JP2001044068A - Compact surface-mounting part and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface mounting part which enables highly accurate and highly reliable mounting, even if an interval of a terminal electrode is small, and to provide its manufacturing method. SOLUTION: A surface-mounting part has a dielectric body 9, having a pair of opposing major surfaces and a side surface intersecting a major surface and electrodes 30, 31 of a specified shape are incorporated into the inside of the body 9. At least one of terminal electrodes 10 to 13 is formed in at least one side surface, to be electrically connected to the electrodes 30, 31, and outer electrodes 22 to 25 are electrically connected to the terminal electrodes 10 to 13 in one major surface. In a protective sheet laminated in one major surface, a notch is formed at a place, where at least a part of an external electrode is exposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a small-sized surface mounting component having a plurality of terminal electrodes and a method of manufacturing the same. The present invention relates to a surface mounting component having an electrode configuration that can be mounted with high reliability without fear of an electrical short, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a terminal electrode on a surface mounting component, a plurality of green sheets having a required electrode pattern formed on the surface are stacked or fired before or after firing. A chip has been formed by cutting a sheet into a rectangular parallelepiped shape, forming terminal electrodes on a predetermined side surface of the chip by dip coating or screen printing, and then performing plating.

However, when the terminal electrodes are formed by the dip coating method or the screen printing method, the terminal electrodes have a structure in which the ends of the terminal electrodes are raised more than the mounting surface of the surface mounting component, that is, the surface mounted on the mounting substrate. However, when the surface mounting components are mounted on the mounting board, the solder often flows into the mounting substrate and the surface mounting components. A problem arises in that the device lacks in withstand voltage stability. In order to solve such a problem and increase the positional accuracy of the surface mounting component and ensure stable withstand voltage, the land area for mounting the component is sufficiently larger than the terminal electrode and extends outside the terminal electrode. Need to be formed on the mounting substrate. Also, since it is necessary for solder to crawl on the terminal electrodes in order to increase the reliability of mounting the surface mount components on the board, secure a land area on the mounting board where a sufficient amount of solder can be applied. I had to. For this reason, there has been a problem that the improvement in mounting density is limited only by reducing the size of the surface mounting component.

[0004] Further, in the case of the dip coating method, since the conductive material adheres to the entire side surface of the laminated chip, usually, 1
Only one terminal electrode can be formed on one side,
Since masking is required to form a plurality of terminal electrodes, there is a disadvantage that the manufacturing process becomes extremely complicated. In the case of using the screen printing method, terminal electrodes can be formed at a fine pitch. On the other hand, since a large number of laminated chips are printed at the same time during mass production, the positioning accuracy of the laminated chips when forming the terminal electrodes is large. There is a disadvantage that it is difficult to manufacture the terminal structure with high accuracy.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above-mentioned problems of the prior art, and a first object of the present invention is to provide a highly reliable mounting method. A second object of the present invention is to provide a component for surface mounting and a method for manufacturing the same, in which even if the distance between terminal electrodes is small, accurate and highly reliable mounting is possible. An object of the present invention is to provide a component and a manufacturing method thereof.

[0006]

According to one aspect of the present invention, there is provided a surface mounting component having a terminal electrode formed on at least one side surface. A surface mounting component comprising: a concave portion including an end of the terminal electrode on one main surface; and an external electrode electrically connected to the terminal electrode in the concave portion.

[0007] In order to manufacture such surface mount components,
The invention according to claim 2, wherein a step of laminating and pressing and bonding a green sheet on which the external electrode is formed and a green sheet having a through hole at a position where a part of the external electrode is exposed; Cutting the integrated green sheet along a surface passing through the through hole to form a chip; and forming a terminal electrode electrically connected to the external electrode on a side surface of the chip. And a manufacturing method characterized by comprising:

[0008] As another manufacturing method, the invention of claim 3 is as follows.
Obtaining a first green sheet having a first through-hole formed at a position where a part of the external electrode is exposed; and forming a second green sheet having the external electrode formed therein and corresponding to the first through-hole. Obtaining a second green sheet having holes formed therein, filling the second through holes with a conductive material so as to be electrically connected to the external electrodes, and forming the first green sheet. And the second green sheet, the first through hole and the second
And a step of laminating and integrating the through holes so as to correspond to a predetermined positional relationship, and forming the integrated green sheet along a surface passing through the first through hole and the second through hole. Cutting to form chips and exposing the conductive material to the side surfaces of each of the chips.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a chip capacitor as one embodiment of a surface mounting component according to the present invention and a method of manufacturing the same will be described below with reference to FIGS.
1 (A) and 1 (B), a chip capacitor 1 includes an uppermost and lowermost protective sheet 2 and 8 made of a dielectric sheet and five dielectric sheets sandwiched therebetween. A body 9 composed of sheets 3 to 7 is provided. Terminal electrodes 10 to 13 are formed on each side surface of the dielectric main body 9.

FIG. 2 shows the shape of each of the protective sheets 2, 8 and the five dielectric sheets 3 to 7 disposed therebetween, and the conductor pattern formed thereon. Notches 14 to 17 are formed on each of the four side surfaces of the dielectric protective sheet 2 disposed on the top, and the notches 14 to 17 are also formed on the four side surfaces of the lower protective sheet 8. Notches 18 to 21 are formed at corresponding positions. For example, when the dielectric sheets 2 and 8 have a size of 1.6 × 3.2 mm, the notches 14, 16, 18, and 20 have a length of 0.8 mm, a depth of 0.3 mm, Chip 15,
The length of 17, 19, 21 is 1.3 mm and the depth is 0.3 mm
It is.

The upper surface of the second dielectric sheet 3 from the top of the chip capacitor 1 is electrically connected to the upper ends of the terminal electrodes 10 to 13 so as to surround the upper ends of the terminal electrodes 10 to 13. Electrodes 22 to 25 are formed, and similarly, a terminal electrode 10 is provided on the lower surface of the second dielectric sheet 7 from the bottom.
13 are electrically connected to the lower ends of the terminal electrodes 10 and
External electrodes 26 to 29 are formed so as to surround the lower end of the thirteen. In this case, as shown in FIG. 1B, the notches 14 to 17 and 18 to 21 formed in the protective sheets 2 and 8 are provided with the upper and lower ends of the terminal electrodes 10 to 13 and the external electrodes 22 to A concave portion having a length and a width that exposes a part of 25 and 26 to 29 is formed.

At the time of mounting, one of the upper surface and the lower surface of the dielectric substrate 9 is placed on a conductive pattern on a mounting substrate, and this conductive pattern and the external electrodes 22 to 25 or 26 are mounted.
To 29 are electrically connected by solder.

On the top surface of the third dielectric sheet 4 from the top of the surface mounting component 1, a pair of opposing terminal electrodes 11, 1
3, an electrode 30 having a predetermined width and shape, each end of which is electrically connected, is formed on the upper surface of the third dielectric sheet 6 from the bottom.
An electrode 31 having a predetermined width and shape electrically connected to the electrode 30 and facing the electrode 30 is formed. No electrodes are formed on the upper and lower surfaces of the dielectric sheet 5 sandwiched between these dielectric sheets 4 and 6, and a capacitor having a value corresponding to the shape of the two electrodes 30 and 31 and the dielectric constant of the dielectric sheet 5 Is made. These electrodes 30, 31 are collectively referred to as internal electrodes.

In FIG. 1, three components for surface mounting are shown.
Although it is embodied as a terminal type chip capacitor, terminal electrodes are provided on each of the four side surfaces. However, when embodied as other components, it is not always necessary to form terminal electrodes on all four side surfaces. In short, it is only necessary to provide a terminal electrode on at least one side according to the design of the component for surface mounting.

Further, in FIG. 1, one terminal electrode is formed on one side, but depending on the embodiment,
A plurality of terminal electrodes can be formed on one side surface. In this case, the protection sheets 2 and 8 are formed with recesses for each individual terminal electrode or to include a plurality of terminal electrodes. In order to manufacture such a surface mounting component, as described in the following manufacturing method, if a method of converting the through hole into a conductor, such as filling the through hole with a conductive material, is employed, a plurality of terminal electrodes are formed at a narrow pitch. Can be formed.

Further, in the chip capacitor 1 of FIG. 1, the external electrodes 22 to 2 are provided on the two dielectric sheets 3 and 7.
5 and 26 to 29 are formed so that the chip capacitor 1 has the same capacitance value regardless of which of the dielectric sheets 3 and 7 is attached to the mounting board. It is also possible to form the external electrodes 26 to 29 only on the dielectric sheet, for example, the dielectric sheet 7, and not to form the external electrodes on the other dielectric sheet 3. In this case, since the dielectric sheet 3 serves as a protective layer, the protective sheet 2 laminated thereon may not be provided.

Next, a method of manufacturing the chip capacitor 1 shown in FIG. 1 will be described. First, the external electrodes 22 to
A green sheet having a through-hole for exposing a part of the conductor pattern corresponding to 25;
, A green sheet having a conductive pattern corresponding to the electrode 30 formed on the upper surface, a green sheet having no conductive pattern formed thereon, and an electrode 31. A green sheet having a conductive pattern formed on the upper surface, a green sheet having a conductive pattern corresponding to external electrodes 26 to 29 formed on the lower surface, and a through hole exposing a part of the conductive pattern corresponding to external electrodes 26 to 29 Are laminated in this order and pressed and integrated.
Then, after firing the integrated green sheet,
A chip having a predetermined shape is obtained by cutting along the plane perpendicular to the green sheet through the center of the through hole. Alternatively, the integrated green sheet may be cut along the plane perpendicular to the green sheet through the center of the through hole to obtain a chip having a predetermined shape, and then firing the chip. . At a predetermined position on the side of each chip obtained in this way,
A terminal material is formed by applying a conductive material so as to be electrically connected to the external electrode.

As a result, a chip having a concave portion at a predetermined position on the upper and lower surfaces to expose an external electrode electrically connected to an end of the terminal electrode is manufactured. Therefore, at the time of mounting, since the upper or lower surface on which the concave portion of the chip is formed is soldered to the conductive pattern on the mounting substrate,
This prevents the solder from flowing out of the recess to form an unnecessary connection, not only improving the mounting accuracy and improving the withstand voltage stability, but also using a land pattern with a smaller area on the mounting board. It should be formed.

It should be noted that, depending on the surface mounting component, it may be necessary to form a plurality of terminal electrodes on at least one side surface with high precision and at a narrow pitch, and to ensure that the solder creeps up. In such a case, a green sheet having a through hole formed at a position where each terminal electrode is to be formed is used. Of these green sheets, an electrode is formed on a predetermined green sheet, and the inside of each through hole of the green sheet except for the uppermost and lowermost green sheets is filled with a conductive material. The green sheets are laminated and pressure-bonded to be integrated.
Before or after firing, the integrated green sheet is cut along a plane perpendicular to the green sheet through the center of the through hole to produce a chip of a predetermined shape. Since the filled conductive material is exposed, it can be used as a terminal electrode.

According to such a manufacturing method, a plurality of terminal electrodes can be accurately formed at a narrow pitch without adding a special step, and can be mounted by utilizing the capillary phenomenon of molten solder. In addition, it is possible to achieve the creeping of the solder in a small area, and it is possible to improve the reliability of the electrical connection between the external electrode and the conductor pattern on the mounting board.

Instead of filling each through hole formed in the green sheet with a conductive material, a conductor is formed on the inner surface of each through hole by means of printing, vapor deposition, sputtering or the like using a conductive material. You may.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to carry out the above-described manufacturing method including a step of forming a through hole in a green sheet and forming a conductor therein, a B having a relative dielectric constant of 70 and a thickness of 100 microns is used.
Using green sheets of a-Ti ceramic material, through holes were formed at predetermined positions of each green sheet by NC processing. A conductive paste (Ag) is formed in through holes formed in the remaining green sheets except for the two green sheets serving as protective sheets.
/ Pd90 / 10), and further, an internal electrode pattern and an external electrode pattern were printed on a predetermined green sheet, and a conductive paint having a thickness of about 15 microns was applied thereto.

Then, a required number of green sheets are laminated between two green sheets to be protective sheets so that the through holes of each green sheet are aligned with each other, and the green sheets are preliminarily kept at 80 ° C. for about 5 minutes. Compression bonding while heating. When properly integrated, dicing was performed by a cutter having a blade thickness of 50 microns along a plane perpendicular to the green sheet through the center of the through hole to produce chips of a desired size. The chip manufactured in this manner is integrally sintered in an air atmosphere at 900 ° C., and the conductor portion is plated with Sn / Ni, so that the chip is located at a position recessed from the main surface by a distance corresponding to one green sheet. Thus, a surface mounting component having a structure in which an external electrode is disposed and a conductor that can be used as a terminal electrode was exposed on the side surface was able to be manufactured.

[0024]

As will be understood from the description of the preferred embodiment of the present invention, the present invention provides that a terminal electrode is electrically connected to a terminal electrode in a recess formed in a main surface which is a mounting surface. Since the external electrodes are provided, it is possible to prevent the solder from flowing out of the concave portion and forming an unnecessary connection portion when soldering to the mounting board. As a result, even when the distance between the terminal electrodes is small, high mounting accuracy and withstand voltage stability can be improved, and not only can highly reliable mounting be realized, but also the mounting substrate can be realized. The area of the upper land pattern can be made smaller.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a surface mounting component according to the present invention, in which (A) is a perspective view and (B) is a top view.

FIG. 2 is an exploded view showing a dielectric layer constituting the surface mounting component shown in FIG. 1 and an electrode pattern formed thereon.

[Explanation of symbols]

1: chip capacitor, 2, 8: protective sheet, 3 ~
7: dielectric sheet, 9: main body, 10 to 13; terminal electrode, 14 to 21: notch, 22 to 29: external electrode,
30, 31: internal electrode

Claims (3)

[Claims] 1. A surface mounting component having a terminal electrode formed on at least one side surface, wherein at least one main surface intersecting with the side surface has a concave portion including an end of the terminal electrode. And an external electrode electrically connected to the terminal electrode. 2. A step of laminating a green sheet having the external electrode formed thereon and a green sheet having a through hole formed at a position where a part of the external electrode is exposed, and crimping and integrating the green sheet. Cutting the formed green sheet along a surface passing through the through-hole to form a chip; and forming a terminal electrode electrically connected to the external electrode on a side surface of the chip. The method for manufacturing a surface mounting component according to claim 1, wherein the component is provided. 3. A step of obtaining a first green sheet having a first through hole formed at a position where a part of the external electrode is exposed, and a step corresponding to the step of forming the external electrode and corresponding to the first through hole. Obtaining a second green sheet having a second through-hole formed therein; filling the second through-hole with a conductive material so as to be electrically connected to the external electrode; Laminating and integrating a first green sheet and the second green sheet such that the first through hole and the second through hole correspond to a predetermined positional relationship; Cutting the formed green sheet along a plane passing through the first through-hole and the second through-hole to form chips, and exposing the conductive material on side surfaces of the respective chips. , Characterized in that it comprises a method of manufacturing a surface mount component of claim 1, wherein.