Buffered quartz crystal
US5233261A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 1991 |
| Grant date | Aug 3, 1993 |
| Priority date | — |
| Expiry date | Dec 23, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/19
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An AT-cut quartz crystal for a quartz crystal microbalance has a buffer layer sandwiched between an adhesion layer and an electrode layer on the front or deposition side of the crystal. The buffer layer can be a zinc layer of 6000 .ANG. sandwiched between a titanium or chromium adhesion layer of 100 to 160 .ANG. and a gold, silver, or aluminum outer electrode layer of about 2000 .ANG.. The zinc layer has a relatively low bulk modulus, and absorbs stress imposed by the deposited layer. The buffer layer prolongs useful crystal life, particularly when depositing dielectric materials. The crystal should have a modest surface roughness as keying-in structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.