1. A magnetic head structure, comprising:
a lower pole;
an upper pole; and,
a backgap structure magnetically coupling said lower pole and said upper pole, said backgap structure having a backgap depth greater than two times a backgap width, wherein said magnetic head structure is a thin film head.
2. The structure as recited in claim 1, wherein said upper pole comprises a yoke magnetically coupled to an upper pole tip, said backgap structure being magnetically coupled to said yoke.
3. The structure as recited in claim 1, wherein said lower pole comprises a lower pole layer magnetically coupled to a lower pole tip, said backgap structure being magnetically coupled to said lower pole layer.
4. The structure as recited in claim 1, wherein
said upper pole comprises a yoke magnetically coupled to an upper pole tip, said backgap structure being magnetically coupled to said yoke; and
said lower pole comprises a lower pole layer magnetically coupled to a lower pole tip, said backgap structure being magnetically coupled to said lower pole layer.
5. The structure as recited in claim 4, wherein said upper pole tip and said lower pole tip are separated by a non-magnetic material.
6. The structure as recited in claim 1, wherein said backgap depth is greater than four times said backgap width.
7. A thin film magnetic head structure, comprising:
a lower pole including a lower pole layer magnetically coupled to a lower pole tip;
an insulating layer in contact with said lower pole layer;
a shield layer in contact with said insulating layer, said shield layer approximately parallel to said lower pole layer;
a coil structure having windings disposed in a plane approximately parallel to said shield layer;
an upper pole including a yoke magnetically coupled to an upper pole tip;
a write gap disposed between said lower pole tip and said upper pole tip at an air bearing surface; and,
a backgap structure magnetically coupling said lower pole layer and said yoke, said backgap structure having a backgap depth greater than two times a backgap width, wherein at least a portion of the windings of said coil structure encircle said backgap structure.
8. The structure as recited in claim 7 wherein said backgap depth is greater than four times said backgap width.
9. The structure as recited in claim 7, wherein said write gap comprises a non-magnetic material.
10. A magnetic head array comprising:
a first thin film magnetic head further comprising
a first lower pole including a lower pole layer magnetically coupled to a first lower pole tip,
a first upper pole including a first yoke magnetically coupled to a first upper pole tip,
a first coil structure having windings disposed in a plane approximately parallel to said lower pole layer,
a first write gap disposed between said first lower pole tip and said first upper pole tip at an air bearing surface, and
a first backgap structure magnetically coupling said lower pole layer and said first yoke, said first backgap structure having a first backgap depth greater than two times a first backgap width, wherein at least a portion of the windings of said first coil structure encircle said first backgap structure;
a second thin film magnetic head further comprising
a second lower pole including said lower pole layer magnetically coupled to a second lower pole tip,
a second coil structure having windings disposed approximately in said plane,
a second upper pole including a second yoke magnetically coupled to a second upper pole tip,
a second write gap disposed between said second lower pole tip and said second upper pole tip at said air bearing surface, and
a second backgap structure magnetically coupling said lower pole layer and said second yoke, said second backgap structure having a second backgap depth greater than two times a second backgap width, wherein at least a portion of the windings of said second coil structure encircle said second backgap structure;
an insulating layer in contact with said lower pole layer; and,
a shield layer in contact with said insulating layer, said shield layer approximately parallel to said lower pole layer,
wherein said first thin film magnetic head is adjacent to said second thin film magnetic head.
11. The array as recited in claim 10, wherein said first write gap and said second write gap are approximately co-planar.
12. The array as recited in claim 10, wherein
said first backgap depth is greater than four times said first backgap width, and said second backgap depth is greater than four times said second backgap width.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of singulating a semiconductor wafer with laser energy while the semiconductor wafer is supported on a mounting tape during singulation, the method comprising the steps of:
depositing a coating material directly onto a portion of the mounting tape adjacent to a perimeter of the semiconductor wafer to form a protective layer covering the mounting tape, the protective layer being deposited with a predetermined thickness sufficient to protect the mounting tape from being cut by the laser beam;
cutting the semiconductor wafer with a laser beam such that the laser beam at least partially impinges upon the protective layer covering the mounting tape during cutting of the semiconductor wafer; and thereafter
removing the protective layer from the mounting tape after singulation of the semiconductor wafer.
2. The method as claimed in claim 1, wherein the coating material is deposited such that the protective layer surrounds a whole perimeter of the semiconductor wafer.
3. The method as claimed in claim 1, wherein the step of removing the protective layer from the mounting tape comprises the step of washing off the coating material with a liquid.
4. The method as claimed in claim 3, wherein the liquid is water.
5. The method as claimed in claim 1, wherein the coating material comprises a material that absorps, reflects andor scatters the laser beam to reduce a laser intensity that is incident on the mounting tape to a level that is below a damage threshold of the mounting tape.
6. The method as claimed in claim 5, wherein the coating material is selected from the group consisting of: a poly(vinylalcohol), a poly(vinylacetate), a poly(vinylacrylate), a poly(ethyleneglycol), a wetting agent, a preservative, a surfactant and a colouring agent.
7. The method as claimed in claim 1, wherein the protective layer has a thickness of at least 10 microns.
8. The method as claimed in claim 1, wherein the coating material is deposited along the mounting tape for a sufficient distance adjacent to the semiconductor wafer to cover an anticipated run-out area of the laser beam.
9. The method as claimed in claim 1, wherein the protective layer adjoins the perimeter of the semiconductor wafer.
10. The method as claimed in claim 1, wherein the step of depositing the coating material on the mounting tape further comprises the step of pumping coating material to a nozzle that is positioned over the mounting tape for controllably dispensing the coating material onto the mounting tape.
11. The method as claimed in claim 10, further comprising the step of supporting the semiconductor wafer and mounting tape on a supporting chuck, and rotating the supporting chuck, semiconductor wafer and mounting tape relative to the nozzle while dispensing coating material from the nozzle.
12. A method of singulating a semiconductor wafer with laser energy while the semiconductor wafer is supported on a mounting tape during singulation, the method comprising the steps of:
depositing a coating material onto a portion of the mounting tape adjacent to a perimeter of the semiconductor wafer to form a protective layer over the mounting tape;
cutting the semiconductor wafer with a laser beam such that the laser beam at least partially impinges upon the protective layer during cutting of the semiconductor wafer; and thereafter
removing the protective layer from the mounting tape after singulation of the semiconductor wafer;
wherein the step of depositing the coating material on the mounting tape further comprises the step of pumping coating material to a nozzle that is positioned over the mounting tape for controllably dispensing the coating material onto the mounting tape; and
further comprising the step of changing a relative distance between the nozzle and the perimeter of the semiconductor wafer so as to deposit the coating material along the mounting tape to cover an anticipated run-out area of the laser beam.
13. The method as claimed in claim 12, wherein the step of changing the relative distance between the nozzle and the perimeter of the semiconductor wafer comprises the step of moving a pivotable arm on which the nozzle is supported relative to the semiconductor wafer.
14. The method as claimed in claim 1, further comprising the step of heating the protective layer after dispensation of the coating material so as to accelerate drying of the coating material before cutting the semiconductor wafer.
15. The method as claimed in claim 1, wherein the laser beam has an ultraviolet wavelength.
16. The method as claimed in claim 1, wherein the step of cutting the semiconductor wafer further comprises the step of generating additional laser beams for cutting the semiconductor wafer at different points simultaneously.
17. A method of protecting a mounting tape supporting a semiconductor wafer from damage during laser singulation of the semiconductor wafer, comprising the steps of depositing a coating material onto a portion of the mounting tape adjacent to a perimeter of the semiconductor wafer to form a protective layer over the mounting tape prior to laser singulation.