JPH0452606B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to electronic components such as film capacitors that have electrodes and are covered with resin.

Conventional configurations and their problems In recent years, with the miniaturization of electronic devices, there has been a demand for film capacitors, which are circuit components, to be made into chips. A common method for making film capacitors into chips is to use comb leads as electrodes and cover them with a resin mold in order to improve solder heat resistance and dimensional accuracy. In order to ensure the characteristics and reliability of the product using this mold packaging method, the structure of the electrical connection between the element and the com lead must not cause deformation of the com lead and have sufficient mechanical holding power for the element. It must be. This is because if the comb lead is deformed, the correction of the deformation of the comb lead during mold clamping will put stress on the electrical connection, which may break the connection or reduce reliability. This is also because a mechanical holding force is required to hold the element at the center of the mold against the flow pressure of the molten and pressurized resin injected into the mold during molding. For this reason, traditionally,
Various electrode lead-out portion structures have been adopted. The conventional example and its problems will be explained below.

In a structure in which the tip of the com lead 1 is bent by bending and connected directly to the electrode surface 2a of the element 2 by welding as shown in Fig. 1a and b, the length l dimension of the element 2 is not determined. Because it is uniform, if welding is performed based on the bending dimension L of COMLEAD 1, tensile force and bending moment will occur in the welded part, resulting in deformation of COMLEAD 1 and insufficient welding strength, resulting in electrical connection failure due to the mold. rate is high.

In addition, as shown in FIGS. 2a and 2b, in the method in which the tip end 3 of the com lead 1 is made into a thin cross-section as shown in the figure and welded to the electrode surface 2a of the element 2, Since the tip 3 of the COMLEAD 1 has a thin cross-section, it can be easily plastically deformed and does not cause warping of the COMLEAD 1 body, but the tensile strength of the welded part is weak and the heat shock during welding However, there are drawbacks such as the tendency for this thin cross-section to break.

Furthermore, as shown in FIGS. 3a and 3b, wire bonding using a wire 4, which is performed in an IC or the like, is also possible, but this has the disadvantage that the holding force of the element 2 is weak and the production cost is high.

Purpose of the Invention In view of the drawbacks of the conventional example, the present invention eliminates the deformation of the com lead, increases the holding force of the element to a predetermined level or more, and thereby improves the product characteristics and reliability when exteriorly molded. It is an object of the present invention to provide an electronic component that can reduce costs by using a highly productive welding method that is used in an electrode extraction method.

Structure of the Invention In order to achieve this object, the present invention comprises an element having electrode surfaces at both ends, and a terminal plate for electrically connecting this element to an external circuit. The electrode lead-out part is punched out and bent so as to be integrated with the element, and the electrode lead-out part is composed of a flat part connected between the electrodes of the element and a lead part narrower than the flat part.

DESCRIPTION OF EMBODIMENTS Hereinafter, FIGS. 4 to 7 will explain one embodiment of the present invention.
This will be explained in detail with reference to the figures.

Figure 4 shows the comb lead 5 that will eventually become a terminal plate with a uniform width by cutting, and the electrode lead-out portion 6 punched at its tip so as to be integrated with the tip.
Figures 5a and b show the element 7 being welded to the com lead 5 using the welding tip 8, and Figures 6a and b show the exterior 9 being welded by resin molding. 1 shows a structure of a film capacitor according to the present invention. The material of Comlead 5 is
Generally made of nickel silver, phosphor bronze, iron alloy alloy, etc.
The thickness is 0.075 m/m to 0.15 m/m. An electrode extension part 6 which is bent so as to be raised by machining at the tip of the com lead 5 is an electrode surface 7a of the element 7.
It consists of a flat part 6a that is connected to the comb lead 5, and a lead part 6b that is narrower than the flat part 6a that connects this flat part 6a and the comb lead 5. The flat part 6a at the tip conducts electricity to the electrode surface of the element It has an area of at least 0.3 mm ² as a physical connection. This has been conventionally used as a connection method for the electrode lead-out part 6, and in adopting the parallel gap welding method, which has high reliability in electrical characteristics and strong strength, 8. This is because it requires a contact area equivalent to two welding chips, which in this example is 0.75 mm ² and has a welding strength of 300 g or more.

Further, the lower lead part 6b connects the welded part to the element 7 and the comb lead 5, and its cross-sectional area and length are adapted to the welding method, and have a cross-sectional area of 0.022~
Specified as 0.075mm ² and length 0.5mm or more. here,
If the lead part 6b is made of a general material and has a cross-sectional area larger than 0.075 ^mm2 and a length longer than 0.5 mm, the rigidity of this part is large and the amount of plastic deformation is small, resulting in uneven dimensions of the element 7 during welding. Also, changes in the welded portion caused by penetration of the electrode surface 7a of the element 7 are elastically deformed, causing the comb lead 5 to warp. As a result, when the warpage of the comb lead 5 is corrected during molding, stress is applied to the welded portion, causing the welded surface to peel off, resulting in a high electrical connection failure rate. In addition, the cross-sectional area of the lead portion 6b
In the case of a general material with a shape smaller than 0.022 mm ² and a length smaller than 0.05 mm, the rigidity of this part is small, so all changes in the welded part are treated as plastic deformation, and the com lead 5 does not warp. ,
Due to the heat shock during welding, this lead part 6
(b), the mechanical tensile strength is low, and the electrical connection failure rate is high.

FIG. 7 shows the change in the disconnection failure rate after molding when the shape of the lead portion 6b was variously changed. In this embodiment, the shape of the lead portion 6b has a cross-sectional area of 0.04
mm ² and length 1 m/m.

Finally, as shown in FIGS. 6a and 6b, the entire electrode lead-out portion is sealed with mold exterior resin 9 to protect the electrical connection, and the comb lead 5 is cut at a predetermined position. , the film capacitor of the present invention can be obtained by bending.

Effects of the Invention As described above, according to the film capacitor of the present invention, parallel gap welding, which has been widely used and is highly reliable, is possible, and reliability of product characteristics can be improved, and productivity and cost can be improved. The practical effect is great.

[Brief explanation of the drawing]

1a, b to 3 a, b are perspective views and front views showing the main structure in the conventional film capacitor manufacturing process, respectively, and FIGS. 4, 5 a, and 6 a are the invention according to the present invention. A perspective view showing the manufacturing process of a film capacitor according to one embodiment, FIG. 5b and FIG. 6b are front views of the parts shown in FIGS. 5a and 6a, respectively, and FIG. FIG. 3 is a diagram showing the relationship between area and disconnection defect rate after molding. 5... Com lead, 6... Electrode extraction part, 6a
... Plan view, 6b ... Lead section, 7 ... Element, 7
a... Electrode surface.

Claims (1)

[Claims] 1. In a resin-clad electronic component consisting of an element having electrode surfaces on both ends and a terminal plate of uniform width that electrically connects this element to an external circuit, one tip of the terminal plate is integrated with this tip. An electrode lead-out part is provided which is punched and bent as shown in FIG.
An electronic component having an area of 0.3 mm ² or more, wherein the lead portion has a cross-sectional area of 0.022 to 0.075 mm ² and a length of 0.5 mm or more.