Thin shield structure for reduced protrusion in a magnetoresistive head
View Patent ↗A magnetic data recording head having reduced thermally induced shield (pole tip) protrusion. The head includes a magnetoresistive sensor sandwiched between first and second shield. The shields have a substantially reduced thickness. The distance between the shields defines a gap (G) and the shields each have a thickness (ST) such that the ratio ST/G is greater than 2, but less than 50. More preferably the ratio ST/G is greater than 2, but less than 20, and yet more preferably, the ratio ST/G is greater than 2 and less than 10.
1. A magnetic head having an air bearing surface (ABS) for use in a data recording system, the magnetic head comprising:
a magnetic write head; and
a magnetic read head separated from the magnetic write head by a non-magnetic, electrically insulating material, the magnetic read head further comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 50 and greater than 2;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 Oe;
wherein the non-magnetic, electrically insulating material separates the magnetic read head from the magnetic write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
2. A head as in claim 1 , wherein each of the first and second shields has a thickness between 0.01 and 5 um.
3. A head as in claim 1 wherein SH is between 5 and 50 um.
4. A head as in claim 1 , wherein G is less than 1000 nm.
5. A magnetic head having an air bearing surface (ABS) for use in a data recording system, the magnetic head comprising:
a magnetic write head; and
a magnetic read head separated from the magnetic write head by a non-magnetic, electrically insulating material, the read head further comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 20 and greater than 2 wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 Oe;
wherein the non-magnetic, electrically insulating material separates the magnetic read head from the magnetic write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
6. A head as in claim 5 , wherein each of the first and second shields has a thickness between 0.01 and 5 um.
7. A head as in claim 5 wherein SH is between 5 and 50 um.
8. A head as in claim 5 , wherein G is less than 1000 nm.
9. A magnetic head having an air bearing surface (ABS) for use in a data recording system, the magnetic head comprising:
a magnetic read head; and
a magnetic write head separated from the magnetic write head by a non-magnetic, electrically insulating layer, the read head further comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 10 and greater than 2;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 Oe;
wherein the non-magnetic, electrically insulating material separates the magnetic read head from the magnetic write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
10. A head as in claim 9 , wherein each of the first and second shields has a thickness between 0.01 and 5 um.
11. A head as in claim 9 wherein SH is between 5 and 50 um.
12. A head as in claim 9 , wherein G is less than 1000 nm.
13. A magnetic recording head, comprising:
a magnetic write element, comprising first and second magnetic poles that are magnetically connected with one another in a back gap region and separated from one another in a pole tip region, and an electrically conductive coil a portion of which passes between the first and second magnetic poles;
a read head, the read head comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 50 and greater than 2;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 Oe; and
a non-magnetic, electrically insulating material separating the read head from the write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
14. A magnetic recording head, comprising:
a magnetic write element, comprising first and second magnetic poles that are magnetically connected with one another in a back gap region and separated from one another in a pole tip region, and an electrically conductive coil a portion of which passes between the first and second magnetic poles;
a read head, the read head comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 20 and greater than 2;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 OeOe; and
a non-magnetic, electrically insulating material separating the read head from the write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
15. A magnetic recording head, comprising:
a magnetic write element, comprising first and second magnetic poles that are magnetically connected with one another in a back gap region and separated from one another in a pole tip region, and an electrically conductive coil a portion of which passes between the first and second magnetic poles;
a read head, the read head comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 10 and greater than 2;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 OeOe; and
a non-magnetic, electrically insulating material separating the read head from the write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
16. A suspension assembly, for use in magnetic recording, comprising:
a suspension arm;
a slider connected with the suspension arm;
a magnetic write element formed on the slider, the magnetic write element comprising first and second magnetic poles that are magnetically connected with one another in a back gap region and are separated from one another by a write gap in a pole tip region, and an electrically conductive coil a portion of which passes between the first and second magnetic poles;
a magnetic read head comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 20 and greater than 2;
a plurality of electrical leads, electrically connected with the write element; and
a plurality of electrical leads, electrically connected with the magnetoresistive sensor;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 OeOe; and
a non-magnetic, electrically insulating material separating the read head from the write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
17. A magnetic data recording system, comprising:
a magnetic medium;
a slider;
an actuator connected with the slider for moving the slider adjacent to a surface of the magnetic medium;
a magnetic write element formed on the slider, the magnetic write element comprising first and second magnetic poles that are magnetically connected with one another in a back gap region and are separated from one another by a write gap in a pole tip region, and an electrically conductive coil a portion of which passes between the first and second magnetic poles; and
a magnetic read head formed on the slider, the read head comprising:
first and second magnetic shields, each shield having a thickness (ST), the first and second shields being separated by a gap (G); and
a magnetoresistive sensor sandwiched between the shields;
wherein each of the shields has a thickness such that ST/G is less than 20 and greater than 2;
wherein the first and second shields each have a shield height (SH), a shield width (SW), and a saturation magnetization (Ms(s)) and wherein ST, SW, SH and Ms(s) are chosen so that the shield demagnetizing field exceeds an applied field H o in a quasistatic test where H o is between 1 and 10,000 OeOe; and
a non-magnetic, electrically insulating material separating the read head from the write head such that the first and second magnetic shields are separated from and not a part of the magnetic write head.
18. A head as in claim 17 , wherein each of the first and second shields has a thickness between 0.01 and 5 um.