JP2007305830A - Method for manufacturig electronic component, electronic component, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a method for manufacturing an electronic component capable of suppressing a short-circuit caused by a conductive adhesive agent, and to provide the electronic component and electronic equipment. <P>SOLUTION: An upper layer outside electrode (a second outside electrode) 6 electrically connected to a spiral coil formed in a sintered body 10 is formed by respectively immersing the both end parts of the sintered body 10 with foundation outside electrodes (first outside electrodes) 4, 5 formed into an Ag/Pd paste bathig fluid. The obtained lamination coil component 1A comprises an almost all regions of outside electrodes formed on a mounting surface 1a compising two layers with the electrodes 4, 5 and the electrode 6 laminated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electronic component, and more particularly to a method for manufacturing a laminated type electronic component mounted on a printed board with a conductive adhesive, an electronic component, and an electronic device.

  Conventionally, in Patent Document 1, in a printed circuit board having a pad on the surface for mounting a surface mounting component using a conductive adhesive, a recess is formed between the pad and another circuit pattern adjacent thereto. Things are listed. According to this printed circuit board, excess conductive adhesive accompanying the mounting of the surface-mounted component is guided to the concave portion, and a short circuit between the pad and another circuit pattern adjacent to the pad can be prevented.

  Patent Document 2 describes an electronic component in which a concave portion for accommodating a conductive adhesive is provided in an external electrode. According to this electronic component, when mounted on a printed circuit board, excess conductive adhesive is accommodated in the recess, and a short circuit due to the conductive adhesive between the external electrodes can be prevented.

However, in the printed circuit board described in Patent Document 1, it has been difficult to form an appropriate recess in the printed circuit board for each electronic component. Further, in the electronic component described in Patent Document 2, the method of forming the recesses on the external electrodes is not clear, and depending on the manufacturing method, there is a possibility that the variation in the depth dimension of the recesses becomes large. For this reason, in the conventional one, excess conductive adhesive is not sufficiently accommodated in the recess, and there is a possibility that a short circuit occurs.
JP-A-9-74260 JP 2001-119121 A

  Then, the objective of this invention is providing the manufacturing method of an electronic component, an electronic component, and an electronic device which can suppress the short circuit by a conductive adhesive.

In order to achieve the above object, a method for manufacturing an electronic component according to the present invention includes:
Laminating a plurality of ceramic green sheets provided with internal electrodes to form a laminate;
Forming a first external electrode on the mounting surface of the laminate;
Firing the laminate to obtain a sintered body;
Forming a second external electrode electrically connected to the internal electrode on the surface of the sintered body including the first external electrode;
It is provided with.

  In the method for manufacturing an electronic component according to the present invention, the first external electrode can be formed by printing a conductive paste on a ceramic green sheet. The second external electrode can be formed by immersing the sintered body in a conductive paste. The first external electrode is formed only in a part of the region where the second external electrode is formed on the mounting surface.

  By the above method, an electronic component having at least two layers in which a part of the external electrode formed on the mounting surface of the electronic component is formed by stacking the first external electrode and the second external electrode can be obtained. Furthermore, electronic devices such as LC filters and high-frequency resonators can be obtained by mounting this electronic component on a substrate with a conductive adhesive.

  According to the present invention, by configuring the external electrode with the first external electrode and the second external electrode, the thickness of the external electrode can be formed to a desired thickness. A predetermined gap can be provided between them. Thereby, the short circuit by the conductive adhesive used at the time of mounting can be prevented.

  Embodiments of an electronic component manufacturing method, an electronic component, and an electronic device according to the present invention will be described below with reference to the accompanying drawings.

(Refer 1st Example and FIGS. 1-4)
FIG. 1 is an exploded view of a laminated coil component 1A according to the first embodiment. This laminated coil component 1A comprises a ceramic green sheet 2a having an internal electrode 3 formed on the surface, a ceramic green sheet 2b having no electrode formed on the surface in advance, and base external electrodes (first external electrodes) 4 and 5. The ceramic green sheets 2c formed on the front and back surfaces are laminated.

  The ceramic green sheets 2a, 2b, 2c are manufactured by the following method. That is, after adding a solvent, a dispersant, and a binder to magnetic ceramic powder such as NiCuZn ferrite and mixing well, a ceramic green sheet having a thickness of about 30 μm is formed by a doctor blade method.

  Further, a via hole is formed at a predetermined position of the inner layer ceramic green sheet 2a with a laser beam or the like. Thereafter, an Ag paste is applied to the surface by screen printing to form the internal electrode 3, and simultaneously, the via hole is filled with the Ag paste to form the via hole conductor 7.

  Next, an external electrode paste is applied to the surface of the ceramic green sheet 2c for the outermost layer (uppermost surface) by screen printing to form a base external electrode 4 having a thickness of about 30 μm. Similarly, an external electrode paste is applied by screen printing to the back surface of the ceramic green sheet 2c for the outermost layer (lowermost surface) to form a base external electrode 5 having a thickness of about 30 μm. As described above, when the base external electrodes 4 and 5 are formed on the uppermost surface and the lowermost surface, any surface may be used as the mounting surface, and the multilayer coil component 1A can be easily mounted on the printed board. Needless to say, the base external electrode may be formed only on one surface to be the mounting surface. Further, when the external electrode paste is applied by screen printing, it can be applied by the same method as the method of forming the internal electrode, so that the base external electrode can be easily formed.

  A plurality of ceramic green sheets 2a, 2b, 2c obtained in this way are sequentially stacked and pressed to form a laminate. This laminated body is cut into a predetermined product size, removed from the binder and fired to obtain a sintered body 10 as shown in FIG. And this sintered compact 10 is barrel-polished.

  The internal electrode 3 is electrically connected in series via the via-hole conductor 7 to form a helical coil in the sintered body 10. The thickness of the base external electrodes 4 and 5 after firing was adjusted to about 18 μm by adjusting the paste specific gravity, the metal content, and the amount of varnish.

  Next, as shown in FIG. 3, both end portions of the sintered body 10 on which the base external electrodes 4 and 5 are formed are respectively immersed in an Ag / Pd (weight ratio 80/20) paste bath, and sintered. An upper external electrode (second external electrode) 6 that is electrically connected to the spiral coil formed in the body 10 is formed. In this case, the Ag / Pd paste has an upper external electrode 6 with a thickness of about 18 μm on the sintered body 10 (side surface) without the base external electrodes 4 and 5 by adjusting the paste specific gravity, metal content, and varnish amount. What was formed was used. The upper external electrode 6 may be formed of the same Ag paste as the internal electrode 3 and the base external electrodes 4 and 5.

  In the laminated coil component 1A thus obtained, as shown in FIG. 4, the entire region of the external electrodes formed on the front and back surfaces (mounting surface 1a) is formed by laminating the base external electrode 5 and the upper external electrode 6 2 It consisted of layers, and its thickness dimension was about 30 μm. The size of the laminated coil component 1A was 1.6 mm in length, 0.8 mm in width and height. Then, by configuring the external electrode with two layers, the thickness of the external electrode can be formed to a desired thickness. That is, when forming the external electrode, in particular, when the external electrode is formed by immersing the sintered body in the paste, the paste extends and spreads, so that the external electrode cannot be formed to a desired thickness. However, if the base external electrodes 4 and 5 are formed in advance and the upper external electrode 6 is further formed on the base external electrodes 4 and 5, the thickness of the base external electrodes 4 and 5 is added to the thickness of the upper external electrode 6. Therefore, a thick external electrode can be formed. As a result, a predetermined gap is formed between the substrate and the laminated coil component. Therefore, when the laminated coil component is mounted on the printed circuit board with the conductive adhesive, the conductive adhesive does not easily extend in the long side direction of the laminated body. Thus, a short circuit due to the conductive adhesive between the external electrodes facing in the long side direction can be prevented.

  Specifically, a conductive adhesive having a thickness of 50 μm was applied on a pad of a printed circuit board, and a laminated coil component was mounted. Then, in the conventional laminated coil component having only the upper external electrode 6 having a thickness of 18 μm without the base external electrodes 4 and 5, the protrusion of the conductive adhesive was 0.2 mm. On the other hand, in the laminated coil component 1A according to the present invention, the protrusion of the conductive adhesive was reduced to 0.09 mm.

(Refer to the second embodiment, FIGS. 5 and 6)
Further, as shown in FIG. 5, the laminated coil component 1B according to the second embodiment has a substantially U-shaped base external electrode 15 and 16 formed on the front and back surfaces (mounting surface 1a), respectively. The distance between the electrodes is increased. As a result, as shown in FIG. 6, a step 32 for accommodating the conductive adhesive in the external electrode is formed. When the laminated coil component 1B is mounted on the pad 31 of the printed circuit board 30 with the conductive adhesive 35, the excess conductive adhesive 35a is accommodated in the step 32, and is formed by the conductive adhesive between the external electrodes. Short circuit can be prevented more reliably.

  Specifically, a conductive adhesive 35 having a thickness of 50 μm was applied on the pad 31 of the printed circuit board 30, and the laminated coil component 1B was mounted. In this case, the protrusion of the conductive adhesive 35 was 0.04 mm.

(Refer to the third embodiment, FIG. 7)
Further, as shown in FIG. 7, in the laminated coil component 1C according to the third embodiment, the base external electrode 17 formed on the front and back surfaces (mounting surface 1a) is formed in a square shape so that the area of the external electrode is substantially reduced. It is a small one. Thereby, when this laminated coil component 1C is mounted on the printed circuit board with the conductive adhesive, the excess conductive adhesive is accommodated in the step, and the short circuit due to the conductive adhesive between the external electrodes is more reliably performed. Can be prevented.

  Specifically, a conductive adhesive having a thickness of 50 μm was applied on the pad of the printed board, and the laminated coil component 1C was mounted. In this case, the protrusion of the conductive adhesive was 0.03 mm.

(Electronics)
Although the above description has been made on the electronic component incorporating the spiral coil, it is possible to configure an electronic device such as an LC filter or a high-frequency resonator by mounting these electronic components on a substrate.

(Other examples)
The electronic component manufacturing method, the electronic component, and the electronic device according to the present invention are not limited to the above-described embodiments, and can be variously modified within the scope of the gist thereof.

  For example, as shown in FIGS. 8 and 9, laminated coil components 1 </ b> D and 1 </ b> E in which strip-shaped base external electrodes 21 and 22 are formed on the front and back surfaces (mounting surface 1 a) may be used. In the laminated coil components 1D and 1E, the conductive adhesive is blocked by the strip-shaped base external electrodes 21 and 22, and the protruding of the conductive adhesive can be more reliably prevented. Furthermore, since the conductive adhesive gradually moves along the strip-shaped base external electrodes 21 and 22 in the short side direction of the laminated coil components 1D and 1E, mounting without leaving bubbles inside the conductive adhesive. Can do.

  In the embodiment, the external electrode has a two-layer structure, but it may have a three-layer structure or more. For example, the base external electrode (first external electrode) may be formed in two or more layers, and the upper external electrode (second external electrode) may be formed in two or more layers. Of course, the shape and arrangement of the internal electrodes are arbitrary.

1 is an exploded configuration diagram showing a first embodiment of an electronic component according to the present invention. The perspective view which shows one Example of the manufacturing method of the electronic component shown in FIG. The perspective view which shows the manufacturing method following FIG. FIG. 4 is an essential part cross-sectional view of an external electrode of the electronic component shown in FIG. 3. The perspective view which shows 2nd Example of the electronic component which concerns on this invention. FIG. 6 is an elevational view schematically showing a state where the electronic component shown in FIG. 5 is mounted on a printed board. The perspective view which shows 3rd Example of the electronic component which concerns on this invention. The top view which shows typically the other Example of the electronic component which concerns on this invention. The top view which shows typically the further another Example of the electronic component which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A-1E ... Laminated coil component 1a ... Mounting surface 2a, 2b, 2c ... Ceramic green sheet 3 ... Internal electrode 4, 5, 15, 16, 17, 21, 22 ... Base external electrode (1st external electrode)
6: Upper external electrode (second external electrode)
10 ... Sintered body

Claims (6)

Laminating a plurality of ceramic green sheets provided with internal electrodes to form a laminate;
Forming a first external electrode on the mounting surface of the laminate;
Firing the laminate to obtain a sintered body;
Forming a second external electrode electrically connected to the internal electrode on the surface of the sintered body including the first external electrode;
A method for manufacturing an electronic component, comprising:   The method of manufacturing an electronic component according to claim 1, wherein the first external electrode is formed by printing a conductive paste on a ceramic green sheet.   The method of manufacturing an electronic component according to claim 1, wherein the second external electrode is formed by immersing the sintered body in a conductive paste.   4. The electron according to claim 1, wherein the first external electrode is formed only in a part of a region of the mounting surface where the second external electrode is formed. 5. A manufacturing method for parts.   5. The electronic component manufactured by the electronic component manufacturing method according to claim 1, wherein a partial region of the external electrode formed on the mounting surface of the electronic component is the first component. An electronic component comprising at least two layers in which the external electrode and the second external electrode are laminated.   An electronic device comprising the electronic component according to claim 5 mounted on a substrate with a conductive adhesive.

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