Method and apparatus for SAW device passivation
US5215546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1991 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Sep 10, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H3/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A passivation layer of dielectric material disposed on the top surface of the SAW device prevents the metallized transducer pattern on the piezoelectric substrate from being exposed to chemical attack. This layer also provides for improved metal acousto-migration resistance through the well-known mechanism of grain boundary pinning. The piezoelectric SAW device substrate includes a dielectric layer which is disposed along the surface over the transducer metallization. The piezoelectric substrate includes metallized regions on top of the dielectric layer which is disposed over the substrate surface and the SAW transducers thereon. These metallized regions form capacitors to the transducer busses and capacitively couple electrical input and output signals to the transducers from external electronic apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.