JPS58202523A - Method of producing 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 method for manufacturing a solid electrolytic capacitor provided with a resin exterior.

In general, solid electrolytic capacitors coated with resin are at risk of deteriorating characteristics due to moisture absorption, so in order to improve moisture resistance, before applying the resin coat, liquid resin with a low fI of 5 degrees and a heat distortion temperature of less than 100 degrees Celsius is used. A method is used in which the resin is immersed in the capacitor under reduced pressure or normal pressure to fill the porous gaps in the capacitor. It is effective in preventing moisture infiltration because it fills well into the porous gaps of the capacitor.However, because it is applied with a low viscosity, it is extremely difficult to coat the outer surface of the capacitor, and at the same time, it has a heat distortion temperature of 100°. Y because it is lower than C
When thermal stress such as mold temperature and resin curing heat is applied during resin exterior work using transfer molding, electrons become high temperature, which rarely causes leakage current deterioration. In addition, when the viscosity of the capacitor is too low, the condensate penetrates into the electrons too well and the contact resistance between the cathode layers and between the cathode particles becomes large. ) was a factor in the deterioration of tan δ.

However, these characteristics tend to deteriorate even more when used in high IJ sea areas.

The present invention has been made in view of the above-mentioned points, and is a solid X-solution capacitor that can reduce the thermal streaking of the capacitor capacitor when it is covered with resin, and can also prevent as much as possible the filling of resin into the gaps between the porous parts of the capacitor element. The purpose of this invention is to provide a method for manufacturing.

The present invention will be explained below. For example, tantalum,
Valve lid powder of aluminum, niobium, etc. is compacted to form an anode body. Next, on the surface of the anode body, a capacitor element is formed by sequentially laminating a binding electric body reflection layer, a Ushihashi layer, a depletion layer, and a negative layer. Then, the capacitor element is fixed in a liquid resin having physical properties such as a density of 500 to 5000 op and a heat distortion temperature of 100°C or more at room temperature under reduced pressure or normal pressure, and then pulled out and cured under predetermined conditions to undercoat. form a layer. Therefore, the exterior material is coated with a resin using a molding method such as injection molding or the like. The molding material in this case may be either a thermosetting resin such as epoxy or silicone or a thermoplastic resin such as polypropylene or polyphenylene sulfide. Figures 1 and 2 show solid 1! obtained by the above method. In the cross-sectional view showing the solution capacitor, (1) is the capacitor element, (2) is the anode lead wire, and (3) is the cathode lead wire.

(4) 1 layer of μ under go, (5) coat with exterior W fat.

As described above, according to the manufacturing method of a one-piece 'A' capacitor made of wt, 0.1~
A capacitor film of about 0.2 m11 is formed, and the formed film is resistant to thermal stress, so leakage current and tan in the process of forming an exterior resin mold are reduced.
It has the advantage of less deterioration in δ characteristics.

Next, the uniqueness of the present invention will be described based on experimental results. A tantalum solid electrolytic capacitor element molded by a known method was immersed in each of the undercoating epoxy resin solutions shown in the table for 10 minutes and then pulled out.
Curing is performed for 0.5 hours to form an undercoat layer.

Leakage current and t a in a tantalum solid electrolytic capacitor with a rating of 20V-4.7PF, which was then transfer molded using epoxy resin molding material and packaged.
A comparison of the characteristics of nJ is shown in the table. The epoxy resin molding material is commonly used and has a spiral flow rating of 100.
1 Glass transition point 160°Oe deformation 1Ji 200°0, transfer temperature at 150°C
Transfer pressure is 6oKt/♂.

There are also 100 pieces for each sample.

As is clear from the above table, in order to suppress the deterioration of leakage current characteristics in the exterior resin molding process as much as possible, the viscosity of the undercoat W resin is preferably 500 to 5000 op. It can be seen that the heat deformation temperature of the coating w resin is required to be 100"C or more. Therefore, the viscosity is 500 to 5000 op at room temperature before molding the exterior resin.

By forming an undercoat layer on the capacitor element using a liquid resin with physical properties such as a heat distortion temperature of 100°0 or more, it is possible to minimize the effects caused by heat and curing stress of the molding resin material during exterior resin molding. It becomes possible to obtain a high-quality solid electrolytic capacitor with suppressed characteristic deterioration. In addition to the above experimental example, the viscosity was 5500ap.
In the case of undercoating using a liquid resin with a heat deformation temperature of 140°0, the undercoat layer was too thick and the dimensions were too large. Ta.

As described above, according to the present invention, before applying the exterior resin, the viscosity is 500 to 5000 op at room temperature, and the heat distortion temperature is 100 °C.
By immersing the capacitor element in a liquid resin with the above physical properties and forming an undercoat layer, leakage can be reduced by 11IL.
Initial characteristics of current and tan δ of solid electrolytic capacitors that can obtain capacitors: 411i! We can provide a manufacturing method.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing a solid electrolytic capacitor according to the present invention. (1)---1□Capacitor element (4)-1111-Undercoat layer (5)----Ichigai MIm Resin Patent Application Hito Marukon Electronics Co., Ltd. (7) Figure 1 Figure 2 Figure 95-

Claims (1)

[Claims] A means for forming a capacitor by molding a valve metal powder, and a means for forming a capacitor by molding the capacitor at room temperature.
5000op, a means for dipping F5 in liquid T* fat having physical properties of heat distortion temperature of 100°C or more and curing the top with heat to form an undercoat layer, and a rear exterior of the means! 1. A method for manufacturing a solid electrolytic capacitor, comprising a means for applying grease.