Inductors and methods for manufacturing inductors

Abstract

The present invention suppresses formation of an external electrode on an insulating coating film of a lead-out section on a surface of an element body, thereby suppressing recesses in a surface of the external electrode and suppressing entry of water into the external electrode.　An inductor according to the present invention comprises: a coil conductor that has a first lead-out section and a second lead-out section forming a pair and that is formed by a band-shaped conductive wire which has a conductor and an insulating coating film; an element body that contains magnetic particles and resin and that encapsulates the coil conductor; an element body protective film that covers a surface of the element body; and external electrodes that are connected to the first lead-out section and the second lead-out section which are exposed from the surface of the element body. The element body has a mounting surface and a pair of end surfaces that are orthogonal to the mounting surface. The first lead-out section and / or the second lead-out section has one main surface that is exposed from the end surface of the element body. An exposed portion that is exposed on the end surface has two sides substantially parallel to the mounting surface of the element body in plan view. The element body protective film has an overlapping part that overlaps with the exposed portion, covering a far side that is one of the two sides of the exposed portion and that is farther from the mounting surface than the other one. The external electrode extends on a surface of the overlapping part.

Claims

1. A coil conductor having a pair of first and second lead portions, formed from a strip-shaped conductor having a conductor and an insulating coating covering the outer circumference of the conductor, A base body containing magnetic particles and resin, which encloses the coil conductor, A protective film covering the surface of the aforementioned substrate, An external electrode connected to the coil conductor, An inductor having, The aforementioned body has a mounting surface that faces the mounting substrate during mounting, and two paired end faces perpendicular to the mounting surface, Each of the first and second lead-out sections, which are strip-shaped conductors, has one main surface of the strip-shaped conductor exposed from the end surface of the base body. The exposed portions exposed on the end faces of the first and second drawers have a plan view shape that is substantially rectangular, with two opposing sides that are substantially parallel to the mounting surface of the base body. The protective film of the substrate covers the far side, which is the side of the two sides of the substantially rectangular shape formed by the exposed portion of at least one of the first and second lead-out portions that is furthest from the mounting surface, and includes an overlapping portion that overlaps with the insulating film that extends to a part of the exposed portion. The external electrode extends to the surface of the superimposed portion of the protective film on the substrate. Inductor.

2. Each of the external electrodes extends from each of the opposing end faces to the mounting surface adjacent to each of the end faces, Each of the first and second extensions has an exposed portion that is exposed from the surface of one of the two end faces that are different from each other. The far side of the exposed portion of the first and second extension portions is at different distances from the mounting surface. In the first or second lead portion, of the first and second lead portions, the one whose far side is further from the mounting surface, the body protective film includes an overlapping portion that covers the far side of the first or second lead portion and overlaps with the insulating film that extends to a part of the exposed portion, and the external electrode extends from the mounting surface along the end face to the surface of the overlapping portion of the body protective film. The inductor according to claim 1.

3. The protective film of the substrate includes an overlapping portion that covers the far edges of the first and second lead portions and overlaps with the insulating film that extends to a part of the exposed portion, in both the first and second lead portions. The external electrode extends from the mounting surface along the end face to the surface of the superimposed portion of the substrate protective film in both the first and second lead-out portions. The inductor according to claim 1.

4. Of the exposed portion of at least one of the first and second pull-out portions, the area of ​​the portion covered by the superimposed portion of the protective film is 20% or less of the area of ​​the exposed portion. The inductor according to any one of claims 1 to 3.

5. A body molding step in which a coil conductor having a first lead portion and a second lead portion, formed from a strip-shaped conductor having a conductor and an insulating coating covering the outer circumference of the conductor, is embedded in a body such that the first lead portion and the second lead portion of the coil conductor are exposed from the surface of the body containing magnetic particles and resin, A protective film formation step for the substrate is formed on the surface of the substrate, which forms a protective film for the substrate that covers the surface of the substrate. A surface treatment step in which a laser beam is irradiated onto the surface of the base body, including the exposed portions of the first and second drawout sections that are exposed from the base body, to remove a portion of the resin and the protective film of the base body on the surface of the base body at the electrode location, A plating layer formation step in which an external electrode is formed on the surface of the base body including the exposed portion by plating, It has, The aforementioned body has a mounting surface that faces the mounting substrate during mounting, and two paired end faces perpendicular to the mounting surface, In the aforementioned body molding process, the coil conductor is embedded in the body such that one main surface of the first lead portion and the second lead portion, which are strip-shaped conductors, is exposed from the end surface of the body, and the plan view shape of the exposed portion exposed from the end surface of the first lead portion and the second lead portion forms a substantially rectangular shape with two opposing sides substantially parallel to the mounting surface of the body. In the surface treatment step, the protective film on the base body is removed from the surface of the base body such that it covers the far side, which is the side of the substantially rectangular shape formed by the exposed portion of at least one of the first and second draw-out portions that is furthest from the mounting surface, and includes an overlapping portion that overlaps with a part of the exposed portion. In the plating layer formation step, the external electrode is formed to extend onto the surface of the superimposed portion of the substrate protective film. A method for manufacturing inductors.

Images