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

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.