JPS598325A - Chip-like solid electrolytic condenser - 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 chip-shaped solid electrolytic capacitor.

Conventionally, chip-shaped solid electrolytic capacitors that are face-bonded and attached to printed circuit boards, etc. have been covered with resin by transfer molding, but these have been large in size and expensive.

Also, as a bare type without transfer molding,
There were metal terminals that could be soldered to the leads pulled out from the capacitor element's positive body, but;
The accuracy of the J'' method was poor, the mechanical strength was low, and it was difficult to automate attachment to the printing radix.

In addition, all of the products mentioned above involve a step of welding a metal terminal to the lead-out lead, which has the disadvantage that the structure is complicated and it is difficult to miniaturize.

The present invention solves the above-mentioned drawbacks and provides a chip-shaped solid electrolytic capacitor that is small and can be easily and inexpensively manufactured.

The present invention will be explained below with reference to embodiments shown in FIGS. 1 to 4.

First, as shown in FIG. 1, the lead-out leads l of a plurality of prismatic, cylindrical, etc. anode bodies 2 made of valve metal such as tantalum or aluminum and having lead-out leads 1 are welded and connected to the power supply bar 3. A dielectric oxide film 4 is formed on the surface of the positive electrode body 2, and a conductive solid electrolyte layer 5 such as manganese dioxide is formed on the film, and a cathode conductive layer 6 such as carbon and carbon paste is formed on the film. are formed sequentially. Next, apply epoxy or other reinforcing material (Δ(grease 7/I) to the lead-out part of the d lead-out lead 1 and harden it, and then apply epoxy powder ice resin to cover the anode body 2 using the electrostatic coating method. Resin r ('j 8 is formed. Then, the resin layer 8 attached to the lead-out lead 1 made of tantalum, aluminum, etc. and the bottom of the anode body 2 is fJ
As shown in FIG. 2, after being selectively removed by air blasting or the like, the remaining resin layer 8 is cured.

Furthermore, the resin layer 8 and foreign matter that have adhered to the lead-out lead 1 are sprayed with alumina (-1 digit), and this 1.1° adhesion is removed by a so-called sandblasting method, and the lead-out lead 1 is Table 1fii dielectric oxide skin 1 copy 4
is removed, and unevenness 1a is formed on the metal surface.

Next, a conductive layer 9 such as silver base is applied to the cathode side electrode portion from which the resin layer 8 at the bottom of the anode body 2 has been removed, and cured. The containing conductive layer 10 is applied and cured. At this time, conductive layer 1
0 is also applied to the anode side and cured.

Next, in order to separate the lead-out lead 1 from the power supply bar 3, a notch is made in the lead-out lead 1. Then, an electrolytic plating layer 11 (electrolytic plating layer 11) is formed on the conductive layer 10 and the lead-out leads on which irregularities 1a are formed on the surface by applying electroless plating treatment made of a metal such as nickel or copper. After the aging treatment, the lead-out lead 1 is bent from the notch and separated from the power supply bar to complete the process.

The chip-shaped solid electrolytic capacitor of the present invention is constructed as described above.

Therefore, since the external electrode does not require a welding process and a metal plating layer is formed, the external dimensions are extremely small, and the oxide film on the surface of the lead-out lead is removed to form unevenness, so the electroless plating layer The adhesion with 11 becomes strong, and the conductivity during handling/1. ) The plating layer does not peel off due to lead bending, etc., and a highly reliable capacitor can be obtained.

The table shows the plating peeling test results for a chip-shaped solid tantalum electrolytic capacitor with a rating of 3.15V and 100ILF.

Fix the tip of the test condition derivation lead, bend the capacitor body 30 degrees in the desired direction, and then return it to its original position. Further, bend it 30' in the opposite diagonal direction and then return it to its original shape.

This cycle is performed once.

FIG. 5 shows the results of a load life test in which a chip-shaped solid tantalum electrolytic capacitor having the same rating as described above was attached to a printed circuit board and a reduced voltage was applied at 125°C.

As is clear from the table and FIG. 5, the product of the present invention has less variation in leakage current characteristics and loss than the conventional product, proving that it is extremely stable.

As mentioned above, the chip-shaped solid electrolytic capacitor of the present invention is
It is small, the electrodes are connected extremely firmly, and it is extremely advantageous in terms of reliability, so it is of great industrial and practical value.

[Brief explanation of the drawing]

Figures 1 to 4 are explanatory diagrams of the manufacturing process of a chip solid electrolytic capacitor according to an embodiment of the present invention, and Figure 5 is a load life test of a chip solid electrolytic capacitor comparing the product of the present invention and a conventional product. (a) is a one-hour characteristic diagram of loss, and (b) is a one-hour characteristic diagram of leakage current. 1: Derivation lead 1a: Unevenness 2: Anode body 4: Dielectric oxide film 5 Two solid electrolyte layers 6: Cathode conductive layer 8: Resin layer 11: Electroless plating layer Patent applicant Nichicon Sprague Co., Ltd. Figure 1 8 Figure 0 9 Figure 2 Figure 41

Claims (1)

[Claims] A dielectric oxide film is formed on the surface of an anode body made of a valve metal having a lead-out lead, and the film is formed.Secondly, a solid electrolyte layer,
After forming a cathode conductive layer and forming a 411i resin layer to cover the anode body using an electrostatic coating method or the like, the resin layer adhering to the exposed lead is removed by a sandblasting method or the like, and the lead-out lead is removed. 1. A chip-shaped solid electrolytic capacitor characterized in that a positive electrode portion is formed by forming irregularities on the surface of the solid electrolytic capacitor and sequentially forming an electroless plating layer thereon.