and the second conductive member 520 may include conductive particles having a particle diameter of about 2 μm to about 10 μm.

For example, the first conductive member 510 and the second conductive member 520 may include an anisotropic conductive film (ACF).

The first conductive member 510 may be disposed between the first electrode 310 and the piezoelectric member 400 to adhere the first electrode 310 to the piezoelectric member 400. In addition, the first conductive member 510 may be disposed on the piezoelectric member 400 to connect the plurality of piezoelectric pillars 410 of the piezoelectric member 400 to each other.

In addition, the second conductive member 520 may be disposed between the second electrode 320 and the piezoelectric member 400 to adhere the second electrode 320 to the piezoelectric member 400. In addition, the second conductive member 520 may be disposed on the piezoelectric member 400 to connect the plurality of piezoelectric pillars 410 of the piezoelectric member 400 to each other.

That is, the first conductive member 510 and the second conductive member 520 may simultaneously play an adhesive role and an electrical connection role.

An application specific integrated circuit (ASIC) 600 may be disposed under the second substrate 220. In detail, the custom integrated circuit 600 disposed in contact with the second substrate 220 may be disposed below the second substrate 220.

The application specific integrated circuit 600 may include an active surface and an inactive surface. In detail, the application specific integrated circuit 600 may include an active surface including a circuit and an inactive surface without a circuit.

For example, the active surface of the application specific integrated circuit 600 may include a processing circuit and / or a sensor, or a sensing device disposed on or in the application specific integrated circuit 600.

The application specific integrated circuit 600 may include a substrate such as silicon (Si), gallium arsenide, silicon carbide (SiC) graphene, or any organic semiconductor material.

In addition, at least one circuit may be disposed on the substrate or inside the substrate.

For example, circuitry on top of or within the substrate may comprise a gate array standard cell, for example the circuitry is configured to perform a particular operation to be implemented. Can be. The apparatus may further include a plurality of input terminals and a plurality of output terminals connected to the gate array or the standard cell. The input terminal may be connected to the first substrate 210 and the second substrate 220, and the output terminal may be connected to an external main board.

5 and 6, the first substrate 210 and the second substrate 220 may be connected to the custom integrated circuit 600 and disposed thereon. In detail, the first substrate 210 and the second substrate 220 may be disposed to be electrically connected to the application specific integrated circuit 600.

In detail, the bottom surface of the second substrate 220 may be disposed in contact with the application specific integrated circuit 600.

The width W1 of the first substrate 210 and the width W2 of the second substrate 220 may be different from each other. In detail, the width W1 of the first substrate 210 may be greater than the width W2 of the second substrate 220. Here, the width may be defined as at least one of the width and length of the substrate.

The first substrate 210 may be bent in one direction to be connected to the custom integrated circuit 600.

For example, the first substrate 210 may include an electrode portion 211 and a connection portion 212. The first electrode 310 may be disposed on the electrode portion 211. In addition, the connection unit 212 may be connected to the application specific integrated circuit 600.

In detail, referring to FIG. 6, the connection part 212 may be bent in one direction. In detail, the connection part 212 may be bent in an upper surface direction of the application specific integrated circuit 600. That is, the connection part 212 may be bent in the direction of the upper surface of the application specific integrated circuit 600 to be in contact with the upper surface of the application specific integrated circuit 600.

Accordingly, the application specific integrated circuit 600 may be connected to the first substrate 210 and the second substrate 220.

The fingerprint sensor according to the embodiment may omit a process of forming a via hole or the like in the piezoelectric layer to connect the first electrode on the first substrate to the application specific integrated circuit. In detail, the first substrate and the second substrate include a flexible printed circuit board on which electrodes are disposed, and since the first substrate is bent and directly connected to the custom circuit, the piezoelectric layer forms holes and the like, The process of connecting a custom integrated circuit can be omitted.

Hereinafter, a fingerprint sensor according to another exemplary embodiment will be described with reference to FIGS. 7 through 16. In the description of the fingerprint sensor according to another exemplary embodiment, the same description as that of the fingerprint sensor according to the above-described embodiment will be omitted, and the same reference numerals will be given to the same configuration.

7 to 9, the piezoelectric member 400 may include a plurality of piezoelectric fibers 430 and a resin layer 420. In detail, the piezoelectric member 400 may include a resin layer 420 and the piezoelectric material, and may include a plurality of piezoelectric fibers 430 disposed in the resin layer 220.

The piezoelectric fibers 430 may be dispersed and disposed in the resin layer 420. In detail, the resin layer 420 may be disposed to surround the piezoelectric fibers 430.

The piezoelectric fibers 430 extend in one direction and may be disposed. For example, the piezoelectric fibers 430 may be disposed extending from one surface of the piezoelectric member in the other surface direction opposite to the one surface.

That is, one end of the piezoelectric fiber 430 may be disposed toward the first electrode, and the other end of the piezoelectric fiber 430 may be disposed toward the second electrode.

The thickness T of the piezoelectric fiber 430 may be about 5 μm or less. The thickness T of the piezoelectric fiber may be defined as a distance from one end of the piezoelectric fiber to the other end. In detail, the thickness T of the piezoelectric fiber 430 may be about 500 nm to about 5 μm.

When the thickness of the piezoelectric fibers exceeds about 5 μm, the number of piezoelectric fibers disposed in one node may be reduced, thereby lowering the fingerprint sensing sensitivity.

Referring to FIG. 10, an effective area AA and an invalid area UA may be defined in the piezoelectric member 200.

The effective area AA may be an area for fingerprint recognition. In addition, the invalid area UA disposed around the effective area AA may be an area where fingerprint recognition is not performed.

The electrode may be disposed on the piezoelectric member 200. For example, the electrode may be disposed on at least one surface of one surface of the piezoelectric member 200 and the other surface opposite to the one surface.

Referring to FIG. 5, the electrode may include a first electrode 310 and a second electrode 320.

The first electrode 310 and the second electrode 320 may cross each other. In detail, the first electrode 310 includes a plurality of first electrode patterns 311 extending in one direction, and the second electrode 320 includes a plurality of second electrodes extending in a direction different from the one direction. The pattern 321 may be included.

Accordingly, the first electrode 310 and the second electrode 320 have a node region N where the first electrode pattern 311 and the second electrode pattern 321 cross in different directions. Can be formed.

Referring to FIG. 11, the piezoelectric member 400 may include a node region N and a non-node region UN.

The piezoelectric member 400 may include piezoelectric fibers 430 disposed on a region corresponding to the node region N and the non-node region UN. In detail, the piezoelectric fibers 430 may be disposed in both the node region N and the non-node region UN.

12 and 13, the piezoelectric fibers 430 disposed in the node region N may be spaced apart from or in contact with each other. In detail, the piezoelectric fibers 430 disposed in the node region N may be disposed to be spaced apart from each other at a predetermined distance or not partially or in contact with each other.

In addition, the separation distance of the piezoelectric fibers 430 disposed in the node region N may be different. In detail, the piezoelectric fibers 430 disposed in the node region N may be spaced apart from each other by a random distance.

For example, the separation distances of the piezoelectric fibers 430 disposed in the node region N may be spaced apart from each other by the same or different distances.

That is, the piezoelectric fibers 430 disposed in the node region N may be spaced apart from each other at random distances, that is, the separation distance of the piezoelectric fibers 430 disposed in the node region N may be It may be irregular.

For example, referring to FIG. 12, the piezoelectric fibers disposed in the node region N may include the first-first distance d1-1, the 1-2th distance d1-2, and the 1-3th distance ( d1-3) and the like can be spaced apart.

The first-first distance d1-1, the 1-2th distance d1-2, and the 1-3th distance d1-3 may be the same or different from each other.

In addition, referring to FIG. 9, the piezoelectric fibers disposed in the non-node area UN may have a second-first distance d2-1, a second-second distance d2-2, and a second-second distance d2. -3) and may be spaced apart from each other.

The second-first distance d2-1, the second-second distance d2-2, and the second-second distance d2-3 may be the same or different from each other.

11 and 13, the piezoelectric fibers 430 disposed in the non-node region UN may be disposed to be spaced apart from or in contact with each other. In detail, the piezoelectric fibers 430 disposed in the non-node region UN may be disposed to be spaced apart at a predetermined distance without being partially or in contact with each other.

In addition, the separation distance of the piezoelectric fibers 430 disposed in the non-node area UN may be different. In detail, the piezoelectric fibers 430 disposed in the non-node area UN may be spaced apart from each other at random distances.

For example, the separation distances of the piezoelectric fibers 430 disposed in the non-node area UN may be spaced apart from each other by the same or different distances.

In addition, the separation distance of the piezoelectric fibers 430 disposed in the node region N may be different from the separation distance of the piezoelectric fibers disposed in the non-node region UN.

In detail, the separation distance of the piezoelectric fibers 430 disposed in the node region N may be smaller than the separation distance of the piezoelectric fibers disposed in the non-node region UN. That is, the piezoelectric fibers 430 may be disposed more densely in the node region N than in the non-node region UN.

In addition, the density of the piezoelectric fibers 430 disposed in the node region N may be different from the density of the piezoelectric fibers disposed in the non-node region UN.

In detail, the density of the piezoelectric fibers 430 disposed in the node region N may be greater than the density of the piezoelectric fibers disposed in the non-node region UN. That is, the piezoelectric fibers 430 may be disposed more in the node region N than in the non-node region UN.

In addition, the number of piezoelectric fibers 430 disposed in the node region N may differ from the number of piezoelectric fibers disposed in the non-node region UN.

In detail, the number of the piezoelectric fibers 430 disposed in the one node region N may be greater than the number of the piezoelectric fibers disposed in the one non-node region UN.

The fingerprint sensor according to another embodiment may control the number of piezoelectric fibers disposed in the piezoelectric member.

In detail, the density or weight of the piezoelectric fibers disposed in the node region on the region of the piezoelectric member may be greater than the density or weight of the piezoelectric fibers disposed in the non-node region.

Accordingly, by increasing the number of piezoelectric fibers in the node region, which is a region in which fingerprint sensing is performed, process efficiency and sensing sensitivity of the fingerprint sensor can be improved.

Hereinafter, the piezoelectric member manufacturing process of the fingerprint sensor according to the embodiment will be described with reference to FIGS. 14 to 16.

Referring to FIG. 14, a plurality of piezoelectric fibers 210 may be manufactured by processing and synthesizing a piezoelectric material into a fiber shape. The piezoelectric fibers 210 may be spaced at a random distance so as to contact or not contact each other to form a bundle.

Subsequently, referring to FIG. 15, the piezoelectric fiber 430 bundle may be inserted into the resin layer 420. The resin layer 420 may be disposed to surround the piezoelectric fibers 430. The resin layer 420 may be disposed to surround the piezoelectric fibers 430. The piezoelectric fibers 430 may be fixed without being inclined inside the resin layer 420 by the resin layer 420.

Accordingly, the piezoelectric member 400 in which the plurality of piezoelectric fibers 430 are disposed may be formed in the resin layer 420.

Subsequently, referring to FIG. 16, the piezoelectric member 400 may be cut. In detail, the piezoelectric member 400 may be cut into the unit piezoelectric members 400 according to a required size. Accordingly, the final piezoelectric member 400 applied to the fingerprint sensor according to the embodiment may be formed.

By the piezoelectric member manufacturing method according to the embodiment, the patterning process for forming a separate piezoelectric material filler (pilar) can be omitted, and the piezoelectric member can be cut and manufactured according to the size of the unit piezoelectric member, so the process efficiency Can improve.

The fingerprint sensor according to the embodiment may be combined with a display panel and the like and applied to the display panel.

Referring to FIG. 17, the display panel according to the embodiment may include a cover substrate 100, a display panel 900, and a fingerprint sensor.

Since the cover base material 100 and the fingerprint sensor are similar to those described above, the following description is omitted.

The display panel 900 may be disposed under the cover substrate 100. The display panel 900 and the cover substrate 100 may be adhered to each other through an adhesive layer 800 such as an optically clear adhesive.

The display panel 900 may include a first substrate 910 and a second substrate 920.

When the display panel 900 is a liquid crystal display panel, the display panel 900 includes a first substrate 910 including a thin film transistor (TFT) and a pixel electrode, and a second substrate including color filter layers. 920 may be formed in a bonded structure with the liquid crystal layer interposed therebetween.

In addition, the display panel 900 includes a thin film transistor, a color filter, and a black matrix formed on the first substrate 910, and the second substrate 920 is bonded to the first substrate 910 with a liquid crystal layer interposed therebetween. It may be a liquid crystal display panel having a color filter on transistor (COT) structure. That is, a thin film transistor may be formed on the first substrate 910, a protective film may be formed on the thin film transistor, and a color filter layer may be formed on the protective film. In addition, a pixel electrode in contact with the thin film transistor is formed on the first substrate 910. In this case, the black matrix may be omitted in order to improve the aperture ratio and simplify the mask process, and the common electrode may be formed to serve as the black matrix.

In addition, when the display panel 900 is a liquid crystal display panel, the display device may further include a backlight unit that provides light from the back of the display panel 900.

When the display panel 900 is an organic light emitting display panel, the display panel 900 includes a self-light emitting device that does not require a separate light source. In the display panel 900, a thin film transistor is formed on the first substrate 910, and an organic light emitting diode is formed in contact with the thin film transistor. The organic light emitting diode may include an anode, a cathode, and an organic light emitting layer formed between the anode and the cathode. In addition, the organic light emitting device may further include a second substrate 920 serving as an encapsulation substrate for encapsulation.

The fingerprint sensor described above may be disposed under the display panel 900.

The fingerprint sensor according to the embodiments may be applied to the locking device. For example, the fingerprint sensor according to the embodiments may be applied to an electronic product or the like and applied as a locking device.

In detail, as shown in FIG. 18, the fingerprint sensor according to the embodiments may be coupled to the door lock and applied as a locking device of the door lock. Alternatively, it may be combined with the mobile phone as shown in FIG. 19 and applied to the locking device of the mobile phone.

Alternatively, the fingerprint sensor according to the embodiments may be applied to a power supply device. For example, the fingerprint sensor according to the embodiments may be applied to a home appliance, a vehicle, and the like.

In detail, as shown in FIG. 20, the power supply device may be combined with a home appliance such as an air conditioner. Alternatively, the present invention may be applied to a vehicle or the like as shown in FIG. 21, and may be applied to a power supply device such as a starting device or a car audio of a vehicle.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. In addition, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

In addition, the above description has been made with reference to the embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains may be illustrated as above without departing from the essential characteristics of the present embodiments. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

Claims (10)

Piezoelectric members; A first substrate disposed on the piezoelectric member; A plurality of first electrode patterns disposed between the piezoelectric member and the first substrate; A first conductive member between the first electrode pattern and the piezoelectric layer; A second substrate disposed under the piezoelectric member; A plurality of second electrode patterns disposed between the piezoelectric member and the second substrate; A second conductive member between the second electrode pattern and the piezoelectric member, The size of the said 1st base material and said 2nd base material is different fingerprint sensor. The method of claim 1, Further comprising an application specific integrated circuit (ASIC) disposed below the second substrate, And the first substrate and the second substrate are disposed in contact with the application specific integrated circuit. The method of claim 2, The size of the first substrate is larger than the size of the second substrate fingerprint sensor. The method of claim 3, wherein The first substrate and the second substrate includes a printed circuit board. The method of claim 1, The first electrode pattern extends in the first direction, The second electrode pattern extends in a second direction crossing the first direction, And the first electrode pattern and the second electrode pattern form a node region that crosses each other. The method of claim 3, wherein And the first substrate is bent and disposed in the side surfaces and the bottom surfaces of the piezoelectric layer on an upper surface of the piezoelectric member. The method of claim 3, wherein The first substrate, An electrode part on which the first electrode pattern is disposed; And A connection portion connected to the custom integrated circuit, And the connection part is bent from the electrode part toward the second substrate. The method of claim 7, wherein And the first conductive member is disposed between the electrode portion and the piezoelectric layer. The method of claim 5, And the node area is disposed at a position overlapping with the piezoelectric pillar. Cover substrate; A display panel disposed under the cover substrate; And A fingerprint sensor disposed under the display panel; The fingerprint sensor, Piezoelectric members; A first substrate disposed on the piezoelectric member; A plurality of first electrode patterns disposed between the piezoelectric member and the first substrate; A first conductive member between the first electrode pattern and the piezoelectric layer; A second substrate disposed under the piezoelectric member; A plurality of second electrode patterns disposed between the piezoelectric member and the second substrate; A second conductive member between the second electrode pattern and the piezoelectric member, A display panel of which the size of the first substrate and the second substrate are different.

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