JPH10335105A - Chip component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip component capable of removing concerns about the mechanical strength of ceramic devices with its central section being narrower than its bilateral section. SOLUTION: An armor film 3 is continuously formed on the central cylinder section and the bilateral prism section of a conductor film 2 and an external electrode film 4 is formed on the bilateral prism section of the conductor film 2, except for the region formed where there is no armor film. Since the mechanically weak section of the ceramic element, with its central section being narrower than the bilateral section, is reinforced by the armor film 4 extending to the bilateral prism section, concerns about the mechanical strength can be removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip component which uses a porcelain element whose center portion is thinner than both side portions, and has an exterior film on the center portion of the porcelain element and external electrode films on both side portions. It is.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 7-307201 by the present applicant discloses a chip component of this type, which discloses a smaller cross-sectional shape between a pair of prism portions. A porcelain element integrally provided with a prismatic or cylindrical part, a conductor film formed on the surface of the porcelain element, an exterior film covering the central prismatic part or the central cylindrical part, and both sides of the conductor film A chip component including an external electrode film covering an upper portion of the prism is disclosed.

According to the structure of this chip component, for example,
A chip resistor can be formed by forming a conductor film from a resistive material and trimming the central part as necessary, and a conductive film is formed from a low-resistance material and a spiral groove is formed in the central part. By doing so, it is possible to configure a chip inductor having a predetermined number of turns of the coil,
Further, a chip jumper can be formed by forming the conductor film from a low-resistance material.

[0004] The above-mentioned chip component can arbitrarily use one of the side surfaces of both external electrode films as a mounting surface, can prevent component rolling and slipping, and can perform stable mounting. Since it has an external shape that does not have it, it has an advantage that it is suitable for bulk supply (a method of supplying chip components stored in a loose state in a line in a predetermined direction).

[0005]

The above-mentioned chip parts are:
Since a porcelain element is used in the center portion which is thinner than the both side portions, if the dimensional difference between the center portion and the both side portions becomes large, there is a possibility that a crack may occur at the boundary portion due to the difference in strength between the two.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a chip component capable of eliminating a concern about strength even when a porcelain element having a central portion smaller than both side portions is used. It is in.

[0007]

In order to achieve the above object, the present invention uses a porcelain element having a central portion narrower than both side portions, wherein an outer film is provided on the central portion of the porcelain element and external electrodes are provided on both side portions. A chip component provided with a film, wherein the outer film extends to both side portions of the porcelain element, and its main feature is that the outer electrode film is in contact with an edge of the outer film.

According to this chip component, the outer film extends to both side portions of the porcelain element, and the outer electrode film is in contact with the edge of the outer film, so that the center portion is thinner than the both side portions. Even in the case of using the element, the weak portion of the porcelain element can be reinforced by the exterior film extending to both sides of the porcelain element.

[0009]

FIG. 1 is an external perspective view of a chip component to which the present invention is applied, and FIG. 2 is a longitudinal sectional view thereof. The chip component shown in the figure has an external appearance having a cylindrical portion having a smaller cross-sectional shape than a pair of square pillars, and 1 in the figure is a porcelain element, and 2 is a conductor film for a circuit. (Hereinafter simply referred to as a conductor film) 3 is an exterior film, and 4 is an external electrode film.

The porcelain element 1 is made of a porcelain material (ceramics) corresponding to the type of component, and has an appearance similar to that of a chip component as shown in FIG. That is, the porcelain element 1 has a pair of square pillars 1 having the same orientation and size.
a and a cylindrical portion 1b having a smaller cross-sectional shape than the rectangular column portion 1a and being coaxially located between the rectangular column portions 1a on both sides.

The conductive film 2 is made of a conductive material according to the type of component, and is formed with a predetermined thickness on the entire surface of the ceramic element 1 by a known thin film forming technique utilizing sputtering, electrolytic / electroless plating, or the like. I have. The thickness of the conductor film 2 is about 3 μm, depending on the type of parts.

The exterior film 3 is made of an epoxy-based resin or a silicon-based glass, etc., and is formed on the center column portion and both side prism portions of the conductor film 2 by a well-known thick film forming technique using paste application and curing. (A part of the four side surfaces adjacent to the central column portion) is formed continuously with a predetermined thickness. The thickness of the exterior film 3 is about 15 μm, and in the illustrated example, the exterior film 3 is extended to about １ ／ of the side of the center column on the four side surfaces of the prisms on both sides.

The external electrode film 4 is made of an electrode material such as silver, nickel or the like, and the exterior film 3 on both side prism portions of the conductor film 2 is formed by a well-known thick film forming technique utilizing paste application and curing. It is formed with a predetermined thickness on the part that is not. The thickness of the external electrode film 4 is 20 to 45 μm.
In the illustrated example, the edge 4a of the external electrode film 4 is in contact with the edge 3a of the exterior film 3 while slightly overlapping the edge 3a.

According to the structure of the chip component shown in FIGS. 1 and 2, a chip resistor can be formed by adopting a material suitable for a resistor for the ceramic element 1 and the conductor film 2. An example of the manufacturing method will be described with reference to FIG.

First, as shown in FIG. 3A, a cylindrical portion 1b having a smaller cross-sectional shape than a pair of square pillar portions 1a.
After obtaining the ceramic element 1 made of an insulating material such as alumina, the ceramic element 1 is integrally barrel-polished and its corners and ridges are rounded.

Next, as shown in FIG. 3B, a conductor film (resistive film) 2 made of a resistive material such as ruthenium oxide is coated on the entire surface of the ceramic element 1 by sputtering, electrolytic / electroless plating, or the like. Form. Further, if necessary, a trimming groove (not shown) is formed in the upper portion of the central cylindrical portion of the conductor film by partial removal processing using a method such as laser beam irradiation or dicing to adjust the resistance value.

Next, as shown in FIG. 3 (c), an exterior paste mainly composed of an epoxy resin or a silicon glass is provided on the central cylindrical portion of the conductor film and a portion on both side prism portions. Is coated using a roller or the like having a peripheral surface shape corresponding to the application region, and is cured by heat treatment such as baking to form the exterior film 3.

Next, as shown in FIG.
In the part where the exterior film 3 is not formed on both side prisms,
An electrode paste containing a metal powder such as silver or nickel is coated by a dipping method (dipping method) or a casting method or the like, and is cured by a heat treatment such as baking to form the external electrode film 4. As described above, a chip resistor having an appearance similar to that shown in FIGS. 1 and 2 can be obtained.

According to the structure of the chip component shown in FIGS. 1 and 2, the porcelain element 1 and the conductor film 2 are made of a material suitable for an inductor, and the conductor film 2 on the central column is formed in a spiral groove. Is formed, a chip inductor having a coil having a predetermined number of turns can be formed. Hereinafter, an example of a method for manufacturing the chip inductor will be described with reference to FIG.

First, as shown in FIG. 3 (a), a cylindrical portion 1b having a smaller cross section than a pair of square pillars 1a.
After obtaining the ceramic element 1 made of a magnetic material such as ferrite integrally provided with the above, a large number of the ceramic elements 1 are barrel-polished at once and the corners and ridges thereof are rounded.

Next, as shown in FIG. 3B, a conductor film 2 made of a low-resistance material such as copper or silver is formed on the entire surface of the porcelain element 1 by sputtering, electrolytic / electroless plating, or the like. . Then, a spiral groove (not shown) is formed in the upper portion of the central cylindrical portion of the conductive film 2 by a partial removal process using a method such as laser light irradiation or dicing to form a coil having a predetermined number of turns.

Next, as shown in FIG. 3 (c), an exterior paste mainly composed of epoxy resin, silicon glass, or the like is provided on the central cylindrical portion of the conductor film and a part of the rectangular prism portions on both sides. Is coated using a roller or the like having a peripheral surface shape corresponding to the application region, and is cured by heat treatment such as baking to form the exterior film 3.

Next, as shown in FIG.
In the part where the exterior film 3 is not formed on both side prisms,
An electrode paste containing a metal powder such as silver or nickel is coated by a dipping method (dipping method) or a casting method or the like, and is cured by a heat treatment such as baking to form the external electrode film 4. Thus, a chip inductor having an appearance similar to that shown in FIGS. 1 and 2 can be obtained.

Of course, the structure of the chip components shown in FIGS. 1 and 2 can be applied to chip components other than the above-described chip resistors and chip inductors, for example, chip jumpers and composite circuit components.

As described above, according to the chip component shown in FIGS. 1 and 2, the outer film 3 is continuously formed on the central column portion of the conductive film 2 and a part on both side prism portions, and the external electrode is formed. Since the film 4 is formed on the rectangular prism portions on both sides of the conductor film 2 where the exterior film 3 is not formed, the strength of the porcelain element 1 can be improved even when the porcelain element 1 whose center portion is thinner than both side portions is used. The weak portion can be properly reinforced by the exterior film 4 extending up to the prism portions on both sides, so that concerns about the strength can be eliminated.

The edge 4a of the external electrode film 4 is
The outer electrode film 4 can prevent the outer film 3 from peeling off from the outer edge 3a because the outer film 3 slightly overlaps and covers the outer edge 3a. Can be enhanced.

Further, since the thickness of the external electrode film 4 is larger than the thickness of the outer film 3, the outer film 3 located on the prism portions on both sides does not hinder the component mounting, and the side surfaces of the outer electrode film 4 Parts can be satisfactorily connected by properly contacting the substrate electrode (land) via a bonding material such as solder.

Further, since the distance between the external electrode films can be made longer than when the external electrode films are formed on the prisms on both sides, even if the longitudinal dimension of the component is small, the external electrode film which can be generated at the time of component mounting can be obtained. The problem of mutual short-circuit (short) can be avoided.

In the embodiment shown in FIGS. 1 and 3,
An example in which the edge 4a of the external electrode film 4 slightly overlaps the edge 3a of the exterior film 3 has been described, but as shown in FIG. 4A, the edge 4a of the external electrode film 4 overlaps. If the margin is increased, the bonding between the external electrode film 4 and the exterior film 3 can be further improved, and the side surface area (connection area) of the external electrode film 4 can be increased. Of course, the external electrode film 4
The edge 4a of the external electrode film 4 does not necessarily have to overlap the edge 3a of the exterior film 3, and as shown in FIG. 4B, the edge 4a of the external electrode film 4 and the edge 3a of the exterior film 3 overlap. Instead, a form that makes contact may be adopted.

Further, in the embodiment shown in FIGS. 1 and 3, the case where the exterior film 4 is formed by using the thick film method is exemplified, but the exterior film 4 is formed by using a molding technique. Is also possible. Hereinafter, the exterior film 4 is formed by molding using a mold.
Will be described with reference to FIG.

First, a pair of mold plates 11 and 12 as shown in FIG. 5A are prepared, and after setting the porcelain element 1 after forming the conductor, the mold is closed. The mold plates 11, 11 hold the porcelain element 1 after conductor formation in a predetermined posture in a mold closed state,
In addition, a cavity having a clearance C corresponding to a portion where the exterior film 4 is formed is defined. Then, as shown in FIG. 5B, the exterior paste P is injected into the clearance C from a gate (not shown), and the injected exterior paste P is cured by heat treatment or the like. There is no particular limitation on the molding method, but in the case of cast molding, the same as the above-mentioned exterior paste can be used as the exterior paste P. If the composition of the exterior paste P is changed, injection molding can be performed. The exterior film can also be formed in a similar manner by transfer molding or transfer molding. If the porcelain element 1 is taken out after the paste is hardened and the porcelain element 1 is taken out, as shown in FIG. Then, a chip component similar to that shown in FIGS. 1 and 2 can be obtained.

Further, in the embodiment shown in FIGS. 1 and 2, a chip component having an external shape having a cylindrical portion having a smaller cross-sectional shape than a pair of square pillar portions is exemplified as a chip component. As shown in FIG. 6, the chip component may have an external shape including a square pillar portion having a smaller cross-sectional shape than a pair of square pillar portions. This chip component is a porcelain element comprising a pair of square pillars having the same orientation and size, and a square pillar having a cross section smaller than the square pillar and coaxially located between the square pillars on both sides. The other configuration is the same as that shown in FIG. 1 and FIG. 2 except that an integrated unit is used.

[0033]

As described in detail above, according to the present invention,
Even in the case of using a porcelain element whose central part is thinner than both sides, the weak part of the porcelain element is properly reinforced with an exterior film extending to both sides to eliminate the concerns of strength and increase the height. We can provide high quality chip parts.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a chip component to which the present invention is applied.

FIG. 2 is a longitudinal sectional view of the chip component shown in FIG. 1;

FIG. 3 is a diagram showing a manufacturing procedure of a chip component;

FIG. 4 is a diagram showing a modified example of a boundary portion between an external electrode film and an exterior film.

FIG. 5 is a diagram showing a procedure for forming an exterior film by molding using a mold.

FIG. 6 is an external perspective view of another chip component to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ceramic element, 2 ... Conductor film, 3 ... Outer film, 3a ... Edge of outer film, 4 ... External electrode film, 4a ... Edge of external electrode film, 1
1,12: mold, C: clearance, P: exterior paste.

Continued on the front page (72) Inventor Tomio Higashi, 1197 Shimada, Inami-cho, Hidaka-gun, Wakayama Prefecture Inside Chuki Seiki Co., Ltd. (72) Inventor Ikuo Kakiuchi 1197, Shimada, Inami-cho, Hidaka-gun, Wakayama Prefecture Chuki Seiki Co., Ltd. (72) Inventor Manabu Teraoka 1197 Shimada, Inami-cho, Hidaka-gun, Wakayama Prefecture Inside Chuki Seiki Co., Ltd.

Claims (4)

[Claims] 1. A chip component comprising a porcelain element having a center portion narrower than both side portions, an exterior film on a central portion of the porcelain element, and an external electrode film on both side portions, wherein the exterior film is A chip component extending to both side portions of a porcelain element, wherein the external electrode film is in contact with an edge of the exterior film. 2. The chip component according to claim 1, wherein the external electrode film covers at least an edge of the exterior film. 3. The chip component according to claim 1, wherein the thickness of the external electrode film is larger than the thickness of the exterior film. 4. The chip component according to claim 1, wherein the exterior film is formed by molding using a mold.