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The automotive electronic systems are composed of two major mechanical elements: an equipment housing or enclosure, and a printed circuit board (PCB) assembly. The PCB is made up of alternating layers of copper and FR-4 glass epoxy laminated together. An estimation of the mechanical reliability of a PCB in an electronic system is considered to be an important part of the overall reliability estimate of the entire system and vibration is often one of the key causes of system and component failures. As different kind of electronic components (like transformers, capacitors, chips etc) are mounted on both sides of the PCB using solder joints, adhesive etc, various complexities are encountered while modeling them for analysis. For avoiding those, simple PCBs without any components are considered for the present study. This paper focuses on the methodology to understand and predict the dynamic behavior of the system using various mechanical tests and simulations.

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.

The estimation of the mechanical reliability of the Printed Circuit Board (PCB) in an electronic system is considered to be an important part of the overall reliability of the system. The vibration often plays the key cause of invalidation and component failures. Since it is known that such vibration factors can induce various failures, an understanding of their dynamic response is warranted. Random vibration test is specified for acceptance tests, screening tests and qualification tests as it more closely represents the true environment in which electronic system must operate. In order to achieve a good vibration analysis, it is first necessary to efficiently and accurately understand the dynamic behavior of the system when subjected to specific environment like random vibration. Once the methodology is built, it can be applied for analyzing various systems with greater confidence in estimating their dynamic response.