Air-bearing design for hydrocarbon and lube pick-up improvements in hard disk drive (HDD)

Patent metadata

Field	Value
Publication number	US-9940960-B2
Application number	US-201615162704-A
Country	US
Kind code	B2
Filing date	May 24, 2016
Priority date	May 24, 2016
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A slider design for a hard disk drive (HDD) features an air-bearing surface (ABS) topography with arrays of micro-dots formed on bases of a multiplicity of cavities at different depths. The design eliminates the accumulation of hydrocarbons (e.g., spindle oil and disk lubricant) deposits in regions of air stagnation within the cavities where backflows and foreflows of air meet and cancel during HDD operation. The micro-dots are small raised regions of various shapes having sizes and spacings in the range between 2 and 100 microns and, in a preferred embodiment, heights of 0.15 microns above the cavity bases.

First claim

What is claimed is:

1. A slider for a hard-disk drive (HDD) comprising:
a slider body of substantially rectangular horizontal cross-section having a leading edge (LE), a trailing edge (TE) parallel to said leading edge and an upper surface defining an air-bearing surface (ABS);
a multiplicity of cavities formed in said slider body, wherein said cavities are formed transversely and symmetrically about a center-line and are formed at different depths relative to said ABS and wherein said cavities include:
a first cavity adjacent to said leading edge having a base formed at a depth E 1 ;
a second cavity adjacent to said trailing edge having a base formed to a depth E 2 ;
a third cavity formed substantially midway between said first and second cavities and having a base formed to a depth E 3 ; and wherein
E 3 >E 2 >E 1 and wherein
at least one of said cavities has an array of micro-dots formed on said cavity base that rise from said at least one cavity base and wherein said micro-dots are dimensioned vertically and horizontally, corresponding to the dimensions of said at least one cavity and configured by a pattern of distribution on said at least one cavity base to eliminate regions of airflow stagnation created during operation of said HDD and, thereby, to eliminate regions of hydrocarbon accumulation.

2. The slider of claim 1 wherein said array of micro-dots is configured to eliminate regions of aerodynamic backflow which create said regions of airflow stagnation when encountering regions of foreflow.

3. The slider of claim 1 wherein said horizontal dimensions are 850 microns in length and 700 microns in width.

4. The slider of claim 1 wherein said micro-dots are formed with arbitrary horizontal cross-sectional shapes, including circles, squares, diamonds or rectangles.

5. The slider of claim 4 wherein all micro-dots in an array have the same one of said arbitrary cross-sectional shapes.

6. The slider of claim 1 wherein said array of micro-dots includes micro-dots of different cross-sectional shapes.

7. The slider of claim 1 wherein said three etch depths, measured from the upper ABS, are E 3 =2.8 microns, E 2 =1.15 microns and E 1 =0.15 microns and there are three cavities formed, each with a base at one of those depths.

8. The slider of claim 7 wherein said array of micro-dots covers the entire base of said cavity whose base is at a depth of 2.8 microns.

9. The slider of claim 8 wherein an array of micro-dots partially covers a base of said cavity whose base is at a depth of 1.15 microns.

10. The slider of claim 2 wherein said micro-dots have horizontal cross-sectional sizes in the range between approximately 2 microns to 100 microns.

11. The slider of claim 9 wherein micro-dots in said array are substantially uniformly spaced with height above said cavity bases of approximately 0.15 microns.

12. The slider of claim 2 wherein the tops of said micro-dots are between approximately 0.01 microns and 0.15 microns below said ABS surface.

13. The slider of claim 1 wherein said horizontal dimensions are 1235 microns in length and 700 microns in width.

Assignees

• Sae Magnetics Hk Ltd
• Headway Tech Inc
• Sae Magnetics Hk Ltd

Inventors

• Cha Ellis
• Yeung Sindy
• Looi Penny Wan Ting
• Ng Ben Kwun Pan

Classifications

• G11B5/6082 Primary

  Design of the air bearing surface · CPC title

• G11B5/6005

  Specially adapted for spacing from a rotating disc using a fluid cushion · CPC title