Samsung Electronics Co., Ltd.

Shuyu Sun

Peng Luo

Keung Youn Cho

Sang Won Lee

Chaoyuan C Chen

Hoa V Pham

Hao Ping Wen

Chao Yuan Chen

Disclosed is a perpendicular recording head for a hard disk drive. The perpendicular recording head includes a yoke that has a plurality of grooves essentially perpendicular to a magnetic flux that flows in a vertical direction relative to the yoke. The perpendicular grooves inhibit residual magnetism in the vertical direction and enhance yoke domain stability.

Perpendicular recording head with a grooved yoke

A perpendicular recording head for a hard disk drive. The head includes a non-magnetic backside shield that minimizes or eliminates the flow of backside flux through the head. The head can be fabricated by forming a non-magnetic backside shield layer on a main pole. Portions of the backside shield and main pole can be removed to form a tapered pole portion. A non-magnetic write-gap layer and write shield are then formed onto the backside shield and main pole.

Dual write gap perpendicular recording head with a non-magnetic backside shield

A hard disk drive with a disk that has a servo field with an A servo burst and a B servo burst. The A servo burst has a trimmed erase band. The trimmed erase band can be created by offsetting the write head relative to a burst centerline to reduce the width of the erase band. For example, the write head can be moved toward a centerline of the A servo burst. The offset can be a function of write current and cylinder location of the disk. The offsets are selected so that the resultant burst profiles do not contain a flat minimum portion.

Erase band compensated offset servo trimming

A calibration method for a fly on demand head of a hard disk drive. The method includes the steps of flying a head over a test track of a disk that is covered with a lubricant. A voltage is applied to a heating element of the head to move the head closer to the disk. The fly height of the head is then determined. The voltage can be incrementally varied until the head makes contact with the disk. This sequence can cause a modulated wear pattern in the lubricant of the disk. The voltage is terminated and the head is allowed to fly over the test track. The head is also moved to adjacent tracks on either side of the test track. A pressure gradient of the flying head moves the lubricant about the disk to mitigate the modulated wear pattern.

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Saratoga, CA, United States of America

Shuyu Sun