Image processing of novel vision-assisted hard disk drive flex cable-actuator manufacturing

While advancing storage capacity for magnetic disk drives into multi-terabyte domain, the corresponding form factor is being reduced due to significant application demand in various consumer electronics sectors and requirements for power reduction. These two inversely trends veer at a point that any misalignment due to mechanical tolerances or assembling inconsistency can result in excessive operating dynamics issues and drive-to-drive final performance variation. Among all mechanical factors, misalignment of flex cable assembly and the corresponding tolerance build up from adjacent parts during manufacturing and packaging into disk drives can result in deviation of real flex cable profile from engineered design case, which inevitably gives rise to issues of uncontrollable variation in mass production. Especially when (1) settling requirement is reaching to hundreds of nanometers and (2) more data sectors are packed in a circular trace than before because of advancement of perpendicular recording technology, low frequency and long settling flex cable dynamics become the most and difficult task to resolve when disk drive’s capacity is beyond a terabyte point. The work presented in this paper suggests a solution to reduce such variation and to ensure flex cable performance at mass production level. An alternative approach in assembling flexible circuitry assembly on to actuator comb and integrated lead suspensions is proposed. Apart from traditional alignment methods, robotic vision guided method and assembling system are adopted and developed. Its capability of reaching micro-scale position and alignment accuracy is demonstrated with lower drive-to-drive flex dynamic performance variation.