# US 2013/0154786 A1 · Laminated common-mode choke coil

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- Number: US 2013/0154786 A1
- Document ID: US20130154786A1
- Status: Published application
- Kind: A1
- Application number: 13/717,117
- Filed: 2012-12-17
- Published: 2013-06-20
- Earliest claimed: 2011-12-20
- Assignees: Taiyo Yuden Co., Ltd.
- Inventors: Takashi NAKAJIMA; Mika TAMANOI; Kenji OTAKE
- Web page: https://patentgrep.com/patent/US20130154786A1

## CPC

- H01F 5/003: {Printed circuit coils}
- H01F 17/0013: {with stacked layers}
- H01F 38/48: {Common mode inductor for reducing or eliminating common mode noise on parallel lines}
- H01F 2017/0073: {with a special conductive pattern, e.g. flat spiral}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

A laminated common-mode choke coil offering higher insulation reliability has a glass ceramic layer, two spiral internal conductors facing each other and sandwiching the glass ceramic layer in between, and insulation layers sandwiching the two internal conductors, wherein the glass ceramic layer contains segregated Al regions and the maximum dimension t1 of each segregated Al region in the glass ceramic layer, in the layer-thickness direction, is no more than 80% of the distance t0 between the two internal conductors.

## Claims

### Claim 1

A laminated common-mode choke coil having a glass ceramic layer, two spiral internal conductors facing each other and sandwiching the glass ceramic layer in between, and insulation layers sandwiching the two internal conductors; wherein the glass ceramic layer contains segregated Al regions where a concentration of Al is substantially higher than that in other areas of the glass ceramic layer, and a maximum dimension of each segregated Al region in the glass ceramic layer, in a layer-thickness direction, is no more than 80% of a distance between the two internal conductors.

### Claim 2 (depends on 1)

A laminated common-mode choke coil according to claim 1, wherein the glass ceramic layer contains glass and filler and the content of Al in the glass is 0.05 to 5 percent by weight.

### Claim 3 (depends on 1)

A laminated common-mode choke coil according to claim 1, wherein the internal conductors are made of a conductor material containing silver.

### Claim 4 (depends on 2)

A laminated common-mode choke coil according to claim 2, wherein the internal conductors are made of a conductor material containing silver.

### Claim 5 (depends on 1)

A laminated common-mode choke coil according to claim 1, wherein the distance between the two internal conductors is a thickness of the glass ceramic layer which is about 5μ to about 25 μm.

### Claim 6 (depends on 1)

A laminated common-mode choke coil according to claim 1, wherein the segregated Al regions are reaction products of an Al component and alkali metal in the glass ceramic layer and conductor material diffused from the internal conductors.

### Claim 7 (depends on 1)

A laminated common-mode choke coil according to claim 1, wherein the segregated Al regions contain higher concentrations of alkaline metal and Ag than those in the other areas of the glass ceramic layer.