Component Rearrangement on Printed Wiring Boards to Maximize the Fundamental Natural Frequency

A methodology to attain the highest fundamental natural frequency of a printed wiring board by rearranging its components has been developed. A general twodimensional rearrangement algorithm is developed by which the rearrangement of the component-lead-board (CLB Introduction Integrated circuit technology has advanced rapidly in the past twenty years. The means to produce electronic equipment with high reliability and minimum overall cost has captured the attention of numerous researchers. Most of these researchers have been concerned with finding the optimal placement [1-6], minimum chip area Another important aspect of building reliable PWBs is to reduce the probability of failure due to mechanically generated motions, which can cause high relative displacement levels of the components and, consequently, high stress levels. These cyclic stress levels often lead to fatigue-induced cracked components and solder joints. One way to reduce the high cyclic stress is to subject the PWB to dynamic loadings whose frequency content is below the PWB's lowest natural frequency