KR20180049617A - Protection device for open mode and electric apparatus with the same - Google Patents

Abstract

The present invention provides an open mode protective device which can simultaneously realize a suppression function of abnormal overheating of the protective device due to an open mode operation of a load and high withstand voltage to withstand even in high voltage, and an electronic device having the same. According to an embodiment of the present invention, the open mode protective device which is individually connected in parallel to a constant current source and the load composed of an LED comprises: a current suppression part composed of a pair of substrates which are separated from each other at a constant interval and are located on the same plane; a protective part to which both end electrodes are individually connected to electrodes of one side surfaces of each of the pair of current suppression parts, and which bypasses overvoltage or overcurrent; and a molding part formed to cover the upper side of the pair of current suppression parts and the protective part. The current suppression part reduces current of the protective part as the temperature or the current of the protective part increases.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an open-mode protection device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open-mode protection device and an electronic device having the same. More particularly, the present invention relates to an open-mode protection device that can simultaneously realize a function of suppressing abnormal overheating of a protection device and a high withstand voltage.

BACKGROUND ART [0002] Recently, lighting devices using LEDs that have high power efficiency and are easy to control have become popular. Particularly, the use thereof is increasing in the fields of backlight of a display device, various lamps of an automobile, and smart lighting using dimming.

Such an LED illumination has a constant current type lighting circuit for providing a constant current to a load made of LED. Here, a protective device is provided to protect the circuit when electrostatic discharge (ESD), electrical over stress (EOS), or surge flows between the constant current source and the load.

In such a constant current type electronic device, when any one of the LEDs is broken due to an electric shock and the load is opened, all the current of the constant current source flows to the protection element. At this time, If it is excessive, it may ignite and cause fire.

Therefore, there is an urgent need to develop a technology capable of preventing ESD, EOS, or surge from being overheated by an open mode of the load, as well as protecting the LED load from overheating.

In addition, such a protection device requires various internal pressure depending on the application to which it is applied, and in particular, it is required to develop a protection device having a high withstand voltage.

KR 1005199 B (December 24, 2010 Enrollment)

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide an open mode capable of simultaneously suppressing abnormal overheating of a protection element according to an open mode operation of a load, And an electronic device having the protection device.

In order to solve the above-described problems, the present invention provides an open mode protection device connected in parallel with a load made up of a constant current source and an LED. Wherein the open mode protection device comprises a current suppressing part including a pair of substrates spaced apart from each other at a predetermined interval and disposed on the same plane; Both ends of which are connected to electrodes on one side of each of the pair of current suppressing portions to bypass an overvoltage or an overcurrent; And a molding part formed to cover the upper side of the pair of current suppressing parts and the protection part. Here, the current suppression unit reduces the current of the protection unit as the temperature or current of the protection unit increases.

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

At this time, the molding member may be made of epoxy.

In addition, electrodes may be formed on both surfaces of the pair of current suppressing portions.

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

At this time, one of the pair of external electrodes may be connected to one side of the constant current source and the load, and the other may be connected to the other side of the constant current source and the load.

In addition, the current suppressing portion may be formed of a PTC (positive temperature coefficient) material or a PPTC (polymeric positive temperature coefficient) material.

The protection unit may be a varistor, a suppressor, a gas discharge tube (GDT), or a diode.

Further, the protective portion may be stacked on top of the pair of current suppressing portions.

At this time, the protector may be connected to the pair of current suppressing parts through the solder.

In addition, the pair of current suppressing portions may be formed of a polymer layer in which conductive fillers are dispersed.

At this time, the conductive filler may be made of a carbon black material.

On the other hand, the present invention relates to a constant current source; A load consisting of an LED driven by the constant current source; A ground terminal to which the constant current source and one side of the load are connected; And an open mode protection element connected in parallel to the constant current source and the load, respectively, and having one side 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 driving unit and a constant current power source.

Meanwhile, the present invention provides an open mode protection device connected in parallel to a load made up of a constant current source and an LED. Wherein the open mode protection device comprises: a pair of PPTC substrates spaced apart from each other at regular intervals and disposed on the same plane; A varistor in which both electrodes are connected to electrodes on one side of each of the pair of PPTC boards; A first external electrode formed on the other surface of any one of the pair of PPTC substrates and connected to one side of the constant current source and the load; A second external electrode formed on the other surface of the other of the pair of PPTC substrates and connected to the other of the constant current source and the load; And a molding part formed on the upper side of the pair of PPTC boards and covering the varistor and filling a space between the pair of PPTC boards.

According to the present invention, since the current restraining part composed of the PTC element or the PPTC element is separately disposed, it is possible to simultaneously realize the function of suppressing the abnormal overheating of the protection element and the high withstand voltage, It is not necessary to increase the thickness of the material in order to increase the breakdown voltage while preventing breakage of the protection device itself due to overheating, thereby realizing thinning.

Further, the present invention suppresses abnormal overheating of the protection device itself, thereby preventing damage to adjacent circuit components and preventing a fire due to ignition of the protection device.

1 is a cross-sectional view of an open mode protection device according to an embodiment of the present invention,
FIG. 2 is a perspective view of the open mode protection device of FIG. 1,
FIG. 3 is an exploded view showing a stacking relationship of the open mode protection element of FIG. 1,
FIG. 4 is an equivalent circuit diagram of the open mode protection device of FIG. 1,
FIG. 5 is a graph showing temperature characteristics of the open mode protection device of FIG. 1,
6 is a schematic configuration diagram of an electronic device having an open mode protection device according to an embodiment of the present invention;
FIG. 7 is a diagram for explaining the normal operation of the load in the electronic device of FIG. 6,
8 is a diagram for explaining the open mode operation of the load in the electronic device of Fig.

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 reference numerals are assigned to the same or similar components throughout the specification.

The open mode protection device 100 according to an embodiment of the present invention includes a current suppressing part 110, a protection part 120 and a molding part 130, as shown in FIGS.

The open-mode protection device 100 protects the circuit including the constant current source and the load by bypassing the ESD, EOS, or surge current flowing from the outside to the ground by being connected in parallel with the load made up of the constant current source and the LED.

The current suppressing portion 110 is formed of a pair of substrates. Here, the pair of current suppressing portions 110 are arranged on the same plane, and are spaced apart from each other at regular intervals. The pair of current suppressing portions 110 may have electrodes 112 and 114 on both sides thereof.

At this time, the electrode 112 formed on one side of the pair of current suppressing portions 110 is connected to the protection portion 120, and the electrode 114 formed on the other side can form a pair of external electrodes . Each of the upper electrodes 112 of the pair of current suppressing portions 110 is an internal electrode connected in series with the protection portion 120 and each of the lower electrodes 114 is connected to the constant current source and the load Respectively.

That is, one of the external electrodes 114 is connected to one end of the constant current source and one end of the load, and the other external electrode 114 can be connected to the other end of the constant current source and the other end of the load . The external electrodes 114 may be disposed on both sides of the lower surface of the open mode protection element 100. At this time, one of the points where the constant current source and the load are connected can be connected to the ground.

Here, the current suppressing portion 110 increases the internal pressure in accordance with the thickness thereof. That is, as the distance between the internal electrode 112 on the upper surface of the base layer 110a and the external electrode 114 on the lower surface of the base layer 110a increases, the current suppressing portion 110 increases the withstand voltage. Therefore, in order to apply to the backlight (BLU) of a display device such as a TV or the like which requires a high withstand voltage, the current suppressing part 110 must have a large gap between the internal electrode 112 and the external electrode 114, Resulting in an increase in the overall thickness of the mode protection element 100.

Therefore, in order to realize thinning without increasing the thickness of the open mode protection device 100 according to the embodiment of the present invention, the current suppressing portions 110 are disposed on the same plane. That is, since the pair of current suppressing portions 110 are disposed on the same plane, the increase in thickness is suppressed, and since the pair of current suppressing portions 110 are arranged electrically in series on both sides around the protection portion 120, Since the suppressing portions 110 are arranged in series, the breakdown voltage can be increased as a result.

The current suppressing unit 110 is electrically connected to both ends of the protection unit 120 at both ends thereof, and senses a temperature or a current of the protection unit 120. At this time, when the load is opened by the breakage of any one of the plurality of LEDs to be protected, all the currents supplied from the constant current source flows to the protection unit 120, The suppression unit 110 reduces the current of the protection unit 120. [

At this time, the current restrainer 110 may be any one of a polymeric positive temperature coefficient (PPTC) device and a positive temperature coefficient (PTC) device that reduces the current according to the temperature rise of the protection unit 120. That is, the current suppressing portion 110 may be made of a PTC material or a PPTC material.

For example, in the case of a PPTC device, the current suppressing portion 110 may include a polymer layer in which a conductive filler is dispersed. That is, the current suppressing portion 110 may be formed of the polymer layer of the base layer 110a. At this time, the conductive filler may be made of a carbon black material.

Here, the internal electrode 112 and the external electrode 114 may be Ni or Cu-plated on the base layer 110a. At this time, plating can be performed by any one of Fe, Ni, Cr and Ag in order to improve the adhesion of the Cu surface. In addition, the external electrode 114 used as a pad may be further plated by any one of Ag, Pt, Sn, Cr, Al, Zn, and Au to improve pinting resistance.

The protection unit 120 is connected to the internal electrodes 112 formed on the upper surface of each of the pair of current suppressing units 110 so that both end electrodes 122 and 124 are connected to bypass the overvoltage or overcurrent. That is, the protection unit 120 may pass an overvoltage or an overcurrent due to ESD, EOS, or surge introduced through one external electrode 114 to another external electrode 114 connected to the ground.

Here, the protection unit 120 may be a single unit manufactured in advance. For example, the protection unit 120 may be any one of a varistor, a suppressor, a gas discharge tube (GDT), and a diode. However, the protection unit 120 is not limited to this, Device.

Thus, by mounting the existing single component on the pair of current suppressing portions 110, not only the manufacturing process can be simplified, but also the current suppressing portion 110 can be easily designed and arranged according to the existing product have.

The protection portion 120 may be stacked on top of the pair of current suppressing portions 110 (see FIG. 3). At this time, the protective portion 120 may be connected to the internal electrodes 112 of the pair of current suppressing portions 110 through the solder. That is, the protection unit 120 may be mounted on the internal electrodes 112 of the pair of current suppressing units 110 through the SMT soldering process.

In addition, the protection unit 120 bypasses the constant current of the constant current source to the ground through the external electrode 114 in the open mode operation of the load made of the LED.

The protection portion 120 may include a varistor material layer. That is, the body 120a of the protection unit 120 may be made of a varistor material.

As another example, the body 120a may be made of a body. Wherein the body comprises at least one of ZnO, BaTiO ₃ , and SrTiO ₃ and at least one of Pr, Bi, Ni, Mn, Cr, Co, Sb, Nd, Si, Ca, La, Mg, Y may be contained as a dopant.

The molding part 130 covers the upper side of the pair of current suppressing parts 110 and the protective part 120 so as to protect the pair of current suppressing part 110 and the protecting part 120, .

The molding part 130 may be formed of a molding member made of epoxy. At this time, the molding member can be filled not only on the upper side of the pair of current suppressing portions 110 but also in the space portion 102 therebetween.

That is, the space portion 102 between the pair of current suppressing portions 110 formed as the pair of current suppressing portions 110 are spaced apart can be filled with the molding member constituting the molding portion 130. At this time, the space portion 102 may be filled with a molding member when molding to surround the outside of the open mode protection element 100 (see FIG. 2).

This makes it possible to compensate for the strength between a pair of current suppressing portions 110 spaced apart from each other. That is, since the pair of current suppressing portions 110 are disposed apart from each other, the coupling strength between the current suppressing portions 110 or the protecting portion 120 can be weakened, The bonding strength can be improved by filling with a member.

Further, by preventing the protection portion 120 from being exposed between the pair of current suppressing portions 110, the protection portion 120 can be safely protected from external force.

Meanwhile, since the molding part 130 is formed so as to cover the upper part of the pair of current suppressing parts 110, the side surfaces of the pair of current suppressing parts 110 are exposed and illustrated. However, And the side surfaces of the current restraining part 110. [0064]

At this time, the external electrode 114 formed on the lower surface of the current suppressing portion 110 may be formed so as to protrude further to the outside than the side surface.

Alternatively, the molding part 130 may be formed on the upper side of the external electrode 114 so that the side surface covers the current suppressing part 110 but does not cover the lower surface of the current suppressing part 110 but exposes the external electrode 114. [ As shown in FIG.

This makes it possible to maintain and control the positioning precision and cutting precision in the manufacturing process to a low level. No additional effort is required to improve precision and manufacturing costs can be reduced.

Such an open mode protection device 100 can be represented by an equivalent circuit in which a current blocking portion P such as a PPTC device or a PTC device is connected in series, as shown in FIG. At this time, the current suppressing portion P can be divided and arranged at both ends of the protecting portion B. [

That is, one end of the pair of current suppressing portions P is connected to the pair of external terminals of the open mode protection element 100, and the other end of the current blocking portions P is connected to the other end of the pair of current suppressing portions P. The pair of current suppressing portions P and one protecting portion P can be connected in series to the external terminals.

As shown in FIG. 5, the open mode protection device 100 according to the embodiment of the present invention has a low resistance value at a constant temperature of 80 to 120 degrees centigrade. That is, the open-mode protection element 100 functions as a protective element such as a varistor to protect the circuit by bypassing ESD, EOS, or surge introduced into the static electricity or the load to the ground.

Also, when a load made of LED is opened from the outside by ESD, EOS or surge, the current and voltage flowing to the open mode protection element 100 continuously increase, and the protection part 120 is overheated. That is, when the load is opened because the power source of the load is a constant current source, all the constant currents provided in the constant current source flow to the open mode protection element 100. At this time, a substantial load of the constant current source is the open mode protection element 100, and in this case, the constant current flows from the constant current source to the open mode protection element 100, and the voltage is increased to infinity.

For example, when the load is in the open state, the open-mode protection element 100, in particular, the protective portion (not shown) may be activated as the voltage across the open-mode protection element 100, 120 are overheated.

At this time, if the open-mode protection element 100 is overheated at a temperature of 150 ° C to 200 ° C, the open-mode protection element 100 increases the resistance of the current-suppression portion 110 and increases the amount of current flowing in the open-mode protection element 100 The voltage across both ends of the protection unit 120 can be reduced to reduce the temperature, so that heat generation can be suppressed. Accordingly, self-breakage due to overheating of the protection unit 120 can be prevented.

The open mode protection device 100 according to the embodiment of the present invention can be used to protect a load on an electronic device having a load made up of a constant current source and an LED.

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

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

The constant current source 10 can supply a current of a predetermined magnitude to the LED load 12. The constant current source 10 may be any one of a constant current power source and a constant current driver. That is, the constant current source 10 is not limited to a particular type, and may be a source for supplying current in a constant current mode, for example, a power source for supplying power to the electronic device 1, And the like.

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

The LED load 12 is supplied with a current of a predetermined magnitude from the constant current source 10, so that the LED may be turned on to have a constant voltage value. For example, when the constant current source 10 supplies a current of 400 mA and the LED load 12 is composed of ten LEDs, a voltage of approximately 25 to 30 V can be outputted to 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 can be connected to the ground terminal. These grounding terminals can be connected to a common ground formed on the circuit board of the electronic device 1. [

The open-mode protection element 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 element 100 is connected to one side of the constant current source 10 and the LED load 12, and the other side thereof can be connected to the other side of the constant current source 10 and the LED load 12 . At this time, one side of the open mode protection element 100 may be connected to the ground terminal.

As described above, when the ESD, EOS, or surge flows from the outside into the LED load 12 while the LED load 12 is in a normal operating state, 100 or the ESD, EOS or surge current (i _ESD ) flows and consequently bypasses the ground terminal, the LED load 12 can be protected from ESD, EOS or surge.

That is, since the resistance of the current suppressing portion 110 such as the PPTC element or the PTC element is very small, the open mode protection element 100 is substantially protected by the protection portion 120 such as ESD, EOS, .

On the other hand, if the protection unit 120 does not have sufficient protection against ESD, EOS, or surge that is externally introduced, some of the LED load 12 may be damaged by ESD, EOS, or surge, State is often generated.

At this time, as shown in FIG. 8, the current (i _open ) of the constant current source 10 flows to the open mode protection element 100.

Accordingly, since the constant current source 10 continuously supplies a constant current, the current flowing in the open mode protection device 100 increases, and the voltage also increases greatly. As a result, the temperature of the protection portion 120 of the open mode protection element 100 gradually rises due to overcurrent and overvoltage.

At this time, when the temperature of the protection unit 120 rises above a predetermined temperature, the resistance value of the current restriction unit 110 increases greatly, thereby reducing the current flowing through the protection unit 120, The voltage can be reduced to suppress the temperature rise.

Thus, by suppressing abnormal overheating of the open mode protection element 100, it is possible not only to prevent damage to the circuit components adjacent to the open mode protection element 100, but also to protect the adjacent elements from flammable materials, It is possible to prevent the fire due to the ignition of the protection device in advance when the white sheet is disposed on the front surface of the LED in order to improve the efficiency of light emitted from the protection device.

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.

1: Electronic device 10: Constant current source
12: LED load 100: open mode protection element
102: Space section 110: Current suppression section
110a: base layer 112: internal electrode
114: external electrode 120:
120a: body 122, 124: electrode
130: molding part

Claims (15)

An open-mode protection element connected in parallel to a load made up of a constant current source and an LED,
A current suppressing portion formed of a pair of substrates spaced apart from each other at regular intervals and disposed on the same plane;
Both ends of which are connected to electrodes on one side of each of the pair of current suppressing portions to bypass an overvoltage or an overcurrent; And
And a molding part formed to cover the upper side of the pair of current suppressing parts and the protection part.
Wherein the current suppression unit reduces the current of the protection unit as the temperature or current of the protection unit increases. The method according to claim 1,
Wherein the space portion between the pair of current suppressing portions is filled with a molding member constituting the molding portion. 3. The method of claim 2,
Wherein the molding member is made of epoxy. The method according to claim 1,
Wherein the pair of current suppressing parts have electrodes formed on both sides thereof. The method according to claim 1,
And the electrodes on the other side of the pair of current suppressing portions form a pair of external electrodes. 6. The method of claim 5,
Wherein one of the pair of external electrodes is connected to one side of the constant current source and the load and the other is connected to the other side of the constant current source and the load. The method according to claim 1,
Wherein the current suppressor is made of a positive temperature coefficient (PTC) material or a polymeric positive temperature coefficient (PPTC) material. The method according to claim 1,
Wherein the protection unit is one of a varistor, a suppressor, a gas discharge tube (GDT), and a diode. The method according to claim 1,
Wherein the protection unit is stacked on top of the pair of current suppressing units. 10. The method of claim 9,
And the protective portion is connected to the pair of current suppressing portions through the solder. The method according to claim 1,
Wherein the pair of current suppressing portions comprise a polymer layer in which conductive fillers are dispersed. 12. The method of claim 11,
Wherein the conductive filler is made of a carbon black material. Constant current source;
A load consisting of an LED driven by the constant current source;
A ground terminal to which the constant current source and one side of the load are connected; And
12. The electronic device according to any one of claims 1 to 12, wherein the open mode protection element is connected in parallel to the constant current source and the load, and one side is connected to the ground terminal. 14. The method of claim 13,
Wherein the constant current source is any one of a constant current driving unit and a constant current type power source. An open-mode protection element connected in parallel to a load made up of a constant current source and an LED,
A pair of PPTC substrates spaced apart from each other at regular intervals and disposed on the same plane;
A varistor in which both electrodes are connected to electrodes on one side of each of the pair of PPTC boards;
A first external electrode formed on the other surface of any one of the pair of PPTC substrates and connected to one side of the constant current source and the load;
A second external electrode formed on the other surface of the other of the pair of PPTC substrates and connected to the other of the constant current source and the load; And
And a molding part covering an upper side of the pair of PPTC boards and a space between the pair of PPTC boards to cover the varistor.

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