KR100924031B1 - Surge Absorber and Manufacturing Method Thereof - Google Patents

Abstract

The present invention provides a surge absorber and a method of manufacturing the same, which make the structure and manufacturing process much simpler than the conventional methods. The proposed surge absorber includes an internal electrode with both ends exposed to opposite opposing outer surfaces of the body within the body; A discharge medium formed on one of both outer surfaces of the body and having a predetermined thickness and connected to one end of an internal electrode exposed on the outer surface; And an external terminal formed on one of the outer surfaces of the body and surrounding the discharge medium, and connected to the other exposed end of the internal electrode on the other outer surface. According to the present invention, not only takes a very simple configuration compared to the existing method, but also can be manufactured in a very simplified process. Since one end of the inner electrode exposed to one outer side of the body and the outer terminal spaced apart by a predetermined gap serve as a gap electrode, the dielectric constant of the body is not significantly affected.

Description

Surge absorber and method of manufacturing the surge absorber

The present invention relates to a surge absorber and a method for manufacturing the same, and more particularly, to a surge absorber and a method for manufacturing the surge absorber that can block the surge voltage or surge current.

Typically, a surge absorber arranges a predetermined empty space (discharge space) between the anode plates to block a surge energy or surge current having a relatively high energy.

1 is a cross-sectional view showing an example of a conventional surge absorber. The surge absorber of FIG. 1 includes a body 10; Gap electrodes 12a and 12b formed on the upper surface of the body 10; A discharge medium 14 filled in a gap (also referred to as a discharge space) between the gap electrode 12a and the gap electrode 12b; And electrodes 16a and 16b formed at both sides of the body 10 and connected to one ends of the gap electrodes 12a and 12b.

The body 10 is comprised of many ceramic sheets or varistor sheets, LTCC, etc. which have alumina etc. as a main component. The gap electrodes 12a and 12b are formed in a predetermined pattern by sputtering or the like on the topmost ceramic sheet of the body 10 (that is, when a protective layer is not shown). That is, in FIG. 1, gap electrodes 12a and 12b are formed by a thin film process, and gaps are formed by such gap electrodes 12a and 12b.

The discharge medium 14 is made of a mixture of metal materials such as Al, Ag, Pt, insulators of Al ₂ O ₃ , SiO ₂ , and epoxy (or silicon). The discharge medium 14 may be filled only in the gap between the gap electrode 12a and the gap electrode 12b, and not only to the gap between the gap electrode 12a and the gap electrode 12b but also to the periphery thereof as shown in FIG. It may be formed.

In FIG. 1, the thin film forming process is used as a method of forming the gap electrodes 12a and 12b. Since the body 10 of FIG. 1 shrinks upon firing, the gap electrodes 12a and 12b must be formed in consideration of the shrinkage ratio, so that the gap between the gap electrodes 12a and 12b can be set to a desired value. However, since it is difficult to accurately consider the shrinkage ratio of the body 10 and the shrinkage ratios of the gap electrodes 12a and 12b should be taken into consideration, the gaps 12a and 12b formed by the thin film forming process may have a desired gap (eg, approximately 10 µm). Is very difficult to obtain).

Since the gap electrodes 12a and 12b and the discharge medium 14 are exposed on the upper surface of the body 10, a separate protective layer (dummy sheet or the like) is used to protect the gap electrodes 12a and 12b and the discharge medium 14. There is a need for a step of further forming an overglazing layer) (not shown).

On the other hand, the surge absorber of FIG. 1 is manufactured by the process of heat-processing again, forming gap electrodes 12a and 12b after baking the body 10. FIG. That is, simultaneous firing of the gap electrodes 12a and 12b and the body 10 in FIG. 1 is not performed.

2 is a cross-sectional view showing another example of a conventional surge absorber. In FIG. 2, most of the components are similar to those of FIG. 1, and the discharge medium 24 is embedded in the body 20. Although reference numerals for the components of FIG. 2 are different from those in FIG. 1, those skilled in the same industry may easily identify corresponding components.

In FIG. 2, the discharge medium 24 is charged in a predetermined portion (discharge space) between the gap electrode 22a and the gap electrode 22b which are disposed to face up and down.

The body 20 of FIG. 2 is comprised of many ceramic sheets or varistor sheets, LTCC, etc. which have alumina etc. as a main component. The discharge medium 24 of FIG. 2 is formed by mixing a metal material such as Ru, Pt, insulator and glass of Al ₂ O ₃ , SiO ₂ .

2, the body 20 and the gap electrodes 22a and 22b are co-fired in structure. For this reason, a manufacturing process is simple compared with FIG.

However, in the case of FIG. 2, the solvent and the like contained in the discharge medium 24 are simultaneously vaporized. Vaporized material until vaporized to come out of the body 20 adversely affects the body 20. For example, peeling phenomenon (cracking, non-adhesiveness, etc.) occurs at the interface between the gap electrodes 22a and 22b and the discharge medium 24 due to evaporated solvent or the like. The body 20 may be distorted during simultaneous firing due to evaporated solvent or the like. Therefore, when the structure of Figure 2 co-fired, not only the impact resistance is weak, but also a problem occurs in the product mass production rate. In addition, since the simultaneous firing method is used, the selection of the discharge medium 24 is limited.

In particular, these problems make it difficult to realize a gap between the gap electrode 22a and the gap electrode 22b at a desired value.

As described above, the surge absorber of FIGS. 1 and 2 not only includes various problems, but also has a complicated structure and thus, a manufacturing process is not easy.

The present invention has been proposed to solve the above-mentioned conventional problems, and an object thereof is to provide a surge absorber and a method of manufacturing the same, which make the structure and manufacturing process much simpler than the conventional method.

In order to achieve the above object, a surge absorber according to a preferred embodiment of the present invention includes an internal electrode exposed at opposite ends of the body to both ends of the body; A discharge medium formed on one of both outer surfaces of the body and having a predetermined thickness and connected to one end of an internal electrode exposed on the outer surface; And an external terminal formed on one of the outer surfaces of the body and surrounding the discharge medium, and connected to the other exposed end of the internal electrode on the other outer surface.

The internal electrode consists of at least one.

On the other hand, a method of manufacturing a surge absorber according to an embodiment of the present invention, the first process of manufacturing a plurality of sheets; Forming an internal electrode pattern on a part of the plurality of sheets, and exposing both ends to opposite opposing outer surfaces of the sheet; A third process of forming a body by laminating a plurality of sheets; A fourth step of forming a discharge medium having a predetermined thickness connected to one end of the internal electrode pattern exposed on one outer surface of the body; And a fifth process of forming external terminals on both outer surfaces of the body, and forming at least one external terminal to surround the discharge medium of the corresponding outer surface.

In the second process, at least one internal electrode pattern is formed on the same sheet or another sheet.

The discharge medium is cured between the fourth process and the fifth process, and the external terminal is baked after the fifth process. In this case, the curing temperature for the discharge medium is made higher than the baking temperature for the external terminal.

According to the present invention of such a configuration, not only takes a very simple configuration compared to the conventional method (FIGS. 1 and 2), but also can be manufactured in a very simplified process.

Since one end of the inner electrode exposed to one outer side of the body and the outer terminal spaced apart by a predetermined gap serve as a gap electrode, the dielectric constant of the body is not significantly affected.

Since the body's dielectric constant is not significantly affected, the cost of the body material can be reduced considerably compared to the existing one.

Hereinafter, a surge absorber and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a view for explaining the configuration and manufacturing process of the surge absorber according to an embodiment of the present invention, Figure 4 is a cross-sectional view taken along the line A-A of FIG.

First, a slurry is produced to produce a plurality of molded sheets that will constitute the body (laminate). For example, a raw material powder is prepared by ball milling water or alcohol with a solvent for 24 hours in a desired composition in which an additive such as Bi ₂ O ₃ , CoO, MnO, etc. is added to a dielectric material having a predetermined dielectric constant. PVB-based binder (binder) is measured as an additive to the prepared raw powder and then dissolved in toluene / alcohol (toluene / alcohol) -based solvent. The slurry is then milled and mixed for about 24 hours in a small ball mill. The numerical values exemplified above are only examples and may vary depending on the manufacturing environment and needs.

This slurry is prepared by a method such as a doctor blade to produce a green sheet having a desired thickness. The manufactured green sheet is cut to a desired length unit to make a plurality of molded sheets 50, 52, and 54. Here, the molded sheet may also be referred to as a dielectric sheet. The sheet described in the claims should be taken to mean a molded sheet. In FIG. 3, the forming sheets 50, 52, 54 may be more as needed.

Then, the internal electrode pattern 52a is printed on the molding sheet 52 as shown in FIG. The inner electrode pattern 52a is later used as either of two gap electrodes. The internal electrode pattern 52a is printed transversely from one end of the molded sheet 52 to the other end. Both ends of the inner electrode pattern 52a are exposed on opposite outer surfaces (ie, left side, right side) of the molding sheet 52. The internal electrode pattern 52a is printed with silver paste using Ag powder.

Subsequently, the molded sheet 50 is laminated on the lowermost layer, and then the molded sheet 52 is laminated thereon (see FIG. 3B). Use a pressure of approximately 500 to 2000 psi for stacking. After that, it is compressed. Use a pressure of approximately 500 to 3000 psi for crimping.

The body 60 formed by lamination and compression is subjected to a degreasing and firing process. The degreasing process is performed at about 300 ° C. and then calcined at about 800 ° C. to 900 ° C. When the firing is completed, since the internal electrode pattern 52a is appropriately called as the internal electrode, it is hereinafter referred to as the internal electrode.

Then, the discharge medium 62 is formed on either of the outer surfaces of the elementary body 60 on either of the outer surfaces (left side in FIG. 3) with a predetermined thickness (for example, about 15 µm) by termination or printing (FIG. 3). (C) of). The thickness of the discharge medium 62 is approximately 15 µm in consideration of shrinkage in a later curing process. The discharge medium 62 is mixed with a metal material such as Al, Ag, Pt, Ru, Cu, W, and an insulator (for example, Al ₂ O ₃ , SiO ₂ ) as a main raw material and epoxy, silicon, glass, etc. as a binder. will be. The discharge medium 62 may be air or a polymer. Of course, if the metal material can facilitate the discharge between the internal electrode 52a and the external terminal 64a for the gap electrode to be formed later and contribute to the surge absorption, the metal material other than the aforementioned metal material is discharged. The metal material of the medium 62 can be used. In particular, since the discharge medium 62 should not react at the baking temperature of the external terminals 64a and 64b to be formed later, the curing temperature of the discharge medium 62 is higher than the external terminal baking temperature. That is, when the discharge medium 62 reacts when the external terminals 64a and 64b are baked after the discharge medium 62 is cured, the discharge medium 62 may not function in the finally manufactured surge absorber. Because it becomes. In consideration of this, it is preferable to select a material of the discharge medium 62.

The discharge medium 62 is cured at a predetermined temperature to bond the body 60. The curing causes the discharge medium 62 to have a desired thickness (about 10 µm). In the embodiment of the present invention, even if the internal electrode 52a for the gap electrode 52 and the body 60 are simultaneously co-fired, the discharge medium 62 is hardened thereafter. In the present invention, it is possible to solve the problem of deterioration of the body 30 due to the vaporization component in the discharge medium.

Subsequently, external terminals 64a and 64b are formed on both outer surfaces of the body 60 using a conventional termination system (see FIG. 3 (d)). The external terminal 64a is formed on one outer side surface portion (ie, the left side surface portion) of the body 60 in the longitudinal direction, and is formed while surrounding the discharge medium 62 formed at the corresponding portion. The external terminal 64b is formed at the other outer side surface portion (ie, the right side surface portion) of the body 60 and connected to one end of the inner electrode 52a for the gap electrode exposed to the corresponding portion.

Finally, the external terminals 64a and 64b are baked at a predetermined temperature to couple the body 60. Of course, the baking temperature of the external terminals 64a and 64b is lower than the curing temperature of the discharge medium 62.

In the embodiment of the present invention, the inner electrode 52a becomes one gap electrode and the outer terminal 64a becomes another gap electrode. Therefore, when a surge voltage or the like flows in, a discharge occurs between the external terminal 64a and the internal electrode 52a.

In the above-described embodiment, only one internal electrode 52a is formed and described. This results in an array structure. That is, when printing the internal electrode pattern 52a, a plurality of prints may be printed on the molded sheet 52 at predetermined intervals. In addition, the internal electrode patterns 52a may be printed on a plurality of molded sheets, respectively.

On the other hand, the present invention is not limited only to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, the technical idea to which such modifications and variations are also applied to the claims Must see

1 is a view for explaining an example of a conventional surge absorber.

2 is a view for explaining another example of the conventional surge absorber.

3 is a view for explaining the configuration and manufacturing process of the surge absorber according to an embodiment of the present invention.

4 is a cross-sectional view taken along the line A-A of FIG.

<Description of Symbols for Major Parts of Drawings>

50, 52, 54: molded sheet 52a: internal electrode

60: body 62: discharge medium

64a, 64b: external terminal

Claims (6)

Internal electrodes exposed at both ends of the body to opposite opposing outer surfaces of the body; A discharge medium formed on one of both outer surfaces of the body with a predetermined thickness and connected to one end of the internal electrode exposed on the outer surface; And An outer terminal formed on one of both outer sides of the body to surround the discharge medium, and on the other outer side thereof, an external terminal connected to the other exposed end of the inner electrode; And a surge component is discharged between one end of an internal electrode exposed to one outer surface of the body and an external terminal formed while surrounding the discharge medium. The method according to claim 1, And the at least one internal electrode. A first process of manufacturing a plurality of sheets; Forming an internal electrode pattern on a part of the plurality of sheets, and exposing both ends to opposite opposing outer surfaces of the sheet; A third step of forming a body by stacking the plurality of sheets; A fourth step of forming a discharge medium having a predetermined thickness connected to one end of an internal electrode pattern exposed on one outer surface of the body; And External terminals are formed on both outer surfaces of the body, and at least one external terminal is formed to surround the discharge medium of the outer surface, thereby disposing one end of the inner electrode pattern exposed to one outer surface of the body and the discharge medium. And a fifth process of discharging the surge component between the external terminals formed while wrapping. The method according to claim 3, The method of claim 2, wherein at least one internal electrode pattern is formed on the same sheet or another sheet. The method according to claim 3, And curing the discharge medium between the fourth process and the fifth process, and baking the external terminal after the fifth process. The method according to claim 5, And a curing temperature of the discharge medium is higher than a baking temperature of the external terminal.

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