Test structures for measuring near field transducer disc length
US9441938B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 2013 |
| Grant date | Sep 13, 2016 |
| Priority date | — |
| Expiry date | Aug 21, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/0021
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Systems and methods for using NFT disc test structures for controlling NFT disc length during manufacture of an HAMR writer are disclosed. An NFT is manufactured concurrently with one or more pairs of pin-disc and disc-less test structures. The NFT disc and pin dimensions may be substantially similar to the pin and disc dimensions of the pin-disc test structure. The disc length of the pin-disc test structure is measured as a function of the difference in resistance between the two test structures and other parameters. Capturing the disc length variation subsequently enables adjustment of the NFT electronic lapping guide stripe height to reduce length variation in the NFT pin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.