Restriction of suspension dimple contact point
A head gimbal assembly (HGA) for a hard disk drive includes a primary dimple having a secondary structure protruding from the primary dimple, where a flexure is movably coupled with a load beam via the primary dimple, and where the secondary structure is configured to restrict the point of contact between the load beam and the flexure. Such an arrangement avoids any shift in the axis of rotation of the flexure, and the attached slider, due to any undesirable protrusion from the primary dimple which may arise in the manufacturing process. Examples of secondary structures include a micro-dimple, a ridge, and an embedded mass of material.
1. A head gimbal assembly (HGA) comprising:
a head slider housing a read-write transducer configured to read from and to write to a rotating disk medium;
a load beam;
a flexure movably coupled with the load beam and to which the head slider is attached; and
a primary dimple comprising a secondary structure protruding from the primary dimple, wherein a width of the secondary structure relative to the diameter of the primary dimple is within a range of 4-6%;
wherein the flexure is movably coupled with the load beam via the secondary structure of the primary dimple.
2. The HGA of claim 1 , wherein the secondary structure is configured to restrict the point of contact between the load beam and the flexure to the secondary structure.
3. The HGA of claim 1 , wherein the secondary structure comprises a micro-dimple.
4. The HGA of claim 3 , wherein the micro-dimple is positioned at an apex of the primary dimple.
5. A hard disk drive comprising the HGA of claim 4 .
6. The HGA of claim 1 , wherein the secondary structure comprises a ridge spanning at least a portion of an arc of an outer surface of the primary dimple.
7. The HGA of claim 6 , wherein the ridge is positioned coincident with and spans the entirety of the longest arc of the outer surface of the primary dimple.
8. The HGA of claim 6 , wherein:
the HGA has a longitudinal pitch direction along its length and a lateral roll direction along its width; and
the ridge is positioned along the pitch direction.
9. A hard disk drive comprising the HGA of claim 8 .
10. The HGA of claim 1 , wherein the secondary structure comprises a mass of material embedded onto the primary dimple.
11. The HGA of claim 10 , wherein the mass of material is positioned at an apex of the primary dimple.
12. A hard disk drive comprising the HGA of claim 11 .
13. The HGA of claim 1 , wherein the primary dimple is constituent to the load beam.
14. The HGA of claim 1 , wherein the primary dimple is constituent to the flexure.
15. The HGA of claim 1 , wherein the primary dimple is substantially hemispherical.
16. A method of manufacturing a suspension component configured for a hard disk drive, the method comprising:
etching a circular pattern from a metal sheet, leaving a protrusion protruding from the etched circular pattern; and
die pressing the metal sheet to form a primary dimple from the etched circular pattern and to form a secondary structure, from the protrusion, protruding from the primary dimple, wherein a width of the secondary structure relative to the diameter of the primary dimple is within a range of 4-6%.
17. The method of claim 16 , wherein:
etching the circular pattern includes leaving the protrusion protruding from the center of the circular pattern; and
die pressing the metal sheet to form the secondary structure includes forming a micro-dimple positioned at an apex of the primary dimple.
18. The method of claim 16 , wherein:
etching the circular pattern includes leaving the protrusion protruding along a centerline of the circular pattern; and
die pressing the metal sheet to form the secondary structure includes forming a spanning at least a portion of an arc of an outer surface of the primary dimple.
19. A hard-disk drive comprising:
a disk medium rotatably mounted on a spindle;
a head slider housing a read-write transducer configured to read from and to write to the disk medium;
an actuator configured to move the head slider to access portions of the disk medium; and
a head gimbal assembly (HGA) comprising a flexure to which the head slider is attached, wherein the flexure comprises:
a load beam;
a flexure movably coupled with the load beam and to which the head slider is attached; and
means for restricting the point of contact between the load beam and the flexure to a portion of a primary dimple via which the flexure is movably coupled with the load beam, wherein a width of the means for restricting relative to the diameter of the primary dimple is within a range of 4-6%.