| Popis: |
The increased vulnerability of the components to various electrical, thermal, mechanical, chemical and electromagnetic stresses poses a big threat in attaining the reliability required for various mission critical applications. Stress screening is a process in which imposed vibration, thermal and electrical stresses are applied for sufficient periods of time to precipitate defects and early life failure characteristics. In this paper, different stress screens are selected and their relative screen strengths are evaluated. The resulting average failure rate in field is calculated and presented for different components of PCB of different quality grades. A comparison of field failure rate without stress screening and with random vibration and temperature cycling stress screenings are carried out by using MATLAB based Graphical User Interface (GUI) tool. |
