JPS62272516A - Chip type solid electrolytic capacitor with fuse - 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 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a chip type capacitor with a fuse, and particularly to a structure in which a fuse is built into an exterior resin.

[Conventional technology]

Solid electrolytic capacitors are generally used in various electronic circuits, and have a low failure rate, but in the event of a failure, the failure mode is often short-circuit failure, and when a large short-circuit current flows, the capacitor element heats up and burns out. It is also possible to reach . When a failure occurs due to this excessive short-circuit current, it is necessary to change the failure mode from short circuit (seat) to open (open) in order to protect the circuit components. ing.

In the prior art, as shown in the perspective view of FIG. 5 and the side cross-sectional view of FIG.
0, an insulator 30 is inserted between the external cathode terminal 15 and the cathode 11it25 for insulation, and a heather 35 is connected by soldering between the external cathode terminal 15 and the cathode 11it25, covered with insulation resin 40, and bent along this wall surface. There is a structure that made it possible.

[Problem that the invention seeks to solve]

The conventional fuse-equipped chip type solid electrolytic capacitor described above has the following drawbacks because the fuse is connected to the cathode layer side.

(1) Since the fuse and the capacitor element are close to each other, when an overcurrent flows, the fuse blows out, and the solder of the cathode layer indirectly melts due to this heat insulation, thermally expands, and destroys the exterior resin. This may short-circuit other wiring circuits, causing secondary disasters, or directly cause burnout of capacitor elements, resulting in even more serious disasters.

(2) When connecting the fuse, since the cathode layer of the capacitor element and the cathode terminal are insulated with resin, there is a risk of a short circuit when the resin hardens, so please insulate the cathode II or cathode terminal in advance. It is necessary to keep it. Furthermore, the surface of the cathode layer is not uniform in shape, including variations in the size of the capacitor element itself, and when soldering is performed automatically, it becomes extremely difficult to set conditions, making the process complicated.

(3) There is a strong demand for chip-type solid electrolytic capacitors to be smaller in size and larger in capacity, so it is necessary to increase the size of the capacitor element to be accommodated and to reduce the thickness of the outer resin as much as possible. However, in order to connect the fuse to the cathode layer, the exterior resin must be made thick to secure space for the connection portion and the fuse itself and to prevent solder from blowing out, which reduces the volumetric efficiency of the capacitance.

[Originality of invention]

The conventional chip-type solid electrolytic capacitor with a fuse described above has a structure in which an insulator is inserted between the external cathode terminal and the cathode layer on the cathode side, and a fuse is connected. The chevron-shaped anode terminal connected to the anode wire of It has an original content in that it is separated by the exterior resin wall.

[Means for solving problems]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such conventional drawbacks and provide a solid electrolytic capacitor with a fuse that has highly reliable electrical characteristics and high volumetric efficiency.

According to the present invention, the chevron-shaped anode terminal connected to the anode wire of the capacitor element and the protruding external anode terminal have a fuse that is connected in a crisscross manner inside the exterior resin, and the chevron-shaped anode terminal has a corner. It has a chamfered exterior resin wall that is cut away.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

1 is a perspective view showing the internal structure of a first embodiment of the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is a front sectional view of FIG. 1.

First, prepare a thin metal strip such as nickel or 42 alloy,
As shown in FIG. 3, a molding means such as a press is used to form a frame 6 in which the chevron-shaped anode terminal 3, the external anode terminal 4, and the cathode terminal 5 having a stepped portion are connected.

Next, the anode body made of a valve metal such as tantalum is anodized, and a manganese dioxide layer, a carbon layer, and a silver venist layer are sequentially deposited thereon to form a solid electrolytic capacitor element (hereinafter referred to as a capacitor) having a cathode portion in the outermost layer. (abbreviated as element) 1 is formed. Anode 1 connected to this capacitor element IK in an upright manner
! 2 is connected to a part of the chevron-shaped anode terminal 3 by means such as welding.

On the other hand, the capacitor element 1 is adhered to the conductive adhesive 7 which has been previously applied in a certain amount to the cathode terminal 5 having the stepped portion, and is dried and fixed. After that, the heats 8 is soldered between the chevron-shaped anode terminal 3 and the external anode terminal 40, or the ends are connected together by wire bonding or the like.
Both ends are fixed, and the fuse 8 is covered with an elastic resin 9 such as silicone resin. Thereafter, it is insulated and exteriorized with an exterior resin 10 such as epoxy resin by means such as transfer molding, and the chevron-shaped anode terminal 3 protrudes beyond the chamfered portions 10a and 10b at the two corners of the anode side of the exterior resin 10.
The terminal portions of the external anode terminal 4 and the external cathode terminal 5 are separated at the wall surfaces of the chamfered portion 10a and lOb of the exterior resin 10.
Separate from the t-IJ-de frame 6 and remove the exterior resin 1.
0 along the wall surface to form a chip type solid electrolytic capacitor with a fuse of the present invention.

When an overcurrent is applied to this finished product, since the fuse is not close to the cathode layer of the capacitor element, accidents such as solder blowout and burnout will not occur until the fuse heats up and is cut. It functions reliably as a safety device, and no secondary disasters occur.

In addition, the anode terminal side has better flatness and dimensional uniformity than the cathode layer, so it is easy to connect a fuse, and it is fully possible to use an automatic wire pumping machine, etc. In addition, the process can be simplified.

In addition, compared to the anode terminal side line and the cathode side, there is sufficient space for connecting the fuse, the chip shape is larger9, the capacitor element shape is not made smaller, and the volumetric efficiency of the capacitance is higher than that of the chip-type solid state VI without a fuse. You can get something similar to the solution capacitor. Furthermore, since the anode terminal is cut off at a corner or a chamfered corner of the exterior resin, even if the anode terminal protrudes a little and is cut, it can be centered with the automatic mounting machine that automatically mounts it to the circuit board, etc. Chip M111i with a fuse that improves the mounting position on circuit boards etc. and has a high probability of mounting! An i1-body electrolyte near/denser is obtained.

〔Example〕

FIG. 4 is a front sectional view showing a second embodiment of the invention.

In the second embodiment, an L-shaped anode terminal 1 having a shape in which one end of the chevron-shaped anode terminal 3 described in the first (7) embodiment is cut is used.
1, and an L-shaped external anode terminal 12 is formed by extending one end of the external anode terminal inside the exterior resin 1o. It is separated.

〔Effect of the invention〕

As explained above, the present invention has the following effects.

1) There is no risk of solder blowout or burnout accidents, and 2) The fuse joining process is simple. 3) A chip-type solid electrolytic capacitor with a fuse can be obtained, which is easy to increase in size and capacity, and 4) is compatible with an automatic mounting machine and has a high probability of mounting.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the internal structure of a first embodiment of the present invention. The second figure is! Fig. 3 is a front sectional view of Fig. 1, Fig. 4 is a front sectional view showing the second embodiment of the present invention, and Fig. 5 is a conventional fuse-equipped one. A perspective view showing the internal structure of a chip-type integral electrolytic capacitor, No. 6
The figure is a side sectional view of FIG. 5. 1... Capacitor element, 2... Anode wire, 3... Mountain-shaped anode terminal, 4, 20...
・External anode terminal, 5.15...Cathode terminal, 6.
... Lead frame, 7 ... Conductive adhesive, 8, 35 ... Fuse, 9 ... Elastic resin, 10.40 ... Exterior resin, 10a. 10b... Chamfered portion, 11... L-shaped anode terminal, 12... L-shaped external anode terminal, 25
・・・・・・Cathode layer, 30・・・Insulator agent Patent attorney Susumu Uchihara −−°)＼−1
．． l Cow l ``Kaya 2 Zuto 4- Figure

Claims (1)

[Claims] In a chip-type solid electrolytic capacitor in which protruding parts of an anode and a cathode terminal facing each other with a capacitor element in between are bent along a wall surface of an exterior resin, a chevron-shaped anode terminal connected to an anode wire of the capacitor element and the protruding part A chip-type solid electrolytic capacitor with a fuse, characterized in that it has a fuse that is connected to an external anode terminal inside the exterior resin, and the chevron-shaped anode terminal is separated by a wall of the exterior resin with chamfered corners.