Browse Prior Art Database

Automated Fly Height Test and Adjust System

IP.com Disclosure Number: IPCOM000107780D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 3 page(s) / 99K

Publishing Venue

IBM

Related People

Balster, CH: AUTHOR [+6]

Abstract

Disclosed is an invention which helps to minimize fly height variation in head/suspension assemblies (HSAs). A schematic diagram of the invention is shown in the figure. Basically, the invention consists of a fully automated fly height tester with fly height adjustment capability. The process cycle time target for one such cell is 10 seconds per HSA.

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Automated Fly Height Test and Adjust System

       Disclosed is an invention which helps to minimize fly
height variation in head/suspension assemblies (HSAs).  A schematic
diagram of the invention is shown in the figure.  Basically, the
invention consists of a fully automated fly height tester with fly
height adjustment capability.  The process cycle time target for one
such cell is 10 seconds per HSA.

      The elements of the invention which will allow this very
aggressive cycle time are as follows:
1.   A slightly-buffered input queue to allow for full fly height
(FH) test of an audit level of parts.  Full FH test of a part would
not fit within an absolute 10-second process cycle time, but with
slight buffering this is not a problem, provided the full FH
characterization does not go beyond a few percent of the population.
2.   A high-speed, high-precision robot 1 will be used to pick each
head from a transfer tray 3, put the HSA into test position on the FH
tester 4 with FRF TV/microscope system plus fly height sensor 5, and
place the tested part in either output tray 7 for HSAs within the FH
specification or output tray 8 for scrap HSAs which could not be
adjusted into the specification.  The robot hand 2 (or end effector)
will be used as the fixture in the FH tester, rather than
transferring the HSA into and out of a test fixture (see the figure).
      Using the robot to hold the part in the FH tester is absolutely
essential for keeping the system process cycle time down.  This can
be done by using a high precision robot and by mounting the robot on
the same air-suspension system as the fly height test spindle.
3.   A remotely-controlled mechanical load/unload device on the robot
hand will be used to load the HSA onto the quartz disk 6 for test,
and to unload the HSA from the disk after the FH test is complete.
In the simplest embodiment of this invention, this load/unload device
would also be used to lower the HSA gram load, thereby adjusting the
FH within specification. An alternative to mechanical gram load
adjustment would be...