随机载荷下电路板振动特性与引脚应力优化方法研究  

Research on Vibration Characteristics of Printed Circuit Board and Optimization Method of Pin Stress

作　　者：胡彬 孙韵韵 巫世晶[1] HU Bin;SUN Yunyun;WU Shijing(School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学动力与机械学院,武汉430072

出　　处：《强度与环境》2025年第1期17-25,共9页Structure & Environment Engineering

基　　金：国家自然科学基金(92473110)。

摘　　要：随着航天电子设备向高性能化发展,在随机载荷等因素影响下,电路板的引脚附近容易出现开裂导致电子设备失效。本文以电路板为研究对象,研究随机载荷下电路板振动特性与引脚应力的优化方法。首先,建立包含元器件和引脚的PCB基板有限元仿真模型,计算电路板各阶固有频率和对应振型的理论值;其次,结合数字图像相关(DIC)技术和锤击法,测量电路板各阶固有频率和振型的试验值,与理论值进行对比并计算固有频率的相对误差;然后,基于所建立的有限元模型,对航天电子设备中常见的QFP封装、引脚材料为可伐合金、引脚数为44个、元器件的质量占PCB板总质量35%的电路板进行分析,研究电路板的自由振动特性和随机激励下的强迫振动特性;最后,从电路板层面和引脚层面进行优化,通过调整PCB板厚度、约束条件、封装元器件位置以及引脚出线方式、弯曲角度、横截面积,有效降低引脚的最大应力。研究结果表明,基于理论模型的固有频率和振型计算结果与试验测量值基本一致,验证了理论模型的有效性;在随机载荷作用下,通过适当提高PCB板厚度、引脚弯曲角度和横截面积,以及调整元器件位置和引脚出线方式,印制电路板的所有引脚应力均显著降低,其中引脚的最大应力值从298.5 MPa下降至55.4 MPa,为减小印制电路板的引脚应力,提高电路板的工作可靠性和使用寿命提供了依据。With the development of aerospace electronic equipment towards high-performance,under the influence of factors such as random loads,cracks near the pins of circuit boards are prone to occur,leading to the failure of electronic devices.This paper takes the circuit board as the research object and studies the optimization methods of circuit board vibration characteristics and pin stress under random loads.Firstly,a finite element simulation model of a PCB substrate containing components and pinsisestablished,and the theoretical values of the natural frequencies and corresponding modes of the circuit board is calculated.Secondly,experimental values of the natural frequencies and modes of the circuit board are measured by combining digital image correlation(DIC) technology and impact hammer testing,and the comparisons between experimental values and theoretical values are conducted,and the relative error of the natural frequencies is calculated.Then,based on the established finite element model,a circuit board commonly found in aerospace electronic equipment with QFP packaging,pins made of copper alloy,44 pins,and components accounting for 35% of the total mass of the PCB is analyzed.The free vibration characteristics of the circuit board and forced vibration characteristics under random excitation are studied.Finally,by adjusting the PCB thickness,constraints,component positions,pin lead-out methods,bending angles,and cross-sectional areas,the circuit board and pins is optimized to effectively reduce the maximum stress on the pins.Results show that the calculated natural frequencies and modes based on the theoretical model are basically consistent with the experimental measurements,verifying the effectiveness of the theoretical model.Under random loads,by appropriately increasing the PCB thickness,pin bending angles,and cross-sectional areas,and adjusting the component positions and pin lead-out methods,the stress on all pins of the printed circuit board is significantly reduced.The maximum stress on the pins decrea

关 键 词：印制电路板 自由振动 响应特性 数字图像相关 

分 类 号：TH114[机械工程—机械设计及理论]