JPH0256808B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to electronic components, and more specifically, to so-called leadless electronic components. In the following description, an aluminum electrolytic capacitor will be explained in detail, but the present invention is not limited to aluminum electrolytic capacitors, and the same applies to other electronic components. Conventional structure and its problems Conventional so-called leadless electronic components of this type,
For example, a chip-type aluminum electrolytic capacitor was constructed as shown in FIGS. 1a and 1b. That is,
An anode foil, which is made by roughening aluminum foil and forming a dielectric oxide film by anodizing, and a cathode foil, which is made by roughening aluminum foil, are wound through a separator and impregnated with a driving electrolyte to form a capacitor. This capacitor element 1 is housed in a cylindrical metal case 2 with a bottom, and the open end is sealed using an elastic sealing material 3 such as rubber to form an aluminum electrolytic capacitor. The lead wire 4 drawn out from the aluminum electrolytic capacitor is electrically and mechanically connected to the comb-shaped terminal 5 by a method such as welding, and a molded resin sheath 6 is applied to the entire body except for the comb-shaped terminal 5 to create a completed product. It was. When these chip-type aluminum electrolytic capacitors are mounted on a printed circuit board, they are coated with a molded resin exterior 6 as described above in order to provide solder heat resistance. 10 for about 5 minutes at a temperature of
The electrolytic capacitor is pressurized at a pressure of Kg/cm ² , and under such harsh conditions, the driving electrolyte of the electrolytic capacitor evaporates, causing characteristic deterioration such as a decrease in capacitance and an increase in tanδ. Since the molded resin exterior 6 is provided, there is a problem in that the product is extremely expensive. Furthermore, since it is a horizontal type, when it is mounted on a printed circuit board, it occupies a large area of the printed circuit board, which is a factor that hinders miniaturization of various devices. OBJECTS OF THE INVENTION The present invention eliminates these conventional drawbacks, and aims to provide an inexpensive vertical type leadless electronic component without deterioration of characteristics. Structure of the Invention In order to achieve this object, the present invention provides an electronic component body which is resin-coated with a powder resin, and an end surface from which a lead wire of the electronic component body is drawn out. and an insulating plate provided with a through hole through which the lead wire passes through, and a space connected to the through hole is provided on the outer surface of the insulating plate, and the through hole is passed through the insulating plate. The tip of the lead wire is bent so as to fit within the space. With this configuration, since the resin layer is formed as the outermost layer, heat from the outside is difficult to be transmitted to the internal elements, and heat resistance is improved. Furthermore, since it is a vertical type leadless electronic component without a molded resin exterior, it is possible to provide a leadless electronic component that occupies a small area on a printed circuit board when mounted at low cost. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 8 regarding an aluminum electrolytic capacitor. In addition, in the figure, the same parts as in FIG. 1 are given the same numbers. In the figure, 1 is a capacitor element similar to the conventional one, with an anode foil made by electrochemically roughening a high-purity aluminum foil and then anodizing it to form a dielectric oxide film, and a roughened aluminum foil. It is constructed by winding a cathode aluminum foil with an insulating paper interposed therebetween, and impregnating the wound material with a driving electrolyte. This capacitor element 1 is housed in a cylindrical metal case 2 with a bottom. Further, a lead wire 4 is connected to the anode foil and the cathode foil of the capacitor element 1. Then, the open end of the metal case 2 is fitted with a sealing member 3 made of any one of styrene-butadiene rubber, ethylene-propylene rubber, isopropylene rubber, isobutyl-isopropylene rubber, or a composite thereof, and subjected to drawing processing. It is sealed by. The outer surface of the metal case 2 is coated with a resin coating layer 2a made of powdered resin. Lead wire 4 connected to the capacitor element 1
penetrates the sealing member 3 and is drawn out from the same end surface. Reference numeral 8 denotes an insulating plate disposed so as to come into contact with the end surface from which the lead wire 4 of the electronic component body is drawn out, and this insulating plate 8 has a through hole 8 through which the lead wire 4 passes.
A is provided. Further, the outer surface of this insulating plate 8 is provided with a recess 8b that forms a space connected to the through hole 8a, and the tip 4a of the lead wire 4 that has passed through the through hole 8a is accommodated in the recess 8b. It is bent like this. In this case, as shown in FIGS. 4a and 4b, the round bar lead wire 4 may have its tip 4a flattened and bent, or the round bar lead wire may remain as it is. good. Next, the resin coating layer 2a on the outer surface of the metal case 2 will be explained. A fluidized dipping method was used for resin coating. The fluidized immersion method has a structure as shown in FIG. 5, in which powdered resin 9 is placed in a tank 10 and then made into a fluidized state by air passing through a permeable membrane from below, and then vibration is applied to the tank 10. The resin surface is made smooth by distributing airflow throughout. Coating is performed by heating the electronic component body to be coated to approximately 100°C, immersing the heated electronic component body in flowing powder resin 9 and bringing it into contact with powder resin 9, and melting the powder resin 9. and make it sticky. Then, the electronic component body is heated to about 100℃ again to melt and harden the sticky powder resin 9, and as a post-cure.
It was left at 95°C for 60 minutes. Thereby, a uniform resin coating layer 2a of 0.1 mm to 0.15 mm was obtained. As the powder resin 9, an epoxy resin having a particle size of about 50 μm was used. As for the heat insulation effect, as shown in FIG.
Figure 8 shows the change in the internal temperature of the electronic component 12 when the electronic component 12 is mounted using the method 3 and soldered in the reflow oven 14 as shown in Figure 7. The surrounding area was measured using a thermocouple wire. The rating of the mounted electronic component 12 is 4V220μF
Outer diameter dimension 6.3 ⁰ × 5 ^L Resin coating thickness is 0.1 ~
It is 0.15mm. As is clear from the figure, there is a large difference in the gradient of temperature rise, and at the highest temperature, the temperature difference with the top surface of the printed circuit board 11 is 80° C., and the temperature reduction effect is large. The table below shows the results of investigating the changes in characteristics before and after reflow, and it can be seen that the characteristics are extremely stable and are not affected by heat.

[Table] By setting the resin thickness to 0.2 mm, the temperature difference with the printed circuit board 11 was 95°C. From this,
If further temperature reduction is required, this can be achieved by increasing the resin thickness. Furthermore, the resin coating method is not limited to the fluidized dipping method described above, but methods such as the cloud coating method and the electrostatic gun method are also possible, and once the resin thickness described above is formed, there will be no difference in characteristics depending on the method. I couldn't help it. In these electrostatic methods, it was necessary to mask the lead wire portion in order to uniformly adhere the resin particles to the outer surface of the metal. Furthermore, when increasing the resin thickness, the fluidized dipping method was effective because it allowed multilayer coating. Effects of the Invention As described above, according to the present invention, since no molded resin exterior is used, it is possible to easily manufacture inexpensive vertical leadless electronic components, and there is no characteristic deterioration. This has the effect that stable leadless electronic components can be obtained.

[Brief explanation of drawings]

Figures 1a and b are cross-sectional views and side views of a conventional chip-type aluminum electrolytic capacitor, Figure 2 is a perspective view of a leadless aluminum electrolytic capacitor according to an embodiment of the present invention, and Figure 3 is a cross-sectional view of a conventional chip-type aluminum electrolytic capacitor. 4a and 4b are perspective views showing a lead shape according to an embodiment of the present invention, FIG. 5 is a structural diagram of a fluidized dipping device, and FIG. 6 is a diagram showing an embodiment of the present invention. FIG. 7 is a front view of the mounting state according to the example, a structural diagram of a reflow oven used for heat resistance evaluation, and FIG. 8 is a temperature characteristic diagram during reflow. 1...Capacitor element, 2...Metal case, 2
a... Resin coating layer, 3... Sealing member, 4
... Lead wire, 8 ... Insulating plate, 8a ... Through hole,
8b... recess, 9... powder resin, 10... tank, 1
1...Printed circuit board.

Claims (1)

[Claims] 1. An electronic component body which is constructed by storing a component element in a case and sealing the open end with rubber, and the lead wires connected to the component element are pulled out through the same end face and the case is coated with resin. an insulating plate disposed so as to be in contact with an end surface from which the lead wire is pulled out and having a through hole through which the lead wire passes, and a space connected to the through hole is provided on the outer surface of the insulating plate; An electronic component characterized in that the tip of the lead wire passing through the through hole is bent so as to fit within the space.