Servowriter Module

This is very specialised high precision equipment for the computer hard disk manufacturing industry. Servowriters are used in the disk drive production process to write digitally generated magnetic reference patterns on the disks’ surface at very high speed. These reference patterns are used to precisely locate the magnetic read/write heads in the normal operation of a disk drive.

The small footprint (A4 paper size) of this compact design along with the ability to vertically stack modules each weighing 50Kg, gave great savings in precious cleanroom floor space. A novel high efficiency vibration isolation device was also incorporated. Previously, servowriters had been large pieces of heavy equipment set out on thick granite tables covered in high-tech laser and servo equipment. Servowriters are used by all hard disk manufacturers such as Seagate, IBM, Western Digital, Fujitsu etc. They are used in the last stages of hard disk assembly to write the data, servo and clock tracks on the disk platens to a very high degree of accuracy and cleanliness. At the time of design, the disk track pitch was 1.27mm (micro metres 10^-6m). Each track consisted of 4 servo tracks plus a guaranteed space between all tracks and servo tracks. Operation is in a cleanroom 100 environment as the disk is open during this process. All materials and components had to be designed and checked for cleanroom 100 compliance.

This machine was designed for Xyratex (formerly IBM).