JPH09283363A - Chip part and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip part having a large electrostatic capacitance and high reliability on quality, also facilitating automatic packaging. SOLUTION: A plurality of the first outer electrodes 3A and the second outer electrodes 3B of the chip laminated ceramic capacitors 1 having the first outer electrodes 3A and the second outer electrodes 3B are arranged to be adjacent to one another for the formation of a parallel body 8. Besides, the surface of the parallel body 8 leaving a part of the lower side thereof is covered with an exterior resin to form an exterior resin film 9 thereby enabling the parallel body 8 to be integrally structured. Furthermore, the parts of the base substance of each chip laminated ceramic capacitor and the parts of the first outer electrodes 3A and the second outer electrodes 3B are exposed. Finally, the chip part is packaged on a circuit substrate through the intermediary of the first and second exposed electrodes 3A and 3B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip part in which a plurality of so-called chip type monolithic ceramic capacitors are integrated into a single structure and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, in order to reduce the size of electronic devices,
The density of electronic components that make up electronic circuits has increased dramatically. For this reason, chip type monolithic ceramic capacitors, which are small but have a relatively large electrostatic capacity, are mainly used as capacitors.

The chip type monolithic ceramic capacitor 1 will be described with reference to FIGS. 6 (a) to 6 (c).

The chip type monolithic ceramic capacitor 1 is
Element body 2, first external electrode 3A and second external electrode 3
B and.

The element body 2 is formed integrally with the ceramic body 4 and the internal electrodes 5A and 5B. Ceramic body 4
Is a rectangular parallelepiped formed of a material having a large dielectric constant, such as barium titanate (BaTiO3). The ceramic body 4 is formed by laminating a ceramic plate 4A having an internal electrode 5A provided on the surface thereof and a ceramic plate 4A having an internal electrode 5B provided thereon. The internal electrode 5A is a rectangular thick film conductor arranged from the central portion of one short side of the ceramic plate 4A to the vicinity of the central portion of the other short side. Also, the internal electrode 5B
Is a rectangular thick film conductor arranged from the central portion of the other short side of the ceramic plate 4A to the vicinity of the central portion of the one short side. In this case, the internal electrodes 5A and 5B are not formed in the long side edge of the ceramic plate 4A, that is, in the fixed range L1 from the long side. The internal electrodes 5A and 5B are formed using, for example, a silver-palladium (Ag-Pd) -based alloy. As a result, the element body 2 is formed in a rectangular parallelepiped shape, one short side of the internal electrode 5A is exposed at the short side surface F1 of the element body 2, and one short side of the internal electrode 5B is the short side surface of the element body 2. Exposed at F2.

The first external electrode 3A has a short side face F1 of the element body 2, a long side face F3 close to the short side face F1, and a front face F.
4, formed so as to cover a part of the back surface F5. Also,
The second external electrode 3B is formed so as to cover a part of the short side face F2 of the element body 2, the long side face F3 close to the short side face F2, the front face F4, and the rear face F5. As a result, the short side surface F
The internal electrode 5A exposed at 1 is the first external electrode 3
A is electrically connected. The internal electrode 5B exposed on the short side surface F2 is electrically connected to the second external electrode 3B. Therefore, the electrostatic capacitance between the internal electrodes 5A and 5B is taken out via the first external electrode 3A and the second external electrode 3B. The first external electrode 3A and the second external electrode 3B are formed, for example, by plating the surface of silver (Ag) with nickel (Ni) and tin (Sn).

The chip type monolithic ceramic capacitor 1 as described above is compared with a ceramic capacitor having a single layer structure by reducing the thickness of the ceramic plate 4 and widening the electrode area by stacking the internal electrodes 5A and 5B. Can be formed into a small size, and a large capacitance can be obtained.

However, when a capacitor having a large electrostatic capacity is required for designing an electronic circuit, the electrostatic capacity of one chip type monolithic ceramic capacitor 1 is insufficient. For this reason, a plurality of chip type monolithic ceramic capacitors 1 are stacked in layers as shown in FIG.
As shown in (b), the first external electrodes 3A are used and the second external electrodes 3B are used in parallel connection with each other using the high temperature solder 6. In some cases, a plurality of chip type monolithic ceramic capacitors 1 are connected in parallel by baking silver paste on the first external electrode 3A and the second external electrode 3B, respectively. Further, as shown in FIG. 7C, when the metal terminals 7 are respectively connected to the first external electrode 3A and the second external electrode 3B by using high temperature solder, and a plurality of chip type multilayer ceramic capacitors 1 are connected in parallel. There was also.

[0009]

However, a plurality of chip type monolithic ceramic capacitors 1 using high temperature solder are used.
When connecting in parallel with each other or when a plurality of chip type monolithic ceramic capacitors 1 are connected in parallel by baking a silver paste, thermal distortion occurs in the chip type monolithic ceramic capacitor 1. Therefore, when the internal stress caused by the thermal strain exceeds the strength of the ceramic plate 4, cracks may occur in the ceramic plate 4 and defects such as shorts may occur between the internal electrodes 5A and 5B.

Further, when the metal terminals 7 are connected to the first external electrode 3A and the second external electrode 3B, respectively, there is a problem that the outer dimensions of the chip type monolithic ceramic capacitors 1 stacked are not constant. It was For this reason, when attempting to mount on a circuit board using an automatic mounting machine, the centering process is difficult and automatic mounting cannot be performed.
Therefore, you have to manually implement each one,
It was a factor of cost increase.

Therefore, an object of the present invention is to provide a chip part and a manufacturing method thereof for solving the above-mentioned object.

[0012]

The present invention is configured as follows to achieve the above object. That is, first, a parallel body in which a plurality of chip type monolithic ceramic capacitors having a first external electrode and a second external electrode are arranged so that the first external electrodes and the second external electrodes are in close contact with each other. And means for fixing the parallel body in an integral structure so as to expose a part of each of the first and second external electrodes of the parallel body.

With this structure, a plurality of chip type monolithic ceramic capacitors are grouped as one structure with the first external electrodes and the second external electrodes being in contact with each other. It becomes a chip component with a capacitance that is several times as large as that of the chip component. Further, each first external electrode and each second external electrode on the lower side of the parallel body are exposed, and connection to the circuit board is performed by connecting each exposed first external electrode and each second external electrode. Done through.

Secondly, in the first invention, the fixing means comprises an exterior resin coating for coating the parallel body.

The surface of the parallel body is covered with an exterior resin coating molded except a part of the lower side, and the plurality of laminated ceramic capacitors are integrated into an integrated structure.

Thirdly, in the first invention, the fixing means comprises a heat-shrink tube for bundling the parallel bodies.

A heat shrinkable tube is covered except a part of the lower side of the side surface of the parallel body, and a plurality of laminated ceramic capacitors are bundled by applying heat. As a result, the parallel body is integrated into a unitary structure.

Fourth, a step of arranging and temporarily fixing a plurality of chip type monolithic ceramic capacitors on a substrate, and a step of providing a mold member for forming the outer shape of the parallel body and injecting a liquid resin into the mold member. And a step of infiltrating the liquid resin while leaving a part of the parallel body temporarily fixed on the substrate on the substrate side, and a step of drying and curing the liquid resin in the state of the parallel body infiltrating. It consists of and.

A chip component in which a plurality of chip type monolithic ceramic capacitors are integrated can be easily mass-produced. As a result of drying and curing the resin while the parallel body is immersed in the liquid resin filled in the mold member, the surface of the parallel body is covered with the exterior resin coating with good dimensional accuracy except for a part on the lower side. Be seen.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) A chip part according to the present invention will be described with reference to FIG. Since the chip type monolithic ceramic capacitor 1 has been described in the conventional example, the description thereof is omitted, and the same components have the same numbers.

The chip part is composed of a parallel body 8 and an exterior resin coating 9.

The parallel body 8 is formed of three chip type monolithic ceramic capacitors 1. When forming the parallel body 8, the element body 2 of one chip type monolithic ceramic capacitor 1 is formed.
The front surface F4 of the other chip type multilayer ceramic capacitor 1 and the back surface F5 of the element body 2 of the other chip type multilayer ceramic capacitor 1 are opposed to each other, and the first external electrode 3A and the second external electrode 3B of one chip type multilayer ceramic capacitor 1 are , A first external electrode 3A and a second external electrode 3B of another chip type monolithic ceramic capacitor 1
Are arranged so that they are in close contact with each other. The parallel body 8 thus formed is placed with one long side surface F3 of the element body 2 of each chip type monolithic ceramic capacitor 1 on the upper side and the other long side surface F3 on the lower side.

The surface of the parallel body 8 is covered with an exterior resin, leaving a part of the lower side. As a result, the parallel bodies 8 are put together as one structure by the exterior resin coating 9.
Also, the lower side of the parallel body 8 is exposed from the exterior resin coating 9,
A part of the element body 2 of each chip type monolithic ceramic capacitor 1 and a part of the first external electrode 3A and the second external electrode 3B are exposed. In this case, the element body 2 has a lower long side surface F.
Assuming that a constant width L2 is exposed from 3, L2 is set shorter than L1. As a result, the internal electrodes 5A and 5B are not formed inside the exposed body 2. Generally, about 80 to 90% of the height of the parallel body 8 is covered with the exterior resin coating 9.

In the chip component thus formed, the first external electrode 3A and the second external electrode 3B exposed from the exterior resin coating 9 are provided to the predetermined terminals of the wiring pattern formed on the circuit board. Will be installed. After that, if the cream solder applied to the predetermined terminals is melted by heating from the outside,
The chip component is mounted on the circuit board. At the same time, the first external electrodes 3A and the second external electrodes 3B of each chip type monolithic ceramic capacitor 1 are electrically connected via solder. As a result, the three chip type monolithic ceramic capacitors 1 are surely electrically connected in parallel. The solder does not adhere to the exterior resin coating 9, but adheres only to the exposed first external electrode 3A and second exposed external electrode 3B. Therefore, the predetermined terminals of the wiring pattern,
Exposed first external electrode 3A and second external electrode 3B
The height of the solder fillet formed between them is kept low. Therefore, the stress generated between the solder fillet and each monolithic ceramic capacitor 1 is reduced, and the crack generated in the element body 2 of each monolithic ceramic capacitor 1 can be prevented. Even if cracks are generated, they are generated in the portion of the element body 2 exposed from the exterior resin coating 9, that is, the portion where the internal electrodes 5A and 5B are not formed. Therefore, the short circuit between the internal electrodes 5A and 5B is performed. Does not occur.

In the above-mentioned embodiment, the chip component composed of three monolithic ceramic capacitors is exemplified.
At least two chip type multilayer ceramic capacitors may be used.

The outer shape of the exterior resin coating 9 is not necessarily limited to the rectangular parallelepiped shape, and a chamfered portion 9A may be provided on the top surface of the exterior resin coating 9 as shown in FIG. When the chamfered portion 9A is provided, even if the chip component is stored in the embossed tape having the embossed hole, the chip component is not caught when it is taken out and can be taken out smoothly.

Further, in the above-mentioned embodiment, the case where the parallel body 8 is integrated into one structure by using the exterior resin coating 9 is illustrated, but the present invention is not limited to this. FIG.
The case where the heat shrinkable tube 10 is used instead of the exterior resin coating 9 will be described with reference to (a) and (b).
The heat shrink tube 10 has the feature of shrinking radially when heated. Therefore, when the heat shrinkable tube 10 covered so that the lower side of the parallel body 8 is exposed is heated, the heat shrinkable tube 10 shrinks so as to bundle the parallel body 8. As a result, the parallel body 8 is integrated into a unitary structure through the heat shrink tube 10. As in the case of using the exterior resin coating 9, the internal electrodes 5A and 5B are not formed inside the exposed element body 2 on the lower side of the parallel body 8. Also,
Since the solder does not adhere to the heat shrinkable tube 10, the height of the solder fillet can be kept low, as in the case of using the exterior resin coating 9. Therefore, it is possible to prevent cracks occurring in the element body 2 of each monolithic ceramic capacitor 1.
Even if a crack occurs, the portion of the element body 2 exposed from the heat-shrinkable tube 10, that is, the internal electrode 5A,
Since it occurs in the portion where 5B is not formed, it is possible to prevent the short between the internal electrodes 5A and 5B.

(Embodiment 2) A method of manufacturing a chip component according to the present invention will be described with reference to FIGS. 4 (a) to 4 (e). Since the chip type monolithic ceramic capacitor 1 has been described in the conventional example, the description thereof is omitted, and the same components have the same numbers.

A substrate 13 having an adhesive layer 12 on the surface of a flat plate 11 is prepared. As the adhesive layer 12, for example, a double-sided tape having front and back surfaces coated with an adhesive is used. After that, in the three chip type monolithic ceramic capacitors 1, one long side surface F3 side of the element body 2 is attached to the adhesive layer 12. In the three chip type monolithic ceramic capacitors 1, the first external electrode 3A and the second external electrode 3B of one chip type monolithic ceramic capacitor 1 are the first external electrodes 3A of the other chip type monolithic ceramic capacitor 1. And the second external electrode 3B
And the parallel body 8 are formed so as to be in close contact with each other.

Next, a cavity 14 having a square opening shape
A mold member 15 for resin molding in which is formed is prepared. The opening-shaped dimension of the cavity 14 is formed to be slightly larger than the vertical and horizontal dimensions L3 and L4 of the parallel body 8 attached to the substrate 13. Further, the depth of the cavity 14 is formed to be slightly larger than the height dimension L5 of the parallel body 8. In addition,
The mold member 15 is formed using a metal or a material whose dimensional change is small when heated. A liquid resin 1 is provided inside the cavity 14 by using a dispenser nozzle 16.
7 is filled.

Next, the substrate 13 is turned over and the parallel body 8 is formed.
Is inserted into the cavity 14 and immersed in the liquid resin 17. The parallel body 8 is arranged so as to be located at the center of the cavity-14. After that, the liquid resin 17 is dried and cured by heating in this state, and the exterior resin coating 9 is formed on the surface of the parallel body 8.

Next, the substrate 13 is pulled up above the die member 15, and the parallel body 8 covered with the exterior resin coating 9 is pulled out from the cavity 14.

Next, the parallel body 8 covered with the exterior resin coating 9 is formed.
Is peeled off from the adhesive layer 12, the chip part is completed.

The cavity 14 provided in the mold member 15 in the above-mentioned embodiment is a rectangular parallelepiped having an opening shape, but as shown in FIG. 5, the hole center is formed around the hole bottom of the cavity 14. Tapered downward toward the side
The surface 14A may be provided. When the parallel body 8 is inserted into the cavity 14, the parallel body 8 is positioned with the taper surface 14A as a guide, so that the parallel body 8 is arranged in the central portion of the recess 13 with high positional accuracy. Also, the taper surface 14
A chamfered portion 9A is formed on the exterior resin coating 9 corresponding to A.

Although the case of forming one chip component has been illustrated in the above description of the embodiment, a manufacturing method in which a large number of chip components are simultaneously formed can be used. In this case, a plurality of parallel bodies 8 are formed on the substrate 13. In addition, the mold member 15 is provided with a plurality of cavities 14 into which the plurality of parallel bodies 8 are respectively inserted. As a result, a large number of chip components can be manufactured at once.

[0036]

The chip component of the present invention has the following effects.

(1) By integrating a plurality of chip-type monolithic ceramic capacitors into an integrated structure by using a means such as exterior resin coating, a chip component having a large capacitance can be easily formed.

(2) Since the chip parts have good dimensional accuracy,
Automatic mounting is possible. In addition, since the chip components are covered with the exterior resin coating, etc., the impact is mitigated even when pressed during centering during automatic mounting using an automatic mounting machine, and the chip-type monolithic ceramic capacitors are not cracked or chipped. Can be prevented.

(3) Since the chips are not connected in parallel using high-temperature solder or the like unlike the conventional stacked chip-type monolithic ceramic capacitors, thermal distortion does not occur inside the chip-type monolithic ceramic capacitors. Further, since the parallel body composed of a plurality of chip type multilayer ceramic capacitors is covered with the exterior resin coating or the like, the exposed area of the first external electrode and the second external electrode of each chip type multilayer ceramic capacitor is reduced. Therefore, the height of the solder fillet formed when the chip component is mounted on the predetermined terminal of the circuit board is kept low,
The stress generated in the solder fillet and the chip type monolithic ceramic capacitor is reduced. As a result, cracks are less likely to occur in the ceramic body of the chip type monolithic ceramic capacitor. Therefore, the flexural strength and the critical strength after heat cycle are improved. Further, even if a crack occurs, since it is the body portion where the internal electrodes exposed from the exterior resin coating and the like are not formed, the short between internal electrodes can be prevented, and the risk of ignition can be avoided. As a result, quality reliability is improved.

The method of manufacturing a chip part has the following effects.

(1) A parallel body composed of a plurality of chip type monolithic ceramic capacitors is soaked in a liquid resin filled in a cavity and then cured as it is. Therefore, it is possible to extremely easily combine the parallel bodies into an integrated structure. Moreover, since the chip components are formed with high dimensional accuracy, automatic mounting becomes possible.

(2) Since the manufacturing method is simple, it is easy to take a large number of chips, that is, to develop a multi-process, and the productivity of chip parts can be improved.

[Brief description of drawings]

1 is a first chip component according to the present invention, and FIG.
1A is an external perspective view, and FIG. 1B is a cross-sectional view taken along the line AA ′ in FIG.

FIG. 2 is an external perspective view of a second chip part according to the present invention.

3 is a third chip part according to the present invention, and FIG.
3A is an external perspective view, and FIG. 3B is a cross-sectional view taken along the line AA ′ in FIG.

FIG. 4 is a schematic view of the manufacturing process of the first chip part according to the present invention.

FIG. 5 is a cross-sectional view of a mold member used in a second chip part manufacturing process according to the present invention.

FIG. 6 is a view showing a general monolithic ceramic capacitor, FIG. 6 (a) is an external perspective view in which a notch is partially provided, and FIG. 6 (b) is an exploded view of an element body forming the monolithic capacitor. It is a perspective view, and FIG.6 (c) is an external appearance perspective view of an element body.

FIG. 7A is an external perspective view showing a state in which general monolithic ceramic capacitors are stacked.
FIG. 7B is a sectional view showing a state in which external electrodes of stacked ceramic capacitors are soldered, and FIG.
FIG. 3 is a cross-sectional view showing a state in which metal terminals are connected to the external electrodes of the stacked ceramic capacitors.

[Explanation of symbols]

 1 Chip Type Multilayer Ceramic Capacitor 2 Element 3A First External Electrode 3B Second External Electrode 4 Ceramic Body 4A Ceramic Plate 5A, 5B Internal Electrode 8 Parallel Body 9 Exterior Resin Coating 9A Chamfer 10 Heat Shrink Tube 11 Flat Plate 12 Adhesive Layer 13 Substrate 14 Cavity 14A Tapered Surface 15 Mold Member 16 Dispenser Nozzle 17 Liquid Resin

Claims (4)

[Claims] 1. A parallel body in which a plurality of chip type monolithic ceramic capacitors having a first external electrode and a second external electrode are arranged so that the first external electrodes and the second external electrodes are in close contact with each other. And a means for fixing the parallel body in an integral structure so as to expose a part of each first external electrode and each second external electrode of the parallel body. 2. The chip component according to claim 1, wherein the fixing means is an exterior resin coating for coating the parallel body. 3. The chip component according to claim 1, wherein the fixing means is a heat shrink tube for bundling the parallel bodies. 4. A step of arranging and temporarily fixing a plurality of chip type monolithic ceramic capacitors on a substrate, a step of providing a die member that forms the outer shape of the parallel body, and injecting a liquid resin into the die member. From the step of infiltrating into the liquid resin leaving a part of the parallel body temporarily fixed on the substrate on the substrate side, and the step of drying and curing the liquid resin in the state where the parallel body is infiltrated. Method of manufacturing different chip parts.