Study Of The Characteristic Of Dust In The Electronic Devices And On The Contacts Interface

Contamination could cause the failure of the electrical contacts and threaten the reliability of the electronic devices. This paper mainly focuses on the study of the characteristic of dust in the failed electronic products, compared with the dust in bouncing simulation tests and those in the unused products. The characteristic of dust on the contacts were further analyzed. Based on the study of the dust characteristic we can construct the effective artificial dust for dust simulation system.Figure out the dust characteristic, including the morphology, size, distribution and components of failed mobile phones. The general trend shows that the number of dusts will decrease with the increase of distance from the entrance. The structure of mobile phones has a great impact on the dust distribution. In morphological point, dusts can be classified as particles and fibers. The number ratio of fiber and particle is 0.05. The fiber size mainly concentrated in 200μm～1000μm; the size of about 95% particles is 10μm～50μm. In short, the particles larger than 50μm are difficult to enter the phone. The compositions of particles are C,O,Mg,Al,Si,S,Cl,K and Ca, and the compositions of fibers are C,O. The analysis of the characteristic of dust on unused connector contacts shows that the size of 65% contaminants is 5～10μm. The experimental results of the size range of dust and the composition of dusts can be used as reference when determine the artificial dust size and component. The distribution of dust can be used to judge the results of simulation experiments. Study the dust characteristic of mobile phones after dust bouncing test. The composition of dusts proves that the particles in these mobile phones do come from the artificial dusts. But they are not consistent with the particles from the fields, so the composition of artificial particles should be improved. Basing on the experimental results from the fields, some organic compounds should be put into the artificial particles. The size range of particles (10μm) is much smaller than these in the mobile phone from the fields.Analysis of the dust characteristic on failure contacts shows that dust has an important effect on the failure. The probability of dust appearance will increase with the increase of distance from the outside space, which is same with the general trend of dust distribution in mobiles of field. So we should optimize the structure of mobiles to reduce the effect of dust on sensitive components. Probability of dust appearance is higher in north than south. This artificial dust composition should be decided according to the simulation requirements.