US 12,322,420 B2
Middle shields two-dimensional magnetic recording read heads
Ming Mao, Dublin, CA (US); Chen-Jung Chien, Mountain View, CA (US); Goncalo Marcos Baião De Albuquerque, San Jose, CA (US); Chih-Ching Hu, Pleasanton, CA (US); Yung-Hung Wang, San Jose, CA (US); and Ming Jiang, San Jose, CA (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Jul. 26, 2023, as Appl. No. 18/226,615.
Claims priority of provisional application 63/421,488, filed on Nov. 1, 2022.
Prior Publication US 2024/0144966 A1, May 2, 2024
Int. Cl. G11B 5/39 (2006.01); H01F 10/32 (2006.01)
CPC G11B 5/3912 (2013.01) [H01F 10/3272 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A read head, comprising:
a first lower shield;
a first sensor disposed over the first lower shield;
a second sensor disposed over the first sensor, wherein a down-track spacing between the first sensor and the second sensor is about 75 nm to about 85 nm;
a first upper shield disposed over the second sensor; and
a middle shield disposed between the first sensor and the second sensor, the middle shield comprising:
a second upper shield disposed over the first sensor;
a read separation gap disposed on the second upper shield, wherein the second upper shield and the read separation gap are substantially planar, extending into the read head substantially perpendicular to a media facing surface (MFS);
a seed layer disposed on the read separation gap, the seed layer comprising a bilayer of Ru/NiFe, Ru/NiCr, SiO2/NiFe, or SiO2/NiCr, or a single layer of NiCr; and
a second lower shield disposed between the read separation gap and the second sensor, the second lower shield being a multilayer shield comprising a CoFe/Ru/CoFe anti-ferromagnetic coupling (AFC) layer or a Ru layer, wherein the second lower shield has a first thickness at the MFS and a second thickness recessed from the MFS, the first thickness being greater than the second thickness.