Spin stand testing system with fine positioner for head stack assembly
View Patent ↗Head stack fixtures for securing head stack assemblies to spin stand testing systems, and spin stand testing systems incorporating such fixtures, are disclosed. Exemplary head stack fixtures comprise a base supporting a piezoelectric actuator. The base includes an attachment mechanism for securing the HSA in such a way that the HSA will pivot relative to the base. When the HSA is secured to the base, the piezoelectric actuator engages the HSA. The piezoelectric actuator is therefore able to pivot the HSA relative to the base for fine positioning of a head of the HSA.
1. A head stack fixture for securing a head stack assembly during spin stand testing, the head stack fixture comprising:
a base including an attachment mechanism for pivotably attaching the head stack assembly; and
a fine positioner, including a piezoelectric actuator, attached to the base and the head stack assembly and configured to pivot the head stack assembly relative to the base,
wherein the fine positioner engages a tang of the head stack assembly.
2. A head stack fixture for securing a head stack assembly during spin stand testing, the head stack fixture comprising:
a base including an attachment mechanism for pivotably attaching the head stack assembly; and
a fine positioner, including a piezoelectric actuator, attached to the base and the head stack assembly and configured to pivot the head stack assembly relative to the base,
wherein the fine positioner further includes an actuator housing having a shape of a parallelogram,
wherein the piezoelectric actuator deforms the parallelogram in order to pivot the head stack assembly, and
wherein the fine positioner further includes a set screw disposed against a first end of the piezoelectric actuator.
3. The head stack fixture of claim 2 wherein the set screw provides a pre-load to the piezoelectric actuator.
4. The head stack fixture of claim 2 wherein the piezoelectric actuator works against the set screw to deform the parallelogram.
5. A spin stand testing system comprising:
a rotatable magnetic recording disk including a track;
a head stack fixture for securing a head stack assembly during spin stand testing, the head stack fixture including
a base having an attachment mechanism for pivotably attaching the head stack assembly; and
a fine positioner, having a piezoelectric actuator, attached to the base and the head stack assembly and configured to pivot the head stack assembly relative to the base; and
a controller configured to actuate the piezoelectric actuator to optimize a read signal from a head of the head stack assembly.
6. The spin stand testing system of claim 5 wherein the fine positioner engages a tang of the head stack assembly.
7. The spin stand testing system of claim 5 wherein the piezoelectric actuator includes lead zirconium titanate.
8. The head stack fixture of claim 5 wherein the fine positioner further includes an actuator housing having a shape of a parallelogram.
9. The head stack fixture of claim 8 wherein the piezoelectric actuator is disposed within the parallelogram.
10. The head stack fixture of claim 8 wherein the piezoelectric actuator deforms the parallelogram in order to pivot the head stack assembly.
11. The head stack fixture of claim 5 wherein the controller actuates the piezoelectric actuator by applying a voltage thereto.
12. The head stack fixture of claim 5 wherein the read signal is generated by reading alignment information on the track with the head.
13. The head stack fixture of claim 5 wherein optimizing the read signal includes using a closed-loop servo.
14. The head stack fixture of claim 5 wherein optimizing the read signal includes maximizing an intensity of the read signal.
15. The head stack fixture of claim 5 wherein the track includes two parallel sub-tracks.
16. The head stack fixture of claim 15 wherein optimizing the read signal includes minimizing a difference between intensities of sub-signals read from the sub-tracks.
17. The head stack fixture of claim 5 wherein optimizing the read signal includes converging on a target value.