Architecture and performance of the ESPER-2 hard-disk drive servo writer

摘要: The servo writer is known as the most accurate and sensitive tool on an HDD (harddisk drive) manufacturing line. ESPER-2 designed a product-independent common which incorporates major advances in equipment cost, reduction of clean-room requirements, writing accuracy. process consists two stages. first stage writes master pattern many ten disks at once with little need for contaminant protection facilities. One such disk then assembled other, raw, file, second proper all surfaces by referring to master. effects off-center discursions mechanical assembly random runout (NRRO, or nonrepeatable runout) product spindle components are eliminated table-lookup actuator control, so that accuracy improved. Neither exceptionally clean environment nor fine parts required second-stage operation.