Systems and methods for correcting fabrication error in magnetic recording heads using magnetic write width measurements

• US 9,387,568 B1
• Filed: 02/27/2013
• Issued: 07/12/2016
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Ilaw, Reymon G., Calub, Augustus C., Yaemglin, Theera, Kiatkhumjaikajorn, Manit, Cheowanish, Ittipon
• Primary Examiner(s): Dunn, Darrin
• Application Number:
  US13/779,693
• Time in Patent Office: 1,231 Days
• US Class Current: 1/1
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 37/048 of sliders and magnetic heads of hard disc drives or the like
• CPC Class Codes: B24B 37/30 for single side lapping of plane surfaces

Abstract

Systems and methods for correcting fabrication error in magnetic recording heads using magnetic write width (MWW) measurements are provided. One such method includes separating a wafer into sections containing row bars, each row bar including magnetic recording heads, selecting a first row bar from a first section of the sections, lapping the first row bar to form sliders, performing a test of a magnetic write width (MWW) on each of the sliders, calculating a first error profile for the first row bar based on results of the magnetic write width tests, generating a second error profile for a stripe height of a component of the sliders based on the first error profile, where the component is selected from a magnetic read head and a magnetic write head, and lapping a second row bar from the row bars of the first section using the second error profile.

Claims

1. A method of correcting for fabrication error in magnetic recording heads, the method comprising:

separating a wafer into a plurality of sections, each section containing a plurality of row bars, each row bar comprising a plurality of magnetic recording heads;

selecting a first row bar from a plurality of row bars of a first section of the plurality of sections;

lapping the first row bar to form a plurality of sliders;

performing a test of a magnetic write width (MWW) on each of the plurality of sliders;

calculating a first error profile for the first row bar based on results of the magnetic write width tests;

generating a second error profile for a stripe height of a component of the plurality of sliders based on the first error profile, wherein the component is selected from the group consisting of a magnetic read head and a magnetic write head; and

lapping a second row bar from the plurality of row bars of the first section using the second error profile.

2. The method of claim 1:

wherein the lapping the first row bar to form the plurality of sliders comprises lapping the first row bar in accordance with a first lapping profile to form the plurality of sliders; and

wherein the lapping the second row bar from the plurality of row bars of the first section using the second error profile comprises lapping the second row bar using a second lapping profile derived from the second error profile and the first lapping profile.

3. The method of claim 1, the calculating the first error profile for the first row bar based on results of the magnetic write width tests comprises calculating the first error profile for the first row bar based on results of the magnetic write width tests and a position within the first row bar of a respective slider among the plurality of sliders.

4. The method of claim 1:

wherein the selecting the first row bar from the plurality of row bars of the first section of the plurality of sections comprises selecting at least three row bars from the plurality of row bars of the first section;

wherein the lapping the first row bar to form the plurality of sliders comprises lapping the at least three row bars to form the plurality of sliders; and

wherein the calculating the first error profile for the first row bar based on results of the magnetic write width tests comprises calculating the first error profile for the at least three row bars based on results of the magnetic write width tests.

5. The method of claim 1, wherein the component is the magnetic read head.

6. The method of claim 1:

wherein the calculating the first error profile for the first row bar based on results of the magnetic write width tests comprises;

calculating a first mean error based on results of the magnetic write width tests for a first half of the plurality of sliders of the first row bar; and

calculating a second mean error based on results of the magnetic write width tests for a second half of the plurality of sliders of the first row bar; and

wherein the generating the second error profile for the stripe height of the component of the plurality of sliders based on the first error profile comprises generating the second error profile for the stripe height of the component of the plurality of sliders based on a first offset from the first mean error and a second offset from the second mean error.

7. The method of claim 6:

wherein the first row bar comprises 54 sliders;

wherein the first half corresponds to sliders 1 to 27 of the first row bar; and

wherein the second half corresponds to sliders 28 to 54 of the first row bar.

8. The method of claim 1, wherein the calculating the first error profile for the first row bar based on results of the magnetic write width tests comprises:

calculating a mean of the results of the magnetic write width tests; and

calculating an offset from the mean of the results for each of the plurality of sliders.

9. The method of claim 1, wherein the lapping the second row bar from the plurality of row bars of the first section using the second error profile comprises lapping the second row bar from the plurality of row bars of the first section using the second error profile and a preselected limit for the stripe height of the component.

10. The method of claim 1:

wherein the selecting the first row bar from the plurality of row bars of the first section of the plurality of sections comprises selecting at least three row bars from the plurality of row bars of the first section;

wherein the lapping the first row bar to form the plurality of sliders comprises lapping the at least three row bars to form the plurality of sliders; and

wherein the calculating the first error profile for the first row bar based on results of the magnetic write width tests comprises;

calculating a mean of the results of the magnetic write width tests for the sliders of the at least three row bars; and

calculating an offset from the mean of the results for each of the plurality of sliders.

11. The method of claim 10, further comprising calculating a resistance for the offsets from the mean for each of the plurality of sliders.

12. The method of claim 10, further comprising:

wherein each of the at least three row bars comprises a preselected number of sliders;

wherein a first half corresponds to one half of the preselected number of sliders for one of the at least three row bars, and a second half corresponds to the other half of the preselected number of sliders of the one of the at least three row bars;

wherein the calculating the mean of the results of the magnetic write width tests for the at least three row bars comprises;

calculating a first mean error based on results of the magnetic write width tests for the first half of the plurality of sliders for each of the at least three row bars; and

calculating a second mean error based on results of the magnetic write width tests for the second half of the plurality of sliders for each of the at least three row bars.

13. The method of claim 12, further comprising:

performing a line fit for the first mean error for the first half;

performing a line fit for the second mean error for the second half; and

generating a fitted mean for each of the plurality of sliders based on the line fits for the first mean error and the second mean error.

14. The method of claim 13, further comprising:

calculating a mean across the at least three row bars using the fitted mean;

calculating a mean across the first half of the at least three row bars using the line fit for the first mean error;

calculating a mean across the second half of the at least three row bars using the line fit for the second mean error; and

calculating a second offset for each slider of the plurality of sliders based on a position and the mean across the first half and the mean across the second half.

15. The method of claim 14, wherein the generating the second error profile for the stripe height of the component of the plurality of sliders based on the first error profile comprises:

converting, for each of the plurality of sliders, the second offset into a stripe height offset for the component.

16. The method of claim 15, further comprising:

converting, for each of the plurality of sliders, the stripe height offset into a resistance offset;

wherein the lapping the second row bar from the plurality of row bars of the first section using the second error profile comprises lapping the second row bar from the plurality of row bars of the first section using the resistance offsets for each of the plurality of sliders.

17. The method of claim 13:

wherein the line fit for the first mean error is a first order line fit or a line fit having an order higher than a first order line fit; and

wherein the line fit for the second mean error is a first order line fit or a line fit having an order higher than a first order line fit.