JPH0611304U - Overcurrent protection parts - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an overcurrent protection component including a fuse element and a resistance element. [Measures] A fuse fuse resistor 31 of a preset size and a resistor body 30 of a preset size are separately formed on one surface of an insulating substrate 10 of a preset size, and one end of the fuse resistor 31 is connected to a terminal T2 to a resistor. One end of the body 30 to the terminal T1, the other end of the fuse resistor 31 and the other end of the resistor 30 to the terminal T3,
Each is electrically connected by the conductor 20. Further, the fuse resistor 31 is provided with a trimming groove 31a having a predetermined width and a predetermined depth, and a melting layer 41 is formed so as to substantially cover the trimming groove 31a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an overcurrent protection device, and more particularly to its structure.

[0002]

[Prior art]

 Conventionally, the line connection end of a telephone has a circuit configuration as shown in FIG. That is, when a surge due to lightning or the like is induced between the lines La and Lb, the resistor R1 and the surge absorber Z1 are used to prevent the surge from reaching the electronic circuit and the handset inside the telephone. I was absorbing the Zazi. Furthermore, if the surge cannot be absorbed completely by the resistor R1 and the surge absorber Z1 and a surge current flows in the electronic circuit inside the telephone, the fuse F1 is melted and a secondary disaster such as ignition due to the surge current occurs. Prevented.

FIG. 6 is a diagram showing the configuration of the resistor R1. The resistor R1 is formed by connecting both ends of a thick film resistor 130 formed on the alumina substrate 110 to two terminals 150 with two conductors 120, and its resistance value is several tens [Ω]. Fuse at about 0.5 [A]. The fusing current value of fuse F1 is 0.27 [A].

[0004]

[Problems to be solved by the device]

 However, the above conventional example has the following problems. That is, since the surge protection resistor R1 incorporated in the telephone is required to have surge resistance, it cannot be replaced with a small component such as a chip resistor. Similarly, the fuse F1 is also required to have a reliable cutoff characteristic, which makes it difficult to reduce the size.

On the other hand, in recent years, electronic circuits inside telephones have been increasingly leadless, and most of the components thereof are assembled by surface mounting. However, as mentioned above, the surge protection resistor R1 and the fuse F1 must be assembled as separate parts, and it is difficult to miniaturize them, which makes automatic mounting difficult. There is a demand for surge protection components that can be used in various applications.

[0006]

[Means for Solving the Problems]

 The present invention is intended to solve the above problems, and has the following configuration as one means for solving the above problems. That is, an overcurrent protection component formed on an insulating substrate of a predetermined size, which comprises a fuse element of a predetermined size formed on one surface of the insulating substrate and a fuse element separated from the fuse element on the surface on which the fuse element is formed. The formed resistance element of a predetermined size, the first conductor connected near one end of the fuse element, the second conductor connected near one end of the resistance element, and the other end of the fuse element. And a third conductor that connects the vicinity of the resistance element and the vicinity of the other end of the resistance element.

[0007]

[Action]

 With the above configuration, it is possible to provide an overcurrent protection component including a fuse element and a resistance element. For example, with the above configuration, it is possible to provide a surge protection component that can simplify the assembling work.

[0008]

【Example】

 Hereinafter, a surge protection component according to an embodiment of the present invention will be described in detail with reference to the drawings. 1A and 1B are views showing a configuration example of a surge protection component according to an embodiment of the present invention. FIG. 1A is a front view and FIG. 1B is a side view.

FIG. 2 is a circuit diagram showing a connection example of this embodiment and its peripheral portion, 1 is this embodiment, 2 is a surge absorber, and La and Lb are lines. In FIG. 1, reference numeral 10 is a substrate, which is an electrically insulating ceramic substrate having a substantially rectangular predetermined thickness, such as an alumina substrate of a sintered body of 96% alumina. In this embodiment, the substrate 10 is not limited to the alumina substrate that has been fired, and may be fired together with a thick film resistor described later using a green sheet such as alumina. .

Reference numeral 31 denotes a fuse resistor, which will be blown when an excessive current flows, which will be described later in detail. The fuse resistor 31 is made of a resistor having a substantially rectangular shape and a predetermined thickness on the substrate 10 by sputtering, vacuum deposition, plating or the like, and the material thereof is nickel-phosphorus or the like. Reference numeral 30 denotes a resistor, which is formed by screen-printing a thick film resistor on the substrate 10 in a substantially rectangular shape and having a predetermined thickness. The material of the thick film resistor is a ruthenium oxide-based material. It is a film paste. The resistance value of the resistor 30 is about 20 to 40 [Ω].

Reference numeral 50 is a clip terminal for electrically connecting the present embodiment to an external circuit. Note that, as shown in FIG. 2, the clip terminals 50 correspond to the terminals T1 to T3, respectively. Reference numeral 20 denotes a conductor, which electrically connects the fuse resistor 31 and the resistor 30 to the terminals T1 to T3 so as to have the circuit configuration shown in FIG. The conductor 20 is formed by a method such as screen printing or direct drawing using a thick film paste such as silver-based, silver-palladium-based, or copper-based paste.

3A and 3B are diagrams showing a detailed configuration example of the fuse resistor 31, in which FIG. 3A is an enlarged front view and FIG. 3B is an enlarged sectional view. In FIG. 3, reference numerals 31a and 31b denote trimming grooves, which are grooves formed on the surface of the fuse resistor 31 to a predetermined length and depth by, for example, a laser beam. The trimming groove 31a sets the fusing current of the fuse resistor 31, and the trimming groove 31a sets the resistance value of the fuse resistor 31. The resistance value of the fuse resistor 31 is adjusted to about 10 [Ω].

Reference numeral 41 denotes a molten layer, which is formed by glass printing or the like by screen printing or direct drawing so as to substantially cover the trimming groove 31a and then volatilizes the solvent component. Although the main constitution of this embodiment is formed as described above, finally, the conductor 20 and the crimp terminal 50 are electrically connected and mechanically fixed by soldering or the like. After that, the entire surface is covered with a protective film such as resin by powder coating, and the surge protection component of this embodiment is completed through steps such as marking and inspection.

Although omitted in the above description, when forming the fuse resistor 31, a predetermined pattern is formed by using a metal mask or the resist film is peeled off after forming a nickel-phosphorus film or the like. Then, the formed nickel-phosphorus film is aged at 260 ° C., for example. When the resistor 30 and the conductor 20 are formed, the thick film paste is printed and then baked at 850 ° C. for 10 minutes, for example.

When an excessive current flows from the terminal T1 of the present embodiment having the above structure to the terminal T2, the nickel-phosphorus film in the trimming groove 31a portion of the fuse resistor 31 has a high current density. Causes a sudden heat generation and melting. When the nickel-phosphorus film of the trimming groove 31a is melted, the temperature in the vicinity of the trimming groove 31a of the melting layer 41 reaches about 900 ° C., so that the glass (melting at about 500 ° C.) contained in the melting layer 41 also melts. Then, nickel-phosphorus and glass are mixed, and the melted and mixed part is in an insulating state. Therefore, the fuse resistor 31 is electrically opened in the trimming groove 31a, and the terminals T1 and T2 of this embodiment are not electrically connected.

In the conventional resistor R1 shown in FIG. 6 without providing the trimming groove 31a on the fuse resistor 31, the minimum setting limit of the fusing current value is about 0.5 [A], Further, in this embodiment, when the fuse resistor 31 is provided with the trimming groove 31a, the minimum setting limit of the fusing current value is about 0.29 [A]. FIG. 4 is a process chart showing an example of the manufacturing process of this embodiment, and particularly shows a process example of forming the fuse resistor 31.

In FIG. 4, a process P 1 is a well-known thick film forming process, in which the conductor 20 and the resistor 30 are formed on the substrate 10. Subsequently, step P2 is a resist film forming step, in which a resist is printed by screen printing or the like on a portion where the nickel-phosphorus film is not formed and dried to form a resist film.

Subsequently, in the plating step of step P3, a film of nickel-lin or the like is formed by electroless plating or the like, and the resist film is peeled off in the resist film peeling step of step P4. In the aging step, the fuse value is exposed to an atmosphere of about 260 ° C. to stabilize the resistance value of the fuse resistor 31. Subsequently, in the trimming step of step P4, the fuse resistor 31 is trimmed to set the fusing current value and the resistance value, and in the melting layer forming step of step P5, a molten layer is formed on the trimming groove 31a. .

Although omitted below, when the step P5 is completed, the surge protection component of this embodiment is completed through steps such as mounting of the clip terminal 50, painting, marking and inspection. As described above, according to the present embodiment, since it is possible to provide a surge protection component integrally including a resistor and a fuse resistor, conventionally, a surge protection resistor and a fuse are respectively provided. It is possible to simplify the work of assembling individual parts into a telephone, etc., and since two parts that were conventionally used can be handled as one part, the parts can be managed and stored easily.

Further, according to the present embodiment, when the fuse fuse is melted, the melted portion is filled with a mixture of glass, so that a reliable breaking characteristic can be obtained. Further, in the present embodiment, the fusing current value can be arbitrarily set to a minimum of about 0.29 [A] by adjusting the length and depth of the trimming groove 31a provided on the fuse resistor. .

[0021]

[Effect of device]

 As described above, according to the present invention, it is possible to provide an overcurrent protection component including a fuse element and a resistance element. For example, according to the present invention, it is possible to provide a surge protection component that can simplify the assembling work.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a surge protection component according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a connection example of the present embodiment and its peripheral portion.

FIG. 3 is a diagram showing a detailed configuration example of a fuse resistor of the present embodiment.

FIG. 4 is a flow chart showing an example of a manufacturing process of the present embodiment.

FIG. 5 is a circuit diagram showing connection of a conventional surge protection component.

FIG. 6 is a diagram showing a configuration of a conventional resistor R1.

[Explanation of symbols]

 10 substrate 20 conductor 30 resistor 31 fuse resistor 31a trimming groove 41 molten layer

Claims (3)

[Scope of utility model registration request] 1. An overcurrent protection component formed on an insulating substrate of a predetermined size, comprising a fuse element of a predetermined size formed on one surface of the insulating substrate, and a fuse element formed on the surface of the fuse element. A resistor element of a predetermined size formed separately; a first conductor connected to one end portion of the fuse element; a second conductor connected to one end portion of the resistor element; and a fuse element of the fuse element. An overcurrent protection component comprising a third conductor that connects the vicinity of the other end and the vicinity of the other end of the resistance element. 2. The fuse element includes at least one groove portion having a predetermined width and a predetermined depth, and a molten layer formed so as to substantially cover the groove portion. Overcurrent protection component. 3. The insulating substrate is an alumina substrate, the fuse element is a metal film, the resistance element is a thick film resistor, and the molten layer contains glass. Overcurrent protection parts.