Structural Vibration Analysis of Electronic Equipment for Satellite under Launch Environment

The impulse between the launch vehicle and the atmosphere can generate a lot of noise and vibration during the process of launching a satellite. In this situation, random vibrations can cause the malfunction of the electronic equipment of the device. In general, the safety of the electronic equipment is related to the natural frequency, shapes of mode and the dynamic deflection of the PCB in the electronic equipment. Structural vibration analysis of PCBs and their electronic components can be performed using either FEM or a vibration test. In this study, the natural frequency and dynamic deflection of a PCB were measured by FEM, and the safety of the electronic components of the PCB were evaluated according to the results. This study presents a unique method for the finite element modeling and analysis of PCBs and their electronic components. The results of the FEA were verified using a vibration test. The method proposed herein may be applicable to various designs ranging from satellite’s electronic equipment to home electronics. Introduction The electronic equipment installed in the satellite is box-shaped, and frames inside the satellite support many of the PCBs, there are also various types of electronic components in the PCBs. The agitation of the satellite caused by the random vibration during the launch process is transmitted to the PCB’s electronic components, thereby causing fatigue fracture. In particular, when the frequency of the random vibration is identical to the natural frequency of the PCB, fatigue fracture can occur at the connection of the electronic components and the PCB. It is generally known that the safety of electronic components is related to their natural frequency, mode shape and dynamic deflection [2]. This study uses a RDU (Remote Drive Unit), which is one of the electronic devices on a satellite, as a model to validate the relationship between launch condition, dynamic deflection, natural frequency, and the safety of PCBs’ electronic components. It will do this by modeling and simulating the PCBs fixed on the inside frame with a 1DOF system. During the process, FEA (Finite Element Analysis) was conducted on the PCB, including the electronic components, in order to find out the natural frequency of the PCB. A natural frequency test was also done on the PCB. The test and FEA results were compared and analyzed to guarantee the reliability of the analysis. At the same time, the safety of the electronic components was also evaluated. Analysis of the Safety of Electronic Components of the PCB The electronic components are soldered to the PCB with lead wire and are installed over a wide area so that they can endure the very harsh conditions present during the dynamic deflection of the PCB Key Engineering Materials Online: 2004-08-15 ISSN: 1662-9795, Vols. 270-273, pp 1440-1445 doi:10.4028/www.scientific.net/KEM.270-273.1440 © 2004 Trans Tech Publications Ltd, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (Semanticscholar.org-13/03/20,17:38:07) Title of Publication (to be inserted by the publisher) caused by the vibrations. The PCB was modeled with a 1DOF system in order to determine the dynamic deflection of the PCB in the launch environment using an analytical method. Eq. 1 shows the equation of motion for the 1DOF system. t P kZ Z c Z m ω cos 0 . .. = + + (1) The relation of the output force to the input force of the 1DOF system is as follows [1, 3]. ] ) 2 ( ) ) ( 1 [( ) 2 ( 1