US 10,311,900 B1Granted

Magnetic core and coil design for double perpendicular magnetic recording (PMR) writers

AssigneeHeadway Technologies, Inc.

InventorsKowang Liu, Yuhui Tang, Moris Dovek

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Abstract

A dual PMR writer is disclosed wherein the better of the two writers on a slider is integrated into a head gimbal assembly to improve area density capability mean and sigma values, and the other writer is disabled. Each of a driving coil (DC) and bucking coil (BC) have two outer portions that form a U shape with a front side, and have a center portion connected to each of the two outer portions with a narrow arm in which direct current resistance (DCR) is enhanced during a write process. As a result, when writer (coil) induced write gap (WG) protrusion is overlaid on the dynamic fly height (DFH) protrusion profile, the net WG protrusion profile has a maximum value at a cross-track position aligned with a main pole tip in the better writer thereby substantially minimizing magnetic spacing loss compared with conventional dual PMR writers.

Claims20

Dependent claims

A dual perpendicular magnetic recording (PMR) writer, comprising:

(a) a first main pole layer in a first PMR writer having a first main pole tip with a leading side and trailing side at an air bearing surface (ABS), and bisected by a first plane that is at a first cross-track position and is orthogonal to the ABS;
(b) a second main pole layer in a second PMR writer having a second main pole tip with a leading side and trailing side at the ABS, and bisected by a second plane that is orthogonal to the ABS, the second plane is at a second cross-track position and a first cross-track width from the first plane;
(c) a bucking coil (BC) with a front side that is between the first and second planes, recessed from the ABS, and formed below the first and second main pole layers, the bucking coil has a substantially U shape and comprises:
(1) a BC center portion with a substantially rectangular shape that extends from the BC front side to a backend that contacts an interconnect;
(2) a BC first outer portion that is connected to the BC center portion with a first arm proximate to the BC front side and first plane;
and
(3) a BC second outer portion that is connected to the BC center portion with a second arm proximate to the BC front side and second plane;
(d) a driving coil (DC) with a front side that is between the first and second planes, recessed from the ABS, and formed above the first and second main pole layers, the driving coil has a substantially U shape and comprises:
(1) a DC center portion with a substantially rectangular shape that extends from the DC front side to a backend that contacts the interconnect;
(2) a DC first outer portion that is connected to the DC center portion with a third arm proximate to the DC front side and first plane;
and
(3) a DC second outer portion that is connected to the DC center portion with a fourth arm proximate to the DC front side and second plane;
and
(e) the interconnect that completes a first circuit such that a first write current passing through the BC first outer portion, first arm, and BC center portion and interconnect to the DC center portion, third arm, and then to the DC first outer portion generates flux in the first main pole layer, or completes a second circuit wherein a second write current passing through the BC second outer portion, fourth arm, BC center portion and interconnect to the DC center portion, second arm, and then to the DC second outer portion generates flux in the second main pole layer.

11 more elements

A method of aligning a write gap (WG) protrusion close point during a write process with a first main pole tip in a first writer or with a second main pole tip in a second writer in a dual perpendicular magnetic recording (PMR) writer;

comprising:
(a) providing a first main pole with the first main pole tip which is bisected by a first plane that is at a first cross-track position and is orthogonal to an air bearing surface (ABS);
(b) providing a second main pole with the second main pole tip which is bisected by a second plane that is at a second cross-track position and is orthogonal to the ABS, wherein the second plane is a first cross-track width from the first plane;
(c) providing a bucking coil (BC) with a front side recessed from the ABS and formed below the first and second main poles and having a center portion extending from the BC front side to a BC backend that contacts an interconnect, and wherein the BC front side of the BC center portion is connected to BC first and second outer portions through first and second arms, respectively;
(d) providing a driving coil (DC) with a front side recessed from the ABS and formed above the first and second main poles and having a center portion extending from the DC front side to a DC backend that contacts the interconnect, and wherein the DC front side of the DC center portion is connected to DC first and second outer portions through third and fourth arms, respectively;
(e) determining a first cross-track WG protrusion profile by passing a first current through a dynamic fly height (DFH) heater in the dual PMR writer;
(f) determining a second cross-track WG protrusion profile by passing a second current through a first circuit comprised of the BC first outer portion, first arm, BC center portion, interconnect, DC center portion, third arm, and DC first outer portion, or through a second circuit comprised of the BC second outer portion, second arm, BC center portion, interconnect, DC center portion, fourth arm, and DC second outer portion;
and
(g) repeating step (f) a plurality of times until an overlay of the second cross-track WG protrusion profile on the first cross-track WG protrusion profile generates a maximum WG protrusion at the first plane when the second current flows through the first circuit, or at the second plane when the second current flows through the second circuit.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/874,986Filed 19 Jan 2018
Granted: 4 Jun 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

G11B 5/3909
Details related to the use of magnetic thin film layers or to their effects: arrangements using a magnetic tunnel junction
G11B 5/1278
Structure or manufacture of heads, e.g. inductive: specially adapted for magnetisations perpendicular to the surface of the record carrier
G11B 5/17
Structure or manufacture of heads, e.g. inductive: construction or disposition of windings
G11B 5/29
Structure or manufacture of heads, e.g. inductive: structure or manufacture of unitary devices formed of plural heads for more than one track

Family

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