KR100990087B1 - Flexible thin film array type temperature sensor and its manufacturing method - Google Patents

Abstract

The present invention provides a temperature sensor that is manufactured in a thin film form by using a printing technique on a flexible substrate, capable of measuring one-dimensional or two-dimensional temperature distribution, and capable of measuring the temperature distribution irrespective of the shape of the temperature measurement object and its It relates to a manufacturing method.

In detail, the manufacturing method of the present invention comprises the steps of: printing a lower metal wiring in the form of a long string in the longitudinal direction on a flexible substrate; Printing a resistive temperature sensing thin film on the lower metal wiring so that the plurality of resistive temperature sensing thin films are spaced apart from each other and arranged in the longitudinal direction of the lower metal wiring; And printing the upper metal wiring on the upper portion of the plurality of resistive temperature sensing thin films and not energizing the lower metal wiring, for each of the plurality of resistive temperature sensing thin films.

Temperature sensor, temperature distribution, printing, printing, flexible board, resistance temperature sensor

Description

Array-type Flexible Thin Film Temperature Sensor and the Fabrication Method Thereof}

The present invention relates to a thin film type temperature sensor capable of measuring a one-dimensional or two-dimensional temperature distribution using a printing technique on a flexible substrate, and capable of measuring the temperature distribution regardless of the shape of the temperature measurement object, and a method of manufacturing the same. will be.

Conventional temperature sensors for measuring the temperature include a thermocouple wire made of two metals, a diode sensor, a resistance temperature detector and the like.

Temperature sensors using dual thermocouples are the most common. The thermocouple is composed of two different metals, and then the one of the two contacts formed by contacting the two metals of the closed circuit is connected to the high temperature, and the other is connected to the low temperature. It is a temperature sensor using the Seebeck effect in which electromotive force is generated depending on the temperature difference between two contacts.

However, such thermocouple temperature sensor is difficult to measure the micro-area temperature of several tens of micrometers, and it is more difficult to measure the temperature distribution of the minute specific region using several thermocouples. In addition, since a contact point must be directly connected to a temperature measuring object, there is also a limit in which accurate temperature measurement is difficult depending on the shape of the temperature measuring object.

A temperature sensor (diode sensor) using a diode is a temperature sensor using a property in which the magnitude of current flowing through the sensor varies depending on the temperature when a voltage is applied to the sensor, and a resistance temperature detector is a temperature sensor using a property in which the resistance varies depending on the temperature. .

Unlike the thermocouple, the above-described diode sensor or resistance temperature detector is manufactured by using a semiconductor process, and has the advantage of measuring temperature in a small region, but since the manufacturing process is very complicated and requires numerous steps, There is a disadvantage in that the consumption of cost is great, and a large area sensor is difficult to manufacture. In addition, when measuring the surface temperature of the temperature measurement target, there is a limit that the temperature sensor must be specially manufactured according to the shape of the measurement target or that the measurement is not possible at all.

An object of the present invention for solving the above problems is to measure the one-dimensional or two-dimensional temperature distribution of the surface to be measured irrespective of the shape of the object to be measured, and the manufacturing process is simple, greatly reducing the consumption of time and cost It is to provide a temperature sensor and a method of manufacturing the same that can be reduced, large-area temperature measurement.

In detail, the present invention provides a method of manufacturing an array type temperature sensor using a flexible insulating substrate and a printing technique, and a method of manufacturing a method for minimizing the number of metal wires of an array type temperature sensor.

According to an aspect of the present invention, there is provided a method of manufacturing a flexible thin film array type temperature sensor, the method including: printing a lower metal wiring in a string form in a longitudinal direction on a flexible substrate; Printing a resistive temperature sensing thin film on the lower metal wiring so that the plurality of resistive temperature sensing thin films are spaced apart from each other and arranged in the longitudinal direction of the lower metal wiring; And printing the upper metal wiring on the upper portion of the plurality of resistive temperature sensing thin films and not energizing the lower metal wiring, for each of the plurality of resistive temperature sensing thin films.

Preferably, the lower metal wiring is composed of a plurality of metal wires in the form of strings long in the length direction of M (M, M> 1 natural number), and a plurality of metal wirings constituting the lower metal wiring are formed. Printed to be formed side by side spaced apart at a predetermined distance in the horizontal direction perpendicular to the longitudinal direction, a plurality of resistance-type temperature sensing thin film on the plurality of metal wires in the longitudinal row of the lower metal wires and the It is printed to be arranged two-dimensionally in a horizontal column, the upper metal wiring is composed of a plurality of (N, N> 2 natural number) of the horizontally long string-shaped metal wiring, Each metal line constituting the upper metal line is printed on the upper portion of the resistance type temperature sensing thin film constituting each column of the two-dimensional array of the resistance type temperature sensing thin film.

The printing of the upper metal wiring, the resistive temperature sensing thin film and the lower metal wiring is characterized in that the printing by screen printing, inkjet printing, gravure printing, or a combination thereof, the upper metal wiring, the resistance temperature sensing The thickness of each of the thin film and the lower metal wiring may be controlled by repeating the printing.

The flexible substrate may be formed of an insulating material, and may be bent in any shape, and any substrate capable of bending may be used. However, the PVC substrate may be used in terms of excellent adhesion between the upper metal wiring and the lower metal and the flexible substrate. It is preferable that it is a polymer thin film substrate like this.

The upper metal wiring and the lower metal wiring contain silver, aluminum, indium tin oxide (ITO), Cu-C, or a mixture thereof, and the resistive temperature sensing thin film may be a heat resistant material, a piezoresistive material, or a combination thereof. It is preferable to contain a mixture of. In this case, the resistance type temperature sensing thin film may further contain a conductive material such as carbon powder, silver powder, etc. to adjust the resistance change according to temperature.

The flexible thin film array type temperature sensor manufactured according to the above-described manufacturing method of the present invention is composed of an insulating material and is manufactured in a thin film form on a flexible substrate to be attached to an arbitrary shape irrespective of the shape of the temperature measurement target and thus the temperature of the surface. It is possible to measure the distribution.The resistive temperature sensing thin film whose resistance varies depending on the temperature has one or two dimensional array, and the resistance change according to the temperature can be measured independently for each resistive temperature sensing thin film so that it can be measured in one or two dimensions. There is a characteristic that can measure the temperature distribution.

The manufacturing method according to the present invention provides a method for manufacturing a temperature sensor capable of measuring one-dimensional or two-dimensional temperature distribution in a thin film form on a flexible / insulating thin film substrate such as paper using inkjet printing or screen printing. Simple, fast manufacturing time, easy control of the sensor structure, can be manufactured in a variety of shapes, such as belt, plate, columnar shape, the temperature sensor can be manufactured in a large area, there is an advantage that can be mass-produced. In addition, in the manufacturing method according to the present invention, since a plurality of resistive temperature sensing thin films arranged to be spaced apart from each other share a lower electrode and / or an upper electrode, the number of metal wires for measuring the resistance of the individual resistive temperature sensing thin films is remarkable. There is an advantage that can be reduced.

The temperature sensor manufactured according to the manufacturing method of the present invention is attached to any shape irrespective of the shape of the temperature measurement object to measure the temperature distribution of the surface, and has the advantage of measuring one-dimensional or two-dimensional temperature distribution. have.

Hereinafter, a flexible thin film array type temperature sensor and a method of manufacturing the same will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided by way of example so that the spirit of the invention to those skilled in the art can fully convey. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms. Also, throughout the specification, like reference numerals designate like elements.

Hereinafter, the technical and scientific terms used herein will be understood by those skilled in the art without departing from the scope of the present invention. Descriptions of known functions and configurations that may be unnecessarily blurred are omitted.

1 is a flowchart illustrating a method of manufacturing a flexible thin film array type temperature sensor according to the present invention. As can be seen in Figure 1, the manufacturing method according to the present invention is to produce an array type temperature sensor using only a printing (printing) method on a flexible substrate, an insulating material, preferably a flexible thin film or a thick film substrate There is a characteristic.

After printing the lower metal wiring on the flexible substrate (s10), by printing a resistance-type temperature sensing thin film on the printed lower metal wiring (s20), the electrical characteristics are changed in accordance with the temperature change has a substantially temperature sensing function A temperature sensing unit (resistive temperature sensing thin films) is formed. Then, by printing the upper metal wiring on the resistive temperature sensing thin film and the flexible substrate (s30), it is possible to independently measure the electrical characteristics change of each of the resistive temperature sensing thin film.

The manufacturing method of the present invention will be described in detail with reference to the flowcharts of FIGS. 2 to 3.

2 is an example illustrating a method of manufacturing a flexible thin film array type temperature sensor capable of measuring a one-dimensional temperature distribution.

As shown in FIG. 2, the flexible thin film array type temperature sensor of the present invention prints the lower metal wiring 20 having a long string shape in the longitudinal direction L on the flexible substrate 10 (FIG. 2 (a)). ), And a plurality of resistive temperature sensing thin films 3 ₀₁ , 3 ₀₂ , 3 ₀₃ , 3 ₀₄ are spaced apart from each other and arranged in the longitudinal direction (L) of the lower metal wiring. The sensing thin film is printed to form a temperature sensing unit 30 (FIG. 2 (b)), and then the lower metal on the plurality of resistance type temperature sensing thin films 3 ₀₁ , 3 ₀₂ , 3 ₀₃ , 3 ₀₄ . It is not energized in contact with the wiring 20, and each of the plurality of resistive temperature sensing thin films 3 ₀₁ , 3 ₀₂ , 3 ₀₃ , 3 ₀₄ , on the plurality of resistive temperature sensing thin films 3 ₀₁ , 3 _02. , 3 ₀₃ , 3 ₀₄ ) is produced by printing the upper metal wiring (41, 42, 43, 44) (Fig. 2 (c)).

In the step S20 of FIG. 1 or the step of forming the temperature sensing unit 30 of FIG. 2 (FIG. 2B), the individual resistance type temperature sensing thin films 3 ₀₁ , 3 ₀₂ , 3 ₀₃ , 3 ₀₄ are It is preferable that the upper portion of the lower metal line and the upper surface of the substrate in contact with the lower metal line on which the individual resistance type temperature sensing thin film is printed. In detail, as shown in FIGS. 2A and 2B, the metal string 20 constituting the lower metal wiring 20 in the horizontal direction H perpendicular to the longitudinal direction L1 is used. When the width is h1, the width h2 of the horizontal direction H of the individual resistance type temperature sensing thin film is preferably equal to or larger than the width of the metal string 20.

As a result, after the step S20, the lower metal wiring 20 and the upper metal wirings 41, 42, 43, and 44 are not electrically connected to each other without forming a separate insulating layer.

In addition, the plurality of resistive temperature sensing thin films 3 ₀₁ , 3 ₀₂ , 3 ₀₃ , 3 ₀₄ formed spaced apart from each other in the longitudinal direction L as shown in FIG. 2 (c) may have a single lower metal wiring 20. By sharing the upper metal wiring (41, 42, 43, 44), the electrical properties (voltage, resistance, current, etc.) of a single resistive temperature sensing thin film independently of each other in a plurality of resistive temperature sensing thin films The number of metal wires (upper metal wires and lower metal wires) can be reduced. In the example of FIG. 2C, one-dimensional temperature distribution may be measured by measuring electrical characteristics of the individual resistance type temperature sensing thin films constituting the temperature sensing unit 20 using only five metal wires instead of eight metal wires.

3 is an example illustrating a method of manufacturing a flexible thin film array type temperature sensor capable of measuring a two-dimensional temperature distribution.

As shown in FIG. 3 (a), the lower metal wiring is composed of metal strings 21, 22, and 23 having a long string shape in a plurality of longitudinal directions L, thereby forming the lower metal wiring. A plurality of metal wires 21, 22, 23 are printed so as to be formed side by side spaced apart at a predetermined distance in the horizontal direction (H) perpendicular to the longitudinal direction (L).

Subsequently, a plurality of resistance-type temperature sensing thin films are arranged in two-dimensional rows and horizontal columns of the lower metal wires on the plurality of metal wires constituting the lower metal wires. It is printed. That is, a plurality of resistive temperature sensing thin films (for example, 3 ₁₁ , 3 ₁₂ , 3 ₁₃ and 3 ₁₄ ) formed on a single metal wiring (constituting the lower metal wiring) spaced apart from each other in the longitudinal direction (L) are formed. constituting the resistive line of the temperature sensing thin film arrangement, and different metal wire (constituting a lower metal wiring) are spaced apart from each other in the horizontal direction (H) at the top a plurality of resistance-type temperature sensing thin film formed (for example, _311, 3 ₂₁ and 3 ₃₁ form a resistive temperature sensing thin film array to form a temperature sensing unit 30 for sensing a two-dimensional temperature distribution.

After the temperature sensing unit 30 is formed, a step of printing the upper metal wirings 41, 42, 43, and 44 is performed. The upper metal wires 41, 42, 43, 44 are composed of a plurality of metal wires 41, 42, 43, 44 in the form of a long string in the horizontal direction, and constitute each of the upper metal wires. Metal wires 41, 42, 43, and 44 are printed on top of the resistive temperature sensing thin film constituting each column of the two-dimensional array of the resistive temperature sensing thin film.

One metal wire constituting the upper metal wire is formed on top of a plurality of resistance type temperature sensing thin films (eg, 3 ₁₁ , 3 _21, and 3 ₃₁ ) formed at the same position in the longitudinal direction (L). Two resistive temperature sensing thin films share one metal wiring constituting the lower metal wiring in the row direction of the resistive temperature sensing thin film array, and one metal constituting the upper metal wiring in the column direction of the resistive temperature sensing thin film array The wiring will be shared.

Therefore, when the resistive temperature sensing thin film array is a JxK array (J is an integer of 1 or more, K is an integer of 1 or more independently of J), the lower metal wiring is composed of J metal wiring, and the upper metal wiring is It consists of K metal wirings.

As a result, the plurality of resistance-type temperature sensing thin films constituting the temperature sensing unit 30 have an advantage of minimizing metal wiring for measuring electrical characteristics independently of each other.

2 and 3 are provided only to help a more general understanding of the present invention, but the present invention is not limited thereto.

In the manufacturing method of the present invention, since the temperature sensor is manufactured through simple printing, the overall size of the temperature sensor, the shape of the resistive temperature sensing thin film, the size of the resistive temperature sensing thin film, the specific shape and size of the metal wiring, the resistive temperature sensing The spacing between the thin films, the specific row of the resistive temperature sensing thin film array, the number of columns, and the like should be adjusted to suit the utilization of the temperature sensor according to the present invention.

The printing of the upper metal wiring, the resistive temperature sensing thin film, and the lower metal wiring may be printing by screen printing, inkjet printing, gravure printing, or a combination thereof. More preferably, the printing of the upper metal wiring, the lower metal wiring and the resistive temperature sensing thin film is screen printing or inkjet printing.

The upper metal wiring and the lower metal wiring preferably contain silver, aluminum, ITO, Cu-C, or a mixture thereof.

Therefore, the wiring ink (or paste) for printing the upper metal wiring and the lower metal wiring contains silver, aluminum, ITO, Cu-C, or a mixture thereof, and for adjusting the viscosity, adhesion and dispersibility. Organics and organic solvents may be contained.

Printing may be performed using a conventional conductive ink known and used in the flexible organic thin film transistor technology as the wiring ink for printing the upper metal wiring and the lower metal wiring.

The resistive temperature sensing thin film can be used as long as the material changes electrical characteristics such as resistance and current according to temperature change, but for accurate and sensitive temperature measurement, the resistive temperature sensing thin film has a large electric resistance change according to temperature. It contains a heat resistant material or a piezoresistive material whose electrical resistance varies greatly with pressure, and preferably contains a heat resistant material. The heat resistance material may be a material used in a conventional thermistor device, and in particular, nickel oxide, manganese oxide, cobalt oxide, or a mixture thereof may be mainly used. The piezoresistive material may be mainly a conventional perovskite-based material.

Therefore, the resistive temperature sensing thin film ink (or paste) for inkjet, gravure, or screen printing the resistive temperature sensing thin film contains a heat resistant electrically conductive material or a piezoresistive electrically conductive material, and has a viscosity similar to that of the wiring ink. It may contain organic substances and organic solvents for adjusting the adhesion and dispersibility.

After the lower metal wiring is printed on the flexible substrate using the wiring ink (or paste) and the resistive temperature sensing thin film ink (or paste), annealing for drying is performed, and after annealing, The resistive temperature sensing thin film is printed, and annealing for drying is performed again, and after the resistive temperature sensing thin film is dried, printing and drying of the upper metal wiring are preferably performed.

The temperature sensor manufactured according to the above-described manufacturing method of the present invention is manufactured in the form of a thin film on the flexible substrate of a thin film or a thick film and is easily deformed by external stress, so that the surface temperature of the measurement object can be measured regardless of the shape of the temperature measurement object. It can be attached to any shape and measure a one-dimensional or two-dimensional temperature distribution.

4 is an example in which the temperature sensor A having the one-dimensional arrangement of FIG. 2 is attached to a tube B through which a fluid (arrow of FIG. 4) flows by bonding both ends of the substrate in the longitudinal direction. As shown in FIG. 4, the temperature sensor according to the present invention can measure the overall temperature distribution instead of the temperature at a specific point, and the change in temperature in one or two dimensions can also be measured in real time.

1 is a flow chart showing a manufacturing method of the present invention,

Figure 2 is a process diagram showing a manufacturing method of the present invention,

Figure 3 is another process diagram showing a manufacturing method of the present invention,

4 is an example of application of the belt-shaped temperature sensor of FIG.

* Description of the symbols for the main parts of the drawings *

10: insulated / flexible substrate 20, 21 ~ 23: lower metal wiring

30: temperature sensing unit 3 ₀₁ ~ 3 ₃₄ : resistance type temperature sensing thin film

41 ~ 44: Upper metal wiring

Claims (5)

Printing the lower metal wiring in the form of a long string in the longitudinal direction on the flexible substrate; Printing a resistive temperature sensing thin film on the lower metal wiring so that the plurality of resistive temperature sensing thin films are spaced apart from each other and arranged in the longitudinal direction of the lower metal wiring; And Printing an upper metal wiring on each of the plurality of resistive temperature sensing thin films and not energizing the lower metal wirings; Method of manufacturing a flexible thin film array type temperature sensor that is produced, including. The method of claim 1, The lower metal wiring is composed of a plurality of metal wires in the form of strings long in the longitudinal direction (M pieces, M> 1 natural number), A plurality of metal wires constituting the lower metal wires are printed to be formed side by side spaced apart at a predetermined distance in the horizontal direction perpendicular to the longitudinal direction, A plurality of resistance-type temperature sensing thin films are printed on the plurality of metal wires so as to be two-dimensionally arranged in a row in the longitudinal direction of the lower metal wires and in a column in the horizontal direction. The upper metal wiring is composed of a plurality of (N, N> 2 natural number) of the metal wiring in the form of a long string in the horizontal direction, Each metal wiring constituting the upper metal wiring is printed on the upper portion of the resistance temperature sensing thin film constituting each column of the two-dimensional array of the resistance type temperature sensing thin film, the flexible thin film array type temperature sensor Manufacturing method. The method according to claim 1 or 2, The printing of the upper metal wiring, the resistive temperature sensing thin film and the lower metal wiring may be printing by screen printing, inkjet printing, or a combination thereof. The method of claim 3, wherein The upper metal wiring and the lower metal wiring contain silver, aluminum, ITO, Cu-C or a mixture thereof; The resistance type temperature sensing thin film is a method of manufacturing a flexible thin film array type temperature sensor, characterized in that it contains a heat resistance material, piezoresistance material or a mixture thereof. A flexible thin film array type temperature sensor manufactured by the manufacturing method of claim 1 or 2 and attached to an arbitrary shape to measure a one-dimensional or two-dimensional temperature distribution.

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