WO2017111450A1

WO2017111450A1 - Open-mode protection device and electronic device having same

Info

Publication number: WO2017111450A1
Application number: PCT/KR2016/014985
Authority: WO
Inventors: 이재욱; 최재우; 조현진; 문지우
Original assignee: 주식회사 아모텍
Priority date: 2015-12-22
Filing date: 2016-12-21
Publication date: 2017-06-29

Abstract

Provided are an open-mode protection device and an electronic device having the same. An open-mode protection device according to an embodiment of the present invention is connected in parallel to each of a constant current source and a load comprising an LED. The open-mode protection device comprises: a first external electrode connected to one side of the constant current source and one side of the load; a second external electrode connected to the other side of the constant current source, the other side of the load, and the ground; a protection unit for causing an overvoltage or an overcurrent flowing into the first external electrode to bypass to the ground through the second external electrode; and a current suppressing unit which is connected in series with the protection unit, detects a temperature or a current of the protection unit, and reduces the current of the protection unit as the temperature or the current increases.

Description

Open mode protection device and electronic device having same

The present invention relates to an open mode protection device and an electronic device having the same, and more particularly, to an open mode protection device and an electronic device having the same, which can suppress abnormal overheating of the protection device according to an open mode operation of a load. will be.

Recently, the use of LED as a lighting device has become common, and in particular, the use of LEDs is increasing rapidly in the fields of backlight of display devices, various lamps of automobiles, smart lighting using dimming, etc., for reasons of lighting efficiency and ease of control.

Such LED lighting has a constant current lighting circuit that provides a constant current to a load consisting of LEDs. In such a constant current system, in a steady state, a constant amount of current is provided from a constant current source so that the LED is turned on to have a constant voltage value. For example, if the constant current source supplies 400 mA of current and the load consists of 10 LEDs, it outputs a voltage of 25 to 30 V.

Here, a protection device is provided to protect a circuit when an electrostatic discharge (ESD), an electrical over stress (EOS), or a surge is introduced between the constant current source and the load. In this case, one side of the protection device is connected to the ground to bypass the introduced ESD, EOS or surge to the ground side.

In such a constant current electronic device, if the protection device does not sufficiently bypass ESD, EOS, or surge, one of the LEDs loaded by ESD (electrostatic), EOS, or surge is broken and the load is left open. It often happens. At this time, all of the current supplied from the constant current source flows to the protection element since the load is open. This provides a constant magnitude of current in the constant current source, resulting in a condition that the voltage rises to infinity. In other words, the voltage of the protection device is continuously increased until a constant amount of current provided from the constant current source flows.

At this time, a high voltage and a high current are continuously introduced into the protection device to increase the temperature of the protection device itself, and in severe cases, a fire may occur due to breakage or ignition of the protection device itself. In particular, if a material easily ignited, such as a white sheet of paper in which the LED is disposed in the TV backlight, is adjacent to the fire, it is very likely to occur.

Therefore, there is an urgent need to develop a technology capable of suppressing overheating of the protection device according to the open mode of the load along with the protection against ESD, EOS or surge against the LED load.

The present invention has been made in view of the above, and provides an open mode protection device capable of suppressing abnormal overheating of the protection device by a constant current source when the load is in the open mode, and an electronic device having the same. There is a purpose.

In addition, the present invention is divided into a current suppression function to provide an open mode protection device and an electronic device having the same that can simultaneously implement the function of suppressing abnormal overheating of the protection device according to the open mode operation of the load and high withstand voltage to withstand high pressure at the same time There is another purpose to provide.

In order to solve the above problems, the present invention provides an open mode protection device connected in parallel to a load consisting of a constant current source and an LED, respectively. The open mode protection device may include a first external electrode connected to one side of the constant current source and the load; A second external electrode connected to the other side of the constant current source and the load and the ground; A protection unit for bypassing an overvoltage or an overcurrent flowing into the first external electrode to the ground through the second external electrode; And a current suppressing unit connected to the protection unit in series and reducing the current of the protection unit as the temperature or current increases by sensing the temperature or current of the protection unit.

According to a preferred embodiment of the present invention, the body of the protection portion is made of a varistor material, the body of the current suppression portion may be made of PPTC material or PTC material.

In this case, each of the protection part and the current suppressing part may be connected to any one of the first external electrode and the second external electrode.

As an example, each of the protection unit and the current suppressing unit may be formed of a single body.

As another example, the protection unit may include a plurality of sheet layers, a first internal electrode and a second internal electrode spaced apart from each other by a predetermined distance, and a connection electrode connected to the second internal electrode, wherein the current suppressing unit is a single unit. It is made of a body, the connection electrode may be disposed in contact with a portion of the current suppressing portion.

In this case, the first internal electrode may be connected to any one of the first external electrode and the second external electrode.

As another example, the current suppressing part may be configured to be connected to each of the first external electrode and the second external electrode, and the protection part may be disposed between the two current suppressing parts.

In this case, the protection part may include a first internal electrode and a second internal electrode on both sides, and the first internal electrode and the second internal electrode may be disposed to contact a part of the current suppressing part.

As another example, the body of the open mode protection device may include a plurality of sheet layers, and the protection part may include a first internal electrode and a common electrode spaced apart from each other by a predetermined distance from the first internal electrode, and the current The suppression unit includes a second internal electrode spaced apart from the common electrode by a predetermined distance, and on both sides of the sheet layer constituting the current suppression unit, for blocking electrical connection with the first external electrode and the second external electrode. An insulating member may be provided.

In this case, each of the first internal electrode and the second internal electrode may be connected to any one of the first external electrode and the second external electrode.

In addition, the current suppressing unit may be any one of a bimetal, a fuse, a polymer positive temperature coefficient (PPTC) device, and a positive temperature coefficient (PTC) device.

The protection unit may be any one of a varistor, a suppressor, a gas discharge tube (GDT), and a diode.

On the other hand, the present invention is an open-mode protection device connected in parallel to a load consisting of a constant current source and LED, respectively, a current suppressing unit consisting of a pair of substrates disposed on the same plane spaced apart from each other at a predetermined interval; A protection unit configured to bypass both an overvoltage and an overcurrent by connecting both electrodes to electrodes on one side of each of the pair of current suppressing units; And a molding part formed to cover an upper side of the pair of current suppressing parts and the protection part. Here, the current suppressing unit decreases the current of the protecting unit as the temperature or current of the protecting unit increases.

According to a preferred embodiment of the present invention, the space portion between the pair of current suppressing portion may be filled with a molding member constituting the molding portion.

In addition, the electrodes on the other side of the pair of current suppressing units may form a pair of external electrodes.

On the other hand, the present invention is a constant current source; A load consisting of LEDs driven by the constant current source; A ground terminal connected to one side of the constant current source and the load; And an open mode protection device as described above connected in parallel to the constant current source and the load, respectively, one side of which is connected to the ground terminal.

According to a preferred embodiment of the present invention, the constant current source may be any one of a constant current driver and a constant current power source.

According to the present invention, by forming a current suppressing portion made of a PTC element or a PPTC element integrally with the protection unit, by sensing the overcurrent or abnormal temperature rise of the protection unit in accordance with the open mode operation of the load to reduce the current, thereby increasing the temperature or current It is possible to suppress the damage to the protection element itself due to abnormal overheating.

In addition, the present invention suppresses abnormal overheating of the protection element itself, thereby preventing damage to adjacent circuit components as well as preventing fire due to ignition of the protection element.

In addition, since the present invention includes the current suppressing unit and the protecting unit as a single body, since the internal electrode does not need to be provided, the production efficiency can be improved by a simple configuration, and the production can be performed at a low cost.

In addition, in the present invention, by arranging the protection portion between the two current suppression portion, the protection portion can be made thin and the operating voltage can be lowered, thereby improving the protection against overvoltage or overcurrent.

In addition, the present invention can implement a function of suppressing abnormal overheating of the protection element and high withstand voltage at the same time by separating and disposing the current suppression portion made of a PTC element or a PPTC element, thereby suppressing an increase in temperature or current of the protection element and thus an abnormality. While preventing the damage of the protection element itself due to overheating, it is not necessary to increase the thickness of the material in order to increase the internal pressure, it is possible to implement a thinner.

1 is a cross-sectional view of an example of an open mode protection device according to an embodiment of the present invention;

2 is an equivalent circuit diagram of the open mode protection device of FIG.

3 is a graph showing the temperature characteristic of the open mode protection device of FIG.

4 and 5 are cross-sectional views of another example of an open mode protection device according to an embodiment of the present invention, and an exploded perspective view showing a stacking relationship of a plurality of sheet layers in a protection unit;

6 and 7 are cross-sectional views and separate perspective views of still another example of the open mode protection device according to an embodiment of the present invention;

8 and 9 are cross-sectional views of still another example of an open mode protection device according to an embodiment of the present invention, and an exploded perspective view showing a stacking relationship between a plurality of sheet layers;

10 is a cross-sectional view of another example of an open mode protection device according to an embodiment of the present invention;

11 is a perspective view of the open mode protection device of FIG.

12 is an exploded perspective view showing a lamination relationship of the open mode protection device of FIG. 10;

FIG. 13 is an equivalent circuit diagram of the open mode protection device of FIG. 10;

14 is a schematic structural diagram of an electronic device having an open mode protection device according to an embodiment of the present invention;

FIG. 15 is a diagram for describing normal operation of a load in the electronic device of FIG. 14. FIG.

FIG. 16 is a diagram for describing an open mode operation of a load in the electronic device of FIG. 14.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

Open mode protection device 100 according to an embodiment of the present invention, as shown in Figure 1, the first external electrode 101, the second external electrode 102, the protection unit 110, and the current suppressing unit 120.

The open mode protection device 100 in the electronic device. It is connected in parallel to a load consisting of a constant current source and an LED, respectively, to protect the circuit including the constant current source and the load by bypassing the ground from ESD, EOS, or surge current flowing from the outside.

The first external electrode 101 is connected to one side of a constant current source and a load of the electronic device. That is, the first external electrode 101 may be connected to a point where one side of the constant current source and one side of the load are connected.

The second external electrode 102 is connected to the constant current source of the electronic device and the other side of the load. That is, the second external electrode 102 may be connected to a point where the other side of the constant current source and the other side of the load are connected. Here, the other side of the constant current source and the other side of the load are connected to ground, whereby the second external electrode 102 is also connected to ground.

The first external electrode 101 and the second external electrode 102 may be disposed on both sides of the open mode protection device 100, respectively.

The protection unit 110 bypasses the overvoltage or overcurrent flowing into the first external electrode 101 to the ground of the electronic device through the second external electrode 102.

The protection unit 110 may be made of a single body (110a), the body (110a) may be made of varistor material. As another example, the body 110a may be made of a body. Wherein the body comprises one or more of ZnO, BaTiO ₃ , and SrTiO ₃ , wherein Pr, Bi, Ni, Mn, Cr, Co, Sb, Nd, Si, Ca, La, Mg, Al, Ti Sn, Nb, and At least one of Y may be included as a dopant.

The protection unit 110 may function as a varistor that bypasses overvoltage or overcurrent to ground.

The current suppressing unit 120 is connected in series with the protection unit 110, and senses the temperature or current of the protection unit 110 and increases the current of the protection unit 110 as the temperature or current increases due to abnormal overheating or overcurrent. Decrease.

The current suppressing unit 120 may be formed of a single body 120a, and the body 120a may be made of a PPTC material or a PTC material. That is, the current suppressing unit 120 may be made of a PPCT device or a PTC device.

For example, in the case of the PPTC device, the current suppressing unit 120 may include a polymer in which the conductive filler is dispersed. That is, the body 120a of the current suppressing unit 120 may be made of a polymer. Here, the conductive filler may be made of a carbon black material.

As described above, in the open mode protection device 100, the protection unit 110 and the current suppression unit 120 having a single body are connected to each other at the connection portion 103 between the first external electrode 101 and the second external electrode 102. Since the surface is bonded and connected horizontally, it is not necessary to provide a separate internal electrode.

In more detail, since one side of the protection unit 110 is connected to the first external electrode 101 and the current suppressing unit 120 connected to the second external electrode 102 has a low resistance value at room temperature, the current The second external electrode 102 may function as the other electrode of the protection unit 110 through the suppressor 120. That is, in the protection unit 110, the first external electrode 101 and the second external electrode 102 may function as electrodes of the varistor.

As a result, since the internal electrode does not need to be provided, the structure is very simple, the production process is simplified, the production efficiency can be improved, and, moreover, the open mode protection device 100 can be produced at low cost.

Here, each of the protection unit 110 and the current suppressing unit 120 may be connected to any one of the first external electrode 101 and the second external electrode 102. For example, the protection unit 110 may be connected to the first external electrode 101, and the current suppression unit 120 may be connected to the second external electrode 102. As another example, the protection unit 110 may be connected to the second external electrode 102, and the current suppression unit 120 may be connected to the first external electrode 101.

As shown in FIG. 2, the open mode protection device 100 may be represented by an equivalent circuit in which a protection unit 110 such as a varistor and a current suppression unit 120 such as a PPTC device or a PTC device are connected in series.

That is, in the open mode protection device 100, each of the protection unit 110 and the current suppressing unit 120 is connected to one of the first external electrode 101 and the second external electrode 102, respectively, and the connection unit 103. By being connected to each other through), the protection unit 110 and the current suppressing unit 120 may be connected in series between the first external electrode 101 and the second external electrode 102.

In the open mode protection device 100 according to the embodiment of the present invention configured as described above, the current suppressing unit 120 has a low resistance value at a constant temperature of 80 ° C to 120 ° C as shown in FIG. 3 ((a ) Area). In this case, the open mode protection device 100 may function as a protection device such as a varistor to protect the circuit by bypassing EOS or surge flowing into the static electricity or the load to ground.

On the other hand, when the load consisting of LED is opened by the ESD, EOS or surge from the outside, the current and voltage flowing to the open mode protection device 100 continuously increases, the protection unit 110 is overheated. That is, when the load is opened because the power of the load is a constant current source, all currents of a constant magnitude provided from the constant current source flow to the open mode protection device 100. At this time, the actual load of the constant current source is the open mode protection device 100, and in this case, a constant magnitude of current flows from the constant current source to the open mode protection device 100, which is a condition that the voltage rises to infinity.

For example, when the load is in an open state, as the voltage across the open mode protection device 100 which is a substantial load rises to the supply power level (200 to 300V), the open mode protection device 100, in particular, the protection unit ( 120 is overheated.

At this time, when the open mode protection device 100 is overheated at a temperature of 150 ° C to 200 ° C, the open mode protection device 100 increases the amount of current flowing in the open mode protection device 100 due to a sudden increase in resistance of the current suppressing unit 120. By reducing the voltage, the voltage at both ends of the protection unit 110 can be reduced to reduce the temperature, so that heat generation can be suppressed (see (b) region). Accordingly, it is possible to prevent damage of the open mode protection device 100 due to overheating of the protection unit 110.

1 and 2, the protection unit 110 is a varistor and the current suppression unit 120 is illustrated and described as being a PPTC device or a PTC device, but is not limited thereto. The protection unit 110 and the current suppression unit 120 are described. ) May be in various forms.

For example, the protection unit 110 may be any one of a suppressor, a gas discharge tube (GDT), and a diode, but is not particularly limited thereto, and may include a device capable of bypassing overvoltage or overcurrent. have.

In addition, the current suppressing unit 120 may be a bimetal that completely blocks the current path to the protection unit 110 according to the temperature of the protection unit 110, or may be a fuse that is blocked according to the current of the protection unit 110. The protection unit 110 may include an element capable of blocking the current path to the protection unit 110 or reducing the current when the protection unit 110 is abnormally overheated or an overcurrent flows.

Hereinafter, various modifications of the open mode protection device 100 according to an embodiment of the present invention will be described with reference to FIGS. 4 to 13.

As shown in FIGS. 4 and 5, in the open mode protection device 100a, the protection unit 110 ′ may include

internal electrodes

112 and 114 and a connection electrode 103a.

That is, the protection unit 110 ′ may include a first internal electrode 112 and a second internal electrode 114 which are spaced apart from each other by a predetermined interval. To this end, the protection unit 110 ′ may be formed of a plurality of sheet layers 111.

Here, the first sheet layer 111a is disposed at the lowermost portion of the plurality of sheet layers 111, and the first inner electrode 112 connected to the first outer electrode 101 or the second outer electrode 102 on an upper surface thereof. ) May be provided. The second sheet layer 111b may be disposed on the upper side of the first sheet layer 111a and the second internal electrode 114 may be provided on the upper surface thereof. The third sheet layer 111c may be disposed above the second sheet layer 111b and disposed on top of the plurality of sheet layers 111. In this case, each of the

sheet layers

111a, 111b, and 111c is illustrated and described as having the same thickness in the drawings, but is not limited thereto.

Each of the plurality of

sheet layers

111a, 111b, and 111c may be made of a varistor material. Through this, the protection unit 110 ′ may function as a varistor having the first internal electrode 112 and the second internal electrode 114.

In this case, the protection unit 110 ′ and the current suppressing unit 120 may be provided with a connection electrode 103a connected to the second internal electrode 114 at the bonding surface. That is, the connection electrode 103a may be disposed to contact a part of the current suppressing unit 120.

The connection electrode 103a may function as one electrode of the current suppression unit 120 and may have a function of connecting the protection unit 110 ′ and the current suppression unit 120. That is, in the current suppressing unit 120, the connecting electrode 103a and the second external electrode 102 may be both end electrodes.

Accordingly, the protection unit 110 ′ may easily adjust the operating voltage by using the distance between the first internal electrode 112 and the second internal electrode 114 and the characteristics of the electrode. Furthermore, since the protection unit 110 ′ forms a lower operating voltage than the protection unit 110 of FIG. 1, the protection unit 110 ′ may improve protection against overvoltage or overcurrent.

Since the configuration of the open mode protection device 100a is the same as that of the open mode protection device 100 of FIG. 1 except for the internal electrode and the connection electrode of the protection unit, a detailed description thereof will be omitted.

As shown in FIGS. 6 and 7, the open mode protection device 100b includes a protection unit 110 disposed between two current suppressing units 120-1 and 120-2 and the current suppressing units 120-1 and 120-2. ").

That is, the two current suppressing units 120-1 and 210-2 are connected to any one of the first external electrode 101 and the second external electrode 102, and the protection unit 110 ″ is connected to the current suppressing unit 120-. 1,120-2) to face each other.

The protection unit 110 ″ may include first internal electrodes 112 ′ and second internal electrodes 114 ′ on both sides of the protection unit 110 ″. In this case, the first internal electrodes 112 ′ and the second internal electrodes may be provided. 114 ′ may be disposed to contact a portion of the current suppressing unit 120.

The first internal electrode 112 ′ and the second internal electrode 114 ′ may function as one electrode of each of the current suppressing units 120-1 and 120-2. That is, in the current suppression unit 120-1, the first external electrode 101 and the first internal electrode 112 ′ form electrodes at both ends, and the current suppression unit 120-2 is the second internal electrode 114 ′. And the second external electrode 102 may form both electrodes.

In this case, the protection unit 110 ″ and the current suppressing units 120-1 and 120-2 may be formed of

single bodies

110a and 120a.

As described above, since the protection unit 110 ″ is disposed between the current suppressing units 120-1 and 120-2, the first external electrode 101 and the second external electrode are provided by the current suppressing units 120-1 and 120-2. Since it is sufficiently spaced apart from the 102, the influence of the first external electrode 101 and the second external electrode 102 can be eliminated, and thus, the thickness of the body 110a of the protective part 110 ″ can be achieved. .

Through this, in the open mode protection device 100b, the protection unit 110 ″ may have a low operating voltage, thereby further improving the protection against overvoltage or overcurrent.

8 and 9, the open mode protection device 100c may be formed of a plurality of sheet layers 111 ′. That is, in the open mode protection device 100c, the protection unit 110 ′ ′ and the current suppression unit 120 ′ may be vertically connected.

Here, the first sheet layer 111a may be provided with a first inner electrode 112 ″ connected to the first outer electrode 101 or the second outer electrode 102 on an upper surface thereof. 120a may be disposed under the first sheet layer 111a, and a common electrode 114 ″ may be provided on an upper surface thereof. The third sheet layer 111c may be disposed above the first sheet layer 111a and disposed on the top of the plurality of sheet layers 111 ′. The fourth sheet layer 111d is disposed below the second sheet layer 120a, and the second inner electrode 122 connected to the first outer electrode 101 or the second outer electrode 102 is disposed on an upper surface thereof. It may be provided. In this case, each of the

sheet layers

111a, 111b, 111c, and 111d is illustrated and described as having the same thickness in the drawings, but is not limited thereto.

The plurality of sheet layers 111 ′ may be made of different materials.

For example, the first sheet layer 111 a disposed between the first internal electrode 112 ″ and the common electrode 114 ″ is made of a varistor material, and the common electrode 114 ″ and the second internal electrode 122 are formed. The second sheet layer 120a disposed therebetween may be made of a PPTC material or a PTC material, in which the third sheet layer 111c and the fourth sheet layer 111d are the same as the first sheet layer 111a. It may consist of a varistor material or of a ceramic material.

At this time, since the second sheet layer 120a made of PPTC material or PTC material has low resistance at room temperature, electrical connection to the first external electrode 101 and the second external electrode 102 should be blocked. To this end, the second sheet layer 120a may be provided with an insulating member 124 at both sides connected to the first external electrode 101 and the second external electrode 102.

The protection unit 110 "'may include a first internal electrode 112", a common electrode 114 ", and a first sheet layer 111a. The protection unit 110"' may include a first internal electrode. The common electrode 114 ″ may be spaced apart from the electrode 112 ″ and the first internal electrode 112 ″ at a predetermined distance.

In addition, the current suppression unit 120 ′ may include a common electrode 114 ″, a second internal electrode 122, and a second sheet layer 120a. Here, the current suppression unit 120 ′ may be a common electrode. And a second internal electrode 122 spaced apart from the common electrode 114 " by a predetermined distance.

In this way, the common electrode 114 "functions as one electrode of each of the protection unit 110" 'and the current suppressing unit 120', and thereby the protection unit 110 "'and the current suppressing unit 120'. May be connected in series between the first external electrode 101 and the second external electrode 102.

Here, the protection unit 110 ′ ′ is illustrated and described as being stacked on top of the current suppressing unit 120 ′, but is not limited thereto. The protection unit 110 ′ ′ may be stacked on any one of the upper and lower portions of the current suppressing unit 120 ′. Can be.

10 to 13, in the open mode protection device 200, two current suppressing units 210 may be disposed on the same plane. The open mode protection device 200 may include a current suppressing unit 210, a protection unit 220, and a molding unit 230.

The current suppressing unit 210 is composed of a pair of substrates. Here, the current suppressing unit 210 is a pair is arranged on the same plane, spaced apart from each other at a predetermined interval. The pair of current suppressing units 210 may have

electrodes

212 and 114 formed on both surfaces thereof.

In this case, the electrodes 212 formed on one side of the pair of current suppressing units 210 may be connected to the protection unit 220, and the electrodes 214 formed on the other side may form a pair of external electrodes. . For example, each of the top electrodes 212 of the pair of current suppressing units 210 is an internal electrode, and is connected in series with the protection unit 220, and each of the bottom electrodes 214 is an external electrode to a constant current source and a load. Each is connected.

That is, one external electrode 214 may be connected to a point at which one side of the constant current source is connected to one side of the load, and the other external electrode 214 may be connected to a point at which the other side of the constant current source is connected to the other side of the load. . The external electrodes 214 may be disposed on both sides of the bottom surface of the open mode protection device 200, respectively. At this time, one of the points where the constant current source and the load are connected may be connected to the ground.

Herein, the current suppressing unit 210 increases withstand voltage according to its thickness. That is, in the current suppressing unit 210, the breakdown voltage increases as the distance between the inner electrode 212 on the upper surface of the base layer 210a and the outer electrode 214 on the lower surface of the base layer 210a increases. Therefore, in order to apply the current suppressing unit 210 to the backlight BLU of a display device such as a TV requiring a high breakdown voltage, the distance between the inner electrode 212 and the outer electrode 214 should be large, but this is open. This results in an increase in the overall thickness of the mode protection element 200.

Therefore, in the open mode protection device 200 according to the embodiment of the present invention, the current suppressing portion 210 is disposed on the same plane to be thinner without increasing the thickness. That is, since the pair of current suppressing portions 210 are arranged on the same plane, the increase in thickness is suppressed, and at the same time, the two currents are arranged in series on both sides of the protection portion 220. Since the suppressing portions 210 are arranged in series, it is possible to increase the internal pressure as a result.

The current suppressing unit 210 is electrically connected in series with both ends of the protection unit 220, and senses the temperature or current of the protection unit 220. At this time, when the load is opened due to damage of any one of the plurality of LEDs to be protected, all of the current provided from the constant current source flows to the protection unit 220 and the current increases as the temperature or current of the protection unit 220 increases. The suppressor 210 reduces the current of the protector 220.

In this case, the current suppressing unit 210 may be any one of a PPTC device and a PTC device to reduce the current as the temperature of the protection unit 220 rises. That is, the current suppressing unit 210 may be made of a PTC material or a PPTC material.

Here, the internal electrode 212 and the external electrode 214 may be Ni or Cu plating treatment on the base layer 210a. At this time, in order to improve the adhesion of the Cu surface it may be plated with any one of Fe, Ni, Cr and Ag. In addition, the external electrode 214 used as the pad may be further plated by any one of Ag, Pt, Sn, Cr, Al, Zn, and Au in order to improve lead splintering.

The protection unit 220 is connected to both

electrodes

222 and 124 on the internal electrodes 212 formed on the upper surfaces of the pair of current suppressing units 210, respectively, thereby bypassing the overvoltage or the overcurrent. That is, the protection unit 220 may pass an overvoltage or overcurrent caused by ESD, EOS, or surge introduced through one external electrode 214 to another external electrode 214 connected to the ground.

Here, the protection unit 220 may be a single component manufactured. For example, the protection unit 220 may be any one of a varistor, a suppressor, a GDT, and a diode, but is not particularly limited thereto, and may include an element capable of bypassing an overvoltage or an overcurrent.

Through this, by mounting an existing single component to a pair of current suppressing unit 210, not only can the manufacturing process be simplified, but also the current suppressing unit 210 can be easily designed and arranged in accordance with the existing product. have.

The protection unit 220 may be stacked on top of the pair of current suppressing units 210 (see FIG. 12). In this case, the protection unit 220 may be connected on the internal electrodes 212 of the pair of current suppressing units 210 through solder. That is, the protection unit 220 may be mounted on the internal electrodes 212 of the pair of current suppressing units 210 through an SMT soldering process.

In addition, the protection unit 220 bypasses the constant current of the constant current source to the ground through the external electrode 214 during the open mode operation of the load consisting of the LED.

The protection unit 220 may include a varistor material layer. That is, the body 220a of the protection unit 220 may be made of a varistor material.

As another example, the body 220a may be made of a body. Wherein the body comprises one or more of ZnO, BaTiO ₃ , and SrTiO ₃ , wherein Pr, Bi, Ni, Mn, Cr, Co, Sb, Nd, Si, Ca, La, Mg, Al, Ti Sn, Nb, and At least one of Y may be included as a dopant.

The molding unit 230 protects the pair of current suppressing unit 210 and the protecting unit 220, and covers the upper side and the protecting unit 220 of the pair of current suppressing unit 210 to package into a single device. It is formed to.

The molding part 230 may be formed of a molding member made of epoxy. In this case, the molding member may be filled not only on the upper side of the pair of current suppressing portions 210 but also in the space portion 202 therebetween.

That is, the space 202 between the pair of current suppressing portions 210 formed as the pair of current suppressing portions 210 are spaced apart may be filled with a molding member constituting the molding portion 230. In this case, the space part 202 may be filled by the molding member during molding to surround the outside of the open mode protection device 200 (see FIG. 11).

Through this, the strength between the pair of current suppressing units 210 spaced apart from each other may be compensated. That is, since the pair of current suppressing portions 210 are spaced apart from each other, the bonding strength may be weakened between the current suppressing portions 210 or between the protection portions 220, thereby molding the space portion 202. Bonding strength can be improved by filling with a member.

In addition, by preventing the exposure of the protection unit 220 between the pair of current suppressing unit 210, it is possible to safely protect the protection unit 220 from the external force.

On the other hand, since the molding part 230 is formed to cover the upper portion of the pair of current suppressing portion 210, it is shown and described that the side of the pair of current suppressing portion 210 is exposed, but is not limited thereto. It may be formed to cover all sides of the current suppressing unit 210.

In this case, the external electrode 214 formed on the bottom surface of the current suppressing unit 210 may be formed to protrude further to the outside than the side surface.

As another example, the molding unit 230 has a side surface covering the current suppressing unit 210, but does not cover the lower surface of the current suppressing unit 210, and the upper side of the external electrode 214 to expose the external electrode 214. It can be formed to cover only.

This allows the manufacturing process to maintain and manage low positional and cutting precision. No additional effort is needed to improve precision, which can reduce manufacturing costs.

As shown in FIG. 13, the open mode protection device 200 may be represented by an equivalent circuit in which a protection unit B such as a varistor and a current suppressing unit P such as a PPTC device or a PTC device are connected in series. In this case, the current suppressing unit P may be dividedly arranged at both ends of the protection unit B.

That is, in the open mode protection device 200, one end of a pair of current suppressing units P is connected to a pair of external terminals, respectively, and the other end of the pair of current suppressing units P of the protection unit B is provided. By connecting both ends, the pair of current suppressing units P and one protection unit P may be connected in series with respect to the external terminals.

The open

mode protection devices

100, 100a, 100c, and 200 according to the embodiment of the present invention may be used in an electronic device having a load including a constant current source and an LED.

As shown in FIG. 14, the electronic device 1 may include a constant current source 10, an LED load 12, a ground terminal, and an open mode protection device 100.

Here, the electronic device 1 is a device having an LED as a load, and may be any one of a backlight (BLU) of a display device such as a TV, various lamps of a vehicle, and smart lighting using dimming.

The constant current source 10 may supply a constant current to the LED load 12. The constant current source 10 may be any one of a constant current power supply and a constant current driver. That is, the constant current source 10 is not limited to a particular form, and may be a source for supplying current in a constant current manner, for example, a power supply for supplying power to the electronic device 1 or an LED load 12. It may be a driving unit for driving.

LED load 12 may be composed of a plurality of LEDs. Here, the LED load 12 may be connected in series with a plurality of LEDs, but is not limited thereto. For example, the LED load 12 may be a plurality of LEDs are connected in series, a plurality of LEDs in series may be connected in parallel, or a plurality of LEDs may be connected in parallel, a plurality of LEDs in parallel may be connected in series. .

The LED load 12 may have a constant voltage value while the LED is turned on to supply a predetermined amount of current from the constant current source 10. For example, when the constant current source 10 supplies a current of 400 mA and the LED load 12 consists of ten LEDs, a voltage of approximately 25 to 30 V may be output at both ends of the load.

Here, one side of the constant current source 10 and the LED load 12 is connected to the ground terminal. That is, the cathode side of the constant current source 10 and the load 12 may be connected to the ground terminal. The ground terminal may be connected to a common ground formed on the circuit board of the electronic device 1.

The open mode protection device 100 may be connected in parallel to the constant current source 10 and the LED load 12, respectively. That is, one side of the open mode protection device 100 may be connected to one side of the constant current source 10 and the LED load 12, and the other side thereof may be connected to the other side of the constant current source 10 and the LED load 12. . In this case, one side of the open mode protection device 100 may be connected to the ground terminal.

As such, when the LED load 12 is in a normal operation state and the ESD, EOS, or surge flows into the LED load 12 from the outside, the electronic device 1 may have an open mode protection device ( The current (i _ESD ) corresponding to ESD, EOS, or surge flows to 100 and consequently bypasses the ground terminal, thereby protecting the LED load 12 from ESD, EOS, or surge.

That is, the open mode protection device 100 functions as a protection device against ESD, EOS or surge such as a varistor by the protection part since the resistance of the current suppression part such as a PPTC device or a PTC device is very small.

On the other hand, if the protection unit does not have sufficient protection against ESD, EOS or surge introduced from the outside, when some of the LED load 12 is damaged by ESD, EOS or surge, the LED load 12 is open Often happens.

At this time, the current (i _open) of the constant current source 10 as shown in Figure 16 to flow both in the open mode, the protection element 100.

Accordingly, since the constant current source 10 continuously supplies a constant current, the voltage also increases greatly while the current flowing in the open mode protection device 100 increases. As a result, the protection unit of the open mode protection device 100 gradually increases in temperature due to overcurrent and overvoltage.

At this time, when the temperature of the protection portion rises above a certain temperature, the resistance value of the current suppressing portion increases greatly, thereby reducing the current flowing through the protection portion, thereby suppressing the temperature rise of the protection portion.

Accordingly, by suppressing abnormal overheating of the open mode protection device 100, in addition to preventing damage to circuit components adjacent to the open mode protection device 100, the adjacent parts are made of a flammable material. When white sheet paper is disposed in front of the LED to improve the efficiency of the light emitted from the fire, it is possible to prevent the fire due to the ignition of the protection element.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments set forth herein, and those skilled in the art who understand the spirit of the present invention, within the scope of the same idea, the addition of components Other embodiments may be easily proposed by changing, deleting, adding, and the like, but this will also fall within the spirit of the present invention.

Claims

An open-mode protection device connected in parallel to a load consisting of a constant current source and an LED,

A first external electrode connected to one side of the constant current source and the load;

A second external electrode connected to the other side of the constant current source and the load and the ground;

A protection unit for bypassing an overvoltage or an overcurrent flowing into the first external electrode to the ground through the second external electrode; And

And a current suppressing unit connected in series with the protection unit and sensing the temperature or current of the protection unit to reduce the current of the protection unit as the temperature or current increases.
The method of claim 1,

The body of the protector is made of varistor material,

The body of the current suppressing unit is an open mode protection device made of a PPTC material or a PTC material.
The method of claim 2,

Each of the protection part and the current suppressing part is connected to any one of the first external electrode and the second external electrode.
The method of claim 3,

Each of the protection unit and the current suppressing unit is an open mode protection device consisting of a single body.
The method of claim 3,

The protection part includes a plurality of sheet layers, a first internal electrode and a second internal electrode spaced apart from each other by a predetermined interval, and a connection electrode connected to the second internal electrode.

The current suppressing unit is made of a single body,

The connection electrode is an open mode protection device arranged to contact a portion of the current suppressing portion.
The method of claim 5,

The first internal electrode is an open mode protection device connected to any one of the first external electrode and the second external electrode.
The method of claim 2,

The current suppressing unit is composed of two connected to each of the first external electrode and the second external electrode,

And the protection unit is disposed between the two current suppressing units.
The method of claim 7, wherein

The protection part has a first internal electrode and a second internal electrode on both sides,

And the first internal electrode and the second internal electrode are in contact with a part of the current suppressing part.
The method of claim 3,

The body of the open mode protection device is made of a plurality of sheet layers,

The protection part includes a first internal electrode and a common electrode disposed to face each other at a predetermined distance from the first internal electrode,

The current suppressing unit includes a second internal electrode spaced apart from the common electrode by a predetermined distance,

And an insulating member on both sides of the sheet layer constituting the current suppressing portion to block electrical connection between the first external electrode and the second external electrode.
The method of claim 9,

Each of the first internal electrode and the second internal electrode is connected to any one of the first external electrode and the second external electrode.
The method of claim 1,

The current suppressing unit is any one of a bimetal, a fuse, a polymer positive temperature coefficient (PPTC) device, and a positive temperature coefficient (PTC) device.
The method of claim 1,

The protection unit is any one of a varistor, a suppressor, a gas discharge tube (GDT) and a diode.
An open-mode protection device connected in parallel to a load consisting of a constant current source and an LED,

A current suppressing unit including a pair of substrates spaced from each other at a predetermined interval and disposed on the same plane;

A protection unit configured to bypass both an overvoltage and an overcurrent by connecting both electrodes to electrodes on one side of each of the pair of current suppressing units; And

A molding part formed to cover the upper side of the pair of current suppressing parts and the protection part,

The current suppressing unit is an open mode protection device for reducing the current of the protection unit as the temperature or current of the protection unit increases.
The method of claim 13,

The space portion between the pair of current suppressing portion is filled with a molding member forming the molding portion protection device.
The method of claim 13,

The electrode of the other side of the pair of current suppressing portion is an open mode protection device that forms a pair of external electrodes.
Constant current source;

A load consisting of LEDs driven by the constant current source;

A ground terminal connected to one side of the constant current source and the load; And

The open mode protection device according to any one of claims 1 to 15, which is connected in parallel to the constant current source and the load, respectively, and one side is connected to the ground terminal.
The method of claim 16,

The constant current source is any one of a constant current driver and a constant current power supply.