JPH09120902A - Chip electronic part and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chip electronic part constituted by simple components and which presents so little asperity on the surface that it can be surface- mounted with ease on both sides. SOLUTION: Electrodes 20 and an electronic device such as a resistor element 16 which are connected with the electrodes 20 are formed on the surface of an insulator chip substrate 12. A protective coat 19 is applied to the surface of the electronic device 16. Swelling portions 28 are formed with the same material as that of the protective coat 19 or with other materials on at least four corners of the substrate 12 on which the electrodes 20 are formed so that their surfaces are at almost the same level as that of the protective coat 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip electronic component such as a chip resistor or a chip capacitor which is surface-mounted on the surface of a circuit board and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, for example, a surface mount type chip resistor 1 is provided with surface electrodes 3 at both ends of a surface of a ceramic substrate 2 as shown in FIG. Is formed. The resistor 4 is printed with ruthenium oxide, for example, and trimmed with a laser or the like. The surface electrode 3 is directly connected to the lower side of both ends of the resistor 4, and the surface of the resistor 4 is covered with a protective coat 6 of glass or resin. Further, surface mounting electrodes 8 are formed on both ends of the substrate 2 so as to cover the surface electrodes 3 and extend over both end faces of the substrate 2 and the back surfaces of the both ends. The surface-mounting electrode 8 is a metal thin film formed by sputtering or the like and further solder-plated, and is an extremely thin electrode having a thickness of, for example, several tens of μm.

In this chip resistor manufacturing method, as shown in FIG. 7, a plurality of rows of front surface electrodes 3 are printed and formed between slits 9 of a large-sized substrate 7 for which a plurality of resistors are formed.
Is formed by printing, and the protective coat 6 is further printed thereon. After that, the surface mounting electrodes 8 are formed by sputtering on the end portions where the slits 9 are formed, and the substrate 2 is divided in the direction perpendicular to the slits 9 so that each surface mounting electrode 8 becomes an end face, and the chip resistor is formed. Form vessel 1.

[0004]

In the case of the above-mentioned conventional technique, as shown in FIG. 6, in the chip resistor 1, the surface mounting electrodes 8 at both ends are thin film electrodes formed by sputtering and plating. The central portion of the surface has a shape raised by the resistor 4 and the protective coat 6. Thus, when the chip resistor 1 is surface-mounted on the circuit board, if the surface side is placed facing the circuit board side,
The surface mounting electrodes 8 at both ends are in a state of floating from the electrodes of the circuit board. And when soldered in this state,
This chip resistor 1 is apt to cause a phenomenon in which it is erected on one surface mounting electrode 8 side of both end portions due to the surface tension of the solder, or a soldering defect occurs. In addition, the chip resistor 1 currently has a size of about 1 mm and tends to be miniaturized year by year, and it is impossible to select the front and back and mount them on a circuit board.

The present invention has been made in view of the above conventional technique, and provides a chip electronic component having a simple structure, having almost no height difference, and capable of being easily surface-mounted, and a method of manufacturing the same. To aim.

[0006]

According to the present invention, an electrode and an electronic element such as a resistor connected to the electrode are formed on the surface of an insulating chip-shaped substrate, and a protective coat covering the surface of the electronic element is formed. A chip electronic component in which a bulged portion having a small difference in height from the surface of the protective coat is formed in the electrode forming portion near at least four corners of the substrate by using the same material as the protective coat. Is.

Further, according to the present invention, an electrode corresponding to each chip-like substrate and an electronic element such as a resistor connected to the electrode are formed on a large insulating substrate which is divided into a large number of chip-like substrates. The surface of the electronic element is covered with a protective coat such as resin, and at the time of printing of the protective coat, a bulge having a small difference in height from the surface of the protective coat is formed on the electrode forming portion near at least four corners of the substrate. This is a method for manufacturing a chip electronic component in which the protruding portion is simultaneously printed and formed using the same material as the protective coat.

In the chip electronic component and the method for manufacturing the same according to the present invention, a bulge portion having a small height difference from the surface of the protective coat is formed on the electrode forming portion near at least four corners of the substrate. The same material as the coat is printed at the same time to reduce the height difference between the four corners of the front and back sides and the center, and when soldering, the chip electronic components are stably soldered to the circuit board electrodes regardless of the front and back sides. It was made to be done.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a first embodiment of a chip electronic component of the present invention. This embodiment relates to a chip resistor 10, in which Ag-Pd, Ag-Pt are formed on the surface of an insulating substrate 12 made of ceramics or the like. A conductive paste such as a metal glaze paste is printed to form the surface electrodes 14, and a resistor 16 made of ruthenium oxide, its metal glaze paste, or carbon paste is formed by printing so as to extend between the surface electrodes 14. Has been done. Further, a glass coat 18 made of lead borosilicate glass is formed on the surface of the resistor 16, and the surface thereof is
A protective coat 19 composed of a glass coat of lead borosilicate glass or a resin coat of an epoxy resin is formed.

The protective coat 19 covers the surface of the resistor 16 and the surface electrode 1 as shown in the printing die 31 of FIG.
4 the four corners extend to the side edges of the surface electrode 14
It is formed into a mold. The bulges 28 at the four corners protruding from the protective coat 19 are slightly lower than the height of the protective coat 19 on the resistor 16 in the printed state. The resistor 16 is formed on the surface of the protective coat 19.
The predetermined characters indicating the resistance value and the like are printed and formed by a paint such as lead borosilicate glass or epoxy resin.

Surface mounting electrodes 20 connected to the surface electrodes 14 are formed on both side surfaces of the substrate 12. The surface-mounting electrode 20 is formed on the outer surface of the metal thin-film electrode 22 by a metal thin-film electrode 22 of, for example, a thickness of several hundreds of liters, nickel-chromium and copper, and is formed on the outer surface of the metal thin-film electrode 22 by several μm. It is composed of a nickel plating 24 as a protective layer with a certain thickness, and a solder plating 26 formed on the outside thereof for ensuring soldering.

Next, a method of manufacturing the chip resistor 10 of this embodiment will be described with reference to FIGS. The chip resistor 10 of this embodiment, as shown in FIG.
A plurality of rows of the surface electrodes 14 are printed and baked at a temperature of about 850 ° C. Then, as shown in FIG. 3B, a resistor 16 is printed between each surface electrode 14 and fired at a temperature of about 850 ° C. The order of forming the surface electrode 14 and the resistor 16 may be reversed. Then, as shown in FIG. 3C, a glass coat 18 is printed on the surface of the resistor 16 and baked at about 600 ° C. Next, as shown in FIG. 3D, the resistor 16 and the glass coat 18 are formed by a laser trimmer.
The trimming groove 17 is formed, trimming is performed, and the resistance value is finely adjusted.

Thereafter, as shown in FIG. 4A, a protective coat 19 is printed on the surfaces of the resistor 16 and the glass coat 18 by silk screen or the like. At this time, the bulging portion 28 is also printed together with the protective coat 19 by the printing die 31. When the protective coat 19 is a resin, it is dried and cured at a temperature of about 150 ° C., and when it is glass, it is cured at a temperature of about 600 ° C.

Thereafter, as shown in FIG. 4B, the metal thin film electrode 22 is formed along the slit 32 on the end surface of the surface electrode 14 and the resistor 16 by sputtering or the like. Then, as shown in FIG. 4C, nickel plating 24 and solder plating 26 are formed. After this, FIG.
As shown in (D), the large substrate 30 is cut in a direction perpendicular to the slit 32 to form the chip resistor 10.

According to the chip resistor of this embodiment, the bulged portions 28 extending to the four corners of the substrate 12 reduce the difference in height between the corners of the four corners of the substrate 12 and the center thereof, and the soldering is performed. This eliminates the standing up of chips and defective soldering during packing.

A chip electronic component according to a second embodiment of the present invention will be described below with reference to FIG. Here, the same members as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. The chip electronic component of this embodiment also relates to the chip resistor. In this embodiment, the bulging portions provided at the four corners of the chip-shaped substrate 12 are not continuous with the protective coat 19, but the protective coat 19 is printed. When forming,
Independent island-shaped bulging portions 34 are printed at the same time. According to this embodiment, the same effect as that of the above embodiment can be obtained.

The chip electronic component and the method for manufacturing the same according to the present invention may have not only a metal thin film electrode but also a thick film structure electrode by a printing method, and a large substrate.
In addition to the slits, split grooves such as V-grooves may be formed vertically and horizontally, and the type thereof does not matter. Also, the electronic element can be used for various electronic elements other than the resistor.

[0018]

According to the chip electronic component and the manufacturing method thereof of the present invention, there is little difference in height between the electrode portion and the electron element portion in the central portion, and even when the chip electronic component is surface-mounted on the circuit board,
It can be mounted in a stable and accurate state regardless of the front and back, improves the yield with solder, and can be manufactured without any increase in man-hours. Further, it can be formed into a stable shape in terms of mounting regardless of the front and back sides, which contributes to downsizing of chip electronic components.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a chip resistor of a chip electronic component according to a first embodiment of the present invention.

FIG. 2 is a front view of a protective coat printing die used in this embodiment.

FIG. 3 is a partial perspective view showing manufacturing steps (A), (B), (C), and (D) of the chip resistor of this embodiment.

FIG. 4 is a partial perspective view showing the next manufacturing steps (A), (B), (C) and (D) of the chip resistor of this embodiment.

FIG. 5 is a front view showing a printing die for a protective coat of a chip electronic component according to a second embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view of a prior art chip resistor of the present invention.

FIG. 7 is a partial perspective view of a part of the manufacturing process of the prior art chip resistor of the present invention.

[Explanation of symbols]

 1,10 Chip resistor (chip electronic component) 2,12 Substrate 3,14 Surface electrode 4,16 Resistor 6,19 Protective coat 7,30 Large substrate 8,20 Surface mounting electrode 22 Metal thin film electrode 28 Swelling Department

Claims (4)

[Claims] 1. An electrode and an electronic element connected to the electrode are formed on the surface of an insulating chip-shaped substrate, and a protective coat covering the surface of the electronic element is provided, and at least four corners of the substrate are provided. A chip electronic component having a bulge portion formed in the vicinity of the electrode formation portion. 2. The bulging portion is formed of the same material as the protective coat so as to reduce a height difference between the electronic element and the electrode. Chip electronic components 3. An electrode corresponding to each chip-shaped substrate and an electronic element connected to this electrode are formed on a large insulative substrate divided into a large number of chip-shaped substrates, and the surface of this electronic element is protective coated. A method of manufacturing a chip electronic component, which is formed by covering the above-mentioned substrate with a bulge portion in the electrode forming portion near at least four corners of the substrate. 4. The bulged portion is formed by printing the same material as the protective coat when printing the protective coat so as to reduce the height difference between the electronic element and the electrode. A method for manufacturing the described chip electronic component.