Virtual Design of Automotive Electronics Towards Vibration Reduction 2011-28-0080

Most modern automotive electronic systems are composed of two major mechanical elements: an equipment chassis or enclosure, and a PCB (Printed Circuit Board) assembly. The PCB is composed of laminated copper and FR-4 glass epoxy. Very small and delicate electronic components are populated on both sides of it. As the amount of electronics on vehicles increases, the electronic control units (ECU) are becoming larger, increasing the size and mass of the board as well. The vibration often plays the key cause of invalidation and component failures.

In the design of PCB assemblies, it is preferable to increase their fundamental natural frequency for improving the fatigue life because the PCB displacements are reduced very quickly. PCBs carrying electronic components are typically fastened with screws to the enclosure. The locations of the supporting screws and the large component placements can be optimized to achieve a maximum fundamental natural frequency for the loaded PCB. With this objective, a fully automated optimization tool based on dynamic structural optimization is developed using the commercially available software. This tool is driven by a user-friendly Excel spreadsheet which takes various geometric, material property and optimization parameters as user inputs and generates the HTML report containing detailed information about various configurations with improved dynamic performance. This tool enables the user to optimize the PCB assembly very early in the design phase without an extensive knowledge of dynamics, finite element or optimization required and thus, addressing the vibration issue proactively.