Areal density improvement of perpendicular magnetic recording (PMR) write head by tuning magnetic flux loops
US9754612B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2015 |
| Grant date | Sep 5, 2017 |
| Priority date | — |
| Expiry date | Nov 20, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/3123
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A PMR writer is disclosed wherein magnetic flux return from a magnetic medium to a main pole is substantially greater through a trailing shield structure than through a leading shield and return path layer (RTP). Magnetic impedance is increased between the RTP and main pole in the leading return loop by modifying the size and shape of the back gap connection (BGC), by decreasing Bs in the RTP or reducing its thickness, or by removing one or more layers in the BGC and replacing with dielectric material or non-magnetic metal to form a dielectric gap between the RTP and main pole. As a result, area density control and bit error rate are improved over a conventional dual write shield (DWS) structure comprising two flux return pathways. Moreover, adjacent track erasure is maintained at a level similar to a DWS design.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.