Non-uniform write gap perpendicular writer for shingle writing
View Patent ↗A PMR writer is disclosed that includes a recessed center section in the write pole trailing edge and a center recessed trailing shield to improve the field gradient at track edge. In all embodiments, there is a non-uniform write gap between the trailing edge and the trailing shield. The recessed portion of the write pole trailing edge and/or center recess of the trailing shield has a thickness from 10 to 40 nm in a down-track direction and a width in a cross-track direction of 20 to 200 nm. The distance between the center recess and a corner of the trailing edge is from 20 to 80 nm. A sequence of steps is provided to fabricate the two embodiments of the present invention.
1. A PMR writer for shingle writing, comprising:
(a) a write pole formed along an air bearing surface (ABS) with a leading edge and sections of a trailing edge formed parallel to a top surface of a substrate, and having two sides wherein each side intersects the trailing edge at a corner, said trailing edge comprises:
(1) a first end section that terminates at a first corner and is formed parallel to the substrate;
(2) a second end section that terminates at a second corner and is formed parallel to the substrate; and
(3) a recessed center section connecting the first and second end sections and wherein the recessed center section is a single curved arc that is formed a lesser distance from the substrate than the first and second end sections;
(b) a write gap formed on the trailing edge and having a non-planar top surface, comprising:
(1) a first write gap end section formed parallel to the trailing edge and aligned above the first corner of the write pole;
(2) a second write gap end section formed parallel to the trailing edge and aligned above the second corner of the write pole; and
(3) a convex curve shaped center section connecting the first and second write gap end sections and wherein the convex curve shaped center section is formed a greater distance from the trailing edge than the first and second write gap end sections such that a variable first thickness of the write gap below the convex curve shaped center section is greater than a fixed second thickness below the first and second write gap end sections;
(c) a side gap that adjoins each side of the write pole and having a side formed substantially parallel to a nearest side of the write pole and located a gap distance therefrom;
(d) a side shield that adjoins a side of each side gap and interfaces with an overlying trailing shield; and
(e) the trailing shield that adjoins a top surface of each side shield and is formed on the top surface of the write gap.
2. The PMR writer of claim 1 wherein the fixed second thickness of the write gap is from 15 to 30 nm.
3. The PMR writer of claim 1 wherein each of the recessed center section of the trailing edge and the convex curve shaped center section of the write gap top surface has a width in a cross-track direction of about 20 to 200 nm.
4. The PMR writer of claim 2 wherein the variable first thickness of the write gap below the convex curve shaped center section is about 20 to 80 nm greater than the fixed second thickness.
5. The PMR writer of claim 1 wherein the first and second write gap end sections and first and second sections of the trailing edge have a width in a cross-track direction of about 20 to 80 nm.
6. The PMR writer of claim 1 wherein the center section of the write gap top surface and recessed center section of the trailing edge each have a semi-circular shape.