JPH07183159A - Flanged tubular electronic component and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] To manufacture a tubular electronic component with a flange that has high mountability on a filter connector or the like, is not easily destroyed by a high voltage surge, and has controllable capacitor characteristics or varistor characteristics with high productivity. Obtain tubular feedthrough capacitors and varistors. [Structure] A conductive coating 11 is formed on the outer and inner surfaces of a ceramic sintered tube 10 having a flange 14 formed on one end of the outer surface.
The outer surface electrode 12 and the inner surface electrode 13 are formed.
The sintered tube is a tubular body having at least a uniform outer diameter, and the flange is formed of heat-resistant resin or baked glass.
In this tubular electronic component 20, a tubular ceramic molded body having at least a uniform outer diameter is fired to produce a sintered tube, and a flange made of heat-resistant resin or baked glass is formed at one outer end of the sintered tube. It is made by forming a conductive film on the entire surface of the sintered tube and then removing the film formed on both end surfaces of the sintered tube to insulate the outer and inner electrodes from each other on the outer and inner surfaces of the sintered tube. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to tubular electronic parts such as tubular feedthrough capacitors for removing high frequency noise, cylindrical capacitors for absorbing surge voltage, feedthrough capacitors with varistor function for absorbing high frequency noise and surge voltage, and their manufacture. Regarding the method. More specifically, the present invention relates to a flanged tubular electronic component having a flange on one end face of a ceramic sintered tube and a method for manufacturing the same.

[0002]

2. Description of the Related Art Among flange-type tubular electronic parts of this type, for example, a flange-type tubular feedthrough capacitor is manufactured by press-molding a granulated powder obtained by mixing ceramic powder and a binder or the like with a flange at one end. After being formed into a tubular shape, this molded body is fired to produce a ceramic sintered tube, and then electroless plating is applied to the entire surface of the sintered tube, or an electrode paste is applied and baked to form an electrode made of a conductive film. Form on the entire surface. Then, both end faces are polished by lap polishing or the like to remove the conductive film on both end faces of the sintered tube. This allows the feedthrough capacitor 6 as shown in FIG.
Is obtained. This feedthrough capacitor 6 has a flange 1a on the outer surface and a through hole 5 inside. A recess 1b is formed above the through hole 5. Flange 1a and recess 1b
An outer surface electrode 2 and an inner surface electrode 3 each made of a conductive film are formed on the outer surface and the inner surface of the formed sintered tube 1 in a mutually insulated state. The feedthrough capacitor 6 functions as a stopper when the flange 1a is mounted on the filter connector, and is excellent in mountability.

[0003]

However, since the flange 1a of the feedthrough capacitor 6 is integral with the sintered tube 1 and forms the neck portion on the sintered tube itself, the shape is complicated and the productivity is reduced. There was a bad drawback. If the feedthrough capacitor is a feedthrough capacitor with a varistor function for absorbing surge voltage, the thickness of the sintered tube, which is a semiconductor element, at the neck is changed to adjust the electrical characteristics such as varistor characteristics. For this reason, when a large amount of energy such as a high voltage surge is absorbed by the feedthrough capacitor, the energy is concentrated at one thin portion, and the capacitor is easily broken.

An object of the present invention is to provide a tubular electronic component with a flange, which has a high mountability on a filter connector or the like, is hard to be destroyed by a high voltage surge, and has a controllable capacitor characteristic or varistor characteristic. Another object of the present invention is to provide a method of manufacturing a tubular electronic component with a flange, which can be manufactured not only by press molding but also by extrusion molding and has high productivity.

[0005]

The structure of the present invention for achieving the above object will be described with reference to FIGS. 1 (a) to 1 (d). In the flanged tubular electronic component 20 of the present invention, a flange 14 is formed on one outer surface end of the ceramic sintered tube 10, and an outer surface electrode 12 and an outer surface electrode 12 made of a conductive film 11 are formed on the outer surface and the inner surface of the sintered tube 10, respectively. The inner surface electrode 13 is formed. The sintered tube 10 is a tubular body having a uniform outer diameter at least, and the flange 14 is made of heat-resistant resin or baked glass.

In this tubular electronic component 20, a tubular ceramic molded body having at least a uniform outer diameter is fired to produce a ceramic sintered tube 10, and a heat-resistant resin or The flange 14 made of baked glass is formed, the conductive film 11 is formed on the entire surface of the sintered tube including the inner surface of the sintered tube 10, and the film 11 formed on both end surfaces of the sintered tube 10 is removed and sintered. An outer surface electrode 12 and an inner surface electrode 13 are formed on the outer surface and the inner surface of the tube 10 while being insulated from each other.

The present invention will be described in detail below. <Tubular molding and firing> First, ceramic powder is prepared according to the application of the tubular electronic component. When the tubular electronic component is a tubular feedthrough capacitor for removing high frequency noise, ceramic powder of high dielectric constant type such as barium titanate type or lead type is prepared. Further, in the case where the tubular electronic component is a tubular feedthrough capacitor with a varistor function or a tubular varistor with a capacitor function whose main purpose is to absorb surge voltage in addition to removing high frequency noise, a dielectric material having capacitance and varistor characteristics, such as oxidation, is used. A ceramic powder of a semiconductor varistor material such as zinc-based, strontium titanate-based, or titanium oxide-based is prepared. In the present specification, the “dielectric material having capacitance and varistor characteristics” refers to a material having a surge absorbing function due to varistor characteristics and also having dielectric characteristics in a voltage range below the varistor voltage. A tubular compact is formed by extrusion molding, press molding or the like using the above ceramic powder. In the extrusion molding, the kneaded material obtained by kneading the ceramic powder and the binder is extruded by an extrusion molding machine to form a tube having a uniform outer diameter. In the press molding, the above-mentioned ceramic powder is mixed with a binder or the like to prepare granulated powder, and the granulated powder is pressed by a press molding machine to form a tube having a uniform outer diameter. The obtained molded body is fired to form a ceramic sintered tube 1 having a straight outer surface and a constant wall thickness D ₁ as shown in FIG. 1 (a).
It becomes 0. A through hole 15 is formed in the center of the sintered tube 10. In addition, as shown in FIG.
It is also possible to form the inner surface end portion 40a of the upper part of 5 with a small diameter.

<Formation of Flange> FIG. 1 (b) or FIG.
As shown in (e), the sintered tube 10 has a flange 14 formed on one outer surface end thereof. The flange 14 is made of a material that can withstand soldering when the tubular electronic component 20 of the present invention is mounted, and has a heat resistant temperature of 300 to 350 ° C.
The heat resistant resin or baked glass of is used. An epoxy resin is mentioned as a heat resistant resin. This flange 1
4 is a liquid or paste heat-resistant resin or glass on one outer surface end of the sintered tube 10 by a dipping method, a screen printing method, a roll printing method or a method of coating with a coating tool such as a brush or a cotton swab. It is formed by applying and applying a treatment such as heating if necessary. When heating or cooling is required, the heat-resistant resin or glass has good adhesion to the sintered tube and the coefficient of thermal expansion is higher than that of the sintered tube so that the flange does not separate from the sintered tube due to heating or cooling. Close materials are preferred.

The dipping method is carried out by immersing only one end of the sintered tube in the liquid resin or glass. In the screen printing method, a large number of sintered tubes are placed on a flat base with their end faces facing downward, and these sintered tubes are preferably fixed in a close-packed structure, and then the upper surface is sintered. The paste resin or glass is applied by printing onto the end surface of the tube. When the resin or glass is applied to one outer surface end of the sintered tube by these methods, the resin or glass extends not only to the end surface but also to at least the outer surface end of the sintered tube. A resin film or glass film 14 'is formed on this end face. If the resin or glass extends to the end of the inner surface,
The protrusion 16 shown in (b) is formed. Apply the resin or glass only to the outer surface end so that the resin or glass does not reach the inner surface end, or in the roll printing method, apply the applicator only to the outer surface end of the sintered tube to apply the sintered tube. By rotating around the through hole, only the flange 14 shown in FIG. 1 (e) is formed. If the inner surface end portion 40a is formed to have a small diameter as shown in FIG. 3A, the inner surface of the through hole 45 can be made straight after the inner surface electrode is formed even by the dipping method or the screen printing method.

The flanges 14 and 44 are required to have a thickness D ₂ such that they are caught when they are mounted on a filter connector or the like. For this reason, the flanges 14 and 44 have a thickness D ₂ of at least about 100 μm when the sintered tubes 10 and 40 are viewed in longitudinal section. Also, by changing the width W of the flange 14 in the length direction of the sintered tube, the contact area between the outer surface electrode and the sintered tube, which will be described later, changes, and thereby the electrical characteristics such as the capacitance and varistor characteristics of the tubular electronic component 20 are changed. You can control. The thickness D ₂ or width W of these flanges is adjusted by the viscosity of the coating liquid, the depth during immersion, the coating speed, and the like.

<Formation of Conductive Film> FIG. 1 (c) or FIG.
As shown in (f), the conductive film 11 is formed on the entire surface of the sintered tube 10 including the inner surface thereof. The conductive film 11 is a plating film, a baking film, a vapor deposition film, or the like. In the case of plating film,
As shown in the enlarged view of FIG. 1C, the film 11 is composed of two layers, for example, an ohmic nickel plating film 11a and a solder plating film 11b formed on the surface thereof.
The solder plating film 11b improves the solderability of the tubular electronic component 20. The nickel plating film 11a is formed on the entire surface of the sintered tube 10 by electroless barrel plating, and the plating film 11b is formed on the entire surface of the sintering tube 10 by electrolytic barrel plating. In the case of a baked film, similarly, a conductive paste containing Ag or Ag and Pd is coated with an applicator such as a brush or a cotton swab, or the paste is liquefied and dip-coated, and then baked and sintered. Formed on the entire surface of 10. You may form the above-mentioned plating film on the surface of a baking film.

<Removal of Conductive Film> After the conductive film 11 is formed on the entire surface of the sintered tube 10, FIG. 1 (d) or FIG.
As shown in (g), the conductive film 1 on both end surfaces of the sintered tube 10
1 and resin film or baked glass film 1 on one end face 1
4'is removed by mechanical means. In addition to the known lapping method, there is a sandblasting method (Japanese Patent Application No. 5-27230) filed by the applicant of the present invention. As shown in the figure, the tubular electronic component 20 or 30 has a structure in which the outer surface electrode 12 and the inner surface electrode 13 sandwich the ceramic sintered tube 10 between them, and the conductive film is divided into two parts so that both electrodes are connected. It is necessary that 12 and 13 are electrically insulated from each other. Therefore, the conductive film is completely removed by the above mechanical method. However, the resin film or the baked glass film 14 'may be removed as shown in the drawing, or may be left in close contact with the sintering tube, though not shown. As shown in FIGS. 3A and 3B, the sintered tube 4
When the inner surface end portion 40a of 0 has a small diameter, the inner surface electrode 4
After forming 3, the inner surface of the through hole 45 can be straightened, and a lead wire (not shown) can be easily inserted.

[0013]

When the tubular electronic component 20 is a feedthrough capacitor with a varistor function, the varistor characteristic is originally exhibited in the thin portion of the sintered tube, but the sintered tube 10 in the portion where the outer surface electrode 12 and the inner surface electrode 13 are formed. Has a uniform wall thickness and does not have a neck as in the past, so even if a lightning surge enters, there is no spot where the surge concentrates, the absorption of large energy is improved, and stable characteristics are exhibited for a long period of time. Since the varistor voltage is proportional to the wall thickness D ₁ of the sintered tube 10, the smaller the wall thickness D ₁ , the lower the varistor voltage.

[0014]

As described above, according to the method of the present invention, the thickness D ₁ is constant during the molding of the sintered tube as compared with the conventional method in which the neck portion is provided during the molding of the sintered tube, and the sintering is performed in the post-processing. Since the flange is added to the tube, the shape of the sintered tube is simple and the molding is easy. Thus, not only press molding but also extrusion molding can be used.

Since the obtained tubular electronic component has a flange as in the conventional product, it has high mountability on a filter connector or the like. Further, since the thickness D _{1 of the} sintered tube is constant, the surge is less likely to be concentrated and stable characteristics are obtained, and the surge is less likely to be broken by the high voltage surge. Further, by changing the width W of the flange or the wall thickness D ₁ of the sintered tube, it is possible to control the capacitor characteristic or the varistor characteristic.

[0016]

EXAMPLES Examples of the present invention will be described below together with comparative examples. <Example> An organic binder was added to a ceramic powder containing titanium oxide as a main component, and the granulated powder was uniformly mixed into a tubular shape having a uniform outer diameter by a press molding machine. The tubular molded body was fired to have an outer diameter of 2.5 as shown in FIG.
A ceramic sintered tube 10 having a diameter of 1.4 mm, an inner diameter of 1.4 mm, and a length of about 2.0 mm was obtained. 300 sintered tubes 10 were prepared. Only one end of these sintered tubes 10 is immersed in an epoxy resin solution to cure the resin, and a resin film 14 'is formed on one end surface of the sintered tubes 10 as shown in FIG. 1 (b). The flange 14 is formed at the end of the outer surface. The flange 14 had a thickness D ₂ of about 200 μm and a width W of about 0.8 mm. As shown in FIG. 1C, these sintered tubes 10 were electrolessly plated with nickel to form a nickel plated film 11a having a thickness of about 2 μm on the entire surface of the sintered tubes. Next, this sintered tube is subjected to electrolytic barrel plating to a thickness of about 10 μm on the surface of the plated film 11a.
The solder plating film 11b of 1 was formed.

Subsequently, the plating film 11 on both end surfaces was removed by lapping. That is, five disk-shaped carriers each having 60 holes were prepared, and 60 sintering tubes were inserted and held in all the holes per carrier. These carriers are sandwiched between upper and lower lap surface plates that rotate upward and downward, and the upper and lower lap surface plates are rotated in opposite directions while the carrier is sandwiched between the upper and lower lap surface plates. The carrier was rotated and revolved while supplying the slurry containing abrasive grains. As a result, both end faces of a large number of sintered tubes 10 are simultaneously lapped, and the plated films 11 on both end faces are polished.
Was scraped off. The resin film 14 'is also scraped off, as shown in FIG.
The feedthrough capacitor 20 with a varistor function shown in (d) was obtained.

<Comparative Example> The same granulated powder as in the example was molded by a press molding machine into a tube having a neck as shown in FIG. This tubular compact was fired to obtain a flanged ceramic sintered tube 1 having an outer diameter of 2 mm, an inner diameter of 1 mm and a length of about 3.2 mm as shown in FIG. The length w of the flange portion of the sintered tube 1 was about 0.8 mm, and the protruding thickness d was about 200 μm. 300 sintered tubes 1 were prepared. In the same manner as in the examples, these sintered tubes were electrolessly plated with nickel to form a nickel plated film on the entire surface of the sintered tube, and then the barrel was electrolytically barrel plated and solder plated on the surface of the plated film. A film was formed. The plating films on both end surfaces of these sintered tubes were removed by the same lapping method as in the example to obtain a feedthrough capacitor 6 with a varistor function.

<Comparative Test> Two pieces each were obtained from the obtained tubular feedthrough capacitor of the example and the tubular feedthrough capacitor of the comparative example.
0 pieces were randomly selected, the varistor voltage of each element was measured, and the average value was calculated. In addition, the waveform (8 × 20) μsec,
A current surge with a current value of 150 A was repeatedly applied 5 times at intervals of 30 seconds, and the change in varistor characteristics before and after repeated application, that is, the rate of change in varistor voltage V _{1 mA} and nonlinear index α were measured. . The results are shown in Tables 1 and 2.

[0020]

[Table 1]

[0021]

[Table 2]

As is clear from Tables 1 and 2, the varistor voltage and the non-linear index before applying the current surge before the surge withstanding test showed substantially the same values in the examples and the comparative examples. Further, although the flanged feedthrough capacitor of the comparative example had substantially the same shape and size as those of the examples, the varistor voltage and the non-linear index deterioration after the current surge was applied were larger than those of the examples.

[Brief description of drawings]

FIG. 1 is a sectional view of a tubular electronic component in a manufacturing sequence according to a method of the present invention. (A) is sectional drawing of the ceramic sintered tube. (B)
And (e) is a sectional view of a sintered tube having a flange.
(C) And (f) is sectional drawing of the sintering tube which formed the electroconductive film on the whole surface. (D) And (g) is sectional drawing of the tubular electronic component.

FIG. 2 is a perspective view of the tubular electronic component shown in FIG.

FIG. 3 is a sectional view of a tubular electronic component in a manufacturing sequence according to another method of the present invention. (A) is sectional drawing of the ceramic sintered tube.
(B) is sectional drawing of the tubular electronic component.

FIG. 4 is a sectional view of a conventional tubular electronic component with a flange.

[Explanation of symbols]

10,40 Ceramic sintered tube 11 Conductive film (plating film) 11a Nickel plating film 11b Solder plating film 12,42 Outer surface electrode 13,43 Inner surface electrode 14,44 Flange 15,45 Through hole 20,30,50 Tubular electronic component (Tubular feedthrough capacitor)

Claims (7)

[Claims] 1. A ceramic sintered tube (10, 40) having a flange (14, 44) formed at one outer end thereof, the sintered tube (10, 40)
In the tubular electronic component with flange (20, 50) on which the outer surface electrode (12, 42) and the inner surface electrode (13, 43) each made of a conductive film (11) are formed on the outer surface and the inner surface of the sintered tube ( A tubular electronic component with a flange characterized in that the flange (14, 44) is formed of a heat-resistant resin or a baked glass, which is a tubular body having a uniform outer diameter of at least 10,40). 2. One end of the inner surface of the ceramic sintered tube (40)
The tubular electronic component with a flange according to claim 1, wherein the (40a) has a small diameter. 3. The tubular electronic component with a flange according to claim 1, wherein the conductive film (11) is a plating film. 4. The tubular electronic component with a flange according to claim 1, wherein the conductive film (11) is a baked film. 5. The flanged tubular electronic component according to claim 1, wherein the conductive film (11) comprises a baking film and a plating film formed on the surface of the baking film. 6. The flanged tubular electronic component according to claim 1, wherein the ceramic sintered tube (10) has one or both of capacitive and varistor characteristics. 7. A ceramic sintered tube (10) is produced by firing a tubular ceramic molded body having at least a uniform outer diameter, and a heat-resistant resin or a baked resin is applied to one outer surface end of the sintered tube (10). A flange (14) made of glass is formed, a conductive film (11) is formed on the entire surface of the sintered tube including the inner surface of the sintered tube (10), and both end surfaces of the sintered tube (10) are formed. The formed film (11) is removed to form outer electrodes on the outer surface and the inner surface of the sintered tube (10), respectively.
A method of manufacturing a tubular electronic component with a flange, wherein the (12) and the inner surface electrode (13) are formed in a mutually insulated state.