KR20170059799A - Circuit protection device - Google Patents

Abstract

An electric shock protector is provided. An electric shock protection device according to an embodiment of the present invention includes at least two varistor material layers disposed between a body contactable conductor of an electronic device and a built-in circuit portion and including a first varistor material layer and a second varistor material layer, And an electric shock protection unit including a plurality of first internal electrodes spaced apart from each other by a predetermined distance and a plurality of second internal electrodes spaced apart by a predetermined distance from the second varistor material layer, The plurality of electric shock protection parts may be connected in parallel.

Description

[0001] The present invention relates to a circuit protection device,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electric shock protection device, and more particularly, to an electric shock protection device that protects a user from a leakage current by a power source and has improved electric characteristics against static electricity.

Recently, the adoption of a metal housing has been increasing in order to improve aesthetics and robustness of portable electronic devices.

However, since the metal housing is excellent in electrical conductivity due to the nature of the material, an electrical path can be formed between the housing and the built-in circuit depending on the specific device or depending on the location. Particularly, since the metal housing and the circuit part form a loop, when a static electricity having a high voltage instantaneously flows through a conductor such as a metal housing having a large exposed surface area, the circuit part such as an IC can be damaged, Measures are required.

On the other hand, such a portable electronic device typically uses a charger to charge the battery. Such a charger rectifies an external AC power source to a DC power source and then converts it to a low DC power source suitable for a portable electronic device through a transformer. Here, in order to enhance the electrical insulation of the transformer, a Y-CAP composed of a capacitor is provided at both ends of the transformer.

However, when the Y-CAP does not have the normal characteristics, such as a non-genuine charger, the DC power may not be sufficiently blocked by the Y-CAP, and furthermore, a leakage current may be generated by the AC power source. Can propagate along the ground of the circuit.

Such a leakage current can be transmitted to a conductor that can be contacted with a human body, such as an external case of a portable electronic device. As a result, it can give a user an unpleasant feeling of crushing, and in a severe case, There is a fear of wearing.

Accordingly, a portable electronic device such as a cellular phone employing a metal case is required to protect the user from leakage current.

In addition, in order to achieve a stable function for interrupting the leakage current or for passing the static electricity because the static electricity generates a momentarily high voltage and the leakage current is harmful to the human body, the electric resistance against the leakage current or the static electricity The development of the

Korean Registered Patent No. 0573364 (Registration date April 17, 2006)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric shock protection device capable of protecting an internal circuit and / or a user from a leakage current caused by static electricity or an external power source, have.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an electronic device comprising at least two varistor material layers disposed between a human contactable conductor of an electronic device and a built-in circuitry, the first varistor material layer and the second varistor material layer being laminated, And an electric shock protection unit including a plurality of first internal electrodes spaced apart from the varistor material layer by a predetermined distance and a plurality of second internal electrodes spaced apart from the second varistor material layer by a predetermined distance, And the plurality of electric shock protection parts are connected in parallel to each other.

Alternatively, the electric shock protection device may pass the static electricity without being destroyed by insulation when the static electricity flows from the electric conductor, and may block the leakage current of the external electric power supplied from the ground of the circuit part.

Vbr> Vin

Here, Vbr is a breakdown voltage of the electric shock protection element,

Vin is the rated voltage of the external power supply of the electronic device.

Alternatively, the rated voltage may be a national standard rated voltage.

Alternatively, each of the first internal electrode and the second internal electrode may be disposed so that at least a part thereof overlaps.

Alternatively, the first internal electrode and the second internal electrode may be arranged so as not to overlap each other.

Alternatively, a buffer layer may be disposed between any one of the plurality of electric shock protection parts and between the neighboring second electric shock protection parts.

Alternatively, the interval between the internal electrode of the first electric shock protection unit disposed on the buffer layer and the internal electrode of the second electric shock protection unit disposed below the buffer layer may be the shortest distance between the first internal electrode and the second internal electrode (d1, d2).

Alternatively, the external protection electrode may include a plurality of external electrodes for connecting the first internal electrode and the second internal electrode to the conductor and the circuit unit.

Alternatively, one of the plurality of external electrodes may be a common external electrode that connects the plurality of electric shock protection elements to the circuit portion.

Alternatively, the plurality of varistor material layers may be any one of a semiconductive material containing at least one of ZnO, SrTiO3, BaTiO3, and SiC, or a Pr and Bi-based material.

Alternatively, the thickness of the first and second internal electrodes may be 2-10 탆.

According to the present invention, a plurality of paths through which static electricity and a leakage current flow can be provided, and the electrical characteristics can be improved by enhancing resistance to external inflow energy by dispersion of electric shock protection or electrostatic protection function.

Further, in the portable electronic device in which the conductor such as the metal case is exposed to the outside, the user and the internal circuit can be protected from the leakage current and the static electricity caused by the external power source by providing the electric shock protection element connecting the conductor and the circuit portion.

1 is a perspective view schematically showing an electric shock protection device according to an embodiment of the present invention,
2 is an exploded perspective view of an electric shock protection device according to an embodiment of the present invention,
3 is a longitudinal sectional view of an electric shock protection device according to an embodiment of the present invention,
4A to 4D illustrate various modifications of the electric shock protection device according to an embodiment of the present invention.
5A and 5B are conceptual diagrams illustrating an application example of an electric shock protection device according to an embodiment of the present invention, and FIGS.
FIGS. 6A and 6B are schematic equivalent circuit diagrams for explaining operation of (a) leakage current and (b) static electricity (ESD) of an electric shock protection device according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

The electric shock protection device 100 according to an embodiment of the present invention is connected between a metal case constituting the outer shape of a portable electronic device and a circuit portion incorporated in the portable electronic device, passes static electricity flowing through the metal case, The leakage current flowing into the circuit portion is prevented from flowing to the metal case. For this, the following conditions can be satisfied.

Vbr> Vin

Here, Vbr is a breakdown voltage of the electric shock protection element,

Vin is the rated voltage of the external power supply of the electronic device.

At this time, the rated voltage may be a standard rated voltage for each country, for example, 240V, 110V, 220V, 120V and 100V.

In addition, the portable electronic device 10 may be in the form of a portable electronic device that is portable and portable. For example, the portable electronic device may be a portable terminal such as a smart phone, a cellular phone, and the like, and may be a smart watch, a digital camera, a DMB, an electronic book, a netbook, a tablet PC, Such electronic devices may comprise any suitable electronic components including antenna structures for communication with external devices. In addition, it may be a device using local area network communication such as Wi-Fi and Bluetooth.

Such a portable electronic device 10 may be made of a conductive material such as a metal (aluminum, stainless steel, etc.) or an outer housing made of carbon-fiber synthetic material or other fiber-based composites, glass, ceramic, plastic, . ≪ / RTI >

At this time, the housing of the portable electronic device 10 may include a conductor 12 made of metal and exposed to the outside. Here, the conductor 12 may include at least one of an antenna for communication between the electronic device and the external device, a metal case, and conductive ornaments.

In particular, the metal case may be provided so as to partially surround or partially surround the side of the housing of the portable electronic device 10. In addition, the metal case may be provided to surround a camera provided to be exposed to the outside on the front surface or the rear surface of the housing of the electronic device.

As described above, the electric shock protection element 100 can be disposed between the body-contactable conductor 12 of the portable electronic device 10 and the circuit portion 14 to protect the internal circuit from leakage current and static electricity Reference).

Such an anti-electrostatic device 100 may be suitably provided in accordance with the number of metal cases provided in the housing of the portable electronic device 10. [ However, when a plurality of metal cases are provided, the metal cases 12a, 12b, 12c, and 12d may be embedded in the housing of the portable electronic device 10 so that the anti-shock devices 100 are individually connected. have.

That is, when the conductor 12 such as the metal case surrounding the side of the housing of the portable electronic device 10 is composed of three parts as shown in FIG. 5A, each of the conductors 12a, 12b, 12c, and 12d All of which are connected to the anti-shock device 100, thereby protecting the circuit inside the portable electronic device 10 from leakage current and static electricity.

When the plurality of metal cases 12a, 12b, 12c and 12d are provided, the anti-shock device 100 may be provided in various ways according to the roles of the metal cases 12a, 12b, 12c and 12d. have.

For example, when the camera of the portable electronic device 10 is exposed to the outside, when the anti-electrostatic device 100 is applied to the conductor 12d surrounding the camera, the anti-electrostatic device 100 May be provided in a form that blocks the leakage current and protects the internal circuit from static electricity.

In addition, when the metal case 12b serves as a ground, the anti-shock device 100 may be connected to the metal case 12b to shield the leakage current and protect the internal circuit from static electricity .

Meanwhile, as shown in FIG. 5B, the electric shock protection device 100 may be disposed between the metal case 12 'and the circuit board 14'. At this time, since the electric shock protection element 100 is for passing static electricity without damaging itself, the circuit board 14 'may have a separate protection element 16 for bypassing the static electricity to the ground. Here, the protection element 16 may be a suppressor or a varistor.

6A and 6B, the electric shock protection device 100 may have a different function depending on the leakage current due to the external power source and the static electricity flowing from the conductor 12. [

6A, when the leakage current of the external power source flows into the conductor 12 through the circuit board of the circuit portion 14, for example, the ground, the electric shock protection element 100 is notified of the breakdown voltage (Vbr) is larger than the overvoltage due to the leakage current, it can be kept open. That is, since the total breakdown voltage Vbr of the electric shock protection device 100 is larger than the rated voltage of the external power supply of the portable electronic device, the electric shockproof protection device 100 maintains the open state without being electrically conducted, It is possible to prevent the leakage current from being transmitted. As a result, the electric shock protection device 100 can protect the user from electric shock by interrupting the leakage current to the external power source which flows from the ground of the circuit part 14. [

Further, as shown in FIG. 6B, when the static electricity flows from the outside through the conductor 12, the electric shock protection element 100 functions as an electrostatic protection element such as a varistor. That is, since the breakdown voltage Vbr of the varistor is smaller than the instantaneous voltage of the static electricity, the electric shock protection element 100 can be electrically conducted to pass the static electricity. As a result, since the first internal electrode 113 and the second internal electrode 114 are provided in the varistor material layer, the electric shock protection device 100 can be prevented from being damaged by the nonlinear voltage characteristic of the varistor material upon the introduction of static electricity from the conductor 12. [ The electrical resistance between the first internal electrode 113 and the second internal electrode 114 is lowered, so that the static electricity can be passed without being destroyed by insulation.

Here, the circuit unit 14 may have a separate protection element for bypassing the static electricity to the ground. As a result, the electric shock protection element 100 can pass the static electricity without being broken by the static electricity flowing from the electric conductor 12, thereby protecting the inner circuit of the following stage.

The electric shock protection device 100 includes a plurality of electric shock protection parts and a plurality of external electrodes, and may be, for example, a varistor.

The plurality of electric shock protection parts include a varistor material layer 110 and a plurality of internal electrodes 113 and 114, respectively, as shown in FIG.

At this time, the varistor material layer may include at least two layers of the first varistor material layer 111 and the second varistor material layer 112 alternately. Here, the first varistor material layer 111 and the second varistor material layer 112 may be any one of a semiconductive material containing at least one of ZnO, SrTiO3, BaTiO3, and SiC, or a Pr and Bi-based material have. In addition, it is preferable that the varistor material layer is set so that the particle size of the varistor material can satisfy the breakdown voltage (Vbr).

The internal electrodes include a plurality of first internal electrodes 113 spaced apart from the first varistor material layer 111 by a predetermined distance and a plurality of second internal electrodes 113 spaced apart from the second varistor material layer 112 by a predetermined distance 114).

Here, the breakdown voltage Vbr of the electric shock protection device 100 may be the sum of unit breakdown voltages formed between the first internal electrode 113 and the second internal electrode 114, which are closest to each other. That is, the breakdown voltage Vbr of the electric shock protection element 100 is determined by the unit breakdown voltage formed between the first internal electrode 113 and the second internal electrode 114, and the first internal electrode 113 and the number of the second internal electrodes 114, as shown in FIG.

At this time, the thicknesses of the first internal electrode 113 and the second internal electrode 114 may be 2-10 탆. If the thicknesses of the first internal electrode 113 and the second internal electrode 114 are less than 2 탆, they can not serve as internal electrodes. If the thickness of the first internal electrode 113 and the second internal electrode 114 exceeds 10 탆, , So that the thickness of the internal electrode or varistor material layer arranged in parallel increases, and the overall size of the electric shock protection element 100 increases, adversely affecting miniaturization.

Each of the first internal electrode 113 and the second internal electrode 114 may be arranged so that at least a part thereof is not overlapped. That is, each of the first internal electrode 113 and the second internal electrode 114 may be disposed so that at least a part of the first internal electrode 113 and the second internal electrode 114 overlap with each other or may be crossed with each other so as not to overlap with each other.

A plurality of electric shock protection parts having the above-described configuration are provided, and a plurality of electric current flow paths are formed.

The plurality of electric shock protection parts 110 include any one of the first electric shock protection part 110a and the second electric shock protection part 110b and the first electric shock protection part 110b, The electric shock protection portion 110a is laminated (see Fig. 2).

Here, the first and second electric shock protection parts 110a and 110b may include the first varistor material layer 111, the second varistor material layer 112, the first internal electrode 113, 2 internal electrodes 114, respectively.

More specifically, the first electric shock protection unit 110a includes a first varistor material layer 111, a second varistor material layer 112, a first inner electrode 113, and a second inner electrode 114, The first internal electrodes 113 are disposed at a predetermined distance from the first varistor material layer 111 and the second internal electrodes 114 are disposed on the second varistor material layer 112, As shown in FIG.

The second electric shock protection unit 110b includes a third varistor material layer 115, a fourth varistor material layer 116, a third internal electrode 117 and a fourth internal electrode 118, The electrodes 111 and 117 are disposed at a predetermined interval in the third varistor material layer 115 and the fourth internal electrode 118 is disposed in the fourth varistor material layer 116 at regular intervals Respectively.

At this time, the first internal electrode, the second internal electrode, the third internal electrode, or the fourth internal electrode are formed so that static electricity or leakage current does not leak to adjacent external electrodes of the internal electrodes, The interval is preferably set.

The spacing L1 between the first internal electrode 113a and the neighboring first internal electrode 113b may be set to be smaller than the distance L1 between the first internal electrode 113 and the second internal electrode 114. [ Is preferably formed to be larger than the shortest distance d1 or the shortest distance d2 between the neighboring second internal electrodes 114 (see FIG. 3).

The spacing L2 between the third internal electrode 117a and the neighboring third internal electrode 117b is set to be the shortest distance between the third internal electrode 117 and the fourth internal electrode 118 (d3) between the first inner electrode (117) and the adjacent third inner electrode (117) or between the adjacent third inner electrodes (117).

It is preferable that the distance between the second internal electrode 114 and the adjacent external electrode 130 is larger than the distance between the first internal electrode 113 and the fourth internal electrode 118, It is preferable that the distance from the external electrode 130 is larger than the distance between the third internal electrodes 117.

The distance d5 between the second internal electrode 114 of the first electric shock protection unit 110a and the third internal electrode 117 of the second electric shockproof protection unit 110b is set to be greater than the distance d5 between the first internal electrode 113 And the shortest distance d3 between the third inner electrode 117 and the fourth inner electrode 118. The shortest distance d1 between the third inner electrode 117 and the second inner electrode 114 and the shortest distance d3 between the third inner electrode 117 and the fourth inner electrode 118,

Specifically, a current flows from the first internal electrode to the second internal electrode through the varistor material layer, and flows from the third internal electrode to the fourth internal electrode.

The distance d5 between the second internal electrode 114 of the first electric shock protection unit 110a and the third internal electrode 117 of the second electric shock protection unit 110b is smaller than the distance d5 between the first internal electrode 113 And the shortest distance d3 between the third inner electrode 117 and the fourth inner electrode 118 is equal to or smaller than the shortest distance d1 between the first inner electrode 114 and the second inner electrode 114 and the shortest distance d3 between the third inner electrode 117 and the fourth inner electrode 118, The respective electric currents flowing to the first electric shock protection unit 110a and the second electric shock protection unit 110b may cross each other and flow.

That is, the current flowing to the first electric shock protection unit 110a flows to the second electric shock protection unit 110b or the electric current flowing to the second electric shock protection unit 110b may flow to the first electric shock protection unit 110a .

The distance d5 between the second internal electrode 114 of the first electric shock protection unit 110a and the third internal electrode 117 of the second electric shock protection unit 110b is smaller than the distance d5 between the first internal electrode 114 113 and the second inner electrode 114 and the shortest distance d3 between the third inner electrode 117 and the fourth inner electrode 118. [

At this time, the buffer layer 120 having a predetermined thickness may be disposed between the second electric shock protection unit 110b and the current transmitted from the metal case to the first electric shock protection unit 110b, The electric current can flow to the circuit portion 14 through the electric shock protection portion of at least one of the first portion 110a and the second electric shock protection portion 110b.

Here, the buffer layer 120 may be formed of the same material as the varistor material layer, or may be formed of a material capable of preventing a current from crossing between the first and second electric shock protection parts 110a and 110b Any material can be used.

The first and second electric shock protection parts 110a and 110b connect the metal and the circuit part through a plurality of adjacent external electrodes, respectively.

Specifically, the plurality of external electrodes include a first external electrode 131 and a second external electrode 132, and the first and second external electrodes 131 and 132 are connected to the outside of the electric shock protection unit 110 Respectively.

At this time, the first outer electrode 131 connects the first and third inner electrodes 113a and 117a of the pair of first and third inner electrodes 113 and 117 to the metal case.

Also, the second external electrode 132 connects the first and third internal electrodes 113b and 117b to the circuit portion.

Accordingly, a plurality of paths through which the static electricity flows into the metal case are formed, so that even if one path is broken, the static electricity flows through the other path.

The plurality of electric shock protection parts may be arranged in various ways in addition to the arrangement shown in FIGS. 1 and 3 as follows.

(Modified Example 1)

The first varistor material layer 111 in which the two first internal electrodes 113 are formed may be stacked under the second varistor material layer 112 in which one second internal electrode 114 is formed.

The third varistor material layer 115 on which the two third internal electrodes 117 are formed may be stacked on the bottom of the fourth varistor material layer 116 on which one fourth internal electrode 118 is formed. (See Fig. 4A).

(Modified example 2)

The plurality of first internal electrodes 113 and the plurality of second internal electrodes 114 may be connected in series in the first and second varistor material layers 111 and 112, 4 internal electrodes 118 may be provided in plural and connected in series in the third and fourth varistor material layers 115 and 116 (see FIG. 4B).

(Modification 3)

Three or more of the electric shock protection elements 110a, 110b, and 110c may be stacked up and down (see FIG. 4C).

(Variation 4)

The first and third external electrodes 131 and 133 may be provided on one side of the electric shock protection unit 110 to be connected to the metal case.

The first outer electrode 131 connects one of the plurality of first inner electrodes 113 to the metal case and the third outer electrode 133 connects the plurality of third inner electrodes 117 The internal electrode 117a may be connected to the metal case.

In this case, the second external electrode 132 is a common external electrode, and a current flowing through the first and third external electrodes 131 and 133 is applied to the first and second electric shock protection parts 110a and 110b, Flows through the second outer electrode 132 and flows to the circuit portion (see FIG. 4D).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: Electric shock protection element
110:
110a, 110b: first and second electric shock protection parts
111, 112, 115, 116: a varistor material layer
113, 114, 117, 118: internal electrodes
120: buffer layer
131, 132, 133: external electrodes

Claims (11)

An electric shock protection element disposed between a body contactable conductor of an electronic device and an internal circuit portion,
At least two varistor material layers stacked with a first varistor material layer and a second varistor material layer; a plurality of first internal electrodes spaced apart from the first varistor material layer at regular intervals; And an electric shock protection unit including a plurality of second internal electrodes spaced apart from each other,
The plurality of electric shock protection parts are laminated,
Wherein the plurality of electric shock protection parts are connected in parallel. The method according to claim 1,
Wherein the electric shock protection device passes the static electricity without being destroyed by insulation when the static electricity flows from the electric conductor and blocks the leakage current of the external electric power supplied from the ground of the circuit part.
Vbr> Vin
Here, Vbr is a breakdown voltage of the electric shock protection element,
Vin is the rated voltage of the external power supply of the electronic device. The method according to claim 1,
Wherein the rated voltage is a national standard rated voltage. The method according to claim 1,
Wherein the first internal electrode and the second internal electrode are disposed so that at least a part thereof overlaps each other. The method according to claim 1,
Wherein the first inner electrode and the second inner electrode are disposed so as not to overlap with each other. The method according to claim 1,
Wherein a buffer layer is disposed between any one of the plurality of electric shock protection parts and between the adjacent second electric shock protection parts. The method according to claim 6,
Wherein a distance between an inner electrode of the first electric shock protection unit disposed on the buffer layer and an inner electrode of the second electric shock protection unit disposed on the lower portion of the buffer layer is set to a shortest distance d1 between the first inner electrode and the second inner electrode , d2). The method according to claim 1,
And a plurality of external electrodes for connecting the first internal electrode and the second internal electrode to the conductor and the circuit portion on the outside of the electric shock protection portion. 9. The method of claim 8,
Wherein one of the plurality of external electrodes is a common external electrode connecting the plurality of electric shock protection elements to the circuit portion. The method according to claim 1,
Wherein the plurality of varistor material layers are any one of a semiconductive material containing at least one of ZnO, SrTiO3, BaTiO3, and SiC, or a Pr and Bi-based material. The method according to claim 1,
Wherein the thickness of the first and second internal electrodes is 2-10 占 퐉.

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