WO2022154300A1

WO2022154300A1 - High-current protection element

Info

Publication number: WO2022154300A1
Application number: PCT/KR2021/019620
Authority: WO
Inventors: 원세희
Original assignee: 주식회사 인세코
Priority date: 2021-01-15
Filing date: 2021-12-22
Publication date: 2022-07-21
Also published as: KR102232139B1

Abstract

The present invention pertains to a surface mount device (SMD) type compact high-current protection element having a structure in which rated current characteristics may be improved without increasing the size of the protection element, in which additional current paths passing through an insulation substrate composed of ceramic may be ensured by forming, on lower connection electrodes to be mounted on a printed circuit board, a plurality of vias (for example, having the number of three to five) connected to fuse element connection electrodes through the insulation substrate, and the cross-sectional area in which current flows may be increased by forming, in the lower connection electrodes, curved terminal walls vertically erected along a plurality of castellation portions (for example, having the number of two to four) formed on the insulation substrate. Thus, there is an advantage that the rated current may be significantly improved without increasing the size of the SMD type compact protection element.

Description

high current protection device

The present invention relates to a high current protection device, and more particularly, a new high current protection device having a structure capable of improving the rated current characteristics without increasing the size of the protection device in a small SMD (Surface Mount Device) type protection device. is about

In general, a fuse is a protection device that blocks an overcurrent in an electrical circuit and has a property of being fused in the overcurrent. In various electric circuits, in particular, a protection element is used in a secondary battery protection circuit.

The protection device, which was conventionally manufactured as a DIP type, is recently replaced with a SMD (Surface Mount Device) type. The SMD type protection element has a higher degree of integration than the DIP type, which is advantageous for reducing the size of parts. In addition, the SMD type protection device has the advantage that it can be applied with high compatibility in various industries using a printed circuit board (PCB). For example, SMD-type protection devices are being applied to many home appliances such as TVs as well as products that have recently grown rapidly, such as smartphones, tablets, laptops, and desktop PCs.

1 is an exploded perspective view illustrating a conventional SMD type small protective device, and FIG. 2 is a perspective view illustrating an assembled state of each component of FIG. 1 .

Referring to FIG. 1 , in a conventional SMD type small protective device, a first fuse connection electrode 22 and a second fuse connection electrode 24 are disposed on an upper portion of an insulating substrate 10 to be spaced apart, and two As a conductor connecting the electrodes, the fuse body 30 is stacked. A first lower connecting electrode 42 and a second lower connecting electrode 44 to be mounted on a printed circuit board (PCB) are disposed under the insulating substrate 10 , and the first lower connecting electrode 42 is disposed on the insulating substrate The second lower connection electrode 44 is bent upward along one sidewall of the insulating substrate 10 to be connected to the first fuse connection electrode 22 , and the second lower connection electrode 44 is bent upward along the other sidewall of the insulating substrate 10 to make the second It is connected to the fuse connection electrode 24 . And a protective cap 50 for protecting the components is coupled to the top.

The protection element of FIG. 1 is installed on the current path of the printed circuit board, and the first lower connection electrode 42 , the first fuse connection electrode 22 , the fuse element 30 , and the second fuse element connection electrode 24 . , when an overcurrent is applied along the conductive line formed in the order of the second lower connection electrode 44 (or in the reverse order), the fuse 30 is melted to block the current path of the printed circuit board. perform the action

However, the flow of current must be maintained smoothly within the rated current, not the overcurrent, and there is a limit to increasing the allowable current when the size of the small protection element is set. For example, in the case of a small protection device having a length of 9.5mm, a width of 5mm, and a height of 2mm, the rated current is only about 10A.

The easiest way to improve the rated current of the protection element is to increase the size of the fuse element. However, portable electric products are increasingly being designed to be compact, and the market wants a protection device having a high rated current even in a small size. For example, if the rated current characteristics of 30A or more are exhibited in the exemplified standard of the protection device, it will be able to have a very large market competitiveness.

An object of the present invention is to provide a compact size of an SMD type small protection device, and an object of the present invention is to provide a high current protection device of a new structure capable of improving the rated current without increasing the size of the protection device.

In the high current protection device according to an embodiment of the present invention, in the SMD (Surface Mount Device) type protection device, a plurality of substrate via holes penetrating up and down along both sides of the long side in the longitudinal direction are formed, and the via holes are formed on both sidewalls, respectively. an insulating substrate on which a plurality of inwardly concave substrate caster parts are formed between the insulating substrates; A plurality of electrode castellations are disposed on the upper surface of the insulating substrate to be spaced apart from each other, each electrode via hole communicating with the substrate via hole is formed along the longitudinal direction, and concave inwardly at a position corresponding to the substrate castellation part. a first fuse connection electrode and a second fuse connection electrode on which an additional portion is formed; a fuse that connects the first fuse-connecting electrode and the second fuse-connecting electrode and melts above a fusing current; They are disposed spaced apart from each other on the lower surface of the insulating substrate, respectively pass through the substrate via hole in the longitudinal direction, are connected to the electrode via hole, and are vertically filled with a conductor therein, and at the end of the substrate casting a first lower connecting electrode and a second lower connecting electrode bent upward to correspond to the portion and having a vertically curved terminal wall connected to the electrode casterization unit; and a protective cap coupled to an upper portion of the insulating substrate to protect the fuse body.

In the high current protection device according to another embodiment of the present invention, three to five substrate via holes are formed along the longitudinal direction of both sides of the insulating substrate, respectively, and the substrate casting part is two on both sidewalls of the insulating substrate. to 4 are formed.

In the high current protection device according to another embodiment of the present invention, the protection cap has an upper surface sealed and a lower surface is recessed toward the upper side to form a space for accommodating the fuse body, and each side wall of the long side is cut toward the upper side provided with a ventilated long groove.

In the high current protection device according to another embodiment of the present invention, the protection cap further includes a ventilation short groove portion cut toward the upper side on each of the front wall and the rear wall of the short side portion.

In the high current protection device according to another embodiment of the present invention, the protection cap further includes a heat inducing surface concave in the longitudinal direction on each of the front wall and the rear wall.

In a high current protection device according to another embodiment of the present invention, the heat-inducing surface portion includes a first heat-inducing surface portion extending from the ventilation short groove portion, and a stepped portion protruding toward each other from each of the front wall and the rear wall. The second heat-inducing surface, which has a narrower width than the first heat-inducing surface, is formed such that the upper portion is narrow and the lower portion is wide.

According to the high current protection device of the present invention, by forming a plurality of vias (for example, 3 to 5) connected to the fuse connection electrode through the insulating substrate in the lower connection electrode mounted on the printed circuit board, ceramic A curvature terminal wall that secures an additional current path passing through the configured insulating substrate, and is installed vertically along a plurality of casterization portions (eg, 2 to 4) formed on the insulating substrate at the lower connection electrode It is possible to increase the cross-sectional area through which the current flows by forming the , so there is an effect that the rated current can be greatly improved without increasing the size of the small SMD type protection device.

In addition, according to the high current protection device of the present invention, a ventilation long groove portion is formed on the long side of the protection cap to pass external air in the width direction of the protection element, and a short side ventilation groove portion is formed on the short side of the protection cap to allow external air in the longitudinal direction. In order to increase the heat dissipation effect in the relatively narrow ventilation end groove part, a heat induction surface with a narrow upper part and a wide lower part is formed to promote the effect of spreading the heat inside the protective cap to the outside. There is an effect that can prevent the lower surface of the protective cap from melting due to the heat generated by the

1 is an exploded perspective view illustrating a conventional SMD type small protective device;

Figure 2 is a perspective view illustrating an assembled state of each component of Figure 1;

3 is an exploded perspective view illustrating a high current protection device according to the present invention;

4 is an exploded perspective view illustrating a state in which the high current protection device of the present invention is partially coupled, and

5 is a rear perspective view illustrating the internal structure of the protective cap in the present invention.

Hereinafter, specific embodiments according to the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Throughout the specification, the same reference numerals are assigned to parts having similar structures and operations. And, the drawings attached to the present invention are for convenience of description, and the shape and relative scale thereof may be exaggerated or omitted.

In describing the embodiments in detail, overlapping descriptions or descriptions of obvious techniques in the art are omitted. In addition, when a certain part "includes" other components in the following description, it means that other components may be further included in addition to the described components unless otherwise stated.

Terms including ordinal numbers such as first, second, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component.

The high current protection device of the present invention is a small size SMD (Surface Mount Device) type that can be applied with high compatibility to various electrical products (eg, smartphones, tablets, notebooks, desktop PCs, TVs, etc.) using a printed circuit board (PCB). In the protection device, it relates to a high current protection device that improves the rated current without increasing the size. The protection element described with reference to the drawings in the following description is provided, for example, with a length of 9.5 mm, a width of 5 mm, and a height of 2 mm. While a small protective device of such a standard has a rated current of 10A in the prior art, the present invention proposes a structure capable of improving the rated current from 30A to 60A in the same standard. Of course, as the illustrated standard increases or decreases, the rated current may also increase or decrease. In addition, the high current protection device of the present invention is concerned that the melting phenomenon of the protection cap may occur as the rated current is increased while maintaining a small size, and thus a structure of the protection cap is further proposed to prevent this. A specific embodiment of the present invention will be described with reference to FIGS. 3 to 5 .

Figure 3 is an exploded perspective view illustrating a high current protection device according to the present invention, Figure 4 is an exploded perspective view illustrating a state in which the high current protection device of the present invention is partially coupled.

Referring to FIG. 3 , the high current protection device of the present invention includes an insulating substrate 100 , a first fuse connection electrode 110 , a second fuse connection electrode 120 , a fuse body 130 , and a first It consists of a lower connection electrode 140 , a second lower connection electrode 150 , and a protective cap 160 .

The insulating substrate 100 is an insulating member formed of a material such as ceramic. The insulating substrate 100 may be provided with a length of 9.5 mm and a width of 5 mm. In the following description, the term 'long side' refers to a longer side of the insulating substrate 100 , that is, a side corresponding to a standard length. And, the 'short side' means a shorter side of the insulating substrate 100 , that is, a side corresponding to the width of the standard.

Referring to FIG. 3 , a plurality of (eg, three to five) substrate via

holes

102 and 106 penetrating up and down on both sides along the longitudinal direction of the long side of the insulating substrate 100 are formed. In the illustrated embodiment, all of the first substrate via holes 102 formed along one long side of the insulating substrate 100 are five, and each of the first substrate via holes 102 may have a diameter of about 1 mm. The second substrate via hole 106 is formed to be symmetrical with the first substrate via hole 102 along the other long side of the insulating substrate 100 .

In addition, a plurality of (for example, 2 to 4) first substrate caster parts 104 concave to have a predetermined curvature inward between the first substrate via holes 102 are provided on one sidewall of the insulating substrate 100 . is formed In the illustrated embodiment, there are four first substrate casterization units 104 . Four second substrate caster parts 108 are formed on the other sidewall of the insulating substrate 100 to be symmetrical with the first substrate caster parts 104 .

Referring to FIG. 3 , the first fuse element connection electrode 110 and the second fuse element connection electrode 120 are spaced apart from each other on the upper surface of the insulating substrate 100 , and the fuse element 130 is stacked to connect the two electrodes. do. The fuse body 130 is made of a material that melts above the fusing current.

As illustrated, the first fuse connection electrode 110 includes five first electrode via holes 112 along the longitudinal direction to communicate with the first substrate via hole 102 . In addition, at the outer end of the first fuse connection electrode 110 , there are four first electrode castings concave inward to have a position and a shape corresponding to the first substrate caster 104 of the insulating substrate 100 . A portion 114 is formed. The second fuse connection electrode 120 also includes five second electrode via holes 122 and four second electrode casting parts 124 so as to be symmetrical with the first fuse connection electrode 110 .

Referring to FIG. 3 , the first lower connecting electrode 140 and the second lower connecting electrode 150 are spaced apart from each other on the lower surface of the insulating substrate 100 . The two electrodes are electrodes for mounting the protection element on a printed circuit board (PCB), and the first lower connection electrode 140 is connected to the first fuse connection electrode 110 in the protection element, and the second lower connection The electrode 150 is connected to the second fuse connection electrode 120 .

The first lower connection electrode 140 has five first vias 142 vertically installed to pass through the first substrate via hole 102 , and the first lower connection electrode 140 has an upper end at the outer end to correspond to the first substrate caster 108 . and four first vertically curvature terminal walls 144 bent to . The first via 142 has a cylindrical shape, and silver (Ag) paste is filled inside the first via 142 to electrically connect the first lower connection electrode 140 and the first fuse connection electrode 110 . make it In the illustrated example, since a total of five first vias 142 are formed, five new current paths may be created for the insulating substrate 100 .

The first vertically curved terminal wall 144 is connected to the first electrode caster 124 of the first fuse connection electrode 110 at an upper end thereof. For example, the first vertical curvature terminal wall 144 and the first electrode caster 124 may be connected to each other by soldering or the like. In the illustrated example, a total of four first vertically curvature terminal walls 144 are concave inwardly, thereby increasing a cross-sectional area through which current flows.

Referring to FIG. 3 , the second lower connection electrode 150 has a shape symmetrical to the first lower connection electrode 140 , and the second via 152 is symmetrical to the first via 142 and has a second vertical curvature. The terminal wall 154 is symmetrical with the first vertically curved terminal wall 144 . Accordingly, five new current paths are added to the insulating substrate 100 by the second via 152 , and the cross-sectional area through which the current flows is added by the second vertically curved terminal wall 154 is also the same.

The protective cap 160 has an upper surface sealed and a lower surface is recessed toward the upper side to form a space for accommodating the fuse body 130 . As shown in FIG. 3 , ventilation

long groove portions

162 and 164 cut toward the upper side are formed on each of the side walls of the long side of the protective cap 160 , and the ventilation ends that are cut toward the upper side are formed on the front and rear walls of the short side, respectively.

Grooves

166 and 168 are formed. Description of these configurations will be described later in detail with reference to FIG. 5 .

5 is a rear perspective view illustrating the internal structure of the protective cap in the present invention, and is shown by rotating the protective cap 160 illustrated in FIG. 3 by 180 degrees.

The high current protection device of the present invention is designed to withstand a high rated current with a small size. For example, when the conventional small SMD type protection device has a standard of 9.5mm in length, 5mm in width, and 2mm in height, if the rated current of 10A is the limit, the high current protection device of the present invention has a rated current characteristic of 30A to 60A in the same standard have By forming three vias on each lower connection electrode and two vertically curvature terminal walls, it may have a rated current of about 30A. As the number of vias and vertical curvature terminal walls is increased, the cross-sectional area where the current path is formed increases, resulting in a higher rated current. For example, as illustrated in FIG. 3 , by forming five vias and four vertically curvature terminal walls on each lower connection electrode, a cross-sectional area of a copper wire capable of applying 60A to a current path cross-sectional area of 5.5 mm2 or more can be configured. It is possible to increase the rated current up to 60A.

The problem is that while the high current protection device of the present invention allows a high rated current in a small size, heat is generated due to a high current due to a trade-off phenomenon, and the protective cap 160, which is most vulnerable to heat, may melt within the rated current. that there is

The present invention provides a solution to this by forming ventilation grooves on each of the four sides of the protective cap 160 . As shown by the thick arrow in Figure 5, the ventilation long grooves (162, 164) pass the outside air in the width direction. And as shown by a thin arrow in FIG. 5, the ventilation

short grooves

166 and 168 pass the outside air in the longitudinal direction. Through such a ventilation structure, the heat inside the protection element can be rapidly discharged to the outside.

Here, since the short side portion of the protection element is smaller than the long side portion, heat dissipation in the longitudinal direction may not be rapidly achieved, and the present invention provides a structure for solving this problem. Referring to FIG. 5 , heat inducing

surface portions

174 , 176 , 184 , and 186 concave inward in the longitudinal direction are formed on each of the front wall and the rear wall of the short side portion of the protective cap 160 .

Since the structure of the front wall and the rear wall of the short side of the protective cap 160 is symmetrical, it will be described with reference to the heat-inducing

surface portions

184 and 186 of the front wall illustrated in FIG. 5 . The heat

induction surface portions

184 and 186 may have a structure in which the first heat guide surface portion 184 and the second heat guide surface portion 186 are spatially partitioned by the stepped portion 182 . The first heat-inducing surface portion 184 is formed as a concave surface extending from the ventilation short groove portion 168 of the front wall. In addition, stepped portions 182 protruding toward each other are formed in the middle height of the front wall, and the second heat-inducing surface portion 186 is narrower than the first heat-inducing surface portion 184 by the stepped portion 182 . It is formed with a concave surface with As such, the heat inducing surface portion having a narrow upper side and a wide lower side is formed, so that the heat inside the protective cap 160 can be rapidly diffused to the outside.

Various modifications can be made to the invention disclosed above without detracting from the basic idea. That is, all of the above embodiments should be interpreted as illustrative and not restrictive. Therefore, the scope of protection of the present invention should be determined according to the appended claims, not the above-described embodiments, and if the components defined in the appended claims are substituted with equivalents, it should be considered as belonging to the protection scope of the present invention.

Claims

In the SMD (Surface Mount Device) type protection device,

an insulating substrate having a plurality of substrate via holes penetrating up and down along both sides of the long side in a longitudinal direction, and having a plurality of substrate casting parts concave inwardly formed between each of the via holes on both sidewalls;

A plurality of electrode castellations are disposed on the upper surface of the insulating substrate to be spaced apart from each other, each electrode via hole communicating with the substrate via hole is formed along the longitudinal direction, and concave inwardly at a position corresponding to the substrate castellation part. a first fuse connection electrode and a second fuse connection electrode on which an additional portion is formed;

a fuse that connects the first fuse-connecting electrode and the second fuse-connecting electrode and melts above a fusing current;

They are disposed spaced apart from each other on the lower surface of the insulating substrate, respectively pass through the substrate via hole in the longitudinal direction, are connected to the electrode via hole, and are vertically filled with a conductor therein, and at the end of the substrate casting a first lower connecting electrode and a second lower connecting electrode bent upward to correspond to the portion and having a vertically curved terminal wall connected to the electrode casterization unit; and

A protective cap coupled to the upper portion of the insulating substrate to protect the fuse body

A high current protection device comprising a.
According to claim 1,

3 to 5 substrate via holes are respectively formed along the longitudinal direction of both sides of the insulating substrate, and 2 to 4 substrate caster parts are respectively formed on both sidewalls of the insulating substrate.
3. The method of claim 1 or 2,

The protective cap has an upper surface sealed and a lower surface is recessed toward the upper side to form a space for accommodating the fuse body, and each side wall of the long side has a ventilation long groove cut toward the upper side.
4. The method of claim 3,

The protection cap is a high current protection device further comprising a ventilation short groove cut upwards on each of the front wall and the rear wall of the short side portion.
5. The method of claim 4,

The protection cap is a high current protection device further comprising a heat-inducing surface concave in the longitudinal direction on each of the front wall and the rear wall.
6. The method of claim 5,

The heat-inducing surface portion has a narrower width than the first heat-inducing surface portion by a first heat-inducing surface portion extending from the ventilation short groove portion, and a stepped portion protruding toward each other from each of the front wall and the rear wall. 2 A high-current protection device in which the heat-inducing surface is divided into a narrow upper part and a wide lower part.