Dimensional consistency of miniature loudspeakers
US11729569B2 · kind B2 · utility
0Cited by
7References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 10, 2019 |
| Grant date | Aug 15, 2023 |
| Priority date | — |
| Expiry date | Jul 23, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2231/003
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor wafer has formed within it a plurality of piston tops of equal area. Each of the piston tops includes a thin flat region from which a majority of the thickness of the original semiconductor wafer may have been removed. A first one of the piston tops has a lower thickness than a second one of the piston tops. The second piston top has at least one hole in it, the volume of the hole corresponding to the difference in thickness between the first and second piston tops, such that the masses of the first and second piston tops differ by less than the variation in thickness between them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.