JPH03200316A - Manufacture of electronic parts - Google Patents

Abstract

PURPOSE:To enable setting arbitrarily the thickness of an external electrode in each part by forming the external electrode through causing a conductive pattern to adhere so that the pattern is divided according to the outer peripheral face side and end face side of a component body. CONSTITUTION:Both end faces of a capacitor element 4 are masked 15 so that conductive paste is prevented from adhering thereto, and the conductive paste 8 is transferred to the outer peripheral face of the capacitor element 4. In this case, the thickness of the conductive paste 8 is thinned as much as possible. After the transfer, the conductive paste 8, 8 having adhered to the capacitor element 4 is dried, then masking 15, 15 is peeled off, and the predetermined quantity of the conductive paste 8 is caused to adhere to both end faces of the capacitor element 4 and to sinter finally to form external electrodes 3, 3. In this manner, the thickness of the external electrode 3 can arbitrarily be set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an electronic component such as a multilayer ceramic capacitor, in which external electrodes are formed on both sides of a chip-shaped electronic component.

[Conventional technology]

For example, a multilayer ceramic capacitor has a structure in which a plurality of ceramic layers (2) (2) are laminated with internal electrode layers (1) (1) sandwiched between them, as shown in Fig. 5. , and on both sides there are external electrodes (3) that electrically connect every other internal electrode layer (1) (1) to enable connection with the outside.
(3) is formed by adhesion.

The formation of the external electrodes (3) (3) is based on the internal electrode layer (1).
A chip-shaped capacitor element (chip-shaped component body) (4) obtained by laminating and integrating ceramics 1 (1) and ceramic 1 (2) (2) - Through holes (6) (6) formed in a plate jig (5)
Insert one capacitor element (
4) Make one end of (4) - protrude evenly from the jig (5). After that, as shown in FIGS. 7 and 8, the protruding ends of each capacitor element (4) (4) are placed on the flat table (7) using a squeegee using a jig (5). dipped in conductive paste (8) applied to a thickness of , the conductive paste (8) is attached to the protruding end, and after drying,
The opposite side of each capacitor element (4) (4) is made to protrude from the jig (5), and the conductive paste (8) is applied to the protruding end in the manner described above and dried. After this, the capacitor elements (4) (4)- are taken out from the jig (5), and by sintering them, the external mold ff1 (3) (
3) is formed by adhesion.

The conductive paste (8) is made by kneading fine powder such as silver or gold with a binder, a solvent, etc., and the binder and solvent are removed during sintering.

[Problem to be solved by the invention]

In order to strengthen the adhesion strength of the external electrode (3) (3) in the above electronic component, as shown in Fig. 5, the thickness (R) of the external electrode (3) at the corner of the capacitor element (4) is Thicker is better. However, if the conductive paste (8) is attached so that this thickness (R) becomes thick, the conductive paste (8) will thickly adhere to the outer peripheral surface and end surface of the capacitor element (4) due to its viscosity, surface tension, etc. . Therefore, the thickness (1) of the outer peripheral surface of the external electrode (3) also increases. When this thickness (1) becomes thicker, the suction nozzle (10) becomes larger when transporting components during mounting work, as shown in Figure 9.
The gap between the capacitor element (4) and the capacitor element (4) becomes larger, and the amount of air leakage increases, which may result in suction errors. In addition, the height of electronic components (H) also increases, so
In some cases, high-density mounting may not be possible because the IC cannot be mounted in a gap between a printed wiring board and an IC.

Conversely, if the thickness (t) of the external electrode (3) is decreased,
The thickness (R) of the corner part also becomes smaller, and when flow soldering is performed, the external electrode (3) is eaten by the solder and the corner part of the capacitor element (4) is exposed, causing it to stick to the printed wiring board. Strength may decrease.

In this way, in chip-shaped electronic components, external electrodes (3
) is preferably as small as possible on the outer circumferential surface side (1) and as large as possible at the corners (R). However, conventional manufacturing methods have not been able to satisfy the above conditions.

This invention aims to provide a manufacturing method that allows the thickness of external electrodes to be set arbitrarily.

[Means to solve the problem]

In the manufacturing method of the present invention, a conductive paste is applied only to both outer circumferential surfaces or both end surfaces of a chip-shaped component body, and after drying the conductive paste, the conductive paste is applied to the remaining external electrode forming portion of the chip-shaped component body. The external electrodes are formed by depositing

[Effect]

With the above method, the external electrodes are formed by separately attaching conductive patterns to the outer circumferential surface side and the end surface side of the component body, so the thickness of the external electrodes can be set arbitrarily for each part.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

As shown in Figure 2, both end faces of the capacitor element (4) obtained by laminating internal electrode layers and ceramic layers alternately are masked (15) (15) to prevent conductive paste from adhering. Make it. Then, as shown in FIG. 3, the outer circumferential surfaces on both sides of the capacitor element (4) are pressed against two rotating transfer rollers (16) with the conductive paste (8) applied to the circumferential surfaces, Conductive paste (8) is applied to the outer peripheral surface of the capacitor element (4).
to be transcribed. The thickness of the conductive paste (8) at this time is made as thin as possible. After the transfer, the conductive base attached to the capacitor element (4) as shown in Figure 4) (8)
(8) is dried, then masking (15) (15
) is peeled off, and conductive paste (8) is applied a predetermined number of times to both end surfaces of the capacitor element (4). At this time, the conductive paste (8) has poor compatibility with the dry conductive paste.
There is no need to climb up to the outer circumferential surface, and this work can be done using the same techniques as in the past. Finally, it is sintered to form external electrodes (3) (3) to form an electronic component as shown in FIG.

The external electrodes (3) (3) are formed by first applying the conductive paste (8) to the end surface of the capacitor element (4), and then applying the conductive paste (8) to the outer peripheral surface.
) may be attached.

Note that the method of the present invention is not limited to multilayer ceramic capacitors, but can also be applied to chip resistors, chimp coils, and the like.

〔Effect of the invention〕

According to this invention, external electrodes can be formed on both sides of the component body, with a thinner thickness on the outer circumferential surface side and a thicker thickness at the corners, and the adhesion strength and solder corrosion resistance of the external electrodes are high. , and can provide an electronic component with a low overall height. Further, since the height is reduced, suction errors by the suction nozzle are reduced, and the IC can be mounted between an IC and a printed wiring board, and the packaging density can be increased.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an electronic component manufactured by the method of the present invention, Figures 2 to 4 are drawings showing the manufacturing process, Figure 2 is a cross-sectional view of a masked capacitor element, and Figure 3 is a
FIG. 4 is a front view for explaining the state at the time of applying the conductive paste for the second time, and FIG. 4 is a front view of the capacitor element to which the conductive paste is applied. Fig. 5 is a cross-sectional view of a multilayer ceramic capacitor manufactured by the conventional method, Fig. 6 is a perspective view showing a part of the jig used during manufacturing, and Figs. 7 and 8 show examples of adhesion of conductive paste. 9 is a sectional view showing a state during suction by a suction nozzle. (3) --- External electrode, (4) --- Part body (capacitor element), (8
)...Conductive paste. Patent applicant: Kansai NEC Co., Ltd.
Figure 1 Figure 4 / (Q% Yoshi et al., 1) 12 2nd VA Figure 5 Figure 3 Figure 6

Claims (1)

[Claims] (1) A method for manufacturing an electronic component in which external electrodes are deposited on both sides of a chip-shaped component body, in which a conductive paste is deposited only on both outer peripheral surfaces or both end surfaces of the chip-shaped component body,
A method of manufacturing an electronic component, characterized in that after drying the conductive paste, the conductive paste is applied to the remaining external electrode forming portion of the chip-shaped component body to form an external electrode.