KR101863818B1 - Transparent electrode structure using for finger print sensor and finger print sensor having the same - Google Patents

Abstract

The present invention provides a transparent electrode structure for a fingerprint sensor with high transmittance and high electric conductivity. According to one embodiment of the present invention, the transparent electrode structure for a fingerprint sensor comprises a first electrode including a plurality of first conductive lines extended in a first direction; a second electrode including a plurality of second conductive lines extended in a second direction forming a predetermined angle with the first direction; and a dielectric layer disposed between the first and second electrodes to electrically insulate the same. The first conductive lines of the first electrode have a width of greater than zero but not greater than 150 μm, an interval of not less than 2 μm but not greater than 50 μm, a transmittance of not less than 70% but less than 100% with respect to a light of 550 nm, a surface resistance of greater than zero but not greater than 20 Ω/□, and a capacitance of not less than 10fF but not greater than 500fF; and exhibit a capacitance decrease of not less than 0.01% but not greater than 50% upon a contact of a fingerprint.

Description

TECHNICAL FIELD [0001] The present invention relates to a transparent electrode structure for a fingerprint sensor and a fingerprint sensor including the transparent electrode structure,

Technical aspects of the present invention relate to a transparent electrode structure for a fingerprint sensor and a fingerprint sensor including the transparent electrode structure.

Recent mobile devices are showing a tendency to enlarge the screen size, and accordingly, they are being developed to minimize or eliminate physical buttons such as a home button. With the tendency of such physical buttons to be removed, the development of integrated buttons in the display is accelerating. In addition, development of a fingerprint sensor integrated with a display has been demanded due to the tendency that a button using a fingerprint appears.

The fingerprint sensor generally employs a capacitance method, and can be roughly divided into a unit cell driving method and a matrix driving method. The unit cell driving method is composed of a plurality of unit cells that individually drive a sensor for recognizing a fingerprint, and can use various materials such as indium tin oxide and silicon, and has a small noise. However, There is a disadvantage in that the transparency is lowered. Therefore, application as a transparent electrode is limited.

In the matrix driving method, an upper electrode extending in the x-axis and a lower electrode extending in the y-axis are alternately arranged in a line-by-line shape, and the device structure is simple, It is possible to fabricate a device with only an electrode, which has a high transmittance. On the other hand, high frequency operation of 10 kHz or more is required because of a disadvantage that noise is large. Indium tin oxide, which is often used for transparent electrodes, has a high resistance, which makes it difficult to drive in a high frequency band of 10 kHz or more. In addition, indium tin oxide has a limitation in that it is difficult to apply to a flexible display due to poor flexibility. Therefore, a transparent electrode having high transmittance and high electrical conductivity is required for a fingerprint sensor.

Korean Registered Utility Model No. 20-0392690

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transparent electrode structure for a fingerprint sensor having high transmittance and high electrical conductivity.

It is another object of the present invention to provide a fingerprint sensor including a transparent electrode structure for a fingerprint sensor having high transmittance and high electrical conductivity.

However, these problems are illustrative, and the technical idea of the present invention is not limited thereto.

According to an aspect of the present invention, there is provided a transparent electrode structure for a fingerprint sensor, including: a first electrode including a plurality of first conductive lines extending in a first direction; A second electrode including a plurality of second conductive lines extending in a second direction having an angle with respect to the first direction; Wherein the first conductive lines of the first electrode have a width in the range of more than 0 탆 and not more than 150 탆 and have a width of not less than 2 탆 Having a transmittance in a range of 70% or more to less than 100% with respect to light of 550 nm and a sheet resistance in a range of 0? /? To 20? /? 500 F or less, and the capacitance exhibits a reduction in the range of 0.01% or more to 50% or less when the fingerprint is contacted.

In some embodiments of the present invention, the second conductive lines of the second electrode have a width in the range of more than 0 탆 and not more than 150 탆, and may have an interval in the range of not less than 2 탆 and not more than 50 탆.

In some embodiments of the present invention, the unit cells formed by crossing the first electrode and the second electrode may have capacitances in the range of 10 fF or more and 500 F or less, respectively.

In some embodiments of the present invention, the dielectric layer may have a thickness in the range of 10 nm or more to 50 μm or less.

In some embodiments of the present invention, the dielectric layer may have a dielectric constant ranging from 2 to 15 or less.

In some embodiments of the present invention, the cover layer further comprises a cover layer disposed on the first electrode, wherein the cover layer has a dielectric constant in the range of 4 or more and 15 or less, and 70% or more to less than 100% It can have transparency.

In some embodiments of the present invention, the first electrode or the second electrode is formed by bonding a first nanostructure having a first diameter and a second nanostructure having a second diameter smaller than the first diameter to each other A hybrid structure may be included.

In some embodiments of the present invention, the first nanostructure may have the first diameter in a range of 100 nm or more and 10 m or less, and the second nanostructure may have a diameter of 10 nm or more and 100 nm or less Lt; RTI ID = 0.0 > of < / RTI >

In some embodiments of the present invention, the first nanostructure forms a main conduction path, and the second nanostructure is disposed in an empty space formed by the first nanostructure to electrically connect the first nanostructure To provide an auxiliary conduction path.

In some embodiments of the present invention, when the conduction path of the first nanostructure is short-circuited, the second nanostructure may provide a conduction path.

In some embodiments of the present invention, the ratio of the first nanostructure to the second nanostructure may range from 10:90 to 90:10.

According to an aspect of the present invention, there is provided a fingerprint sensor including a transparent electrode structure for a fingerprint sensor.

In some embodiments of the invention, it may have a driving frequency in the range of 10 kHz to 1 MHZ.

In some embodiments of the invention, the ridge and valley capacitance variation of the fingerprint can range from greater than 0.01% to less than 50%.

In some embodiments of the invention, it may have a drive voltage in the range of 1 V to 100 V or less.

The fingerprint sensor according to the technical idea of the present invention includes a transparent electrode structure for a fingerprint sensor in which a linear first electrode and a linear second electrode intersect each other in a matrix manner and the first electrode and the second electrode are connected to each other And is composed of a first nanostructure and a second nanostructure of different diameters. The first nanostructure forms a main conduction path and the second nanostructure is disposed in an empty space formed by the first nanostructure to electrically connect the first nanostructure to provide an auxiliary conduction path, It is possible to prevent a short-circuiting phenomenon of the electrode of the mesh structure of the electrode assembly, thereby providing uniform and improved electrical characteristics.

In addition, the fingerprint sensor improves the fringing capacitance with respect to the use restriction in the high frequency range for noise reduction according to the shape of the matrix, and thus, the sensitivity of the fingerprint sensing can be formed.

In addition, since the fingerprint sensor uses a nanostructure, the conventional indium tin oxide can have flexibility that is difficult to provide. Therefore, the fingerprint sensor can be used as a security method for various mobile devices and can be applied to wearable electronic devices and the like.

The effects of the present invention described above are exemplarily described, and the scope of the present invention is not limited by these effects.

1 is a schematic view showing a fingerprint of a human body detected by a fingerprint sensor according to an embodiment of the present invention.
2 is a schematic diagram showing a method of driving a fingerprint sensor according to an embodiment of the present invention.
3 is a plan view of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.
4 is a cross-sectional view of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.
FIG. 5 is a graph illustrating a change in capacitance of a transparent electrode structure for a fingerprint sensor according to an exemplary embodiment of the present invention when the fingerprint is contacted.
6 is a schematic view illustrating a method of forming an electrode included in a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.
7 is a scanning electron micrograph of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.
8 is a graph showing a change in sheet resistance according to an electro-spinning time of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.
9 is a graph showing a change in transmittance according to an electrospinning time of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.
10 is a photograph showing a fingerprint sensor according to an embodiment of the present invention.
11 is a graph showing the change in capacitance at the time of fingerprint contact measured using the fingerprint sensor of FIG.
FIG. 12 is a graph showing a change in capacitance at the time of fingerprint contact with respect to the fingerprint sensor according to an embodiment of the present invention with respect to the total area of the fingerprint sensor.
FIG. 13 is a graph showing a change in capacitance according to a thickness of a cover layer of a fingerprint sensor according to an embodiment of the present invention. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. The scope of technical thought is not limited to the following examples. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the present specification, the same reference numerals denote the same elements. Further, various elements and regions in the drawings are schematically drawn. Accordingly, the technical spirit of the present invention is not limited by the relative size or spacing depicted in the accompanying drawings.

1 is a schematic view showing a fingerprint of a human body detected by a fingerprint sensor according to an embodiment of the present invention.

Referring to FIG. 1, fingerprints of the human body have unique fingerprint patterns that vary from person to person. However, the fingerprints can be divided into arches, whorls, simple loops, and double-looped (double loops). These fingerprints are formed by a ridge 1, which is a protruding part, and a valley 2, which is a part depressed to form the fingerprint pattern. Generally, the ridge 1 has a width in the range of not less than 100 μm and not more than 400 μm, and the valley 2 has a width in the range of not less than 60 μm and not more than 220 μm. The average of the width of the valley 2 is about 109 탆.

2 is a schematic diagram showing a method of driving a fingerprint sensor according to an embodiment of the present invention.

2, when the ridge 1 of the fingerprint comes into contact with the electrode 3 of the fingerprint sensor or comes into contact with the protective film 4 located on the electrode 3, the valley 2 of the fingerprint and the electrode 3, A space is formed between the electrodes 5 and 6 and the space 5 functions as the capacitor 5. Therefore, the reaction signal is generated by the capacitor 5, that is, the region where the capacitor 5 is generated becomes the reaction signal generation region. Specifically, the ridge 1 and the valley 2 are sensed using the difference in capacitance caused by the difference in distance between the ridge 1 and the valley 2 from the fingerprint sensor.

3 is a plan view of a transparent electrode structure 100 for a fingerprint sensor according to an embodiment of the present invention. 4 is a cross-sectional view of a transparent electrode structure 100 for a fingerprint sensor according to an embodiment of the present invention.

Referring to FIGS. 3 and 4, the transparent electrode structure 100 for a fingerprint sensor includes a first electrode 110, a second electrode 120, and a dielectric layer 130. In addition, the transparent electrode structure 100 for a fingerprint sensor may further include a cover layer 140 positioned on the first electrode 110. The use of the transparent electrode structure 100 for a fingerprint sensor is not limited to a fingerprint sensor and can be applied to various fields.

The first electrode 110 includes a plurality of first conductive lines 111 and 112 extending in a first direction. The second electrode 120 includes a plurality of second conductive lines 121 and 122 extending in a second direction having an angle with respect to the first direction. The predetermined angle may be more than 0 degrees and less than 90 degrees, for example, the first electrode 110 and the second electrode 120 may be perpendicular to each other. The first electrode 110 and the second electrode 120 may form a matrix. A unit cell 190 is formed in a red circular region formed by intersecting the first electrode 110 and the second electrode 120.

At least one of the first electrode 110 and the second electrode 120 should satisfy the following dimensions. The width W of the first conductive lines 111 and 112 of the first electrode 110 may range from more than 0 μm to less than 150 μm since the period of the ridge and valley of the fingerprint is at most 150 μm. Similarly, the second conductive lines 121, 122 of the second electrode 120 may have a width in the range of more than 0 탆 and not more than 150 탆. The interval S between the first conductive lines 111 and 112 of the first electrode 110 can be determined according to the average period between the ridges and the valleys of the fingerprint, 112 may range from 2 탆 or more to 50 탆 or less. Similarly, the distance between the second conductive lines 121 and 122 of the second electrode 120 may range from 2 탆 or more to 50 탆 or less. The first electrode 110 may be referred to as an upper electrode because the first electrode 110 may be disposed on the upper side and the lower electrode may be disposed on the lower side. The materials constituting the first electrode 110 and the second electrode 120 will be described in detail below.

The dielectric layer 130 may be disposed between the first electrode 110 and the second electrode 120 to electrically isolate the first electrode 110 and the second electrode 120 from each other. The dielectric layer 130 may comprise a transparent material that transmits light. In addition, the dielectric layer 130 may comprise a material that selectively passes light of a desired wavelength. The dielectric layer 130 may include, for example, glass, quartz, silicon oxide, aluminum oxide, hafnium oxide, or a polymer, and may include, for example, an epoxy-based photoresist such as SU-8, polyvinyl alcohol PVA), polyvinylpyrrolidone (PVP), polyimide, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), or polydimethyl Siloxane (PDMS), and the like.

The cover layer 140 may be disposed on the first electrode 110 to protect the first electrode 110 from fingerprint contact or external environment. The cover layer 140 may comprise a transparent material that transmits light and may include a material that is substantially the same as the material applied to the dielectric layer 130.

The transparent electrode structure 100 for a fingerprint sensor may have a transmittance in a range of more than a predetermined level, for example, 60% or more and less than 100% with respect to light. For example, the transmittance may be 70% Lt; RTI ID = 0.0 > transmissivity. ≪ / RTI > This transparency can implement a fingerprint sensor integrated into the display.

The transparent electrode structure 100 for a fingerprint sensor may have a sheet resistance of, for example, in the range of more than 0 Ω / □ and 20 Ω / □ or less, for example, in a range of more than 0 Ω / □ to 10 Ω / Lt; / RTI > Here, "□" means "square". This range of sheet resistance allows AC drive in high resolution patterns.

Hereinafter, a capacitance change caused by the transparent electrode structure 100 for a fingerprint sensor will be described in detail.

In the case of a thin film capacitor array such as the transparent electrode structure 100 for a fingerprint sensor, the following two kinds of capacitances should be taken into account, namely, a parallel capacitance and a fringing capacitance. The parallel capacitance is the capacitance of the region where the electrodes cross (190 in FIG. 3), and the fringing capacitance is the capacitance between the edge and the edge of the electrode. Therefore, the total capacitance is expressed by the sum of the parallel capacitance and the fringing capacitance as expressed by the following equation.

W is the width of the electrode, l is the length of the electrode, d is the distance between the upper electrode and the lower electrode, and h is the thickness of the electrode)

5 is a graph for explaining a change in capacitance at the time of fingerprint contact with the transparent electrode structure 100 for a fingerprint sensor according to an embodiment of the present invention.

Referring to FIG. 5, the capacitance of the transparent electrode structure for the fingerprint sensor decreases when the fingerprint is contacted. When a ridge or valley of the fingerprint is brought into contact, a decrease in capacitance appears, and the degree of decrease may range from 0.01% or more to 50% or less. 5, the lowering of the capacitance when the ridge is contacted is shown to be larger than that when the contact is made to the valley, but this is merely an example, and the case where the capacitance is lowered when the valley is contacted is also included in the technical idea of the present invention.

Referring again to FIG. 3, the transparent electrode structure 100 for a fingerprint sensor according to the technical idea of the present invention may have the following characteristics.

The transparent electrode structure 100 for a fingerprint sensor may have a total capacitance of, for example, a value in the range of 10 fF or more and 500 F or less. The unit cells 190 formed by crossing the first electrode 110 and the second electrode 120 may have capacitances ranging from 10 fF to 500 FF, for example. If the capacitance is larger than the above range, high-frequency driving may be difficult. The transparent electrode structure 100 for a fingerprint sensor may exhibit a reduction in the range of 0.01% or more to 50% or less when the fingerprint is contacted. In this case, the range of the reduction may be an average value according to time or the like.

The dielectric layer 130 may have a thickness representing the capacitance value, and may have a thickness ranging from, for example, 10 nm or more to 50 μm or less. The dielectric layer 130 may have a dielectric constant ranging, for example, from 2 to 15, inclusive.

The dielectric constant of the cover layer 140 is important for increased sensitivity. The cover layer 140 may have a dielectric constant in the range of, for example, greater than or equal to 4 and less than or equal to 15. The cover layer 140 may have a transmittance of, for example, 70% or more and less than 100%. The cover layer 140 may be composed of the same or similar material as the dielectric layer 130 as described above.

When a fingerprint sensor is formed using the transparent electrode structure 100 for a fingerprint sensor, in order to drive the fingerprint sensor, high-frequency driving is required to reduce noise. For example, a range of 10 kHz to 1 MHZ , For example, a driving frequency in the range of 100 kHz or more to 1 MHZ or less. The fingerprint sensor may have a capacitance variation ranging from 0.01% or more to 50% or less depending on the ridge and valley of the fingerprint. The fingerprint sensor may have a driving voltage in a range of 1 V to 100 V. The driving voltage range is suitable for use in a wearable device and a smart device.

Hereinafter, the structure and materials of the first electrode 110 or the second electrode 120 of the transparent electrode structure 100 for a fingerprint sensor according to the technical idea of the present invention will be described in detail.

6 is a schematic view illustrating a method of forming an electrode included in a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.

Referring to FIG. 6, the first electrode 110 or the second electrode 120 includes a first nanostructure having a first diameter and a second nanostructure having a second diameter smaller than the first diameter. And a hybrid structure formed by bonding. The first nanostructure may form a main conduction path and the second nanostructure may be disposed in an empty space formed by the first nanostructure to electrically connect the first nanostructure to provide an auxiliary conduction path. In addition, when the conduction path of the first nanostructure is short-circuited due to the formation of the fine pattern, the conduction path can be provided by the second nanostructure.

The first nanostructure may have the first diameter, for example, in the range of 100 nm or more to 10 m or less. The first nanostructure may include a conductive material, and may include, for example, a metal such as silver (Ag), gold (Au), aluminum (Al), copper (Cu) (Cr), nickel (Ni), iron (Fe), and the like. The first nanostructure may be formed using a coaxial electrospinning method or a nanotrott method.

The second nanostructure may have the second diameter, for example, in the range of 10 nm or more and 100 nm or less. The second nanostructure may include a conductive material and may include, for example, a metal such as silver (Ag), gold (Au), aluminum (Al), copper (Cu) (Cr), nickel (Ni), iron (Fe), and the like. The first nanostructure and the second nanostructure may comprise the same or different materials. The second nanostructure may be formed by a method such as electrospinning, air spraying, electric spraying or bar coating.

In the case of a two-dimensional electrode such as a metal electrode or an indium tin oxide transparent electrode, since the parallel capacitance is larger than the fringing capacitance, there is a limit in forming the shape of the electrode pattern in order to increase the contact sensitivity. However, since the transparent electrode structure for a fingerprint sensor according to the technical idea of the present invention can maximize the fringing capacitance by forming a one-dimensional electrode (i.e., a linear electrode) composed of the first electrode and the second electrode, A high contact sensitivity can be realized by using a simple linear pattern instead of forming the contact pattern.

When the electrode is composed of only the first nanostructure, it is difficult to form a high-resolution pattern. When the electrode is composed of only the second nanostructure, the nanostructure has a high resistance. For example, at a high frequency of 10 kHz or more, It is difficult to drive at a high frequency of 100 kHz or more. According to the technical idea of the present invention, the transparent electrode structure for a fingerprint sensor can increase the fringing capacitance and enable high-frequency driving by having the first nanostructure and the second nanostructure. Also, the ratio of the first nanostructure to the second nanostructure can be adjusted to form a mesh structure, thereby maximizing the fringing capacitance.

7 is a scanning electron micrograph of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.

Referring to FIG. 7, the transparent electrode structure for a fingerprint sensor includes the first nanostructure and the second nanostructure as illustrated in the schematic view of FIG. The first nanostructure and the second nanostructure are composed of silver. The transparent electrode structure for the fingerprint sensor has a sheet resistance of 1.61 ± 0.1 Ω / □ with a transmittance of 88% at 550 nm.

Hereinafter, in the case of forming the first nanostructure first and then forming the second nanostructure by electrospinning, the characteristics of the transparent electrode structure for the fingerprint sensor are analyzed according to the electrospinning time. As the electrospinning time is increased, the amount of the second nanostructure is increased.

8 is a graph illustrating a change in sheet resistance according to an electrospinning time of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.

Referring to Fig. 8, the sheet resistance of 1.61 + - 0.1 [Omega] / □ was shown in 40 seconds of electrospinning, and the sheet resistance was decreased as the electrospinning time was increased thereafter. In the range of the electrospinning time within about 100 seconds, the decrease of the sheet resistance was abruptly appeared, and in the electrospinning time after 100 seconds, the decrease of the sheet resistance was gentle.

9 is a graph showing a change in transmittance according to an electrospinning time of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.

Referring to FIG. 9, in the case of 40 seconds of electrospinning, it shows a transmittance of 88% with respect to 550 nm light, after which the transmittance was decreased as the electrospinning time was increased. In the range of the electrospinning time within about 100 seconds, the decrease of the sheet resistance was abruptly appeared, and in the electrospinning time after 100 seconds, the decrease of the sheet resistance was gentle.

Table 1 is a table showing the characteristics of a transparent electrode structure for a fingerprint sensor according to an embodiment of the present invention.

Sheet resistance
(Ω / □) Permeability
(%) Maximum line width
(탆) High frequency drive
Availability When touching the fingerprint
Capacitance change The first nanostructure 3 90 200 X X The second nanostructure 30 90 20 X X Hybrid structure 30 98 50 X X Hybrid structure 20 94 50 O 8% Hybrid structure 10 93 50 O 9% Hybrid structure 1.2 88 50 O 15% Hybrid structure 1.1 85 50 O 15% Hybrid structure 0.9 73 50 O 16% Hybrid structure 0.8 65 50 O 12% Hybrid structure 0.7 55 50 O 9% Hybrid structure 0.5 49 50 O 6% Hybrid structure 0.05 38 50 O 4% Hybrid structure 0.012 21 50 O 3%

Referring to Table 1, in the case of forming the hybrid structure according to the technical idea of the present invention, the sheet resistance can be reduced as compared with 30 Ω / □ when only the second nanostructure is contained, and even if only the first nanostructure Can be reduced as compared with 3 Ω / □ in case of including. This is because the content of the second nanostructure is increased and the second nanostructure is disposed in an empty space formed by the first nanostructure to provide an extended conduction path. However, it is noted that as the second nanostructure is increased, the permeability is decreased.

Therefore, optimum conditions can be derived based on permeability of 60% or more, sheet resistance of 20 Ω / □ or less, and capacitance change of 7% or more due to fingerprint contact. Accordingly, the ratio of the first nanostructure to the second nanostructure can be set to be, for example, in the range of 10:90 to 90:10, for example, in the range of 30:70 to 90:10 Respectively. The range may be derived by analyzing the shape distribution of the first nanostructure and the second nanostructure using a microscope for a transparent electrode structure for a fingerprint sensor.

10 is a photograph showing a fingerprint sensor according to an embodiment of the present invention. FIG. 9 is a graph showing a change in capacitance at the time of fingerprint contact measured using the fingerprint sensor of FIG.

10 and 11, a transparent fingerprint sensor in which transparent linear electrodes are intersected with each other is manufactured. The change in capacitance when the ridge and the valley are in contact with each other is confirmed by moving the finger at a voltage of 3 V at a frequency of 150 kHz. As the capacitance value changes upon contact between the ridge and the valley of the fingerprint, the fingerprint sensor has high sensitivity.

FIG. 12 is a graph showing a change in capacitance at the time of fingerprint contact with respect to the fingerprint sensor according to an embodiment of the present invention with respect to the total area of the fingerprint sensor.

Referring to FIG. 12, the shape of the ridge and the valley of the fingerprint are clearly shown in different colors representing different capacitance values, and thus it can be confirmed that the fingerprint sensor has high sensitivity.

FIG. 13 is a graph showing a change in capacitance according to a thickness of a cover layer of a fingerprint sensor according to an embodiment of the present invention. FIG.

Referring to FIG. 13, it can be seen that the change in capacitance is reduced as the thickness of the cover layer is increased.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. Will be apparent to those of ordinary skill in the art.

1: ridge, 2: valley, 3: electrode, 4: protective film, 5: capacitor
100: transparent electrode structure for fingerprint sensor,
110: first electrode, 111, 112: first conductive lines,
120: second electrode, 121, 122: second conductive lines, 130: dielectric layer,
140: cover layer, 190: unit cell,

Claims (15)

A first electrode comprising a plurality of first conductive lines extending in a first direction;
A second electrode including a plurality of second conductive lines extending in a second direction having an angle with respect to the first direction;
And a dielectric layer disposed between the first electrode and the second electrode to electrically isolate the first electrode and the second electrode,
Wherein the first electrode includes a hybrid structure formed by combining a first nanostructure having a first diameter and a second nanostructure having a second diameter smaller than the first diameter,
Wherein the first nanostructure has the first diameter in a range of 100 nm or more and 10 m or less and the second nanostructure has the second diameter in a range of 10 nm or more and 100 nm or less,
The first nanostructure forms a main conduction path,
Wherein the second nanostructure is disposed in an empty space formed by the first nanostructure and electrically connects the first nanostructure to provide an auxiliary conduction path so that when the conduction path of the first nanostructure is short- Providing a conduction path by the second nanostructure,
Wherein the ratio of the first nanostructure to the second nanostructure ranges from 10:90 to 90:10,
Wherein the first conductive lines of the first electrode have a width in the range of more than 0 占 퐉 to 50 占 퐉 and have an interval in the range of 2 占 퐉 to 50 占 퐉,
Has a transmittance in the range of more than 55% to less than 93% with respect to 550 nm light,
Having a sheet resistance in the range of more than 0.7? /? To less than 10? /?
With capacitances in the range from 10 fF to 500 F,
Wherein a change in capacitance due to fingerprint contact when the fingerprint is contacted shows a decrease in the range of more than 9% to less than 50%. The method according to claim 1,
Wherein the second conductive lines of the second electrode have a width in the range of more than 0 占 퐉 to 150 占 퐉 and have an interval in the range of 2 占 퐉 to 50 占 퐉. The method according to claim 1,
Wherein a unit cell formed by intersecting the first electrode and the second electrode has a capacitance in a range of 10 fF or more and 500 F or less, respectively. The method according to claim 1,
Wherein the dielectric layer has a thickness in the range of 10 nm or more to 50 占 퐉 or less. The method according to claim 1,
Wherein the dielectric layer has a dielectric constant in the range of 2 or more to 15 or less. The method according to claim 1,
And a cover layer disposed on the first electrode, wherein the cover layer has a dielectric constant in a range of 4 or more and 15 or less, and has a transmittance of 70% or more to less than 100% . The method according to claim 1,
Wherein the second electrode comprises a hybrid structure formed by bonding the first nanostructure and the second nanostructure to each other. delete delete delete delete A fingerprint sensor comprising a transparent electrode structure for a fingerprint sensor according to any one of claims 1 to 6. The method of claim 12,
A fingerprint sensor having a driving frequency in the range of 10 kHz to 1 MHZ. delete The method of claim 12,
Wherein the fingerprint sensor has a driving voltage in a range of 1 V to 100 V inclusive.

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