MULTILAYER COIL PART - MURATA MANUFACTURING CO

Title:

MULTILAYER COIL PART

Document Type and Number:

WIPO Patent Application WO/2012/172921

Kind Code:

A1

Abstract:

This multilayer coil part has a magnetic body section (2) that is made of an Ni-Zn system ferrite material and a Cu-based coil conductor (3) that has been wound into a coil shape. The coil conductor (3) is buried inside the magnetic body section (2) to form a part element body (1). The part element body (1) is divided into a first region (6) that is located close to the coil conductor (3) and a second region (7) that comprises the region other than the first region (6). The grain size ratio (D1/D2) between the average crystal grain size (D1) of the magnetic body section (2) in the first region (6) and the average crystal grain size (D2) of the magnetic body section (2) in the second region (7) is equal to or lower than 0.85. The molar quantity of CuO content in the ferrite material is set to 6 mol% or less, and the ferrite material is baked in a reductive atmosphere with the oxygen partial pressure being equal to or lower than the Cu-Cu2O equilibrium oxygen partial pressure. Thus, a multilayer coil part that exhibits not only little fluctuation of inductance and excellent thermal shock resistance when subjected to a thermal shock or an external stress but also excellent direct-current superposition characteristics can be obtained without requiring any complicated step.

Inventors:

YAMAMOTO ATSUSHI (JP)
NAKAMURA AKIHIRO (JP)
NOMIYA YUKO (JP)
ANKYU TOMOYUKI (JP)
NAITO OSAMU (JP)

Application Number:

PCT/JP2012/062758

Publication Date:

December 20, 2012

Filing Date:

May 18, 2012

Export Citation:

Click for automatic bibliography generation Help

Assignee:

MURATA MANUFACTURING CO (JP)
YAMAMOTO ATSUSHI (JP)
NAKAMURA AKIHIRO (JP)
NOMIYA YUKO (JP)
ANKYU TOMOYUKI (JP)
NAITO OSAMU (JP)

International Classes:

H01F17/00; H01F1/34

Foreign References:

JPH05175032A	1993-07-13
JP2010278075A	2010-12-09
JP2003272912A	2003-09-26
JP2006237438A	2006-09-07
JP2005244183A	2005-09-08
JPH0645307U	1994-06-14
JP2694757B2	1997-12-24
JP2006237438A	2006-09-07

Other References: