Composite substrate and thickness-tendency estimating method for piezoelectric substrate
US10566518B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2017 |
| Grant date | Feb 18, 2020 |
| Priority date | — |
| Expiry date | Mar 16, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/02614
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A composite substrate according to the present invention includes a support substrate having a diameter of 2 inches or more, and a piezoelectric substrate having a thickness of 20 μm or less and bonded to the support substrate to transmit light. The piezoelectric substrate has a thickness distribution shaped like a fringe. A waveform having an amplitude within a range of 5 to 100 nm in a thickness direction and a pitch within a range of 0.5 to 20 mm in a width direction appears in the thickness distribution of the piezoelectric substrate in a cross section of the composite substrate taken along a line orthogonal to the fringe, and the pitch of the waveform correlates with a width of the fringe. In the piezoelectric substrate, the fringe may include either parallel fringes or spiral or concentric fringes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.