JPH11112157A - Case for electronic parts, and electronic parts using this, and electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the permeation of only hydrogen gas, and shut off the permeation of electrolyte, steam, etc., by equipping a part of the case to accommodate each kind of element with a gas permeation part consisting of a ceramic porous body whose average pore specified. SOLUTION: The base 1 of fine ceramics is equipped with a storage 1a, and a case for electronic parts is constituted of the base 1 and a cap 2 entirely made of porous ceramics. Here, it will do to make the cap 2 out of fine ceramics, and also make its one part serve as the gas permeating part of porous ceramics. An electrolytic capacitor is stored in the storage 1a of the base 1, and an electrode terminal for connection is led out to the external terminal at the bottom surface from the through hole of the base 1, and further the cap 2 is joined for sealing to the topside of the base 1 through sheet material such as glass or the like. The communication pore of the porous ceramics is 0.01-2 μm in average diameter, and hydrogen gas permeates it, but it can shut off the permeation of the steam. Accordingly, it can let the hydrogen gas generated at excessive currents go outside, and prevent the permeation of steam from outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case for an electronic component for hermetically sealing various elements, and an electronic component using the case, particularly an electrolytic capacitor.

[0002]

2. Description of the Related Art As shown in FIG. 5, an electrolytic capacitor has an electrolytic capacitor element 15 in a metal case 11.
Are arranged, and the electrode terminals 14, 14 connected thereto are held by the sealing plug 12, and the case 11 is caulked and fixed around the sealing plug 12. The electrolytic capacitor element 15 is formed by winding kraft paper between an anode foil and a cathode foil and impregnating with an electrolytic solution.
Reference numerals 4 and 14 are connected to each anode foil and cathode foil.

In this electrolytic capacitor, it is necessary to maintain the sealing property so that the internal electrolytic solution and water vapor do not leak to the outside. However, when an excessive current flows, hydrogen gas is generated in the case 11. Therefore, there is a problem that the internal pressure increases and the case 11 is damaged. Therefore, there is a demand for a structure that allows the generated hydrogen gas to escape, but not the electrolytic solution or water vapor.

For this purpose, for example, the sealing plug 12 is formed of a gas selective permeable resin such as a polysulfide-modified epoxy resin, and only the generated hydrogen gas is released to the outside.

[0005]

However, in the electrolytic capacitor using the sealing plug 12 made of the above-described gas selective permeable resin, the hydrogen gas permeation speed is slow and it is not possible to cope with rapid gas generation. Could be damaged.

In addition, the sealing performance at the sealing portion by caulking the metal case 11 and the sealing plug 12 is insufficient, and there is a possibility that the electrolyte or the like inside leaks.

Further, the conventional electrolytic capacitor has a structure provided with the electrode terminals 14 and cannot be surface-mounted.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a case for accommodating various elements, in which a part is provided with a gas permeable portion made of a ceramic porous body having an average pore diameter of 0.01 to 2 μm. It is characterized by the following.

Further, the present invention is characterized in that various elements are housed in the above-mentioned case for an electronic component, and an electrode terminal connected to this is provided on an outer surface of the case to constitute an electronic component.

Further, the present invention is characterized in that an electrolytic capacitor element is housed in the above-mentioned case for an electronic component, and an electrode terminal connected thereto is provided on an outer surface of the case to constitute an electrolytic capacitor.

[0011]

According to the present invention, an electronic component case is provided with a gas permeable portion made of a ceramic porous body having an average pore diameter of 0.01 to 2 μm, so that the electrolytic solution and water vapor are blocked and hydrogen gas is removed. Can escape quickly,
The possibility of breakage due to an increase in internal pressure can be eliminated.

If the case itself is formed of ceramics, hermetic sealing using glass or a sealer is easy, and if an electrode terminal is provided on the surface of the case itself, surface mounting becomes possible.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

The electronic component case shown in FIG. 1A is composed of a base 1 having a storage section 1a and a cap 2,
The base 1 is made of dense ceramics, and the cap 2 is entirely made of porous ceramics to form a gas permeable portion 3.

In another embodiment, as shown in FIG. 1 (b), the cap 2 may be formed of dense ceramics and a part thereof may be provided with a gas permeable portion 3 made of porous ceramics. .

Next, an electrolytic capacitor using this case is shown in FIG. Using the case of FIG. 1 (a), the electrolytic capacitor element 5 is housed in the housing part 1a of the base 1, and the electrode terminal 4a connected thereto is led out from the through hole 1b of the base 1 to the lower surface. Are formed with external terminals 4b. Further, the cap 2 is bonded to the upper surface of the base 1 via a sealing material 6 such as glass or a sealer, and sealed.

As shown in the enlarged view of FIG. 3, the porous ceramic constituting the gas permeable portion 3 has pores 32 connected to each other.
Since the average diameter of the pores 32 is 0.01 to 2 μm, hydrogen gas can be transmitted therethrough, but permeation of the electrolytic solution and water vapor can be cut off. Therefore, when an excessive current flows, the hydrogen gas generated in the capacitor element 5 in the storage section 1a can pass through the gas permeable section 3 and escape to the outside, and also allows the electrolyte solution, water vapor and the like in the storage section 1a to escape. In addition, it is possible to prevent water vapor and the like from entering from outside.

Here, the reason why the average pore diameter of the porous ceramic constituting the gas permeable portion 3 is set to 0.01 to 2 μm is as follows.
If the thickness is less than 0.01 μm, the permeation rate of the hydrogen gas becomes extremely slow, while if it exceeds 2 μm, the electrolyte leaks.

The porosity of the gas permeable section 3 is 5
It is preferable to set the range to 40%. This is because if the porosity is less than 5%, the porosity becomes too dense to allow gas permeation, while the porosity is less than 40%.
If the ratio exceeds, the firing shrinkage is large and the dimensional variation is large.

The average pore diameter and porosity can be measured by a mercury intrusion method.

The material of the porous ceramics constituting the gas permeable portion 3 is alumina ceramics containing Al ₂ O ₃ as a main component and containing 4% or less of SiO ₂ , but other materials such as silicon carbide, zircon, etc. Ceramics can also be used.

When the porous ceramics constituting the gas permeable portion 3 is manufactured, particles 31 such as fused alumina are used, a binder is added to the particles 31, and the particles 31 are formed into a predetermined shape. By baking at 1000 to 1600 ° C., each particle 31 is sintered in a partially joined state, and a gap between each particle 31 can be formed as a pore 32. At this time, it is preferable to use spherical particles.

In this manner, the porous ceramic constituting the gas permeable portion 3 has a structure in which the pores 32 communicate with each other, and can rapidly transmit hydrogen gas. Further, since the average diameter of the pores 32 can be freely adjusted by changing the primary particle diameter of the particles 31 used, the gas permeable portion 3 having a predetermined average pore diameter can be easily obtained. For example, as described above, in order for the average pore diameter to be in the range of 0.01 to 2 μm, it is necessary to use particles 3
The primary particle size of 1 may be in the range of 1 to 10 μm.

On the other hand, the base 1 and the cap 2 in the embodiment of FIG. 1 (b) are formed of dense ceramics, and the material thereof is alumina ceramics, mullite, forsterite, cordierite, etc., and is preferably used. The same kind of porous ceramics as the gas permeable portion 3 is used.

When the external terminals 4b are formed on the surface of the base 1 as shown in FIG. 2, Ag, Pd, W, M
An external terminal 4b having a predetermined shape can be easily formed by applying a paste of a high melting point metal such as o or Mn on the base 1 and firing the paste. And this external terminal 4
Is formed on the lower surface of the base 1 so that the lower surface can be placed on a circuit board and surface-mounted.

Further, since both the base 1 and the cap 2 constituting the case are made of ceramics, if they are joined together by a sealing material 6 such as glass or a sealer, a high sealing property can be maintained, and the storage portion 1a Can stably hold the capacitor element housed in the housing.

Next, another embodiment of the present invention will be described.
The electronic component shown in FIG. 4 accommodates an element 23 that forms a contact point such as a relay or a switch. The base 22 that holds the electrode terminal 24 is formed of the above-described porous ceramic body, and serves as a gas permeable portion. is there. The base 22 is covered and sealed with a lid 21 made of resin, metal, or the like. A gas such as ozone is generated by the discharge from the element 23 forming the contact, but the gas can be satisfactorily discharged from the base 22 forming the gas permeable portion.

As still another embodiment, in the electrolytic capacitor having the structure shown in FIG. 5, the sealing plug 12 may be formed of the above-mentioned porous ceramic body.

Although the electrolytic capacitor and the contact element have been described in the above embodiments, the electronic component case of the present invention can be used for housing various elements such as an electric double layer capacitor.

[0030]

Embodiments of the present invention will be described below.

As an example of the present invention, an electrolytic capacitor shown in FIG. 2 was manufactured. Base 1 has an Al ₂ O ₃ content of 96
% Of dense alumina ceramics, and its dimensions were 7 × 5 × 4 mm. The cap 2 serving also as the gas permeable portion 3 is formed of porous alumina ceramics having various average pore diameters as shown in Table 1, and the size is 7 × 5 ×
1 mm. The capacitor element 5 is housed in the housing part 1a of the base 1 and the cap 2 is sealed with an epoxy-based sealing material 6.
Were joined to obtain an electrolytic capacitor.

On the other hand, a conventional electrolytic capacitor shown in FIG. 5 was prepared as a comparative example. Three of each of these electrolytic capacitors were prepared, and a voltage-free reverse voltage test was performed at 1 A / unit, and the rate of occurrence of breakage of the container after 5 minutes from the generation of hydrogen gas was examined. Also, the presence or absence of leakage of the internal electrolyte was examined.

As shown in Table 1, the electrolytic capacitor of the comparative example shown in FIG. 5 had a high rate of breakage because the generated hydrogen gas was released at a low speed.

Also, in the electrolytic capacitor of the present invention shown in FIG. 2, when the average pore diameter of the gas permeable portion 3 was less than 0.01 μm, the breakage rate was high because hydrogen gas was hard to escape. On the other hand, when the average pore diameter exceeded 2 μm, leakage of the electrolyte occurred.

On the other hand, in the embodiment of the present invention in which the average pore diameter of the gas permeable portion 3 is in the range of 0.01 to 2 μm,
Since hydrogen gas can be quickly released, the rate of occurrence of breakage is low, and there is no leakage of the electrolyte, which is an extremely excellent result.

[0036]

[Table 1]

[0037]

As described above, according to the present invention, there is provided a ceramic case for accommodating an electronic component, wherein a part of the case is formed of a porous material having an average pore diameter of 0.01 to 2 μm. By providing the portion, it is possible to transmit only hydrogen gas without transmitting electrolytic solution or water vapor.

Further, the present invention provides an electrolytic capacitor in which a capacitor element is housed in the above-mentioned case for an electronic component, and an electrode terminal connected to the capacitor element is provided on an outer surface of the case, so that an excessive current flows. The generated hydrogen gas can be quickly released, and damage to the case due to an increase in internal pressure can be prevented. In addition, since leakage of the internal electrolyte and water vapor can be shut off, the capacitor element can be stably held.

Further, since the case is formed of ceramics and provided with electrode terminals on its surface, it can be surface-mounted on a circuit board.

[Brief description of the drawings]

FIGS. 1A and 1B are exploded perspective views showing an electronic component case of the present invention.

FIG. 2 is a sectional view showing an electrolytic capacitor of the present invention.

FIG. 3 is an enlarged view of a gas permeable portion of the electronic component case of the present invention.

FIG. 4 is a sectional view showing another embodiment of the electronic component case of the present invention.

FIG. 5 is a sectional view showing a conventional electrolytic capacitor.

[Explanation of symbols]

 1: Base 1a: Storage section 2: Cap 3: Gas permeable section 4a: Electrode terminal 4b: External terminal 5: Capacitor element 6: Seal material

Claims (3)

[Claims] 1. A case for an electronic component, comprising a housing portion for various elements, and a gas permeable portion made of a ceramic porous body having an average pore diameter of 0.01 to 2 μm in a part thereof. 2. An electronic component, wherein various elements are housed in the electronic component case according to claim 1, and external terminals connected to the various components are provided on the outer surface of the case. 3. An electrolytic capacitor, wherein a capacitor element is housed in the electronic component case according to claim 1, and an external terminal connected to the capacitor element is provided on an outer surface of the case.