Surface-mount inductor and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-2022392694-A1
Application number	US-202217820196-A
Country	US
Kind code	A1
Filing date	Aug 16, 2022
Priority date	Dec 28, 2015
Publication date	Dec 8, 2022
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 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.

2 . The manufacturing method according to claim 1 , 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.

3 . The manufacturing method according to claim 2 , 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.

4 . The manufacturing method according to claim 1 , wherein the forming an external terminal includes forming a second plating layer on the conductive paste layer.

5 . The manufacturing method according to claim 4 , 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.

6 . The manufacturing method according to claim 1 , wherein during the forming a first plating layer, the first plating layer having a mesh structure is formed.

7 . The manufacturing method according to claim 1 , wherein during the forming a first plating layer, the first plating layer having a slit structure is formed.

8 . The manufacturing method according to claim 2 , wherein the forming an external terminal includes forming a second plating layer on the conductive paste layer.

9 . The manufacturing method according to claim 2 , 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

• H01F2017/048

  with encapsulating core, e.g. made of resin and magnetic powder · CPC title

• 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

• H01F27/292 Primary

  Surface mounted devices · CPC title

• H01F41/10 Primary

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

• H01F27/2828

  Construction of conductive connections, of leads · CPC title