Surface-mount inductor and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-2018308628-A1
Application number	US-201816019399-A
Country	US
Kind code	A1
Filing date	Jun 26, 2018
Priority date	Dec 28, 2015
Publication date	Oct 25, 2018
Grant date	—

Abstract

A surface-mount inductor comprises a molded body containing a metal magnetic powder; at least one coil buried in the molded body such that lead-out end parts at both ends of the coil are at least partially exposed on a surface of the molded body; and an external terminal formed over an exposed surface of each of the lead-out end parts. A metal magnetic powder exposed portion is formed at least around the exposed surface. The external terminal at least includes a first plating layer formed over the metal magnetic powder exposed portion and the exposed surface of the lead-out end part, and a conductive paste layer formed on the first plating layer and made of a solidified conductive paste. Consequently, the surface mount inductor comprises an external terminal having high connection reliability.

First claim

What is claimed is:

1 . A surface-mount inductor comprising:
a molded body containing a metal magnetic powder; at least one coil buried in the molded body such that lead-out end parts at both ends of the coil are at least partially exposed on a surface of the molded body; and an external terminal formed over an exposed surface of each of the lead-out end parts and a metal magnetic powder exposed portion formed at least around the exposed surface, the external terminal at least including a first plating layer formed over the metal magnetic powder exposed portion and the exposed surface of the lead-out end part, and a conductive paste layer formed on the first plating layer and made of a solidified conductive paste.

2 . The surface-mount inductor according to claim 1 , wherein the external terminal includes the first plating layer, the conductive paste layer, and a second plating layer formed on the conductive paste layer.

3 . The surface-mount inductor according to claim 2 , wherein:
the conductive paste layer has one or more conductive-paste-layer non-formation regions, and the first plating layer and the second plating layer are directly bonded in the conductive-paste-layer non-formation regions.

4 . The surface-mount inductor according to claim 1 , wherein:
the molded body has a rectangular shape having upper and bottom surfaces opposite to each other and four side surfaces, and the lead-out end parts at both ends are respectively exposed on first and second side surfaces opposite to each other.

5 . The surface-mount inductor according to claim 4 , wherein:
the metal magnetic powder exposed portion is formed entirely on the first side surface and the second side surface other than the exposed surfaces of the lead-out end parts, and the first plating layer and the conductive paste layer are formed entirely on the first side surface and the second side surface including the exposed surfaces of the lead-out end parts.

6 . The surface-mount inductor according to claim 4 , wherein the lead-out end parts at both ends of the coil are led out from the first and second side surfaces opposite to each other.

7 . The surface-mount inductor according to claim 1 , wherein the first plating layer has a mesh structure.

8 . The surface-mount inductor according to claim 1 , wherein the first plating layer has a slit structure.

9 . The surface-mount inductor according to claim 2 , wherein:
the molded body has a rectangular shape having upper and bottom surfaces opposite to each other and four side surfaces, and the lead-out end parts at both ends are respectively exposed on first and second side surfaces opposite to each other.

10 . The surface-mount inductor according to claim 2 , wherein the first plating layer has a mesh structure.

11 . The surface-mount inductor according to claim 2 , wherein the first plating layer has a slit structure.

12 . A manufacturing method of a surface-mount inductor having at least one coil buried in a molded body containing a metal magnetic powder, the method comprising:
molding by placing the at least one coil in a molding die and filling a material for a molded body into the molding die to obtain the molded body, wherein the coil is buried in the molded body such that lead-out end parts at both ends of the coil are at least partially exposed on a surface of the molded body; and forming an external terminal over an exposed surface of each of the lead-out end parts and a metal magnetic powder exposed portion formed at least around the exposed surface, the forming an external terminal at least including forming a first plating layer over the metal magnetic powder exposed portion and the exposed surface of the lead-out end part, and forming a conductive paste layer made of a solidified conductive paste on the first plating layer.

13 . The manufacturing method according to claim 12 , wherein:
the molded body has a rectangular parallelepiped shape having upper and bottom surfaces opposite to each other and four side surfaces, and during the molding, the molded body is molded such that the lead-out end parts at both ends are respectively exposed on first and second side surfaces opposite to each other.

14 . The manufacturing method according to claim 13 , wherein the metal magnetic powder exposed portion is formed entirely on the first side surface and the second side surface other than the exposed surfaces of the lead-out end parts.

15 . The manufacturing method according to claim 12 , wherein the forming an external terminal includes forming a second plating layer on the conductive paste layer.

16 . The manufacturing method according to claim 15 , wherein one or more conductive-paste-layer non-formation regions are formed in the conductive paste layer to directly bond the first plating layer and the second plating layer in the conductive-paste-layer non-formation regions.

17 . The manufacturing method according to claim 12 , wherein during the forming a first plating layer, the first plating layer having a mesh structure is formed.

18 . The manufacturing method according to claim 12 , wherein during the forming a first plating layer, the first plating layer having a slit structure is formed.

19 . The manufacturing method according to claim 13 , wherein the forming an external terminal includes forming a second plating layer on the conductive paste layer.

20 . The manufacturing method according to claim 13 , wherein during the forming a first plating layer, the first plating layer having a mesh structure is formed.

Assignees

• Murata Manufacturing Co

Inventors

• Muneuchi Keita

Classifications

• H01F41/0246

  Manufacturing of magnetic circuits by moulding or by pressing powder (magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36) · CPC title

• H01F27/2828

  Construction of conductive connections, of leads · CPC title

• H01F17/04

  with magnetic core · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• H01F41/10 Primary

  Connecting leads to windings (making electric connections in general H01R43/00) · CPC title