WO2023054742A1 - Biometric and fingerprint recognition sensor structure and electronic card using same - Google Patents

Abstract

The present invention relates to a biometric and fingerprint recognition sensor structure and an electronic card using same. Disclosed is a biometric and fingerprint recognition sensor structure comprising: a fingerprint sensing electrode array having a plurality of fingerprint sensing electrodes; biometric electrodes formed, so as to be electrically separated, along the outer edge of the fingerprint sensing electrode array; and biometric electrodes including a first biometric electrode and a second biometric electrode that are separated from each other by a distance of D2, wherein a material having a surface specific resistance (Ω/cm2) of 1012-1013 is formed to a height of D1 on the upper portion of the biometric electrodes. According to the biometric and fingerprint recognition sensor structure and the electronic card using same according to the present invention, the biometric electrodes are formed according to an appropriate design and thus can be formed by the same process as the fingerprint sensing electrodes, unlike in the prior art in which biometric electrodes have to be formed by a separate process from fingerprint sensing electrodes.

Description

Biometric and fingerprint recognition sensor structure and electronic card using the same

The present invention relates to a biometric and fingerprint recognition sensor structure capable of biometric authentication and an electronic card using the same, and more particularly, to a biometric and fingerprint recognition sensor structure having an insulator on top of a biometric authentication electrode and an electronic card using the same.

Credit cards are used to relieve the inconvenience of carrying a large amount of cash. When registering a credit card, a password is given so that only the person himself/herself can use it, and the credit card is signed and used. You can conveniently carry your credit card with you, but when you need cash, insert your credit card into an ATM and enter your password to withdraw cash. Even when making a payment using a credit card online, you must enter a password, so you can proceed with payment relatively safely. Unlike this, when purchasing goods offline, payment is completed if the card is inserted into the card slot of the terminal installed in the store and can be used normally.

Credit cards have the advantage of being easy to use, but can cause a lot of loss when lost. If a credit card is lost and not reported as lost, the person who finds it can use someone else's lost credit card to make purchases at offline stores and pay for public transportation, resulting in a lot of financial loss for the original owner of the credit card. will wear If the password is exposed and lost or stolen, it is possible to withdraw cash, resulting in greater financial loss.

Due to this problem, there is an attempt to mount a fingerprint sensor on a credit card in order to increase the security of the credit card. Fingerprint sensors can be classified into capacitive fingerprint sensors, ultrasonic fingerprint sensors, and optical fingerprint sensors according to the driving method. can On the other hand, since the fingerprint sensor has a problem in that authentication is easily passed by forged fingerprints made of silicon or the like, a technology to supplement this problem is needed.

The present invention has emerged due to the above necessity, and an object of the present invention is to provide a biometric and fingerprint recognition sensor structure capable of rejecting authentication when authentication is attempted using a forged fingerprint, and an electronic card using the same.

The above object of the present invention is a fingerprint sensing electrode array composed of a plurality of fingerprint sensing electrodes, biometric authentication electrodes formed to be electrically spaced apart along the outer rim of the fingerprint sensing electrode array, and biometric authentication electrodes are spaced apart from each other by D2. It consists of a first electrode for biometric authentication and a second electrode for biometric authentication formed by ^placing a surface resistivity (Ω / cm 2 ) on top of the biometric authentication electrode ^. Characterized in that a material having a D1 height is formed It can be achieved by biometric and fingerprint recognition sensor structures.

Another object of the present invention is a biometric and fingerprint recognition sensor structure, and a biometric and fingerprint authentication chip that authenticates whether the biometric and fingerprints match or not using an output value sensed from the biometric and fingerprint recognition sensor structure, and key information of the holder. It includes an IC chip having a small capacity memory for storing, and the body and fingerprint recognition sensor structures are formed to be electrically spaced apart from a fingerprint sensing electrode array composed of a plurality of fingerprint sensing electrodes and an outer edge of the fingerprint sensing electrode array. The electrodes for authentication and the electrodes for biometric authentication are composed of a first electrode for biometric authentication and a second electrode for biometric authentication formed at a distance of D2 from each other, and the surface specific resistance (Ω/cm2) of the upper part of the electrode for biometric authentication is 10 ¹² ~ 10 ¹³ This can be achieved by an electronic card characterized in that the material is formed to the height of D1.

According to the biometric and fingerprint recognition sensor structure and the electronic card using the same according to the present invention, conventionally, the biometric authentication electrode had to be formed through a separate process from the fingerprint sensing electrode, but if formed according to an appropriate design, it is formed through the same process as the fingerprint sensing electrode. I was able to do it.

1 is a block diagram of an electronic card according to an embodiment of the present invention;

2 is a plan view of a biometric fingerprint recognition sensor installed on an electronic card in a state in which cover film lamination has been completed and a cutaway view in the direction A-A' in the plan view;

3 is a plan view of a biometric fingerprint recognition sensor installed on an electronic card in a state in which cover film lamination is completed, and a BB′ direction cutaway view of the plan view.

4 is an equivalent circuit diagram of elements related to biometric authentication in the biometric and fingerprint recognition sensors according to the present invention.

5 is a voltage waveform diagram sensed and output from the biometric and fingerprint recognition sensors shown in FIGS. 2 and 3 when a square wave is applied to the driver.

6 is a conceptual diagram illustrating a process in which electric charges are polarized to a biometric fingerprint when a voltage is applied to a first electrode for biometric authentication;

7 is a graph showing experimental results in a state in which there is no touching object between biometric authentication electrodes and in a state in which a biometric fingerprint is touched;

8 is a graph showing experimental results in a state in which thick conductive rubber is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched;

9 is a graph showing experimental results in a state in which a thin conductive rubber is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched;

10 is a graph showing experimental results in a state in which a fake fingerprint made of wet clay is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched;

11 is a graph showing experimental results in a state in which a fake fingerprint made of dry clay is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched;

12 is a graph showing experimental results in a state in which a fake fingerprint made of silicon is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched;

13 is a plan view of a biometric fingerprint recognition sensor in which biometric electrodes are formed in a ring shape in the biometric fingerprint recognition sensor, and a cutaway view in the direction A-A' in the corresponding plan view;

[Description of code]

A/D: analog/digital converter

60: IC chip

70: input button

80: display unit

90: battery

100: biometric and fingerprint recognition sensor

101: fingerprint sensing electrode

102: semiconductor wafer

103: fingerprint detection detection circuit electrode

104: mold

105: fingerprint sensor array

106: Amplifier

107: first electrode for biometric authentication

109: second electrode for biometric authentication

110: biometric and fingerprint authentication chip

111: signal processing unit

113: control unit

200: base substrate

210: cover film

300: electronic card

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Also, in the present specification, "on ~ or ~ on top" means located above or below the target part, and does not necessarily mean located on the upper side relative to the direction of gravity. Further, when a part such as a region, plate, etc. is said to be "on or over" another part, this is not only when it is in contact with or spaced "directly on or above" the other part, but also when another part is in the middle thereof. Including if there is

In addition, in this specification, when one component is referred to as “connected” or “connected” to another component, the one component may be directly connected or directly connected to the other component, but in particular Unless otherwise described, it should be understood that they may be connected or connected via another component in the middle.

Also, in this specification, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

An electronic card meant in the present invention refers to a card having a thin thickness including an IC (Intergrated Circuit) chip therein. In the past, cards where information necessary for credit card payment was stored on magnetic strips were widely used. Since these magnetic strips are easy to duplicate and are vulnerable to security, electronic cards that store security-required information in IC chips are used. is being replaced by

1 is a configuration diagram of an electronic card according to an embodiment of the present invention. An electronic card 300 according to the present invention includes an IC chip 60, a display unit 80, an input button 70, a battery 90, a biometric and fingerprint authentication chip 110 and a biometric on a base substrate 200. and a laminated structure in which the fingerprint recognition sensor 100 is provided and the cover film 210 is laminated thereon. In the electronic card shown in FIG. 1, the display unit 80, the battery 90 and the input button 70 do not necessarily need to be provided.

The base substrate 200 has a structure in which a printed circuit board is laminated on a main base film. The main base film may be implemented using a hard curing resin. In FIG. 1, the main base film and the printed circuit board are shown as one substrate without any distinction. The IC chip 60 is a semiconductor chip having a small-capacity memory for storing key information of the cardholder. In general, an IC chip is composed of a golden contact terminal that can be seen with the naked eye and a semiconductor chip provided under the contact terminal. The display unit 80 is a display element for displaying whether a fingerprint has been authenticated, etc., and can be implemented as a thin organic EL or electric interlocking display. The input button 70 is a switch for receiving a user input for turning on/off power or selecting an operation mode, and may be implemented as a toggle button or a dome switch. The battery 90 is a module for applying power to each circuit element and can be implemented as a secondary battery capable of charging and discharging, a thin mercury battery, or a solar cell. In the case of having an antenna and the like and operating each circuit element by receiving wireless energy using induced electromotive force through the antenna, the battery 90 may be omitted. The biometric and fingerprint recognition sensor 100 is a sensor that detects a user's fingerprint and biometrics, and in the present invention, a capacitive fingerprint sensor is used as a fingerprint authentication sensor. The biometric and fingerprint authentication chip 110 is a chip that authenticates whether biometrics and fingerprints match by using the output value sensed by the biometric and fingerprint recognition sensor 100.

The cover film 210 is a film for protecting circuit elements mounted on the base substrate 200 and is laminated on the base substrate 200 and the circuit elements. Of course, a window 211 for exposing the contact terminal of the IC chip to the outside may be formed in the cover film 210 .

2 shows a plan view of a biometric fingerprint recognition sensor installed on an electronic card in a state where cover film lamination is completed and a cutaway view in the direction A-A' in the plan view, and FIG. A plan view of the fingerprint recognition sensor and a BB'-direction cutaway view of the plan view are shown. As shown in FIGS. 2 and 3 , the biometric and fingerprint recognition sensor 100 is composed of a capacitive fingerprint sensing electrode 101 for sensing a fingerprint and biometric authentication electrodes 107 and 109 . A plurality of fingerprint sensing electrodes 101 are arranged in an array form to form a fingerprint sensing electrode array 105 . The biometric authentication electrodes 107 and 109 are composed of a first electrode 107 for biometric authentication and a second electrode 109 for biometric authentication disposed along the circumference of the fingerprint sensing electrode array 105 . As shown in the cross-sectional view of FIG. 2 (b), the fingerprint sensing electrode array 105 has a structure in which a fingerprint sensing electrode 101 and a fingerprint sensing sensing circuit electrode 103 are installed in pairs. As for the shape and arrangement of the electrodes of the fingerprint sensing electrode array 105, since there are various technologies known through conventional fingerprint sensing sensors, any one may be applied.

The applicant of the present invention has proposed and registered a technology for authenticating biometrics using two electrodes (a first electrode for biometric authentication and a second electrode for biometric authentication) that come into contact with a living body (Korean Registered Patent No. 10-1972318).

However, in Korean Registered Patent No. 10-1972318, there is a restriction that two electrodes for biometric authentication must be formed to be exposed so as to be in direct contact with the living body. In order to form the electrode for biometric authentication in this exposed form, unlike the process of forming the electrode for the fingerprint detection sensor, a separate process must be used to implement the biometric authentication electrode, so it is very expensive to manufacture a fingerprint recognition sensor capable of biometric authentication. There was a problem with consumption.

The present invention is to solve the problem of increasing manufacturing cost, as shown in FIG. An object of the present invention is to propose a fingerprint recognition sensor structure capable of biometric authentication.

A biometric and fingerprint recognition sensor 100 capable of biometric authentication according to the present invention includes a fingerprint sensor array 105 formed on a semiconductor wafer 102, a first electrode 107 for biometric authentication, and a second electrode 109 for biometric authentication. The fingerprint sensor array 105, the first electrode 107 for biometric authentication, and the second electrode 109 for biometric authentication are configured to be covered with the mold 104 up to the top. The first electrode 107 for biometric authentication and the second electrode 109 for biometric authentication are formed along the outer circumference of the fingerprint sensor array 105 and are arranged to maintain a minimum separation distance of 'D2' from each other. Here, the minimum separation distance means a positional distance measured closest among the separation distances between the first electrode 107 for biometric authentication and the second electrode 109 for biometric authentication. The biometric and fingerprint recognition sensor 100 includes an amplifier 106 and an A/D converter for amplifying electrical signals sensed by each electrode. A biometric and fingerprint recognition sensor structure 300 is formed by forming a cover film 210 in a laminated manner on top of the biometric and fingerprint recognition sensor 100 and the mold 104 constituting the same.

A method of performing biometric authentication using the biometric authentication electrodes 107 and 109 in the biometric and fingerprint recognition sensor 100 according to the present invention will be briefly described. 4 is an equivalent circuit diagram of elements related to biometric authentication in the biometric and fingerprint recognition sensors according to the present invention. Reference symbol 'Z' represents an equivalent circuit of a living body. In the equivalent circuit of devices related to biometric authentication, the second electrode 109 for biometric authentication is connected to the ground, and one end of the first electrode 107 for biometric authentication is connected to the ground through a resistor Re and a driving unit 121, In addition, the first electrode 107 for biometric authentication is also connected to the sensing unit 123. The sensing unit 123 is composed of an amplifier and a D/A converter and outputs a voltage value sensed by the first electrode 107 for biometric authentication as a digital value. The biometric and fingerprint authentication chip 110 performs biometric authentication using the output voltage value.

An operation principle for performing biometric authentication will be briefly described using FIG. 4 . With the first electrode 107 for biometric authentication and the second electrode 109 for biometric authentication positioned close to the living body Z, the driver 121 applies a square wave having a single cycle to the first electrode 107 for biometric authentication, In a state where the voltage measured by the first electrode 107 for biometric authentication is stabilized, the voltage value sensed by the first electrode 107 for biometric authentication is output to the biometric and fingerprint authentication chip 110 . The biometric and fingerprint authentication chip 110 includes a signal processing unit 111 and a control unit 113, and the signal processing unit 111 has the highest measured voltage value, which is the highest value of the voltage value sensed from the sensed voltage value, and the lowest value of the sensed voltage value. The lowest measured voltage value is detected, the measured voltage width (Vw) obtained by the difference between the highest measured voltage value and the lowest measured voltage value, and the time required for the detected voltage to reach a specific range from the lowest measured voltage value to the highest measured voltage value (Tm) signal processing. The control unit 113 applies necessary operation control signals to the driving unit 121 , the sensing unit 123 , and the signal processing unit 111 . The biometric and fingerprint authentication chip 110 authenticates biometrics by using the measured voltage width (Vw) and the required time (Tm) detected by the biometric signal processing unit 111.

In FIG. 4, the biometric and fingerprint recognition sensor 100 is shown as having a first electrode for biometric authentication 107, a second electrode for biometric authentication 109, and a sensing unit 123, but the resistance Re and the driving unit Vi are also shown. Of course, it can be implemented as a component included in the biometric and fingerprint recognition sensor 100. In addition, the biometric and fingerprint authentication chip 110 is shown as being composed of only the signal processing unit 111 and the control unit 113, but it includes a small-sized memory and can be implemented to include various components for biometric authentication is of course

By the way, as shown in FIGS. 2 and 3, when manufacturing the biometric and fingerprint recognition sensor 100, since the biometric authentication electrodes 107 and 109 are manufactured using the same manufacturing process as the fingerprint sensing electrode 101, biometric authentication The dragon electrodes 107 and 109 are formed to be sunk in the mold 104 . In addition, in order to manufacture an electronic card, since the cover film 210 is laminated on the top of the mold 104, the electrodes for biometric authentication (107, 109) cannot directly touch the living body, and the living body and the living body through the mold 9104 and the cover film 210. It is a situation that needs to be contacted.

According to the experiments of the inventors of the present application, when the mold 104 and the cover film 210 are formed of a material having a specific surface resistance (Ω/cm 2 ) of 10 ¹² to 10 ¹³ , charge polarization occurs only for a short time after being charged with a living body. It was found that biometric authentication can be performed by measuring the charge polarization phenomenon that occurs in a short time through the electrodes 107 and 109 for biometric authentication. 5 is a voltage waveform diagram sensed and output from the biometric and fingerprint recognition sensors shown in FIGS. 2 and 3 when a square wave is applied to the driver. As shown in FIG. 5(a), when a square wave having an instantaneous voltage and a t1 duration is applied through the driver, the sensing voltage as shown in FIG. 5(b) is output to the biometric and fingerprint recognition sensor 100. A period t0 indicates a delay time at which electric polarization starts. The charging section t1 is a section in which a voltage charged to the mold and the cover film is generated by the human voltage of the driver, and the rapid decay section t2 is a section in which the charged charge decays in a relatively short time, and a gradual decay section ( t3) means a period in which the charge remaining after charging gradually decays for a relatively long time.

In the present invention, when the mold 104 and the cover film 210 are formed of a material having a specific surface resistance (Ω/cm 2 ) of 10 ¹² to 10 ¹³ , the characteristics of the charged electric charge attenuating in the rapid decay period (t2) are compared. By doing so, it was found that it was possible to determine whether or not it was alive. When the mold 104 and the cover film 210 are formed of a material having a surface specific resistance (Ω/cm2) of 10 ¹² to 10 ¹³ , the resistance (Re) is 150KΩ to 500KΩ in order to maintain sensitivity for determining whether or not a living body is present. It is better to use the

When the mold 104 and the cover film 210 are formed of a material having a specific surface resistance (Ω/cm 2 ) of greater than 10 ¹³ , since they have non-conductive properties, no electrification occurs, and thus, biometrics cannot be authenticated. In addition, the surface specific resistance (Ω/cm 2 ) of the mold 104 and the cover film 210 is greater than 10 ¹² When formed with a small material, it shows characteristics close to that of a conductor, so the charging phenomenon occurs in a very short period of time, making it difficult to confirm biometric authentication.

A cover film having a surface specific resistance (Ω/cm2) of 10 ¹² to 10 ¹³ may be any one selected from epoxy film, polyester film, polyimide film, and vinyl series, or a mixture of two or more selected materials. there is.

According to the inventors of the present invention, in order to enable biometric authentication in a biometric and fingerprint recognition sensor structure formed such that the biometric authentication electrode is recessed in the mold, the surface specific resistance of the material forming the mold 104 and the cover film 210 ( Ω/cm2), the minimum separation distance (D2) between the biometric authentication electrodes and the thickness (D1) of the mold 104 and the cover film 210 stacked on top of the biometric authentication electrodes are such that the minimum separation distance (D2) is 300 μm or less. In this case, it should have the same characteristics as Equation 1. Even if the relationship satisfies Equation 1, when the minimum separation distance (D2) exceeds 300 μm, the measured capacitance is too small and the measurement accuracy is less than 90%, making it difficult to use. Therefore, the maximum value of the minimum separation distance D2 is 300 μm.

According to Equation 1, D2 should be formed to be larger than twice D1 and smaller than three times D1. When the minimum separation distance (D2) is less than twice the D1, it was found that electrification did not occur to the living body and electrification appeared and disappeared only between the cover film and the mold (the dielectric polarization phenomenon as shown in FIG. 6 described later did not appear in the living body). hmm). This is expected to be because the charge generated at the + electrode does not polarize the living body and flows out to the ground. When the minimum separation distance D2 is greater than three times D1, it is difficult to measure electrification generated between the biometric first electrode 107 and the biometric second electrode 109.

[Equation 1]

In Equation 1, D1 represents the distance between the upper surface of the biometric authentication electrode and the living body (measured while the body is placed on top of the biometric authentication electrode for biometric authentication), and D2 represents the first electrode for biometric authentication and the second electrode for biometric authentication. represents the minimum separation distance between As a result, D1 represents the total thickness of the mold 104 and the cover film placed on the upper surface of the biometric authentication electrode. In Equation 1, D2 cannot exceed 300 μm, so the maximum value of D1 is calculated as 150 μm. Since D1 is the thickness of the mold and cover film stacked on the upper surface of the bioelectrode, it is difficult to form less than 20 μm with current technology. Therefore, D1 in Equation 1 satisfies the range of 20 μm or more and 150 μm or less.

6 is a conceptual diagram illustrating a process in which electric charges are polarized in a biometric fingerprint when a voltage is applied to the first electrode for biometric authentication. As shown in FIG. 6, electric charges and electrons are generated by the electric charge supplied to the first electrode 107 for biometric authentication ( FIG. 6(a) ), and the electric charges and electrons generated in this way are applied to the finger F located at the top. Inducing charges and electrons with opposite polarity to au, charges of opposite polarity are induced in the fingers located on the upper part of the battery electrode 109 (FIG. 6(b)), and then the ground electrode 109 also charges. induced ( FIGS. 6(c) and 6(d) ). As described above, when the minimum separation distance (D2) is smaller than twice the D1, charging does not occur to the living body, and charging appears and disappears only between the cover film and the mold.

The inventor of the present invention has a biometric authentication electrode width of 1.2 mm, a minimum separation distance (D2) of 0.15 mm, and a surface specific resistance (Ω/cm 2 ) of 1.1*10 ¹³ 0.02 mm layered on the upper surface of the biometric authentication electrode. and in a state in which polyvinyl chloride having a surface specific resistance (Ω/cm2) of 1.1*10 ¹² is formed to a thickness of 0.05 mm (D1 is 0.07 mm) on the upper part of the mold, a counterfeit formed of conductive rubber having a first thickness and a second thickness Fingerprints, fake fingerprints made of clay in wet and dry conditions, fake fingerprints made of silicon, and biometric fingerprints were tested. The driving signal was applied to the first electrode for biometric authentication while increasing by 5 Hz between 30 Hz and 75 Hz, and the time (Tm) required to reach 63.2% of the measured voltage width (Vw) from the lowest measured voltage was measured. A total of 1,000 measurements were taken for each fake fingerprint, 10 samples were sampled, the average value was extracted, and the frequency and time required (Tm) were displayed with 100 pointers.

7 is a graph showing experimental results in a state in which there is no touching object between biometric authentication electrodes and in a state in which a biometric fingerprint is touched. As shown in FIG. 7 , it can be seen that the required time Tm is clearly distinguished between no-touch (triangle point) and biometric fingerprint touch (circular point). Specifically, in the case of the biometric fingerprint, the required time (Tm) has a value in the range of 350 to 550, while the no-touch has a value of 320 or less, so it can be seen that both are clearly distinguished in the entire frequency range. It was found that the discrimination power was the greatest when the frequencies were 40 Hz and 45 Hz.

8 is a graph showing experimental results in a state in which thick conductive rubber is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched. As shown in FIG. 8, in the case of a fake fingerprint made of thick conductive rubber (point marked x), the required time (Tm) does not have a value less than 450, whereas in the case of a biometric fingerprint (circular dot), a value less than 450 is obtained at all frequencies. It can be seen that the two can be distinguished because they have in the range.

9 is a graph showing experimental results in a state where a thin conductive rubber is placed between biometric authentication electrodes and in a state where a biometric fingerprint is touched. As shown in FIG. 9, in the case of a fake fingerprint made of thin conductive rubber (points marked with x), the required time (Tm) appears to be about 220 or values exceeding the prediction of 1,000 or more are measured, but in the case of biometric fingerprints (circular dots) It can be seen that is present in a stable range between 360 and 560.

10 is a graph showing test results in a state in which a fake fingerprint made of wet clay is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched. As shown in FIG. 10, it can be seen that both exhibit clearly differentiated characteristics of time required (Tm). In the case of fake fingerprints (points marked with x) made of wet clay, the measured value of time required (Tm) was often found around 220.

11 is a graph illustrating test results in a state in which a fake fingerprint made of dry clay is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched. As shown in FIG. 11, it can be seen that the fake fingerprint (x-marked dot) and the biometric fingerprint (circular dot) made of dry clay show distinct characteristics of the required time (Tm). The best discrimination was achieved at the 70 Hz measurement frequency.

12 is a graph illustrating test results in a state in which a fake fingerprint made of silicon is placed between biometric authentication electrodes and in a state in which a biometric fingerprint is touched. As shown in FIG. 12, it can be seen that both have partially overlapping ranges. In the case of silicon fingerprints (points marked with x), the time required (Tm) is approximately 600 or higher, while biometric fingerprints (circular dots) are less than 600. It can be seen that values of 450 or less are distributed, whereas values of 450 or less are not distributed in the silicon fingerprint.

As can be seen from the experimental graphs shown in FIGS. 7 to 12, it can be seen that various forged fingerprints cannot be clearly distinguished from biometric fingerprints using a single fixed frequency square wave. Therefore, it can be seen that it is possible to distinguish between the two by applying square waves of a plurality of frequencies and measuring the required time (Tm) for each frequency.

13 illustrates a plan view of a biometric fingerprint sensor in which biometric electrodes are formed in a ring shape in the biometric fingerprint sensor, and a cross-sectional view in the direction A-A' in the plan view. When viewed from a plan view, the first electrode 107 for biometric authentication is formed along the entire outer edge of the fingerprint sensing electrode array 105, and along the entire outer edge of the first electrode 107 for biometric authentication with the distance D2 spaced apart. The second electrode 109 for biometric authentication is formed.

In the case of the shape of the electrodes for biometric authentication shown in FIG. 2, when the first electrode 107 for biometric authentication and the second electrode 109 for biometric authentication are in close contact with both biometric authentication electrodes at the ends where they are narrowly facing each other, whether or not the biometric authentication is properly performed. A signal capable of detecting is output, but if the middle of both biometric authentication electrodes is contacted for a long time without contacting the narrow end, or if only one biometric authentication electrode is biased, a signal of sufficient magnitude is not output. case occurs On the other hand, if the electrode for biometric authentication is formed in a ring shape as shown in FIG. 13, the first electrode 107 for biometric authentication and the second electrode 109 for biometric authentication can contact each other no matter where they are touched. Therefore, it was confirmed that a stable biometric authentication signal can be obtained.

Although the preferred embodiments of the present invention have been described and illustrated using specific terms above, such terms are only used to clearly explain the present invention, and the embodiments and described terms of the present invention are the technical spirit and scope of the following claims. It is obvious that various changes and changes can be made without departing from the above. Such modified embodiments should not be individually understood from the spirit and scope of the present invention, and should be said to fall within the scope of the claims of the present invention.

Claims (10)

1. A fingerprint sensing electrode array consisting of a plurality of fingerprint sensing electrodes;

   electrodes for biometric authentication formed to be electrically spaced apart along an outer edge of the fingerprint sensing electrode array;

   The biometric authentication electrodes are composed of a first electrode for biometric authentication and a second electrode for biometric authentication formed at a distance D2 from each other,

   A biometric and fingerprint recognition sensor structure, characterized in that a material having a specific surface resistance (Ω/cm 2 ) of 10 ¹² to 10 ¹³ is formed to a height of D1 on the upper part of the biometric authentication electrode.
2. According to claim 1,

   The D2 has a value of 300 μm or less, and the D1 and the D2 satisfy relational expression 1

   - The minimum value of D1 is 20㎛ -

   Biological and fingerprint recognition sensor structure characterized by.

   Relation 1

   
3. According to claim 2,

   The surface resistivity (Ω/cm2) of 10 ¹² to 10 ¹³ material is at least one selected from an epoxy film, a polyester film, a polyimide film, and a vinyl-based biological and fingerprint recognition sensor structure.
4. According to claim 2,

   The biometric and fingerprint recognition sensor structure, characterized in that the electrodes for biometric authentication are formed at opposite positions along the outer edge of the fingerprint sensing electrode array at a distance D2 from each other.
5. According to claim 2,

   The biometric authentication electrodes

   A first electrode for biometric authentication formed along the entire outer edge of the fingerprint sensing electrode array, and

   A biometric and fingerprint recognition sensor structure, characterized in that it is formed as a second electrode for biometric authentication formed while maintaining a minimum separation distance D2 along the entire outer edge of the first electrode for biometric authentication.
6. A biometric and fingerprint recognition sensor structure;

   A biometric and fingerprint authentication chip that authenticates whether the biometric and the fingerprint match using the output value sensed by the biometric and fingerprint recognition sensor structure, and

   It includes an IC chip having a small capacity memory for storing the holder's main information,

   The biometric and fingerprint recognition sensor structures

   A fingerprint sensing electrode array composed of a plurality of fingerprint sensing electrodes;

   Electrodes for biometric authentication formed to be electrically spaced apart along an outer edge of the fingerprint sensing electrode array;

   The biometric authentication electrodes are composed of a first electrode for biometric authentication and a second electrode for biometric authentication formed at a distance D2 from each other,

   An electronic card, characterized in that a material having a specific surface resistance (Ω/cm 2 ) of 10 ¹² to 10 ¹³ is formed to a height of D1 on the upper part of the biometric authentication electrode.
7. According to claim 6,

   The D2 has a value of 300 μm or less, and the D1 and the D2 satisfy relational expression 1

   - The minimum value of D1 is 20㎛ -

   Electronic card characterized by.

   Relation 1

   
8. According to claim 7,

   The material having a surface specific resistance (Ω/cm 2 ) of 10 ¹² to 10 ¹³ is at least one selected from an epoxy film, a polyester film, a polyimide film, and a vinyl-based electronic card.
9. According to claim 8,

   The electronic card, characterized in that the biometric authentication electrodes are formed at opposite positions along the outer edge of the fingerprint sensing electrode array at a distance D2 from each other.
10. According to claim 8,

    The biometric authentication electrodes

    A first electrode for biometric authentication formed along the entire outer edge of the fingerprint sensing electrode array, and

    The electronic card characterized in that it is formed as a second electrode for biometric authentication formed while maintaining a minimum separation distance D2 along the entire outer edge of the first electrode for biometric authentication.

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