JP2786018B2 - Chip type solid electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type solid electrolytic capacitor, and more particularly to a product exterior structure.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a chip-type solid electrolytic capacitor of this type (hereinafter referred to as a chip capacitor) has a capacitor element 1 and a first lead terminal 3a connected to an anode lead 2 derived from the element. First, the first lead terminal 3a is welded to a capacitor having a structure in which a heat-resistant insulating resin 4 is packaged by transfer molding and a capacitor element 1 and an anode lead 2 derived from the element as shown in FIG. It is broadly divided into those with a structure exposed without performing.

[0003]

The above-described chip capacitor shown in FIG. 5 is suitable for automatic mounting because it has a high resistance to impact for mold molding by transfer molding and has high dimensional accuracy of the exterior. However, it requires a large amount of investment in equipment such as a molding machine and a mold, and the electric characteristics are deteriorated due to the injection pressure during molding and the residual stress after molding. There was a drawback that the external dimensions became large in comparison.

On the other hand, the chip capacitor of FIG. 6 has good volumetric efficiency and is inexpensive and inexpensive. However, it is more vulnerable to impact than the chip capacitor of FIG. In addition, there was a problem that the shape was not adjusted, so that it was not suitable for automatic mounting.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce deterioration in characteristics due to injection pressure during molding and residual stress after molding generated in a transfer mold exterior product, and to achieve miniaturization.
Another object of the present invention is to provide a chip-type solid electrolytic capacitor having improved impact resistance as compared with an exposed structure and capable of reducing deterioration of electrical characteristics.

[0006]

The chip-type solid electrolytic capacitor of the present invention has a film electrode portion formed on opposing side walls.
A solid electrolytic capacitor element housed in the a box-like heat-resistant film substrate, the anode lead derived from the element
And a lead terminal connected, Shirubedenpe to the film electrode portion
After the connection with a paste or solder cream, the outer surface of the component body except for the heat-resistant film substrate and the film electrode portion is covered with a heat-resistant insulating resin.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is an assembled perspective view of one embodiment of the present invention.

In FIG. 1, FIG. 1 (a) shows a component body before assembly, in which a first lead terminal 3a is welded to an anode lead 2 derived from a capacitor element 1. FIG. Next, FIG.
On the heat-resistant film substrate 5 (thickness: 100 to 150 μm) formed into a box shape shown in FIG.
(Formed on opposing side walls of the heat-resistant film substrate 5)
Pre conductive paste or cream solder 7 that)
Is applied, and as shown in FIG.
Then, as shown in FIG. 1D, a heat-resistant insulating resin 4 such as epoxy resin is applied to the outer surface of the component body excluding the heat-resistant film substrate 5 and the film electrode portion 6. The film electrode portion 6 is solder-finished with a thickness of 4 to 10 μm in order to improve the soldering at the electrode portion provided on the heat-resistant film substrate 5.

Next, FIG. 1D shows a chip capacitor according to an embodiment of the present invention, and FIG.
As shown in Table 1, the volume of the completed product in the capacitor element of 35 V-0.1 μF is reduced by about 50% as compared with the conventional example.

[0010]

[0011] Further, when the leakage current defect ratio after the exterior of the two was compared, as shown in Table 2, in the transfer mold exterior structure of the conventional example, FIG. 0.15% was generated. On the other hand, in the embodiment of the present invention, since the potting is performed by the liquid resin, the deterioration is extremely small and the defective rate is 0.02%.

[0012]

The quality of the leakage current exceeded 50 nA, which was regarded as defective.

Next, a comparison of the impact resistance between the product of the present invention and the embodiment of FIG. 1D and the device exposed structure of the conventional example shown in FIG.
As shown in the figure, since the conventional example has an element exposed structure, stress is applied to the roots of the capacitor element 1 and the anode lead 2 to lead out.
If it exceeds 0 g, the leakage current is greatly deteriorated.

On the other hand, the embodiment of the present invention
And the entire anode lead 2 was covered with the heat-resistant insulating resin 4, and a maximum load of 3 kg was applied, but no deterioration was observed. Therefore, in the embodiment, the strength is increased about four times or more as compared with the conventional exposed structure.

The impact resistance was measured by pressing the upper part of the product using a tension gauge having a maximum load of 3 kg as shown in FIG. 4 and actually measuring the load at which the leakage current deteriorated.

FIG. 2 is a perspective view of another embodiment of the present invention. In the first embodiment, the mounting direction is only one plane, but in the second embodiment, the film electrode 6 of the heat-resistant film substrate 5 is provided on each plane as shown in FIG. Can be implemented. As a result, it is possible to prevent open failure due to rollover during mounting.

[0018]

As described above, the present invention has the following effects because it is formed by combining a heat-resistant film substrate formed in a box shape and a chip capacitor having a conventional element exposed structure.

(1) When the capacity of the internal element is the same, the product of the present invention is
The size is reduced by about 50%.

(2) The conventional molded article is largely deteriorated by molding pressure, whereas the article of the present invention is slightly deteriorated due to potting with a liquid resin. For example, comparing the leakage current defect rate, the conventional product is 0.15% and the present invention product is 0.02%
And about 1/8.

(3) The impact resistance is about four times as high as that of the element exposed structure. Also, automatic mounting is facilitated by using the heat-resistant film substrate as a guide.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure and an assembling process of an embodiment of the present invention.

FIG. 2 is a perspective view of another embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a product pressing load and a leakage current of the first embodiment of the present invention and a conventional example (the structure of FIG. 6).

FIG. 4 is a schematic diagram of measurement of impact resistance.

FIG. 5 is a side view of an example of a conventional chip-type solid electrolytic capacitor having a transfer mold exterior structure.

FIG. 6 is a side view of an example of a conventional chip-type solid electrolytic capacitor having an element exposed structure.

[Explanation of symbols]

 Reference Signs List 1 capacitor element 2 anode lead 3a first lead terminal 3b second lead terminal 4 heat-resistant insulating resin 5 heat-resistant film substrate 6 film electrode 7 cream solder

Claims (1)

(57) [Claims] 1. A film electrode portion is formed on opposing side walls.
A solid electrolytic capacitor element housed in a box-shaped heat-resistant film substrate and an anode lead derived from the element
Continue the the lead terminals, conductive page on the film electrode portion
A chip-type solid electrolytic capacitor characterized in that after connecting with a strike or solder cream, the outer surface of the component body excluding a heat-resistant film substrate and a film electrode portion is covered with a heat-resistant insulating resin.