KR20160087173A - Thermistor And Method of the Same - Google Patents

Abstract

The present invention relates to a thermistor which comprises: a thermistor body including a thermistor material; an external electrode formed on an external side of the thermistor body; and a plurality of internal electrodes formed in the thermistor body and electrically connected to the external electrode, wherein the internal electrodes comprise graphene. The graphene having a better electrical conductivity than copper is included in the internal electrodes to form the internal electrodes to have a thin thicknesses, thereby providing a micro and ultra-thin thermistor.

Description

TECHNICAL FIELD [0001] The present invention relates to a thermistor and a method of manufacturing the same,

The present invention relates to a thermistor provided with an internal electrode including graphene and a method of manufacturing the same.

Thermistor is a kind of resistor, which is an electronic part that uses the property that the resistance of material changes according to temperature.

It is also referred to as a thermal variable resistor. It is mainly used as a sensor to prevent the circuit electricity from rising to a certain level or to detect the temperature of the circuit.

 Assuming that the resistance of the thermistor varies linearly with temperature, the relationship between resistance and temperature is defined as: ΔR = change in resistance, ΔT is the change in temperature, and ΔR = kΔT when k is the temperature coefficient of resistance do.

There are two types of thermistors depending on the temperature coefficient of resistance. If k> 0, the resistance of the thermistor increases with temperature. This thermistor is called a positive temperature coefficient thermistor (PTC thermistor). On the contrary, when k <0, the resistance of the thermistor decreases as the temperature increases, which is called an NTC thermistor (Negative Temperature Coefficient Thermistor). For a typical resistor other than a thermistor, the value of k is made to be as close as possible to 0, so that there is little resistance change with temperature.

The thermistor is fabricated so that the change in resistance is caused largely by a minute temperature change. Therefore, thermistors are used for thermometers, thermometers, hygrometers, barometers, anemometers, etc., which involve minute temperature measurements. PPTCs, such as PolySwitch, are used for reusable fuses that cut off the overcurrent, while negative-purpose thermistors (NTC) are also used to limit inrush current when the equipment is turned on.

However, in the case of a conventional thermistor, a metallic material is used as the internal electrode. However, since it is difficult to make the thickness of the internal electrode thin due to the limit of the allowable current density of the metal, it has been difficult to provide an ultra-small and ultra-thin thermistor.

Korean Patent Laid-Open Publication No. 1998-079879

The present invention has been made to solve the above-described problems and disadvantages of conventional thermistors, and it is an object of the present invention to provide an ultra-small, ultra-thin thermistor including internal electrodes with graphene having a very large allowable current density, have.

The above object of the present invention is achieved by a thermistor comprising a thermistor body including a thermistor material, an outer electrode formed on an outer surface of the thermistor body, and a plurality of inner electrodes formed inside the thermistor body, The internal electrode is achieved by providing a thermistor including graphene.

At this time, the outer electrode may further include a plating layer on the outer surface thereof, and the inner electrode may be formed by depositing graphene on a metal seed layer.

Also, the internal electrode may include a floating electrode.

Another object of the present invention is to provide a ceramic substrate, a plurality of internal electrodes formed on the ceramic substrate, a thermistor layer formed between the internal electrodes, an external electrode electrically connected to the internal electrode and formed on an outer surface of the ceramic substrate, And a protective layer formed on the internal electrode and the thermistor material, wherein the internal electrode is formed by providing a thermistor including graphene.

It is still another object of the present invention to provide a method of manufacturing a semiconductor device, which comprises fabricating a sheet containing a thermistor material and a polymer, forming a metal seed layer in the form of an internal electrode pattern on the sheet, Forming a plurality of internal electrodes by transferring the graphene pattern, forming a thermistor body by laminating the sheets on which the internal electrodes are formed, and forming external electrodes on the external surface of the body so as to be electrically connected to the internal electrodes The present invention provides a method of manufacturing a thermistor including a thermistor.

Still another object of the present invention is to provide a method of manufacturing a semiconductor device, which comprises preparing a ceramic substrate, forming a metal seed layer in the form of an internal electrode pattern on the ceramic substrate, forming a graphene film on the substrate using an electrophoretic deposition (EPD) Forming a plurality of internal electrodes by transferring a pattern, forming a thermistor layer between the plurality of internal electrodes, forming external electrodes on the external surface of the ceramic substrate to be electrically connected to the internal electrodes, And forming a protective layer on the internal electrode and the thermistor layer.

As described above, the thermistor according to the present invention includes the graphene having a very high permissive current density in the internal electrode, so that the thickness of the internal electrode can be made thinner than the internal electrode of the conventional thermistor, Can be provided.

In addition, if an internal electrode containing graphene is formed on the polymer resin film, a transparent and flexible ultra thin film type thermistor can be provided.

1 is a cross-sectional view of a thermistor according to an embodiment of the present invention;
2 is a cross-sectional view of a thermistor according to another embodiment of the present invention;
3 is a plan view of a thermistor according to another embodiment of the present invention.
4 is a plan view of a thermistor according to another embodiment of the present invention.
5 is a schematic diagram of an electrophoretic deposition (EPD) process during the manufacturing process of the thermistor according to the present invention.
6 is a flowchart of a method of manufacturing a thermistor according to an embodiment of the present invention.
7 is a flowchart of a method of manufacturing a thermistor according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The present embodiments are provided so that the disclosure of the present invention is complete and that those skilled in the art will fully understand the scope of the present invention. Like reference numerals refer to like elements throughout the specification.

The terms used herein are intended to illustrate the embodiments and are not intended to limit the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is to be understood that the terms 'comprise', and / or 'comprising' as used herein may be used to refer to the presence or absence of one or more other components, steps, operations, and / Or additions.

In addition, the embodiments described herein will be described with reference to cross-sectional views and / or plan views, which are ideal illustrations of the present invention. In the drawings, the thicknesses of the films and regions are exaggerated for an effective description of the technical content. The shape of the illustration may be modified by following and / or by tolerance or the like. Accordingly, the embodiments of the present invention are not limited to the specific forms shown, but also include changes in the shapes that are generated according to the manufacturing process. For example, the etched area shown at right angles may be rounded or may have a shape with a certain curvature.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a thermistor according to an embodiment of the present invention.

1, a thermistor 100 according to an exemplary embodiment of the present invention includes a thermistor body 120 including a thermistor material, an external electrode 130 formed on an outer surface of the thermistor body 120, And a plurality of inner electrodes 110 formed in the inner electrode 120 and electrically connected to the outer electrode 130. The inner electrode 110 may include graphene.

The thermistor material may include an oxide-based material including Ni, Co, Cu, Mn, and Fe as the negative-temperature thermistor material, and may include Mn, Sr, and Pb added to BaTiO ₃ as a positive thermistor material But is not limited thereto.

The thermistor body 120 may be formed by laminating a ceramic green sheet including the thermistor material and includes an internal electrode 110 including a graphene.

The internal electrode 110 may include a metal seed layer 111 and a graphene layer 112 formed on the metal seed layer 111 by an electrophoretic deposition (EPD) method.

The metal seed layer 111 may be formed on the ceramic green sheet in the form of an internal electrode pattern so that oxidized graphene or reduced graphene may be deposited in the form of an internal electrode pattern during electrophoretic deposition, which will be described later.

The internal electrode according to the present embodiment includes graphene having an allowable current density of about one million times that of copper, so that the internal electrode can be formed thinner than the conventional one, and the thickness of the entire thermistor can be reduced.

The internal electrodes may be spaced apart from each other, and may be electrically connected to the external electrodes, and may include a floating electrode 110a, which is not electrically connected to external electrodes but is spaced apart from other internal electrodes have.

The thermistor body 120 includes the thermistor material. Since the resistance of the thermistor material changes according to a change in temperature, a current can flow between the separated internal electrodes in a specific temperature range, Or as a thermometer.

The outer electrode 130 formed on the outer surface of the thermistor body 120 may include a metal layer 131, a first plated layer 132 and a second plated layer 133, The second plating layer 131, the first plating layer 132, and the second plating layer 133 in this order.

The metal layer 131 may be formed by sintering a conductive paste containing a metal such as silver (Ag) or copper.

The first plating layer 132 may be formed by plating metal such as nickel to prevent the metal layer 131 from being oxidized.

The second plating layer 133 may be formed by plating tin (Sn) or the like on the first plating layer 132.

2 is a cross-sectional view of a thermistor according to another embodiment of the present invention.

Referring to FIG. 2, the thermistor 200 according to another embodiment of the present invention includes a ceramic substrate 240, a plurality of internal electrodes 210 spaced apart from each other on the ceramic substrate, An outer electrode 230 electrically connected to the inner electrode and formed on an outer surface of the ceramic substrate and a protection layer 250 formed on the inner electrode and the thermistor material, The internal electrode 210 may include graphene.

The ceramic substrate may be an alumina substrate such as Al ₂ O ₃ , but is not limited thereto.

The internal electrodes 210 may be spaced apart from each other on the ceramic substrate and may include a metal seed layer 211 and a graphene layer 212 formed by an electrophoretic deposition (EPD) method on the metal seed layer ).

The metal seed layer 211 may be formed on the ceramic substrate in the form of an internal electrode pattern so that oxide graphene or reduced graphene may be deposited in the form of an internal electrode pattern during electrophoretic deposition, which will be described later.

The internal electrode 210 according to the present embodiment includes graphene having an allowable current density of about one million times that of copper, so that the internal electrode 210 can be formed to have a thin thickness compared to the conventional one, and the thickness of the entire thermistor can be made thin have.

The thermistor layer may comprise a thermistor material, a portion thermistor material Ni, Co, Cu, Mn, and may include an oxide-based, including Fe or the like, the BaTiO ₃ as a positive temperature coefficient thermistor material Mn, Sr, Pb, and the like. However, the present invention is not limited thereto, and may be formed between the spaced apart internal electrodes.

The outer electrode 230 formed on the outer surface of the ceramic substrate may include a metal layer 231, a first plating layer 232 and a second plating layer 233. The metal layer 231 may be formed on the outer surface of the ceramic substrate. The first plating layer 232, and the second plating layer 233 in this order.

The metal layer 231 may be formed by sintering a conductive paste containing a metal such as silver (Ag) or copper.

The first plating layer 232 may be formed by plating a metal such as nickel to prevent the metal layer 231 from being oxidized.

The second plating layer 233 may be formed by plating tin (Sn) or the like on the first plating layer 232.

The passivation layer 250 may include a first passivation layer 251 and a second passivation layer 252 to prevent the internal electrode 210 and the thermistor layer 220 from being exposed to the outside .

The first passivation layer 251 may be formed of a glass material and the second passivation layer 252 may be formed of a polymer resin, but the present invention is not limited thereto.

3 is a top view of a thermistor according to another embodiment of the present invention.

3, the thermistor 300 of the present embodiment includes a polymeric resin film 320 as a film-type thermistor and a plurality of internal electrodes 310 formed on the polymeric resin film 320, May be graphene deposited on a metal seed layer.

The polymeric resin film 320 may be formed of a resin such as polyethylene (PE) resin, polypropylene resin (PP), nylon, polyacetal, polyvinyl chloride resin (PVC), polystyrene, acrylic resin, ABS resin, (EPR), a natural rubber (NR) resin, a polyimide-based resin, a polyester-based resin, or the like, and may include a thermistor material whose resistance varies with temperature.

The internal electrodes 310 may be spaced apart from each other on the polymer resin film 320. A metal seed layer and a graphene layer formed by an electrophoretic deposition (EPD) method may be formed on the metal seed layer .

The metal seed layer may be formed on the polymeric resin film in the form of an internal electrode pattern so that the graphene oxide or the reduced graphene may be deposited in the form of an internal electrode pattern during electrophoretic deposition, which will be described later.

The thermistor 300 of this embodiment can be manufactured transparently by using the polymeric resin film 320 as a transparent material and by controlling the material and the thickness of the metal seed layer to fabricate an ultra-thin and ultra-thin transparent film thermistor have.

4 is a plan view of a thermistor according to another embodiment of the present invention.

4, the thermistor of the present embodiment 400 includes a polymer resin film 420 as a film-type thermistor and a plurality of internal electrodes 410 formed on the polymer resin film 420,

The internal electrode 410 may be formed of a graphene deposited on a metal seed layer, and may further include an ultra-small chip-type thermistor connected to the internal electrode 410.

The polymeric resin film 420 may be formed of a resin such as polyethylene (PE) resin, polypropylene resin (PP), nylon, polyacetal, polyvinyl chloride resin (PVC), polystyrene, acrylic resin, ABS resin, (EPR), a natural rubber (NR) resin, a polyimide-based resin, a polyester-based resin, or the like, and may include a thermistor material whose resistance varies with temperature.

The internal electrodes 410 may be spaced apart from each other on the polymeric resin film 420 and may include a metal seed layer and a graphene layer formed by an electrophoretic deposition (EPD) method on the metal seed layer .

The metal seed layer may be formed on the polymeric resin film in the form of an internal electrode pattern so that the graphene oxide or the reduced graphene may be deposited in the form of an internal electrode pattern during electrophoretic deposition, which will be described later.

The thermistor of this embodiment can be manufactured transparently by using the polymeric resin film as a transparent material and by controlling the material and thickness of the metal seed layer to manufacture an ultra-small, ultra-thin transparent film thermistor.

FIG. 5 is a schematic view of an electrophoretic deposition (EPD) process in a manufacturing process of a thermistor according to the present invention, and FIG. 6 is a flowchart of a method of manufacturing a thermistor according to an embodiment of the present invention.

5 and 6, a method of manufacturing a thermistor according to an embodiment of the present invention includes fabricating a sheet including a thermistor material and a polymer, forming a metal seed layer in the form of an internal electrode pattern on the sheet, Forming an internal electrode by transferring a graphene pattern onto the sheet using an electrophoretic deposition (EPD) method; forming a thermistor body by laminating the sheet on which the internal electrode is formed; And forming an external electrode to be electrically connected to the internal electrode.

In the step of fabricating the sheet including the thermistor material and the polymer, an oxide-based negative-acting thermistor material including Ni, Co, Cu, Mn, Fe, etc., or a positive temperature coefficient thermistor material in which Mn, Sr, Pb or the like is added to BaTiO 3 material A composite of a thermistor material such as a material and a polymer can be processed into a sheet form.

In the step of forming the metal seed layer in the form of an internal electrode on the sheet, a metal seed layer is formed on the sheet in the form of an internal electrode pattern of the thermistor.

In the step of forming the internal electrode by transferring the graphene pattern to the sheet 520 using the electrophoretic deposition (EPD) method, the cathode 560 is connected to the metal seed layer 510 of the sheet 520, The cathode 570 is immersed in the solvent 580 in which the graphene oxide or the reducing graphene 590 is dispersed and the sheet 520 connected to the cathode 570 and the cathode 560 is immersed in the solvent, Fin 590 may be deposited on the metal seed layer 510 on the sheet 520.

At this time, the graphene oxide or the reduced graphene can be produced by a generally known method, and in particular, a Hummer's Method may be used.

Further, it is possible to have a plus charge through further modification to the graphene oxide or the reduced graphene, thereby increasing the rate at which graphene is deposited on the metal seed layer connected to the cathode.

In the step of forming the thermistor body by laminating the sheets on which the internal electrodes are formed, a plurality of sheets having the internal electrodes formed thereon may be heated and pressed through a laminating process to form the thermistor body.

Thereafter, the thermistor body is formed into a sintered body through a sintering process.

In the step of forming the outer electrode to be electrically connected to the inner electrode on the outer surface of the thermistor body, an outer electrode is formed on the outer surface of the thermistor body so as to be electrically connected to the inner electrode. The outer electrode includes a metal layer, 2 plating layer, and may be formed in the order of a metal layer, a first plating layer, and a second plating layer on the basis of a thermistor body.

The metal layer may be formed by sintering a conductive paste containing a metal such as silver (Ag) or copper.

The first plating layer may be formed by plating a metal such as nickel to prevent oxidation of the metal layer.

The second plating layer may be formed by plating tin (Sn) or the like on the first plating layer.

7 is a flowchart of a method of manufacturing a thermistor according to another embodiment of the present invention.

Referring to FIG. 7, a method of manufacturing a thermistor according to another embodiment of the present invention includes preparing a ceramic substrate, forming a metal seed layer in the form of an internal electrode pattern on the ceramic substrate, forming an electrophoretic deposition (EPD) Forming a plurality of internal electrodes by transferring a graphene pattern onto the ceramic substrate using the method of the present invention; forming a thermistor layer between the plurality of internal electrodes; forming a protective layer on the internal electrode and the thermistor material .

The ceramic substrate may be an alumina substrate such as Al ₂ O ₃ , but is not limited thereto.

In the step of forming the metal seed layer in the form of an internal electrode pattern on the ceramic substrate, a metal seed layer is formed on the ceramic substrate in the form of an internal electrode pattern of the thermistor. At this time, the metal seed layer may be formed such that the internal electrodes are spaced apart from each other.

In the step of forming a plurality of internal electrodes by transferring a graphene pattern onto the ceramic substrate by using an electrophoretic deposition (EPD) method, the cathode is connected to the metal seed layer of the ceramic substrate, The sheet to which the anode and the cathode are connected is immersed in a solvent in which the fin is dispersed and the power is applied so that the graphene oxide or the reduced graphene is deposited on the sheet metal layer.

In the step of forming the thermistor layer between the plurality of internal electrodes, a thermistor layer including a thermistor material is formed between internal electrodes formed to be spaced apart from each other.

In the step of forming the outer electrode to be electrically connected to the inner electrode on the outer surface of the ceramic substrate, an outer electrode is formed on the outer surface of the ceramic substrate so as to be electrically connected to the inner electrode, A plated layer, and a second plated layer, and may be formed in the order of a metal layer, a first plating layer, and a second plating layer on the basis of a thermistor body.

The metal layer may be formed by sintering a conductive paste containing a metal such as silver (Ag) or copper.

The first plating layer may be formed by plating a metal such as nickel to prevent oxidation of the metal layer.

The second plating layer may be formed by plating tin (Sn) or the like on the first plating layer.

In the step of forming the protective layer on the internal electrode and the thermistor layer, a protective layer may be formed so that the internal electrode and the thermistor layer are not exposed to the outside. The protective layer may be formed of a multi- Structure.

The first passivation layer may include a glass material, and the second passivation layer may include a polymer resin, but the material is not limited thereto.

The foregoing detailed description is illustrative of the present invention. It is also to be understood that the foregoing is illustrative and explanatory of preferred embodiments of the invention only, and that the invention may be used in various other combinations, modifications and environments. That is, it is possible to make changes or modifications within the scope of the concept of the invention disclosed in this specification, the disclosure and the equivalents of the disclosure and / or the scope of the art or knowledge of the present invention. The foregoing embodiments are intended to illustrate the best mode contemplated for carrying out the invention and are not intended to limit the scope of the present invention to other modes of operation known in the art for utilizing other inventions such as the present invention, Various changes are possible. Accordingly, the foregoing description of the invention is not intended to limit the invention to the precise embodiments disclosed. It is also to be understood that the appended claims are intended to cover such other embodiments.

100, 200, 300, 400: thermistor
110, 310, 410: internal electrodes
110a: floating internal electrode
111, 111a and 211: a metal seed layer
112, 112a, 212: graphene layer
120: Thermistor body
220: Thermistor layer
320, 420: Polymer film
130, 230: external electrodes
131, 231: metal layer
132, 232: first plating layer
133, 233: Second plating layer
240: Ceramic substrate
250: protective layer
251: first protective layer
252: second protective layer
510: Metal Seed Layer
520: composite sheet
560: cathode
570: anode
580: Solvent
590: Graphene

Claims (15)

A thermistor body including a thermistor material;
An outer electrode formed on an outer surface of the thermistor body; And
And a plurality of internal electrodes formed inside the thermistor body and electrically connected to the external electrodes,
Wherein the internal electrode comprises graphene. The method according to claim 1,
The thermistor material is an oxide-based negative-acting thermistor material including Ni, Co, Cu, Mn, and Fe, or a thermistor material that is a positive temperature coefficient thermistor material to which Mn, Sr, and Pb are added to a BaTiO3 material. The method according to claim 1,
And a plating layer on the outer surface of the external electrode. The method according to claim 1,
Wherein the internal electrode is a graphene deposited on a metal seed layer. The method according to claim 1,
Wherein the internal electrode comprises a floating electrode. A ceramic substrate;
A plurality of internal electrodes spaced apart from each other on the ceramic substrate;
A thermistor layer formed between the spaced apart internal electrodes;
An outer electrode electrically connected to the inner electrode and formed on an outer surface of the ceramic substrate; And
And a protective layer formed on the internal electrode and the thermistor material,
Wherein the internal electrode comprises graphene. The method according to claim 6,
Wherein the thermistor layer comprises an oxide-based negative-acting thermistor material including Ni, Co, Cu, Mn, Fe, or the like, or a positive-temperature characteristic thermistor material to which Mn, Sr, Pb or the like is added to BaTiO3 material. The method according to claim 6,
And a plating layer on the outer surface of the external electrode. The method according to claim 6,
Wherein the internal electrode is a graphene deposited on a metal seed layer. Polymeric resin film; And
And a plurality of internal electrodes formed on the polymeric resin film,
Wherein the internal electrode is a graphene deposited on a metal seed layer. 11. The method of claim 10,
The polymeric resin film may be at least one selected from the group consisting of a polyethylene (PE) resin, a polypropylene resin (PP), a nylon, a polyacetal, a polyvinyl chloride resin (PVC), a polystyrene, an acrylic resin, an ABS resin, (EPR), a natural rubber (NR) resin, a polyimide-series resin, and a polyester-series resin. Fabricating a sheet comprising a thermistor material and a polymer;
Forming a metal seed layer in the form of an internal electrode pattern on the sheet;
Transferring a graphene pattern onto the sheet using an electrophoretic deposition (EPD) method to form a plurality of internal electrodes;
Forming a thermistor body by laminating sheets having the internal electrodes formed thereon; And
And forming an outer electrode on an outer surface of the body so as to be electrically connected to the inner electrode. 13. The method of claim 12,
Wherein the thermistor material is an oxide based negative-acting thermistor material including Ni, Co, Cu, Mn, and Fe, or a positive temperature coefficient thermistor material to which Mn, Sr, Pb and the like are added to BaTiO3 material. Preparing a ceramic substrate;
Forming a metal seed layer in the form of an internal electrode pattern on the ceramic substrate;
Transferring a graphene pattern onto the substrate using an electrophoretic deposition (EPD) method to form a plurality of internal electrodes;
Forming a thermistor layer between the plurality of internal electrodes;
Forming an outer electrode on the outer surface of the ceramic substrate so as to be electrically connected to the inner electrode; And
And forming a protective layer on the internal electrode and the thermistor layer. 15. The method of claim 14,
Wherein the thermistor material is an oxide based negative-acting thermistor material including Ni, Co, Cu, Mn, and Fe, or a positive temperature coefficient thermistor material to which Mn, Sr, Pb and the like are added to BaTiO3 material.

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