Method and apparatus for measuring a pitch static attitude of a head stack assembly

1. A tester for measuring a pitch static attitude of a head stack assembly comprising:

a laser transmitter configured to transmit laser beams;

a laser receiver configured to receive the laser beams from the laser transmitter, wherein the laser transmitter and the laser receiver are configured to receive a head stack assembly comprising sliders between the laser transmitter and the laser receiver;

a zero reference plane located between the laser transmitter and the laser receiver;

a tower reference plane located between the laser transmitter and the laser receiver, wherein the tower reference plane defines an aperture; and

a controller configured to measure a pitch static attitude of the head stack assembly by at least:

determining a zero axis using the zero reference plane and the laser beams;

determining a first horizontal position of the aperture and a second horizontal position of the aperture using the zero axis and the laser beams;

determining a mid-point of a first slider of the head stack assembly using the first horizontal position and the second horizontal position;

determining a first vertical position of the aperture using the zero axis and the laser beams;

determining a first horizontal line using the first vertical position; and

generating a pitch static attitude reference line corresponding to a pitch static attitude of the first slider based on a least squares approximation using the mid-point of the first slider and the first horizontal line.

2. The tester of claim 1 wherein the zero reference plane and the tower reference plane are integrally formed.

3. The tester of claim 1 wherein the first horizontal position is located in a horizontal direction opposite the second horizontal position.

4. The tester of claim 1 wherein the controller is further configured to perform auto gage verification by:

determining whether the first horizontal position matches a first assigned horizontal position; and

indicating a tester failure when the first horizontal position does not match the first assigned horizontal position.

5. The tester of claim 1 wherein the controller is further configured to perform auto gage verification by:

determining whether the second horizontal position matches a second assigned horizontal position; and

indicating a tester failure when the second horizontal position does not match the second assigned horizontal position.

6. The tester of claim 1 wherein the controller is further configured to perform auto gage verification by:

determining whether the first vertical position matches a first assigned vertical position; and

indicating a tester failure when the first vertical position does not match the first assigned vertical position.

7. The tester of claim 1 wherein the controller is further configured to measure a pitch static attitude of the head stack assembly by:

determining a mid-point of a second slider of the head stack assembly using the first horizontal position and the second horizontal position;

determining a second vertical position of the aperture using the zero axis and the laser beams;

determining a second horizontal line using the second vertical position; and

generating a pitch static attitude reference line corresponding to a pitch static attitude of the second slider based on a least squares approximation using the mid-point of the second slider and the second horizontal line.

8. The tester of claim 7 wherein the first vertical position is located in a vertical direction opposite the second vertical position.

9. The tester of claim 7 wherein the second slider is located in a vertical direction opposite the first slider.

10. The tester of claim 7 wherein the controller is further configured to perform auto gage verification by:

determining whether the second vertical position matches a second assigned vertical position; and

indicating a tester failure when the second vertical position does not match the second assigned vertical position.

11. A method for measuring a pitch static attitude of a head stack assembly comprising sliders using a tester comprising a laser transmitter that transmits laser beams to a laser receiver, a zero reference plane, a tower reference plane defining an aperture, and a controller, wherein the head stack assembly is placed between the laser transmitter and the laser receiver and the zero reference plane and the tower reference plane are placed between the laser transmitter and the laser receiver, the method comprising:

determining a zero axis using the zero reference plane and the laser beams;

determining a first horizontal position of the aperture and a second horizontal position of the aperture using the zero axis and the laser beams;

determining a mid-point of a first slider of the head stack assembly using the first horizontal position and the second horizontal position;

determining a first vertical position of the aperture using the zero axis and the laser beams;

determining a first horizontal line using the first vertical position; and

generating, using the controller, a pitch static attitude reference line corresponding to a pitch static attitude of the first slider based on a least squares approximation using the mid-point of the first slider and the first horizontal line.

12. The method of claim 11 wherein the zero reference plane and the tower reference plane are integrally formed.

13. The method of claim 11 wherein the first horizontal position is located in a horizontal direction opposite the second horizontal position.

14. The method of claim 11 further comprising:

determining whether the first horizontal position matches a first assigned horizontal position; and

indicating a tester failure when the first horizontal position does not match the first assigned horizontal position.

15. The method of claim 11 further comprising:

determining whether the second horizontal position matches a second assigned horizontal position; and

indicating a tester failure when the second horizontal position does not match the second assigned horizontal position.

16. The method of claim 11 further comprising:

determining whether the first vertical position matches a first assigned vertical position; and

indicating a tester failure when the first vertical position does not match the first assigned vertical position.

17. The method of claim 11 further comprising:

determining a mid-point of a second slider of the head stack assembly using the first horizontal position and the second horizontal position;

determining a second vertical position of the aperture using the zero axis and the laser beams;

determining a second horizontal line using the second vertical position; and

generating a pitch static attitude reference line corresponding to a pitch static attitude of the second slider based on a least squares approximation using the mid-point of the second slider and the second horizontal line.

18. The method of claim 17 wherein the first vertical position is located in a vertical direction opposite the second vertical position.

19. The method of claim 17 wherein the second slider is located in a vertical direction opposite the first slider.

20. The method of claim 17 further comprising:

determining whether the second vertical position matches a second assigned vertical position; and

indicating a tester failure when the second vertical position does not match the second assigned vertical position.