Analysis of Structurally Transmitted Vibration of HDD in Notebook Computer

Characteristics of structurally transmitted hard disk drive (HDD) vibrations induced by different built-in vibration sources, including speakers, fans and a CD/DVD drive in a notebook PC, are examined. It is found that at the high frequencies above 1000 Hz, the structurally transmitted HDD out-of-plane vibration is dominated by the vibrations induced by the speakers. The effects of the chassis design and HDD mounting on vibration transmission from speakers to HDD via chassis in the notebook PC are investigated. It is concluded that, in general, softer chassis and softer HDD mounting is helpful in suppressing the structurally transmitted vibrations of HDD at frequencies above 1000 Hz in a notebook PC. Furthermore, the HDD softer mounting modes should be kept away from the low order harmonics of the built-in fans and CD/DVD drive.