JPH04348512A - Chip type solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To prevent deterioration in electric property of a solid electrolytic capacitor by lightening the mechanical stress in mounting or forming with the expansion and contraction of anode and cathode lead terminals. CONSTITUTION:One part each of anode and cathode lead terminals 2 and 3 has a winding shape, and further the anode and cathode lead terminals 2 and 3 are covered with heat-insulating resin 4.

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 the structure of anode and cathode lead terminals.

0002

[Prior art] Conventional chip-type solid electrolytic capacitors are
As shown in FIG. 2, the anode lead 7 and the anode lead terminal 2 of the capacitor element 1 are connected by welding, and the cathode layer 6 and the cathode lead terminal 3 are connected with a conductive adhesive 8.・Take out the cathode lead terminals 2 and 3 and cover them with the insulating resin 5 by a method such as transfer molding, then insert the anode and cathode lead terminals 2 and 3 exposed from the insulating resin 5 along the insulating resin 5. It is constructed by bending.

0003

[Problems to be Solved by the Invention] This conventional chip-type solid electrolytic capacitor suffers from mechanical stress due to thermal expansion and contraction of the insulating resin 5 when soldering to a circuit board, and mechanical stress during forming during bending of lead terminals. There is a problem in that a load is applied to the capacitor element 1 due to physical stress, which deteriorates the electrical characteristics of the capacitor.

An object of the present invention is to provide a chip-type solid electrolytic capacitor that solves the problem of deterioration of capacitor electrical characteristics due to mechanical stress caused by thermal expansion and contraction of an insulating resin when mounted on a circuit board and mechanical stress caused when lead terminals are bent. It is about providing.

[0005]

[Means for Solving the Problems] In the chip type solid electrolytic capacitor of the present invention, a part of the positive and negative electrode lead terminals has a meandering shape, and further, the positive and negative electrode lead terminals are coated with a resin having heat insulating properties. It has a lot of characteristics.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view of a chip type solid electrolytic capacitor according to an embodiment of the present invention.

In FIG. 1, a solid electrolytic capacitor is manufactured by anodizing an anode body made of a valve metal such as tantalum, and sequentially depositing a manganese dioxide layer 6a, a carbon layer 6b, and a silver paste layer 6c thereon to form a cathode layer 6. Then, capacitor element 1 is formed. Next, the anode lead 7 made of the same kind of metal and made of the same metal as the capacitor element 1 is connected to the anode lead terminal 2 having a meandering shape by welding.

Further, the cathode layer 6 of the capacitor element 1 and the cathode lead terminal 3 having a meandering shape are connected with a conductive adhesive 8.

Next, after covering the anode and cathode lead terminals 2 and 3 with a resin 4 having heat insulating properties, they are covered with an insulating resin such as epoxy by a transfer molding method, and the insulating resin 5 is exposed. The anode and cathode lead terminals 2 and 3 are bent along the insulating resin 5 to form a chip type solid electrolytic capacitor. At this time, since the anode and cathode lead terminals 2 and 3 are covered with a resin 4 having heat insulating properties, the meandering portions of the anode and cathode lead terminals 2 and 3 can be easily expanded and contracted.

Next, in another embodiment of the present invention, the anode and cathode lead terminals 2 and 3 are formed using a resin 4 that can generate air bubbles inside a foamed resin material made by adding a foaming material to an emulsion of a thermoplastic resin.
After covering it, it is covered with an insulating resin 5 such as epoxy to form a chip type solid electrolytic capacitor. At this time, due to the foaming treatment, the anode and cathode lead terminals 2 and 3 are covered with resin 4 that swells with gas, so the zigzag portions of the anode and cathode lead terminals 2 and 3 can expand and contract more easily, making it possible to connect the solid electrolytic capacitor. Mechanical stress during mounting on a circuit board and mechanical stress during forming can be alleviated.

[0011] When conducting a soldering heat resistance test after humidity resistance and storage of the chip type solid electrolytic capacitor according to the present invention, 5 out of 100 defective electrical characteristics occurred in the conventional technology, but the first
In Example 2, two deteriorations in characteristics were observed, and in Example 2, no defective electrical characteristics occurred.

0012

[Effects of the Invention] As explained above, in the present invention, a part of the anode/cathode lead terminals 2, 3 has a meandering shape, and furthermore, the anode/cathode lead terminals are coated with a resin having heat insulating properties. The mechanical stress generated by thermal shock when mounting a solid electrolytic capacitor on a circuit board and the mechanical stress generated during forming can be alleviated by expanding and contracting the positive and cathode lead terminals, and the electrical characteristics of solid electrolytic capacitors It has the effect of preventing deterioration.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an example of a conventional chip-type solid electrolytic capacitor.

[Explanation of symbols]

1 Capacitor element 2 Anode lead terminal 3 Cathode lead terminal 4 Resin 5 Insulating resin 6 Cathode layer 6a Manganese dioxide layer 6b Carbon layer 6c Silver paste layer 7 Anode lead 8 Conductive adhesive

Claims (2)

[Claims] 1. A chip-type solid electrolytic capacitor obtained by taking out positive and negative electrode lead terminals from a capacitor element having a negative electrode layer and an anode lead and covering the positive and negative electrode lead terminals with an insulating resin, wherein a part of the positive and negative electrode lead terminals has a meandering shape. A chip-type solid electrolytic capacitor, further comprising: the anode and cathode lead terminals being coated with a resin having heat insulating properties. 2. The chip-type solid electrolytic capacitor according to claim 1, wherein the resin is made of a material obtained by adding a foaming material to a thermoplastic resin.