Tuning fork type crystal unit and bar type crystal unit
US6930440B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2003 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | Oct 30, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/21
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A tuning fork type quartz crystal unit has a base and a pair of arms extending from respective ends of the base in a crystallographic Y direction of quartz crystal. Each of the arms comprises a first crystal member and a second crystal member which extend in the Y direction. The first crystal member and the second crystal member are joined to each other in a crystallographic YZ plane by a direct bonding such that the first crystal member and the second crystal member have respective crystallographic X directions oriented away from each other and extending parallel to each other. Each of the arms has excitation electrodes disposed respectively on a pair of exposed surfaces thereof which lie in the YZ plane. The direct bonding comprises, for example, a siloxane bond by which the first crystal member and the second crystal member are joined to each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.