CN107871573B

CN107871573B - Fuse resistor and method for manufacturing the same

Info

Publication number: CN107871573B
Application number: CN201610848282.XA
Authority: CN
Inventors: 姜斗园; 金炫昌; 文皇帝; 申雅岚
Original assignee: Smart Electronics Inc
Current assignee: Smart Electronics Inc
Priority date: 2016-09-23
Filing date: 2016-09-23
Publication date: 2020-02-07
Anticipated expiration: 2036-09-23
Also published as: CN107871573A

Abstract

Disclosed are a fuse resistor and a method of manufacturing the same, and more particularly, a fuse resistor and a method of manufacturing the same, which are installed at a circuit of an electronic product to prevent the electronic product from being damaged due to an inrush current, an internal temperature rise, and a continuous overcurrent. The fuse resistor can simplify an assembly process by coupling the temperature fuse and the lead wires in a modular manner and fixing the fuse lead wires on the lead wires in an integrated manner to form an under-molded unit. The fuse resistor has a simple structure and can be miniaturized due to an integrated structure in which the temperature fuse and the lead wire are embedded.

Description

Fuse resistor and method for manufacturing the same

Technical Field

The present invention relates to a fuse resistor and a method of manufacturing the same, and more particularly, to a fuse resistor installed at a circuit of an electronic product to prevent the electronic product from being damaged due to an inrush current, an internal temperature rise, and a continuous overcurrent, and a method of manufacturing the same.

Background

Generally, in a circuit of a large electronic product such as an LCD television, a PDP television, a protection device such as a temperature fuse resistor for protecting the circuit is provided at an input terminal. Therefore, the protection device prevents the electronic product from being damaged by an inrush current generated when the power is turned on, an internal temperature rise, and a continuous overcurrent.

Such a fuse resistor includes a resistor, a temperature fuse, and a lead wire connected between the resistor and the temperature fuse.

In addition, when the fuse opens, debris is generated within the fuse resistor. In order to prevent other electronic devices from being affected by debris, the resistor and the thermal fuse are enclosed in a housing, and a filler is filled in the housing.

Here, silicon oxide (SiO) is used in consideration of heat resistance, conductivity, curability, and the like₂) The clay-like filler of (2) as a filler. Generally, a housing formed of a ceramic material is used as the housing. The ceramic case is used as a general resistive case.

Further, the end of the lead wire extends to be drawn out to the outside of the case. In the conventional fuse resistor, the ends of the lead wires are soldered to the printed circuit board, and thus the resistor and the temperature fuse are mounted upright at the printed circuit board.

Therefore, in the case where an inrush current flows, such a fuse resistor as set forth above limits the inrush current to a certain current using a resistor. In the case of introducing an overcurrent, heat generated by heat generation of the resistor is transferred to the thermal fuse by the above-mentioned filler, and then the fuse formed of solid-phase lead or of polymer particles provided inside the thermal fuse is broken to generate an open circuit. Thus, the circuit of the electronic product is protected.

Fig. 6A and 6B are views illustrating a conventional fuse resistor. Referring to fig. 6A and 6B, korean patent No. 10-1060013 discloses a fuse resistor including: a resistor 10; a thermal fuse 20 configured to generate an open circuit due to a heat generation; leads 31 and 33 connecting the resistor 10 and the thermal fuse 20 in series; a case 40 having an open face to accommodate the resistor 10 and the temperature fuse with a groove 41 formed on one wall of the case 40 having ends of

lead wires

31 and 33 led out to the outside; the filler 50 fills the space inside the case 40, and the resistor 10 and the thermal fuse 20 are embedded in the filler 50 having the filler 50 formed of silicon oxide.

It is difficult to miniaturize the fuse resistor 10 described in korean patent No. 10-1060013. In addition, since the pair of

lead wires

31 and 32 and the pair of

lead wires

33 and 34 connect the resistor 10 and the thermal fuse 20, respectively, and then the lead wire 31 of the resistor 10 and the lead wire 33 of the thermal fuse 20 are connected to each other, the process of producing the fuse resistor is also complicated.

Disclosure of Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a temperature fuse capable of simplifying an assembly process by coupling the temperature fuse and a lead wire in a modular manner and fixing a fuse lead wire on the lead wire in an integrated manner to form a lower mold unit, and a method of manufacturing the same.

Another object of the present invention is to provide a fuse resistor having a simple structure and capable of being miniaturized due to an integrated structure of an embedded temperature fuse and a lead wire, and a method of manufacturing the same.

In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a fuse resistor comprising: a resistor; a fuse wire including a first wire portion coupled to one side of the resistor, a second wire portion connected to a substrate, and a temperature fuse, one end of the temperature fuse being coupled to the first wire portion, and the other end of the temperature fuse being coupled to the second wire portion; a lead connected to the other side of the resistor; a lower molding unit injection-molded in a state where a portion of the fusing lead and a portion of the lead are spaced apart from each other by a certain distance; and an upper case having a cylindrical shape, provided at one side thereof with an opening, accommodating the resistor, a portion of the fuse lead wire, and a portion of the lead wire, and coupled to the lower molding unit.

The upper case may be filled with a filler, the filler may be formed of cement, and the lower molding unit may be formed of resin having a lower thermal conductivity than that of the filler.

The lower mold unit may be formed to have a thickness to accommodate a portion of the first wire part, a portion of the second wire part, and the temperature fuse.

A distance from a horizontal center line of the resistor to an upper surface of the lower molding unit may be less than a distance from the horizontal center line of the resistor to an upper surface of the temperature fuse.

A distance from a horizontal center line of the resistor to an upper surface of the lower molding unit may be greater than a distance from the horizontal center line of the resistor to a lower surface of the temperature fuse.

The lower molding unit may be provided at an edge portion thereof with a seating portion, and the seating portion may have a width corresponding to a thickness of the upper case.

The resistor may include a wire-wound resistor including a ceramic rod, a pair of terminals disposed at both ends of the ceramic rod, and a lead wire wound around the ceramic rod, and silicon may be coated at surfaces of the ceramic rod and the lead wire to form a coating layer.

According to another aspect of the present invention, a method of manufacturing a fuse resistor includes: preparing fusing leads and leads; coupling both ends of a resistor to the fuse lead and the lead, respectively; forming a lower molding unit by insert injection molding, wherein a portion of the fuse lead and a portion of the lead are embedded in the lower molding unit and spaced apart from each other by a certain distance; filling an inner space of an upper case with a filler through an opening, wherein the upper case is cylindrical in shape and is provided at one side thereof with the opening; and coupling the upper case to the lower molding unit such that the resistor is embedded in the upper case.

The fuse lead may include a first wire part coupled to one side of the resistor, a second wire part connected to a substrate, and a temperature fuse, one end of the temperature fuse being coupled to the first wire part, and the other end of the temperature fuse being coupled to the second wire part; and the first wire part, the second wire part, and the temperature fuse may all have the same diameter.

Drawings

The above and other objects, features and other advantages of the present invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1A is a perspective view illustrating a fuse resistor according to an embodiment of the present invention;

FIG. 1B is an exploded perspective view illustrating a fuse resistor according to an embodiment of the present invention;

FIG. 2A is a cross-sectional view of FIG. 1A;

FIG. 2B is a cross-sectional view illustrating a coating on a resistor according to the present invention;

fig. 2C is a cross-sectional view illustrating a fill layer on a resistor in accordance with the present invention;

FIG. 2D is a cross-sectional view of a fill layer different from that of FIG. 2C on a resistor according to the present invention;

FIG. 3 is a perspective view illustrating a temperature fuse according to an embodiment of the present invention;

FIG. 4 is a view illustrating a fuse resistor having a lower molding unit different from the structure of FIG. 2A;

FIG. 5A is a view illustrating a fuse wire according to the present invention;

FIG. 5B is a diagram illustrating coupling of leads to a resistor in accordance with the present invention;

FIG. 5C is a view illustrating a lower molding unit formed by fusing the lead wires and insert injection of the lead wires;

fig. 5D is a view illustrating coupling of the upper case to the lower molding unit; and is

Fig. 6A and 6B are views illustrating a conventional fuse resistor.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Referring to fig. 1A, 1B, 2A, 2B, 2C, 2D and 3, a fuse resistor denoted by reference numeral "100" according to the present invention may be provided to be applied to a circuit of an electronic product. The fuse resistor may include: a resistor 110; fuse and lead

wires

120 and 130 respectively coupled to both ends of the resistor 110; a lower molding unit 140 injection-molded in an embedded manner in a state where a portion of the fusing wire 120 and a portion of the wire 130 are spaced apart from each other by a certain distance; an upper case 150 coupled to the lower molding unit 140; and a packing 160 filling the inner space of the upper case 150.

When an overcurrent is applied, the resistor 110 radiates heat so that the thermal fuse 125 mounted on the fuse lead 120 is opened. As shown in fig. 2B, for example, the resistor 110 is a wire-wound resistor including a ceramic rod 111, terminals 117 provided at both ends of the ceramic rod 111, and a wire 113 wound around the ceramic rod 111.

In addition, a coating layer 115 may be formed on the surface of the resistor 110, as shown in fig. 2B, or a filling layer 115' or 115 ″ may be formed on the surface of the resistor 110, as shown in fig. 2C and 2D.

Coating 115 may be used to protect wire 113 and may be used to improve explosion-proof performance. As shown in fig. 2B, the coating layer 115 may be formed by thinly coating silicon on the surfaces of the ceramic rod 111 and the wire 113.

The filler layer 115' or 115 "may be used to maximize the explosion-proof performance of the resistor 110. As shown in fig. 2C and 2D, the filling layer 115' or 115 ″ may fill the space between the pair of terminals 117 with silicon. At least the thickness of the filler layers 115' and 115 "may be the same as the thickness of the terminal 117. Therefore, the lead 113 can be completely sealed.

In the event that an abnormal current is applied and the resistor 110 explodes, the coating layer 115 or the filling layer 115' or 115 ″ may primarily absorb the impact and noise generated by the explosion. Therefore, the explosion-proof performance of the product is improved.

Fuse wire 120 and wire 130 are coupled to each terminal 117 of resistor 110.

The fuse wire 120 includes: a first lead portion 121 coupled to the resistor in a state where the first lead portion 121 is bent downward; a second lead portion 123 connected to the substrate; and a thermal fuse 125. In this case, one end of the thermal fuse 125 is coupled to the first wire part 121, and the other end of the thermal fuse 125 is coupled to the second wire part 123.

As described above, the thermal fuse 125 is embedded between the first and second

lead parts

121 and 123 of the fuse wire 120, so that the structure can be simplified and miniaturized.

The thermal fuse 125 is opened due to heat radiated from the resistor 110 to generate an open circuit. Therefore, the thermal fuse 125 serves to protect devices mounted on the circuit.

Further, as shown in fig. 3, the temperature fuse 125 may include a fusible part 126 and a bent part 127 embedded in a central part of the fusible part 126. For example, the fusible portion 126 may include tin or a tin alloy. Upon heating, the fusible parts 126 are opened to block the electrical connection.

The bend 127 may be used to collect the melted fusible portion 126. For example, the bend 127 may include chloride, fluoride, resin, or the like.

In coupling the temperature fuse 125 with the first and second

lead parts

121 and 123, one end of the fusible part 126 formed of a metal material is brought into contact with each end of the first and second

lead parts

121 and 123, and then welding is performed. In this case, the diameter of the thermal fuse 125 may be the same as each diameter of the first and

second wire parts

121 and 123. When the diameter of the temperature fuse 125 is larger than each of the diameters of the first and second

lead parts

121 and 123, at least the bent part 127 is formed to have a diameter smaller than each of the diameters of the first and second

lead parts

121 and 123. Thus, the fusible parts 126 should be in contact with the first and second

lead parts

121 and 123.

In the temperature fuse 125, if the fusible part is formed to be embedded into the central portion of the bent part and the heat supplied from the resistor heats the bent part and then heats the fusible part, the melting time is delayed and the fusing performance is lowered. Further, since the bent portion formed of a dielectric material is disposed on the temperature fuse, the bent portion cannot be coupled using a spot welding process. Therefore, the temperature fuse 125 may preferably have a structure in which the bent portion 127 is embedded in the fusible portion 126.

The upper case 150 may include any one of thermosetting resin, thermoplastic resin, and ceramic material. The upper case 150 is cylindrical and is provided with an opening 151 at one side. The resistor 110, a portion of the fuse wire 120, and the wire 130 are embedded in the upper case 150 through the opening 151.

The opening 151 of the upper case 150 is sealed by the lower molding unit 140. The packing 160 providing explosion proof performance fills the inner space of the upper case 150.

The filler 160 may absorb shock and noise when the resistor 110 explodes. For example, the filler 160 may include cement, silicon, and resin such as epoxy.

As shown in fig. 2A, the lower molding unit 140 is insert injection molded to accommodate an interface between the temperature fuse 125 and the first and

second wire parts

121 and 123. In this case, the lower molding unit 140 seals the interface of both ends of the temperature fuse 125. Accordingly, it is possible to prevent the temperature fuse 125 from being damaged or the first and second

lead parts

121 and 123 from being separated during the assembly process.

In addition, the resistor 110, the fuse wire 120, and the wire 130 are modularized by the lower mold unit in an integrated manner, and thus, it is easy to couple the lower mold unit 140 to the upper case 150. Further, the fuse wire 120 and the wire 130 are spaced apart from each other by a certain distance, and thus, defective products can be reduced during surface mounting of the fuse resistor.

The lower molding unit 140 is formed in a block shape or a plate shape having a size corresponding to the opening 151 of the upper case 150 to seal the opening 151. The seating part 141 is provided at an edge region of the upper surface of the lower molding unit 140 to have a width corresponding to the thickness of the upper case 150. In this case, the lower molding unit 140 is coupled to the upper case 150 in an engagement manner.

Further, as shown in fig. 4, the lower molding unit 140' may be injection molded such that the temperature fuse 125 is not embedded in the lower molding unit 140' and only one side of the second wire part 123 is embedded in the lower molding unit 140 '.

Hereinafter, in the case where the filler 160 is formed of cement and the lower molding unit 140 is formed of resin, fusing characteristics between the lower molding unit 140 of fig. 2A and the lower molding unit 140' of fig. 4 will be compared.

In the case of the lower mold unit 140 of fig. 2A, a distance d1 from the horizontal center line c of the resistor 110 to the upper surface of the lower mold unit 140 is smaller than a distance d2 from the horizontal center line c of the resistor 110 to the upper surface of the temperature fuse 125.

In the case of the lower mold unit 140 'of fig. 4, a distance d1' from the horizontal center line c of the resistor 110 to the upper surface of the lower mold unit 140 is greater than a distance d3 from the horizontal center line c of the resistor 110 to the lower surface of the temperature fuse 125.

The disconnection characteristic of each of the lower molding units 140 and 140' will be given. In fig. 4, a space between the lower molding unit 140' and the resistor 110 is larger than that of fig. 2A, and the amount of the filler 160 is larger than that of fig. 2A. In this case, the heat of the resistor 110 is absorbed and radiated to the outside of the packing 160, so that the heat transferred to the thermal fuse 125 is relatively reduced.

However, in fig. 2A, the temperature fuse 125 is completely embedded in the lower molding unit 140 having a lower thermal conductivity than the filler 160, and a space between the lower molding unit 140 and the resistor 110 is narrow. Thus, heat conduction from the resistor 110 to the thermal fuse 125 through the first wire portion 121 is increased as compared with the heat conduction of fig. 4. Therefore, the breaking performance is improved according to the above description.

Hereinafter, a method of manufacturing the fuse resistor will be explained with reference to the drawings.

First, referring to fig. 5A, a fuse wire 120 and a lead wire 130, which are coupled by a first wire part 121, a thermal fuse 125 and a second wire part 123, are prepared.

The temperature fuse 125 is coupled to the first and

second wire parts

121 and 123 using a soldering process, a spot welding process, or an ultrasonic welding process.

Then, referring to fig. 5B, after both ends of the resistor 110 are coupled to the fuse wire 120 and the lead wire 130, respectively, the fuse wire 120 and the lead wire 130 are bent.

Subsequently, referring to fig. 5C, the fuse wire 120 and the lead wire 130 are injection-molded by insert to form the lower molding unit 140. Herein, the lower molding unit 140 is injected to accommodate the temperature fuse 125 and a portion of the second lead part 123 of the fuse lead 120.

Then, referring to fig. 5D, an upper case 150 having a cylindrical shape and provided with an opening 151 at one side is prepared. The upper case 150 is arranged with an opening 151 facing upward. The packing 160 fills the inner space of the upper case 150. After the resistor 110 modularized by the lower molding unit 140 is embedded in the upper case 150, the lower molding unit 140 is coupled to the upper case 150. Thus, the manufacturing of the fuse resistor is completed.

In summary, according to the present invention, the thermal fuse 125 is embedded in the fuse wire 120 to form a simple structure, and thus, miniaturization of products can be implemented. The fuse wire 120 and the wire 130 are fixed in an integrated manner to form the lower molding unit 140. In this case, the lower molding unit 140 is coupled to the upper case 150, and thus, the manufacturing method may be simplified.

As apparent from the above description, according to the present invention, the thermal fuse and the lead wire are coupled to form one module, and the fuse lead wire and the lead wire are fixed in an integrated manner to form a lower molding unit. Thus, the assembly process is simplified.

Further, according to the illustrated embodiment of the present invention, the temperature fuse and the lead wire are formed as an embedded structure in an integrated manner, and thus, the structure is simple and miniaturized.

Although exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Accordingly, the scope of the invention should not be limited or limited by the embodiments described herein, and should be construed to include the following claims and equivalents thereof.

Claims

1. A fuse resistor, comprising:

a resistor;

a fuse wire including a first wire portion coupled to one side of the resistor, a second wire portion connected to a substrate, and a temperature fuse, one end of the temperature fuse being coupled to the first wire portion, and the other end of the temperature fuse being coupled to the second wire portion;

a lead connected to the other side of the resistor;

a lower molding unit injection-molded in a state where a portion of the fusing lead and a portion of the lead are spaced apart from each other by a certain distance, the lower molding unit being injection-molded to accommodate the temperature fuse; and

an upper case having a cylindrical shape, the upper case being provided at one side thereof with an opening, the upper case accommodating the resistor, a portion of the fuse lead, and a portion of the lead, and the opening being coupled to the lower molding unit,

the lower molding unit is formed to have a thickness to accommodate a portion of the first wire part, a portion of the second wire part, and the temperature fuse,

the upper case is filled with a filler formed of cement, and the upper case and the lower molding unit are coupled.

2. The fuse resistor of claim 1, wherein:

the lower molding unit is formed of a resin having a lower thermal conductivity than the filler.

3. The fuse resistor according to claim 1, wherein a distance from a horizontal center line of the resistor to an upper surface of the lower molding unit is smaller than a distance from the horizontal center line of the resistor to an upper surface of the temperature fuse.

4. The fuse resistor according to claim 1, wherein the lower molding unit is provided at an edge portion thereof with a seating portion, and the seating portion has a width corresponding to a thickness of the upper case.

5. The fuse resistor of claim 1, wherein:

the resistor includes a wire-wound resistor including a ceramic rod, a pair of terminals arranged at both ends of the ceramic rod, and a wire wound around the ceramic rod, and

silicon is coated at the surfaces of the ceramic rod and the wire to form a coating layer.

6. A method of manufacturing a fuse resistor, comprising:

preparing a fusing lead and a lead, wherein the fusing lead comprises a first lead part, a second lead part connected with a substrate and a temperature fuse, one end of the temperature fuse is coupled to the first lead part, and the other end of the temperature fuse is coupled to the second lead part;

coupling both ends of a resistor to the first lead portion of the fuse lead and the lead wire, respectively;

forming a lower mold unit by insert injection molding, wherein a portion of the fuse lead and a portion of the lead are embedded in the lower mold unit and spaced apart from each other by a certain distance, the lower mold unit is formed to have a thickness accommodating a portion of the first wire part, a portion of the second wire part, and the temperature fuse, and the lower mold unit is injection molded to accommodate the temperature fuse of the fuse lead;

filling an inner space of an upper case through an opening with a filler formed of cement, wherein the upper case is cylindrical in shape and is provided with the opening at one side thereof; and is

Coupling the upper case to the lower molding unit such that the resistor is embedded in the upper case.

7. The method of manufacturing a fuse resistor as recited in claim 6, wherein:

the first wire portion, the second wire portion, and the thermal fuse all have the same diameter.