JP4373942B2 - Manufacturing method of electronic parts - Google Patents

Description

The present invention relates to a method for manufacturing an electronic component in which external electrodes are provided on the surface of an element body.

As a conventional electronic component of this type, there is a multilayer piezoelectric actuator described in Patent Document 1. In this multilayer piezoelectric actuator, a pair of external electrodes separated by grooves formed in the multilayer body is provided on the surface of the multilayer body having portions where a plurality of piezoelectric layers and a plurality of internal electrodes are alternately stacked. Is provided.
JP 2003-17769 A

  However, in the above-described multilayer piezoelectric actuator, for example, when an external circuit such as an FPC (flexible printed circuit board) is soldered to the pair of external electrodes in order to give a potential difference between the pair of external electrodes, The pair of external electrodes are connected to each other, which may cause a short circuit.

Therefore, the present invention has been made in view of such circumstances, and when soldering an external circuit such as an FPC to the first external electrode and the second external electrode provided on the surface of the element body, It is an object of the present invention to provide an electronic component manufacturing method capable of manufacturing an electronic component capable of preventing the first external electrode and the second external electrode from being connected by solder.

In order to achieve the above object, an electronic component manufacturing method according to the present invention includes an element body, a first external electrode provided on a surface of the element body and used as a terminal electrode of a common electrode , A method of manufacturing an electronic component comprising: a second external electrode provided on the surface of the body and used as a terminal electrode of the individual electrode, the step of forming the external electrode on the surface of the element body; and a laser By irradiating with light, the external electrode is divided to form the first external electrode and the second external electrode, the groove separating the first external electrode and the second external electrode, and the first external electrode Forming a protrusion along the groove-side edge and the groove-side edge of the second external electrode on the element body .

In the electronic component manufactured by the method of manufacturing an electronic component according to the present invention, a groove separating the first external electrode and the second external electrode is formed in the element body, and the first external electrode A convex portion is formed along at least one edge of the groove-side edge and the groove-side edge of the second external electrode. Accordingly, when an external circuit such as an FPC is soldered to the first external electrode and the second external electrode, the solder in which the convex portion is melted is blocked and the groove is a solder pool of the molten solder. Therefore, according to the electronic component manufactured by the method of manufacturing an electronic component according to the present invention, an external circuit such as an FPC is soldered to the first external electrode and the second external electrode provided on the surface of the element body. At this time, it is possible to prevent the first external electrode and the second external electrode from being connected by solder.

Further, the convex portions as compared with the first and second external electrodes, since the Rukoto formed by a material having a low solder wettability, an external circuit such as an FPC to the first external electrodes and second external electrodes When soldering, the molten solder is reliably dammed by the convex portion.

Further, the convex portions, since the Rukoto the body integrally formed with the convex portion is less likely to fall off from the element body.

The groove is Runode formed by laser light irradiation, it is possible to form a fine groove, the electronic component can be miniaturized. Furthermore, by forming grooves in the element body by laser light irradiation, convex portions can be formed simultaneously along both edges of the grooves.

According to the electronic component manufacturing method of the present invention, when an external circuit such as an FPC is soldered to the first external electrode and the second external electrode provided on the surface of the element body, the first external electrode is soldered. An electronic component that can prevent the electrode and the second external electrode from being connected can be manufactured .

  Hereinafter, a multilayer piezoelectric element which is a preferred embodiment of an electronic component according to the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIGS. 1 and 2, the multilayer piezoelectric element 1 includes a substantially rectangular parallelepiped element body 2. In the element body 2, a plurality of piezoelectric layers 5 in which internal electrodes 4 are formed and a plurality of piezoelectric layers 7 in which internal electrodes 6 are formed are alternately stacked. The element body 2 is configured by being stacked on both sides in the stacking direction (hereinafter, simply referred to as “stacking direction”), and has side surfaces 2 a and 2 b that are parallel to and opposed to the stacking direction. The internal electrodes 4 and 6 are made of a conductive material mainly composed of silver and palladium, and the piezoelectric layers 5, 7 and 9 are made of a piezoelectric ceramic material mainly containing lead zirconate titanate.

  On each piezoelectric layer 5, the edge on the side surface 2a side of the internal electrode 4 does not reach the side surface 2a, and the edge on the side surface 2b side of the internal electrode 4 reaches the side surface 2b. On the other hand, on each piezoelectric layer 7, the edge on the side surface 2a side of the internal electrode 6 reaches the side surface 2a, and the edge on the side surface 2b side of the internal electrode 6 does not reach the side surface 2b.

  Further, a groove 11 extending along a direction orthogonal to the stacking direction is formed on the side surface 2 a of the element body 2. The groove 11 is located on the side surface 2a between a set of internal electrodes 6 arranged in parallel along the stacking direction and a bottom surface 2c that is one end surface of the element body 2 in the stacking direction.

  An external electrode (first external electrode) 12 is integrally formed on the bottom surface 2 c side of the side surface 2 a partitioned by the groove 11, the bottom surface 2 c and the side surface 2 b, and the side surface 2 a partitioned by the groove 11. An external electrode (second external electrode) 13 is formed on the opposite side of the bottom surface 2c of the electrode. That is, the external electrode 12 and the external electrode 13 are separated by the groove 11. The external electrode 12 is connected to the side surface 2b side edge of the internal electrode 4 at the side surface 2b, and the external electrode 13 is connected to the side surface 2a side edge of the internal electrode 6 at the side surface 2a. The external electrodes 12 and 13 are made of Cr, Cu, Ni, Au, Ag, or a Cu—Ni alloy.

  Further, as shown in FIG. 3, convex portions 14 are formed on both edges of the groove 11 along the edge 12 a on the groove 11 side of the external electrode 12 and the edge 13 a on the groove 11 side of the external electrode 13. And the convex part 15 is formed. The convex portion 14 is formed integrally with the piezoelectric layer 9, and the convex portion 15 is formed integrally with the piezoelectric layer 7.

  In the multilayer piezoelectric element 1 configured as described above, the element body 2 is divided into a plurality of actuator portions 22 by a groove 21 extending in a direction orthogonal to the groove 11 as shown in FIG. And the internal electrode 6 is used as the piezoelectric actuator 20 by being made into the common electrode 23 and the separate electrode 24, respectively. The bottom surface of the groove 21 reaches the convex portion 14 formed along the edge 12 a of the external electrode 12. That is, the convex portion 14 is divided by the groove 21.

  The piezoelectric actuator 20 configured as described above is used in various devices in a state where the end surface on the bottom surface 2c side of the element body 2 is fixed to a predetermined part. At this time, as shown in FIG. 5, the FPC 26 is attached to the end surface of the element body 2 on the side surface 2 a side as an external circuit. Specifically, each of the external electrode 12 and the external electrode 13 is connected to a predetermined electrode of the FPC 26 by solder 27 on the end surface on the side surface 2 a side of the element body 2.

  For each external electrode 12 and actuator unit 22, between the common electrode 23 maintained at a predetermined potential, for example, by connection to the ground via the external electrode 12, and the individual electrode 24 of any actuator unit 22. By applying a potential difference using the divided external electrode 13 as a terminal electrode, the actuator unit 22 is displaced.

  Next, a method for manufacturing the multilayer piezoelectric element 1 will be described.

  First, a base paste is prepared by mixing a piezoelectric ceramic material mainly composed of lead zirconate titanate with an organic binder, an organic solvent or the like, and the base paste is used to form a green body that becomes the piezoelectric layers 5, 7, 9. The sheet is formed by the doctor blade method. Moreover, an organic binder, an organic solvent, etc. are mixed with the metal material which consists of silver and palladium of a predetermined ratio, and the electrically conductive paste for electrode pattern formation is produced.

  Subsequently, using the conductive paste, an electrode pattern corresponding to the internal electrode 4 and an electrode pattern corresponding to the internal electrode 6 are formed on separate green sheets by screen printing. Then, a green sheet on which an electrode pattern corresponding to the internal electrode 4 is formed, a green sheet on which an electrode pattern corresponding to the internal electrode 6 is formed, and a green sheet to be the piezoelectric layer 9 are laminated in the order described above. A laminate green is produced.

  Subsequently, while the laminate green is heated at a predetermined temperature (for example, about 60 ° C.) and pressed in the stacking direction at a predetermined pressure (for example, about 100 MPa), the laminate green is brought to a predetermined size. Disconnect. The laminate green is degreased at a predetermined temperature (for example, about 400 ° C.), and then fired at a predetermined temperature (for example, about 1100 ° C.) for a predetermined time (for example, about 2 hours). To obtain a laminate.

  Subsequently, external electrodes made of Cr, Cu, Ni, Au, Ag, or Cu—Ni alloy are formed on the end faces corresponding to the side surfaces 2a, 2b and the bottom surface 2c of the element body 2 in the laminated body by a thin film forming method (sputtering). Or a vacuum deposition method). The external electrode may be formed by printing and baking Ag or Au paste. Then, the laminated body is irradiated with laser light on the end face corresponding to the side surface 2a of the element body 2 and scanned with the laser light along a direction orthogonal to the laminating direction, so that the external electrodes are divided and the external electrodes 12, 13 are separated. And the groove 11 are formed. Thus, by forming the groove 11 by laser light irradiation, both edge portions of the groove 11 are raised, so that the convex portions 14 and 15 can be simultaneously formed along both edge portions of the groove 11.

  Subsequently, the laminated body on which the external electrodes 12 and 13 are formed is subjected to a polarization treatment (for example, an electric field is applied for 3 minutes so that the strength becomes 2 kV / mm in an environment of a temperature of 120 ° C.). The multilayer piezoelectric element 1 is obtained.

  As described above, in the multilayer piezoelectric element 1, the groove 11 separating the external electrode 12 and the external electrode 13 is formed in the element body 2, and the edge 12a of the external electrode 12 on the groove 11 side and Convex portions 14 and convex portions 15 are formed along each of the edge portions 13 a on the groove 11 side of the external electrode 13. Accordingly, as shown in FIG. 5, when soldering the FPC 26 to the external electrode 12 and the external electrode 13 on the side surface 2a of the element body 2, the solder 27 in which the convex portions 14 and 15 are melted is dammed up. The groove 11 becomes a solder pool of the melted solder 27. Therefore, according to this multilayer piezoelectric element 1, it is possible to prevent the external electrode 12 and the external electrode 13 from being connected by the solder 27 when the FPC 26 is soldered to the external electrode 12 and the external electrode 13.

  Moreover, each convex part 14 and 15 consists of piezoelectric ceramic materials which have lead zirconate titanate as a main component, and each external electrode 12 and 13 consists of Cr, Cu, Ni, Au, Ag, or Cu-Ni alloy. . Thus, since each convex part 14 and 15 is formed with the material with low solder wettability compared with each external electrode 12 and 13, when soldering FPC26 to external electrode 12 and external electrode 13, The melted solder 27 is reliably dammed by the convex portions 14 and 15.

  In addition, since the convex portions 14 and 15 are formed integrally with the piezoelectric layers 7 and 9, the convex portions 14 and 15 are difficult to drop off from the element body 2.

  The present invention is not limited to the embodiment described above.

  For example, in the above-described embodiment, each of the protrusions 14 and 15 is formed integrally with the piezoelectric layers 7 and 9, but each of the protrusions 14 and 15 is external as shown in FIG. It may be formed on the external electrode 12 and the external electrode 13 along the edge 12 a of the electrode 12 and the edge 13 a of the external electrode 13. In this case, the convex part 14 and the convex part 15 are formed by solder resist or resin, for example.

  Moreover, in the said embodiment, although the convex part 14 and the convex part 15 were formed along each of the edge part 12a of the external electrode 12, and the edge part 13a of the external electrode 13, as FIG. The convex portion 14 or the convex portion 15 may be formed along at least one of the edge portion 12 a of the electrode 12 and the edge portion 13 a of the external electrode 13.

  Moreover, in the said embodiment, although the groove | channel 11 was formed by irradiation of the laser beam with respect to the element | base_body 2, you may form the groove | channel 11 by cutting etc. FIG.

1 is a perspective view of a multilayer piezoelectric element that is an embodiment of an electronic component according to the present invention. FIG. 2 is an exploded perspective view of the multilayer piezoelectric element shown in FIG. 1. It is a principal part expanded sectional view along the III-III line | wire shown by FIG. It is a perspective view of the piezoelectric actuator comprised from the lamination type piezoelectric element shown by FIG. It is sectional drawing along the VV line shown by FIG. FIG. 5 is an enlarged cross-sectional view of a main part of a modification of the multilayer piezoelectric element shown in FIG. 1. FIG. 5 is an enlarged cross-sectional view of a main part of a modification of the multilayer piezoelectric element shown in FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Laminated piezoelectric element (electronic component), 2 ... Element body, 11 ... Groove, 12 ... External electrode (1st external electrode), 12a ... Edge part, 13 ... External electrode (2nd external electrode), 13a ... edge part, 14, 15 ... convex part.

Claims (1)

An element body, a first external electrode provided on a surface of the element body and used as a terminal electrode of a common electrode; and provided on a surface of the element body and used as a terminal electrode of an individual electrode A second external electrode, and a method of manufacturing an electronic component comprising:
Forming an external electrode on the surface of the element;
The external electrode is divided by laser light irradiation to form the first external electrode and the second external electrode, and a groove that separates the first external electrode and the second external electrode; and Forming a convex portion along the groove-side edge of the first external electrode and the groove-side edge of the second external electrode on the element body. Manufacturing method .

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