# US 10,502,982 B2 · Optical modulator

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,502,982 B2
- Document ID: US10502982B2
- Status: Granted
- Kind: B2
- Application number: 16/397,289
- Filed: 2019-04-29
- Published: 2019-08-22
- Granted: 2019-12-10
- Earliest claimed: 2015-09-30
- Assignees: Sumitomo Osaka Cement Co., Ltd.
- Applicants: Sumitomo Osaka Cement Co., Ltd.
- Inventors: Kei Katou; Toshio Kataoka; Junichiro Ichikawa
- Web page: https://patentgrep.com/patent/US10502982B2

## CPC

- G02F 1/0102: {Constructional details, not otherwise provided for in this subclass}
- G02F 1/0121: {Operation of devices; Circuit arrangements, not otherwise provided for in this subclass}
- H05K 1/0216: {Reduction of cross-talk, noise or electromagnetic interference (grounding H05K1/0215)}
- H05K 1/028: {Bending or folding regions of flexible printed circuits (H05K1/0283 takes precedence)}
- H05K 1/119: {Details of rigid insulating substrates therefor, e.g. three-dimensional details (H05K1/117 takes precedence)}
- H05K 1/147: {at least one of the printed circuits being bent or folded, e.g. by using a flexible printed circuit (H05K1/148 takes precedence)}
- H05K 2201/052: Branched
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS

## Abstract

An optical modulator including an optical modulation element mounted inside a housing, in which at least a portion of an electric line is connected to an external circuit board through a flexible printed circuit, and which is disposed on the external circuit board. A recess portion that mounts the flexible printed circuit is formed on an outer bottom surface of the housing and at a part where the flexible printed circuit is connected, and a device for preventing a resonance mode is provided such that a resonance mode of a microwave and a millimeter wave or a parallel plate mode is prevented from being generated among a surface A of the recess portion facing the flexible printed circuit, an electric wiring part B provided on the flexible printed circuit overlapping the surface A when seen in a plan view, an electric wiring part C provided on the external circuit board overlapping the surface A when seen in a plan view.

## Claims

### Claim 1

An optical modulator including an optical modulation element mounted inside a housing, in which at least a portion of an electric line is connected to an external circuit board through a flexible printed circuit, and which is disposed on the external circuit board,
wherein a recess portion that mounts the flexible printed circuit is formed on an outer bottom surface of the housing and at a part where the flexible printed circuit is connected,
a plurality of signal lines disposed in the flexible printed circuit,
means for preventing a resonance mode are provided such that a resonance mode of a microwave and a millimeter wave or a parallel plate mode is prevented from being generated among a surface A of the recess portion facing the flexible printed circuit, an electric wiring part B provided on the flexible printed circuit overlapping the surface A when seen in a plan view, and the external circuit board overlapping the surface A when seen in a plan view, and
wherein in the means for preventing a resonance mode, no conductor including an electric wiring part is provided on a surface of the external circuit board overlapping the surface A when seen in a plan view and at least one of a clearance or a dielectric constant between the surface A and the electric wiring part B is set to be locally varied.

### Claim 2 (depends on 1)

The optical modulator according to claim 1, wherein in the means for preventing a resonance mode, at least any one of a pillar electrically connecting the surface A and the electric wiring part with each other or a pillar electrically connecting the electric wiring part B and the electric wiring part with each other is provided.

### Claim 3 (depends on 1)

The optical modulator according to claim 1, wherein electric wirings are respectively formed on both surfaces of the flexible printed circuit, and a via hole, electrically connecting ground wirings on both the surfaces with each other is formed.

### Claim 4 (depends on 1)

The optical modulator according to claim 1, wherein a distance of at least a part between the surface A and the electric wiring part B is 25 μm or smaller.