Investigation of nano-particle's size distributions and charging characteristics in operating HDD

As the flying height of a slider in a hard disk drive decreases, the head and disk are more likely to come in contact and to generate contamination particles. Since particle contamination can cause serious problems including thermal asperity, its removal is very important to increase storage capacity. When particles are generated in a HDD, particles could be charged by several charging mechanism and have few number of elementary charge. In this paper, size distributions of particles from HDD and amount of particle charge with some rotational speed variations are shown. Also, the average numbers of elementary charge are calculated from experimental data. Following analysis from SEM images of charged particles, we can confirm some trends of experimental results