JPS58106731A - Method of producing fuse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a fuse, and particularly to an improvement in a method for manufacturing a fuse of a type in which an insulating substrate is used as a support and a fuse portion is formed on the side surface of the support.

For example, fuses have conventionally been used in which an insulating substrate made of ceramic, phosphor, or the like is used as a support, and a fuse portion is formed on the side surface of the support. FIG. 1 is a diagonal mgm diagram showing an example of this type of fuse. Referring to No. 111, the fuse 1 uses a ceramic substrate 2 as an insulating substrate as a support. A notch is formed in a part of 1i3 of the ceramic substrate 2, and a fuse portion 4 is formed in this notch. No, electrodes 5.6 are formed on both sides of the ceramic substrate 2, that is, on the top and bottom surfaces. Electrode 5.6&t is shorted by fuse aI$4. Fuse IE4 and electrode 5.6 are made of the same electrically conductive material, as will be explained later. The fuse 1 shown in FIG. 1 uses a ceramic substrate 2 as a support and the fuse part 4 is provided on the side i13 of the ceramic substrate 2. Therefore, even if an external force is applied when mounting the electronic device on the buttock, it will not deform or deform. It has the advantage that it is almost never destroyed, causing no damage to handling, and is relatively small, so it does not require wasted installation space. However, in the method for manufacturing the fuse 1, there are various similar points, as will be explained in detail below.

The fuse 1 is manufactured by electrolessly plating a conductive material such as copper, nickel, lead, or zinc onto a ceramic substrate 2 in which a notch is formed, and then polishing the side surface. By polishing the side surfaces, electrodes 5.6 are formed on both sides of the ceramic substrate 2, and at the same time, the fuse portion 4 is formed from the conductive material left in the notch. by the way,
When the fuse 1 is mounted on a printed circuit board like other electronic components, etc., it is desirable that a terminal such as a lead wire be connected to the fuse 1 in advance. This is because it is possible to eliminate the work of installing the component that holds the fuse 1 on the printed circuit board in advance, and it is possible to automatically test the printed circuit board at the same time as other electronic components. Therefore, it is required to connect a terminal such as a lead wire in advance to the electrode 5.6 of the fuse 1 shown in FIG. By the way, in general, in electronic components, terminals such as lead wires 11 are connected by solder dipping in order to achieve high efficiency. However, it is not possible to connect terminals such as lead wires to the electrodes 5.6 of the fuse 1 shown in FIG. This is because the solder will also adhere to the fuse portion 4 during solder immersion. If solder adheres to the fuse portion 4, the characteristics of the fuse portion 4 will change, making it impossible to obtain a fuse 1 having uniform fusing characteristics.

Therefore, although the fuse 1 shown in FIG. 1 has various advantages as mentioned above, the only way to connect the terminals for replacing the lead wires is to connect them individually with a trowel or the like every 1 W, which is extremely difficult. Workability was poor.

Furthermore, in the fuse 1 shown in FIG.
Because the fuse is exposed, there is also the disadvantage that when it blows, the conductive material that makes up the fuse section 4 will scatter and be scattered around the surrounding electronic components, leading to deterioration of the characteristics of the electronic device and even malfunction. did.

Therefore, the main object of the present invention is to provide a method for manufacturing a fuse that can be mounted on a printed circuit board or the like with high efficiency, without causing the material constituting the fuse to scatter to the outside during willi.

In summary, this invention forms an insulating coating so as to cover a fuse portion formed in a notch on the side surface of an insulating substrate,
Next, the method for manufacturing a fuse includes the step of connecting terminals to a pair of electrodes formed on both sides of an insulating substrate by solder dipping.

The above objects and other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

FIGS. 2 to 7 are diagrams for explaining one embodiment of the present invention in the order of steps.

FIG. 2 is a perspective view showing a ceramic substrate as an insulating substrate used in an embodiment of the present invention. First, a ceramic substrate 12 as an insulating substrate having a notch 14a formed in the side surface 13 is prepared. Two or more cutouts 14a may be provided. Next, the ceramic substrate 12
A conductive material with excellent fusing properties, such as nickel, lead, zinc, etc., is deposited over the entire body, for example, by electroless plating. Insulation entirely covered with such a conductive material 5
- The side surface 13 of the magnetic substrate 12 is then polished by, for example, centerless polishing or sandblasting.

As a result, the conductive material attached to the negative surface 13 is removed. Polishing is performed to leave the conductive material in the notch 14a. Therefore, the conductive material remains on the upper and lower surfaces of the insulating substrate 12 and the notch 14a. In this way, the fuse strand 11 as shown in perspective view in FIG. 143 is assembled. Fuse cord 1
1 is an insulating substrate 1 in which a notch is formed on the side 1Ii13.
2, and a pair of electrodes 1i15°16 formed on both sides of the substrate.
and a fuse portion 14 formed in the notch. The fuse portion 14 is constructed by adhering a conductive material to a portion shown as a notch 14a in FIG.

Further, the electrode 15 and 'R-16 are short-circuited by the fuse part 14.

The process up to this point is the same as the conventional method for manufacturing the fuse 1 described with reference to FIG.

Next, at least the fuse portion 14 is coated with, for example, a paraffin-based impregnating agent. FIG. 4 shows 6- a fuse element 11 whose fuse portion 14 is coated with an impregnating agent;
FIG. 3 is a diagram corresponding to a cross-sectional view taken along line IV-IV in FIG. 3. Referring to FIG. 4, an impregnating agent 1118 is formed in the fuse portion 14 of the fuse element 11. As shown in FIG. ' Next, an insulating film is formed to cover at least the fuse portion 14 of the fuse element 11. FIG. 5 is a perspective view showing the fuse element 11 on which an insulating coating is formed.

Referring to FIG. 5, fuse part 1 of fuse element 11
4 and its vicinity, for example, applying insulating paint or
An insulating film 19 is formed by baking. 6th
The figure is a sectional view showing the structure of the fuse element 11 on which the insulating film 19 is formed, and is a sectional view taken along the line Vl-VI in FIG. FIG. 6 is shown schematically and on a different scale from FIG. 5 in order to facilitate understanding of the structure of the fuse element 11. As is clear from FIG. 6, the insulating coating 19 is formed to cover the vicinity of the fuse portion 14, but the impregnated layer shown in FIG. 4 has completely disappeared. That is, the impregnating agent layer 18 disappears between the conductive material constituting the fuse portion 14 and the insulating liquid 1119, leaving an empty space 1I2.
0 is formed. The voids 20 are generated when, for example, a paraffin-based impregnating agent is melted and absorbed into the insulating paint during the formation of the insulating coating 19, that is, when the insulating paint is applied and baked. Functions as a knee plasty agent. The void 1120 is formed to stabilize the fusing characteristics of the fuse portion 14. Fuse part 1
When the insulation coating 19 is formed on the surface of 4, the insulation coating 19
The fusing characteristics of the fuse part 14 change depending on the thickness of the insulating liquid 1119 and the fuse 11.
By providing the gap 20 between the fuse part 14 and the fuse part 14, it is possible to make the fusing characteristics of the fuse part 14 more constant.

Next, the portion of the electrode 15 that is not covered with the insulating liquid 1119 is
．． 16, glue and bran as terminals 21.22 respectively
is connected. FIG. 7 shows the fuse element 11 to which the leads 21, 22 are connected, ie the fuse 31 obtained according to this embodiment. It is a diagram. Lead wire 21.
The connections 22 are made by solder dipping, which is commonly used for connecting lead wires to electronic component elements. When connecting the lead wires 21 and 22 by dipping in solder, as is clear from FIGS. 6 and 7, since the fuse portion 14 is covered with an insulating film 19, there is a risk that solder may adhere to the fuse portion 14. Therefore, it is possible to connect the lead wires 21 and 22 with high efficiency.

As described above, in this embodiment described with reference to FIGS. 2 to 7, since the fuse portion 14 is covered with the insulating coating 19, the lead wires 21 and 22 as terminals are
It becomes possible to easily connect by solder dipping, which was previously impossible.

Therefore, it is possible to automatically mount the electronic component onto the printed circuit board in the same way and at the same time as other electronic components.

Further, since the fuse part 14 is covered with an insulating coating 19, even if the fuse part 14 blows during use,
Splashing of the conductive material constituting the fuse portion 14 is effectively eliminated. Further, since the void 1120 is formed between the =9- fuse portion 14 and the insulating coating 19, the fusing characteristics of the fuse portion 14 can always be kept uniform.

#I8wI and FIG. 19 are partial sectional views for explaining examples in which the fuse 31 obtained in this embodiment is actually used. As is clear from FIG. 8, the fuse 31 can be directly inserted into the printed circuit board 32 since the lead wires 21 and 22 have already been connected. The lead wires 21.22 inserted into the printed circuit board 32 are fixed by solder 1133.34 formed on the lower surface of the printed circuit board 32 by soldering.

Also, as is clear from the 9th FM, the bin terminal 35.3
6 is buried, the lead wire 21°2
By directly inserting fuse 3, you can connect fuse 3 with one touch.
1 can be attached and detached. Therefore, the fuse 31 of this embodiment, like other general electronic components connected to lead wires, can be easily and effectively attached to or detached from the board.

10- Note that in the above embodiment, the ceramic substrate 12 was used as the insulating substrate, but the insulating substrate may be formed using an insulating material other than ceramics, and the waste material can also be used. It is possible.

Furthermore, although the lead strings 21 and 22 are shown as the terminals connected to the fuse element 11, the terminals are not limited to the lead strings and may have various shapes. Furthermore, the insulating coating 19
is formed of an insulating paint, but may be formed of various insulating materials such as other insulating resins or glass. Further, the thickness of the insulating liquid 1119 does not have to be so thick as to follow the shape of the fuse portion 14, and can be formed to have various thicknesses.

As described above, according to the present invention, since the insulating coating that covers at least the fuse portion of the fuse element is formed on the fuse element, terminals such as lead bran can be connected by solder dipping, which was previously impossible. becomes possible.

Therefore, for example, a lead ring can be connected easily and inexpensively, and as a result, a fuse can be easily and automatically attached to a printed circuit board, etc., in the same way and at the same time as an electronic component to which a general lead ring is connected. becomes possible. Since the fuse part is covered with an insulating coating, when the fuse part melts, the conductive material that makes up the fuse part will fly outside! This makes it possible to effectively solve the problem.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a type of fuse to which the present invention can be utilized. 2a1 is a perspective view showing a ceramic substrate as an insulating substrate used in one embodiment of the present invention. FIG. 3 is a perspective view showing a fuse element used in 1*wAgl of the present invention. Figure 4 shows the fuse element Ii with the fuse part coated with an impregnating agent.
It is a garden map, and is a view corresponding to a cross section taken along line IV-IV in FIG. 3. FIG. 5 is a perspective view showing a fuse element on which an insulating film is formed. FIG. 6 is a cross-sectional view of a fuse element on which an insulating film is formed.
FIG. FIG. 7 is a perspective view showing a fuse obtained according to an embodiment of the present invention. FIG. 18 and FIG. 9 are partial cross-sectional views showing an example of the use of a fuse obtained according to an embodiment of the present invention. In the figure, 11 is a fuse element, 12 is a ceramic substrate as an insulating substrate, 13 is one side, 14a is a notch, 1
4 is a fuse part, 15.16 is an electrode, 19 is an insulating coating,
31 indicates a fuse. Patent applicant Murata Manufacturing Co., Ltd. 13- Figure 1 Figure 2 Figure 3 Figure 4 Figure 7 Figure 8 Figure 91: Qj 131

Claims (1)

[Scope of Claims] An insulating substrate having at least one notch formed on a side surface, a pair of electrodes formed on both sides of the substrate, and a pair of electrodes formed in the notch and connecting the pair of electrodes. a that covers at least the fuse part of the fuse element;
A method for manufacturing a fuse, comprising the steps of: forming a coating on a fuse element, and then connecting a terminal to a pair of electrodes of the fuse element by solder dipping.