Magnetic head evaluation apparatus and method for manufacturing magnetic disk drive using the same
View Patent ↗Embodiments in accordance with the present invention provide a low-priced magnetic head evaluation apparatus capable of evaluating characteristics at high speed. According to one embodiment, a magnetic head evaluation apparatus includes a spindle motor, a VCM actuator as a head moving mechanism, and a ramp mechanism. A spindle motor used in a product HDD is used for the spindle motor. A VCM actuator used in the product HDD is used for the VCM actuator. A ramp mechanism used in the product HDD is used for the ramp mechanism. The apparatus further includes a non-contact type position detector such as a laser length measuring instrument. The non-contact type position detector irradiates a side surface of a load beam with a laser beam. An absolute position of the load beam over a magnetic disk is detected by detecting light reflected off the side surface of the load beam. Mounting of an HGA relative to the load beam is achieved by using a caulking hole in a mount plate.
1. A magnetic head evaluation apparatus, comprising:
a magnetic disk for recording thereon information as a signal;
a mechanism for rotatably driving the magnetic disk;
a magnetic head for writing/reading a signal to/from the magnetic disk;
a head gimbal assembly (HGA) for supporting the magnetic head above the magnetic disk; and
a mechanism for driving the HGA;
wherein a spindle motor used in a product hard disk drive (HDD) is used as the mechanism for rotatably driving the magnetic disk;
wherein a voice coil motor (VCM) actuator used in the product HDD is used as the mechanism for driving the HGA; and
wherein a non-contact type position detector is used as a mechanism for detecting a position of the magnetic head above the magnetic disk;
wherein the VCM actuator includes a load beam and spring having a first end fixed to the bottom of the load beam; and
wherein the HGA is mounted to the load beam using a second end of the spring that presses up against a caulking hole of a mount plate of the HGA.
2. The magnetic head evaluation apparatus according to claim 1 ,
wherein the non-contact type position detector includes a laser length measuring instrument which irradiates part of the VCM actuator with a laser beam and detects the position of the magnetic head with light reflected off the part of the VCM actuator.
3. The magnetic head evaluation apparatus according to claim 1 , further including a servo signal write mechanism and a servo following mechanism,
wherein the magnetic head is positioned at a specific area above the magnetic disk based on an output from the non-contact type position detector; and
wherein the servo signal write mechanism writes a servo signal in the specific area and the servo following mechanism lets the magnetic head follow the specific area for evaluating electromagnetic conversion characteristics.
4. The magnetic head evaluation apparatus according to claim 1 , further including a ramp mechanism used in the product HDD,
wherein the HGA is mounted relative to the load beam by using the ramp mechanism.
5. The magnetic head evaluation apparatus according to claim 4 ,
wherein, if the magnetic head is to be disposed above an upper surface of the magnetic disk, a lift tab on a leading end of the HGA is first placed at the ramp mechanism and the mount plate is then mounted to the load beam.
6. The magnetic head evaluation apparatus according to claim 4 ,
wherein, if the magnetic head is to be disposed below a lower surface of the magnetic disk, the load beam is moved to a location away from the ramp mechanism and the mount plate of the HGA is mounted to the load beam.
7. A method for manufacturing a magnetic disk drive, comprising the steps of:
manufacturing a magnetic head;
mounting a suspension on the magnetic head to form a head gimbal assembly (HGA);
screening the HGA using a magnetic head evaluation apparatus;
mounting the screened HGA on a first voice coil motor (VCM) actuator; and
assembling a magnetic disk, the first VCM actuator, and a first spindle motor in a hard disk drive (HDD) cabinet;
wherein the magnetic head evaluation apparatus uses a second spindle motor equivalent to the first spindle motor as a mechanism for rotatably driving an evaluation magnetic disk, a second VCM actuator equivalent to the first VCM actuator as a mechanism for driving an HGA to be evaluated, and a non-contact type position detector as a mechanism for detecting a position of the HGA to be evaluated above the evaluation magnetic disk; wherein the second VCM actuator includes a load beam and spring having a first end fixed to the bottom of the load beam; and wherein the HGA is mounted to the load beam using a second end of the spring that presses up against a caulking hole of a mount plate of the HGA.
8. The method according to claim 7 ,
wherein the non-contact type position detector includes a laser length measuring instrument which irradiates part of the second VCM actuator with a laser beam and detects the position of the HGA to be evaluated with light reflected off the part of the second VCM actuator.