Cartridge screening technique by using the electrical dynamic bearing resistance
AssigneeSeagate Technology LLC
InventorsEng Hock Lim, Quek Leong Choo, Myint Ngwe, Kah Liang Gan, Beng Wee Quak
Life of this patent
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Abstract
A method for characterizing a bearing cartridge based on a preload applied to the bearing cartridge used in a disc drive, to increase disc drive yield rates. The method begins by loading the bearing cartridge on to a test fixture and to an actuator assembly such that the actuator is rotatably attached to the base by the bearing cartridge. Then, the method includes inducing a steady swing in the actuator. Then, the method includes measuring a voltage drop that occurs across the bearing cartridge during the steady swing to characterize the preload applied to the bearing cartridge.
Claims20
(Once Amended) A method of characterizing a bearing cartridge for use in a disc drive based on a preload applied to the bearing cartridge, comprising steps of:
- (a) mounting the bearing cartridge to a base and an actuator such that the actuator is rotatably attached to the base by the bearing cartridge;
- (b) inducing a steady swing in the actuator to simulate a seek operation of the disc drive;
- (c) applying a voltage to a voltage divider that includes a bearing cartridge;
- (d) measuring a voltage drop that occurs across the bearing cartridge during the steady swing of the actuator to characterize the bearing cartridge based on a preload applied to the bearing cartridge;
- and
- (e) characterizing the bearing cartridge based on the measured voltage drop.
A test fixture, comprising:
- a base;
- a voice coil motor-shaft-actuator assembly;
- a preloaded bearing cartridge disposed in the voice coil motor-shaft-actuator assembly such that it is rotatably attached to the base;
- voice coil motor circuitry to apply a voltage signal to the voice coil motor to induce a steady swing in the voice coil motor-shaft-bearing cartridge-actuator assembly;
- and
- a voltage divider circuit to measure a voltage drop that occurs across the bearing cartridge during the steady swing of the actuator assembly to characterize the bearing cartridge based on a preload applied to the bearing cartridge.
(Once Amended) A test system, comprising:
- a base;
- an actuator;
- a preloaded bearing cartridge disposed in the actuator such that it is rotatably attached to the base;
- and
- means for characterizing the bearing cartridge based on an electrical resistance of the bearing cartridge.
Dependencies are inferred from the claim text.