JP2004266169A - Chip capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve electrical and mechanical connection between a lead for the anode and a conductive terminal to be connected thereto, shorten the lead for the anode while preventing shortcircuiting between the anode and the cathode due to the partial leakage of an conductive adhesive agent, and make a chip capacitor small, in the chip capacitor that a metallic sintered body is formed as the anode on an insulation substrate. <P>SOLUTION: In a capacitor 1, a conductive adhesive agent 7 is provided on the surface of a conductive terminal on one surface of an insulation substrate 5 that is provided with conductive terminals 6 on its both ends wherein its upper and lower surfaces are electrically connected with each other, and a lead 2 for anode and a cathode layer 4 are provided on its upper part. In such a chip type capacitor provided with the capacitor 1, a metallic intermediate body 8 holding a conductive adhesive agent is provided between a lead wire for anode and a conductive terminal to be connected thereto. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a chip capacitor. In particular, the present invention relates to a chip capacitor in which a capacitor element having a metal sintered body as an anode body is provided on an insulating substrate.
[0002]
[Prior art]
FIG. 3 shows a conventional example of a chip type capacitor in which a capacitor element having a metal sintered body as an anode body is provided on an insulating substrate (for example, see Patent Document 1). The capacitor element 1 is formed by pressure-molding the fine powder of the valve action metal or the like in which one end of the anode lead 2 of the valve action metal is embedded, and heat-sintering it in a vacuum to form a dielectric over the entire surface. The capacitor element 1 is manufactured by forming a body coat layer, and further forming a solid electrolyte layer and a cathode layer 4 thereon in this order. The insulating substrate 5 is provided at both ends with metal conductive terminals 6 whose upper surface and lower surface are electrically connected, a conductive adhesive 7 is provided on one surface of the conductive terminals, and a capacitor is provided on the upper surface thereof. Element 1 is provided. The anode lead wire 2 and the cathode layer 4 are electrically connected to the conductive terminals 6 of the insulating substrate 5 by a conductive adhesive 7 and the like, respectively. However, since the anode lead wire 2 and the conductive terminal 6 are separated from each other, generally, a metal intermediate body 8 such as a wire such as a wire or a plate material such as a sleeper is provided between them. And it coat | covers with the exterior material 9 of an insulating resin.
[0003]
[Patent Document 1]
JP-A-2001-267181 (page 13, line 2 to page 19, line 10, FIG. 1).
[0004]
[Problems to be solved by the invention]
In the conventional example described above, the metal intermediate is a mere wire, a mere plate, and the surface area is not large because it is an outer peripheral surface, so it is not only difficult to improve electrical and mechanical connection. However, if a large amount of the conductive adhesive is applied to obtain the same, a part of the conductive adhesive flows out and the anode and the cathode are easily short-circuited.
An object of the present invention is to improve the electrical and mechanical connection between the anode lead and the conductive terminal connected to the anode lead, and to prevent the anode and the cathode from being short-circuited by the conductive adhesive to form a chip. It is to provide miniaturization of a capacitor.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention provides an insulating substrate having conductive terminals whose upper and lower surfaces are electrically connected at both ends, and a conductive adhesive on one surface of the conductive terminals. In a chip-type capacitor provided with a capacitor element having an anode lead and a cathode layer thereon, a metal intermediate for capturing a conductive adhesive is provided between the anode lead and the conductive terminal connected thereto. More specifically, the present invention provides a chip-type capacitor provided with a metal intermediate such as a hole, a net, a twisted wire, or a sponge.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a chip capacitor of the present invention.
Reference numeral 1 denotes a capacitor element, which is formed by pressing a fine powder made of a valve action metal or the like in which one end of an anode lead 2 made of a valve action metal such as tantalum, aluminum, or niobium is embedded, using a pressing mold. After pressing to form a green compact (green pellet), the green pellet is manufactured by heat sintering in vacuum. Thereafter, a dielectric coating layer is formed on the entire surface of the sintered body 3, and a solid electrolyte layer such as manganese dioxide and a cathode layer 4 are successively formed thereon by a carbon paste or the like to form the capacitor element 1. To manufacture. The sintered body 3 may be manufactured from a valve metal powder and a binder mixed sheet, and is not particularly limited.
[0007]
Reference numeral 5 denotes an insulating substrate, on both ends of which a metal conductive terminal 6 such as plating or foil copper having an upper surface and a lower surface electrically connected is provided. A conductive adhesive 7 made of a paste such as copper or copper is provided, a capacitor element 1 is provided thereon, and the anode lead wire 2 and the cathode layer 4 are respectively connected to the conductive terminal 6 of the insulating substrate 5 and the conductive adhesive. 7 are electrically connected.
After the capacitor element 1 is provided on the insulating substrate 5, the conductive adhesive 7 on the anode lead side may be dropped from the upper surface of the anode lead side by a dispenser or the like.
[0008]
Reference numeral 8 denotes a metal intermediate, which is inserted between the anode lead 2 and the conductive terminal 6. Good electrical conductivity, good corrosion resistance when combined, good adhesion with conductive adhesive 8, good weldability, and excellent ability to hold conductive adhesive. To be elected. For example, a metal such as iron, nickel, cobalt, copper, aluminum, zinc, tantalum, niobium, or an alloy thereof, such as a porous body, a mesh body, a twisted wire body, or a spongy body is used. Irregularity treatment by sandblasting or etching or plating may be applied to those surfaces.
[0009]
Pore-shaped materials such as punching metal and straight-etched metal are used to mechanically or chemically provide holes that penetrate the front and facing surfaces, such as round holes, long holes, square holes, diamonds, and turtle holes. There is no particular limitation on the hole shape.
The net-like material is a net-like material such as expanded metal or metal wire fabric, and the twisted-wire-like material is a twisted or stranded wire of a plurality of fine wires. Examples of spongy bodies include sintered bodies such as metal fibers and powders and hollow metal bodies such as spongy etched metals.
[0010]
The hole-shaped body can freely design the hole diameter and shape depending on the place, and the mesh-shaped body can have high flexibility and can easily follow external stress. In addition, the twisted wire-shaped body has characteristics such that existing electric wires and ropes can be used and the cost is low, and the spongy body-shaped body is easy to obtain a desired three-dimensional shape.
[0011]
The range of the void diameter is about 1 μm to 1 mm in terms of a round hole, and preferably about 50 μm to 0.5 mm. Although the overall porosity is about 0.01 to 0.9, a method of removing a part of the twist is particularly used for a twisted linear body having a large porosity and difficult to be obtained.
The thickness of the wire of the twisted linear body or the metal wire fabric is about 1 μm to 1 mm, and preferably about 50 μm to 0.5 mm.
[0012]
If the metal intermediate 8 is in the form of a thin plate, it may be wound up to a required thickness, folded, or folded at a required height. Moreover, you may put a heartwood and wind it. The metal intermediate 8 may be joined to the anode lead 2 by welding or the like before providing the capacitor element 1 on the insulating substrate 5.
Reference numeral 9 denotes an exterior material, which is made of an insulating polymer resin or the like.
[0013]
FIG. 2 shows a state in which the capacitor element 1 is provided on the insulating substrate as viewed from above. The metal intermediate 8 may be as large as the anode lead width, but is preferably as large as the metal conductive terminal area on the insulating substrate in order to reduce connection strength and connection resistance.
When the metal intermediate 8 and the anode lead 2 are welded, in the case of a hole-shaped body, if the gap is eliminated or reduced in the welded portion, welding becomes easier. Conversely, in the case of a twisted linear body, if the other parts are loosened, the conductive adhesive 7 can be easily held. In addition, if a core material of bulk metal is inserted only in a portion to be welded, welding becomes easy.
[0014]
【The invention's effect】
As described above, the chip-type capacitor according to the present invention has a hole-like body, a mesh-like body, a twisted-like body, or a spongy-like body that holds a conductive adhesive between the anode lead and the conductive terminal connected thereto. Since the metal intermediate is provided, the surface area is large, and therefore, the ability to capture the conductive adhesive in the metal intermediate is large. Therefore, while improving the electrical and mechanical connection between the anode lead and the conductive terminal connected to the anode lead, the surface of the metal intermediate has excessive conductive property to improve the electrical and mechanical connection. There is no need to apply adhesive. Accordingly, the lead for the anode can be shortened while preventing a short circuit between the anode and the cathode due to the excessive conductive adhesive, so that the miniaturization of the chip type capacitor can be provided.
Further, it is possible to provide a chip-type capacitor in which an excessive amount of the conductive adhesive does not overflow into the cut surface, which is the outer peripheral surface of the chip, and does not impair reliability such as poor moisture resistance.
In addition, since there are more gaps than the bulk metal body, it can be made a soft body, easily follow external stress, and easily obtain connection reliability. Also, when the metal intermediate is joined to the anode lead by welding or the like, and then the metal intermediate is cut into an appropriate size, a load due to stress is not easily applied to the capacitor element.
[Brief description of the drawings]
FIG. 1 is a sectional view of the present invention.
FIG. 2 is a top view of the present invention before coating with an exterior material.
FIG. 3 is a sectional view of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Capacitor element 2 ... Lead for anode 3 ... Sintered body 4 ... Cathode layer 5 ... Insulating substrate 6 ... Conductive terminal 7 ... Conductive adhesive 8 ... Metal intermediate 9 ... Exterior material.

Claims (2)

A conductive adhesive is provided on the conductive terminal surface on one side of an insulating substrate having conductive terminals whose upper and lower surfaces are electrically connected to both ends, and an anode lead and a cathode layer are provided on the upper side. A chip capacitor provided with a capacitor element, wherein a metal intermediate for capturing a conductive adhesive is provided between an anode lead and a conductive terminal connected thereto. A conductive adhesive is provided on the conductive terminal surface on one side of an insulating substrate having conductive terminals whose upper and lower surfaces are electrically connected to both ends, and an anode lead and a cathode layer are provided on the upper side. Chip-type capacitor provided with a capacitor element, wherein a metal intermediate of a hole-like body, a mesh-like body, a twisted-wire body or a spongy body is provided between an anode lead and a conductive terminal connected thereto. Type capacitors.

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