JP2817526B2 - Chip type electric double layer capacitor - Google Patents

Abstract

PURPOSE:To obtain a small-sized product excellent in heat resistance wherein cracks are hardly generated on the sheath resin surface, by a method wherein the expansion stress of an element is dispersed under high temperature environments like the inside of a reflow furnace, by arranging an insulative resin injection hole in the element central part, and forming columnar insulative resin. CONSTITUTION:A porous separator which is arranged in an electric double layer capacitor element and has non-electron conductivity is formed in a doughnut type. Doughnut type carbon paste electrodes 7 are arranged on both sides of the porous separator. Doughnut type nonconductive gaskets 6 are arranged on the outer and the inner peripheral parts of the carbon paste electrodes. On both sides of the above device, doughnut type conductive separators 5 are arranged, thereby constituting an electric double layer capacitor element. On the upper and the lower surfaces of an element laminate farmed by laminating the electric double layer capacitor elements, a doughnut type upper electrode plate 2 and a doughnut type lower electrode plate 3 are arranged, respectively, and molding is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric double layer capacitor, and more particularly, to a structure of a chip type electric double layer capacitor for surface mounting and a structure of an upper electrode plate and a lower electrode plate.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable reduction in the size and thickness of portable electric devices such as headphone stereos and cordless telephones. Electric double-layer capacitors mounted on these electronic devices are becoming smaller and thinner like other electronic components, and demands for surface mounting are increasing. Conventionally,
As one of means for obtaining a large-capacity capacitor as this kind of electric double-layer capacitor, US Pat.
As disclosed in the specification of Japanese Patent No. 63, there is an apparatus utilizing the generation of an electric double layer by contacting carbon powder with an electrolytic solution. FIG. 4 is a cross-sectional view of a cylindrical electric double layer capacitor element (hereinafter, referred to as an element). In FIG. 4, 5 is a conductive separator that is both electron conductive and ion impervious, 7 is a carbon paste electrode made of powdered activated carbon and an electrolyte solution, and 8 is an ion permeation provided for preventing conduction between the carbon paste electrodes. A non-conductive gasket 6 is provided to hold the carbon paste electrode and to shield it from the outside world.

FIG. 5 is a sectional view of a conventional chip type electric double layer capacitor. In FIG. 5, reference numeral 1 denotes an exterior thermoplastic resin having an insulating property;
The upper and lower electrode plates having a and 3a are element stacks in which the element 4 is stacked. In the conventional electric double layer capacitor, the lead terminal 2 is provided on the upper and lower surfaces of the element laminate 4a.
The upper electrode plate 2 having a and the lower electrode plate 3 having the lead terminal portion 3a are set in a molding die in a state where the lead terminal portions are arranged to protrude in opposite directions, and a predetermined vertical direction of the electrode plate is set. Under such a pressure, an insulating resin such as a thermoplastic resin is injected into a mold for molding.

[0004]

In the above-mentioned conventional surface mount type electric double layer capacitor, an upper electrode plate and a lower electrode plate are arranged at predetermined positions on the upper and lower surfaces of a cylindrical element laminate, respectively. Molding was performed with a thermoplastic resin while the element laminate was pressed through a plate. Therefore, under the high temperature environment such as immersion in a solder dip tank at 230 ° C. for 10 seconds, cracks are caused in the exterior insulating resin due to expansion stress of the element caused by release of gas remaining in the element and gas adsorbed by powdered activated carbon. There was a problem of entering. Also, as described above, with the surface mounting of electronic components, the size and thickness of the components themselves can be reduced, and this problem tends to increase.

SUMMARY OF THE INVENTION An object of the present invention is to provide a small chip type electric double layer capacitor which is excellent in heat resistance without cracking of an exterior insulating resin due to expansion stress of an element even in a high temperature environment in a solder dipping bath. Is to do.

[0006]

An electric double layer capacitor according to the present invention is an electric double layer capacitor which exhibits a capacitance by an electric double layer.
A multilayer body is formed by stacking multiple multilayer capacitor elements in series.
And placing one electrode plate on each of the upper and lower sides of the laminate,
Mold forming leaving the part to be the connection terminal with the outside
In the chip-type electric double layer capacitor formed by sheathed with electrically insulating resin by, the electric double layer capacitor element
Is a doughnut-shaped porous separator having non-electronic conductivity.
And the separators are arranged vertically with the porous separator interposed therebetween.
Donut-shaped carbon paste electrode, and the carbon
Placed on the outer and inner periphery of the paste electrode
A donut-shaped non-conductive gasket and the carbon paper
On the side of the strike electrode facing the porous separator,
Non-conductive gasket and inner non-conductive gasket
Donut-shaped conductive separator placed on top of
And the electrode plate is in a donut shape.
By combining the laminate and the electrode plate
Has a structure having a through hole in the center in the stacking direction,
In the through hole present at the center of the laminate and the electrode plate
Was filled with the same resin as the electrically insulating resin of the exterior.
It is characterized by the following.

[0007]

Next, the present invention will be described with reference to the drawings. Figure 1 is a schematic view for illustrating a constitution of a first embodiment of the present invention (a) is a top view, (b) the A-A ₁ cross-sectional view of a top view (a), (c) is a right side view (e ) BB ₁ sectional view, (d)
Bottom view is, (e) is a right side view, and FIG. 3 is a diagram showing the structure of the electric double layer capacitor device of the present invention, C-C ₁ section of (a) a lower surface <br/> view (b) FIG. 3B is a bottom view.

In FIGS. 1 and 3, first, the diameter is 8.0 m.
m, two elements 4 each having a thickness of 1.1 mm are stacked to obtain an element stack 4a. The central part of the element stack 4a has a diameter of 2 m.
There is a hole of m. One side having a hole of 2 mm in diameter at the center of the upper and lower surfaces of the element laminate 4a is 9.8 mm in thickness and 0.2 in thickness.
A pair of electrode plates 2 and 3 each of which is formed by projecting lead terminals 2a and 3a having a thickness of 0.2 mm and a length of 3.0 mm with a square of mm and protruding from an iron / nickel alloy. The electrode plates 2 and 3 are arranged so as to maintain the relative positional relationship between the element stacks 4a, fixed, and then set in a mold having a hollow portion having a length of 13 mm, a width of 12 mm and a thickness of 3.0 mm. The element stack 4a is compressed to a thickness of about 80% of the no-load state by four pins (not shown) through upper and lower pins 2 and 3, and the thermoplastic resin such as PPS (polyphenylene sulfur) is used. The insulating resin 1 having high heat resistance is injected into the entire gap in the mold, and the insulating resin injection gate 1 at the upper center of the lower electrode plate 3
Inject and mold from c. The insulating resin injection gate 1c is commonly called a pin point gate, and is automatically cut from the root of the product when the mold at the time of completion of molding is opened. The upper electrode plate side hole 1a and the lower electrode plate side hole 1b are traces of the mold pins. Even after the completion of the molding of the element laminate 4a, the capacitor is compressed to a thickness of about 80% at the time of no load, so that the capacitor has a low equivalent series resistance.
Thus, the electric double layer capacitor according to the first embodiment of the present invention was obtained.

FIG. 2 is a drawing for explaining a second embodiment of the present invention, and FIGS. 1 (b) and 1 (b) of the first embodiment respectively.
It is sectional drawing corresponding to (c). The first embodiment is different from the first embodiment in that the lower electrode plate 3 has a fixed caulking rate and is provided with an insulator-coated stopper 3b provided for improving heat resistance, and an insulator-coated stopper-provided anti-stopper friction preventing wall 2b provided on the upper terminal electrode plate. The only difference is that

Next, each of the first and second embodiments of the present invention and the conventional chip type electric double layer capacitors 100 will be described.
For 0 pieces, a solder tank was subjected to a immersion test at 240 ° C. for 10 seconds to measure a crack generation rate and a product thickness increase rate, and the results are shown in Table 1.

[0011]

As is apparent from the results shown in Table 1, the electric double layer capacitor of the present invention has a remarkable improvement in heat resistance as compared with the conventional example.

[0013]

As described above, according to the present invention, since the insulating resin injection hole is provided in the central portion of the element, the columnar insulating resin is formed in the central portion of the element, and the expansion of the element in a high temperature environment such as in a reflow furnace. This has the effect of dispersing the expansion stress against the stress, and providing a tough electric double layer capacitor in which the surface of the exterior resin is less likely to crack.

In the second embodiment of the present invention, as shown in FIG. 2, the lower electrode plate and the upper electrode plate are provided with a stopper coated with an insulating material and a friction preventing wall against the stopper. Therefore, in the electric double layer capacitor of the second embodiment of the present invention, the result of immersion in the solder bath obtained by the electric double layer capacitor of the first embodiment of the present invention could be exceeded. The second aspect of the present invention
In the embodiment of the present invention, the presence of the stopper has an effect that the molding can be performed without pressing and holding by the pressing jig.

[Brief description of the drawings]

[1] In the drawings of the first embodiment of the present invention (a) is a top view, (b) the A-A ₁ cross-sectional view, (c) the B-B ₁ cross-sectional view, (d) is a bottom view (E) is a right side view.

FIG. 2A is a drawing of a second embodiment of the present invention, wherein FIG.
_{1 is a} cross-sectional view, and (b) is a BB ₁ cross-sectional view.

[3] In the drawings of the elements of the chip-type electric double layer capacitor according to the present invention, (a) is C-C ₁ cross-sectional view, (b) is a bottom <br/> view.

FIG. 4 is a cross-sectional view of a conventional electric double layer capacitor element.

5 is a A-A ₁ cross-sectional view of a conventional electric double layer capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating resin 1a Upper electrode plate side hole 1b Lower electrode plate side hole 1c Insulating resin injection gate 2 Upper electrode plate 2a Lead terminal of upper electrode plate 2b Anti-friction wall against stopper 3 Lower electrode plate 3a Lead terminal of lower electrode plate 3b stopper 4 element 4a element stack 5 conductive separator 6 non-conductive gasket 7 carbon paste electrode 8 porous separator 9 insulating coating film

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01G 9/155 H01G 9/016 H01G 9/058

Claims (1)

(57) [Claims] 1. An electric double layer having an electrostatic capacity.
By stacking multiple air-double layer capacitor elements in series,
None, one electrode plate at the top and bottom of the laminate
Leave the part that should be the connection terminal with the outside of the mold
In a chip-type electric double-layer capacitor externally formed of an electrically insulating resin, the electric double-layer capacitor element has non-electronic conductivity.
Donut-shaped porous separator, and the porous separator
Donut-shaped carbon placed vertically above and below the radiator
A paste electrode and an outer peripheral portion of the carbon paste electrode;
Donut-shaped non-conductive gas
Sket and porous separator of the carbon paste electrode
The non-conductive gasket of the outer peripheral part
And arranged to hang on the non-conductive gasket on the inner circumference
And donut-shaped conductive separator
By making the electrode plate a donut shape,
The stack of the laminate and the electrode plate is placed in the center in the stacking direction.
A structure having a through-hole communicating with the inside of the laminate and the through-hole existing in the center of the electrode plate.
A chip-type electric double-layer capacitor , wherein the same resin as the outer insulating resin is filled .