Hitachi Global Storage Technologies Netherlands B.v.

Michael Cosci

Paul Marion Green

Garth Wade Helf

The method of the invention for servo track writer calibration consists of writing magnetic servo tracks and performing optical analysis using Kerr effect microscopy. After the servo tracks are written on the disk, the disk is placed in the optical inspection device having Kerr effect microscopy capability which allows the operator to directly observe the location of 'track zero' which is conventionally the track nearest to the inner diameter (ID) of the disk. An embodiment of the method comprising measuring a plurality of distances from a selected points on the track zero to obtain an average measurement indicative of a position of track zero on the magnetic disk. The measured data is then used to calibrate or adjust the servo writer.

Servo track writer calibration

A method of yield improvement for manufactured products includes providing an identification plan for parts and processing equipment, whereby each part and each piece of equipment is given unique and traceable identification data. A database is provided into which the parts identification data and the processing equipment identification data are stored, and related. The parts are processed in at least one processing stage by the processing equipment to yield processed parts, and the processed parts are tested for defects. Problems are then identified through the testing of the processed parts. The related parts identification data and the processing equipment identification data are retrieved from the database, and the data is analyzed to trace the parts to the appropriate processing equipment. Corrections and repairs are made to the processing equipment to correct the problems. Improvement to yield of the manufactured products is then confirmed.

Method for yield improvement of manufactured products

A system for improving manufacturing yields, which includes at least one manufacturing facility into which unprocessed parts enter. An identification plan is provided for the unprocessed parts, by which each unprocessed part is given unique and traceable unprocessed part identification data. Processing equipment is included by which the unprocessed parts are turned into processed parts. There are identification plans for the processing equipment and for the processed parts by which each piece of equipment and each processed part is given unique and traceable processing equipment identification data. At least one computer terminal is connected to a database into which the unprocessed parts identification data, the processed parts identification data and the processing equipment identification data is stored, and related. This data is retrievable to allow processed parts with defects to be traced to the processing equipment by which it was processed for repair or modification of the processing equipment.

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San Jose, CA, United States of America

Michael Cosci