摘要CCGA器件结构相较其他封装器件有很多优点,它的焊点是柱状的阵列,柱状阵列更便于散热,且比焊球结构抗疲劳能力高。CCGA器件结构是影响CCGA器件性能的主要因素之一。为了改善CCGA器件的性能,优化CCGA器件的结构,我建立了CCGA封装体有限元数值模拟分析模型,在温度循环加载的工作条件下,对CCGA封装体的应力、应变分布规律用应力应变云图表现出来并进行分析,为了预测封装体的热疲劳寿命,本文采用频率和温度修正的Coffin一Manson方程。数值分析结果为提高CCGA封装体的可靠性和优化设计提供了理论依据。具体的内容如下:
建立CCGA有限元模型,模拟加载热循环的条件下对CCGA封装体在热循环加载条件下的受力变形进行分析,查看应力应变云图,对CCGA器件变形的原因和原理进行分析,对热疲劳寿命进行预测。39973
对CCGA封装体结构和焊点进行优化研究和设计。影响器件性能的结构方面的因素主要有陶瓷载体和基板的尺寸以及焊料柱的尺寸。研究陶瓷载体长度和基板厚度对其可靠性的影响时,通过运算分析,得到以下结论:加长陶瓷载体长度,能延长CCGA器件疲劳寿命,有利于提高器件可靠性和减小封装面积与芯片面积的比值,便于封装;增加基板厚度相当于增加了基板的体积,使热循环过程下,器件结构产生的等效应力增加了,疲劳寿命降低。焊点优化考虑焊点高度、直径和间距对其可靠性的影响,结果如下:焊柱直径不变,随着焊点高度的增加,CCGA封装体热疲劳寿命增加;焊柱高度不变,随着焊点直径变大,热疲劳寿命降低;焊点高度因素对其可靠性的影响大于直径;同时疲劳寿命还与焊柱间距及其阵列分布相关。 毕业论文关键词:陶瓷柱栅阵列封装;有限元;热循环;应力;应变
Structural optimization design of CCGA device
Abstract
The structure of the CCGA device has many advantages compared to other packaging devices, its solder joints are columnar array, columnar array is more convenient for cooling, and the structure of the welding ball is better than the structure of anti fatigue. CCGA device structure is one of the main factors that affect the performance of CCGA device. In order to improve the performance of CCGA, optimize the structure of CCGA, I set up the CCGA package body finite element numerical simulation analysis model under temperature cyclic loading conditions, the CCGA package should stress and strain distribution by stress and strain nephogram performance and analysis, in order to predict the thermal fatigue life of the package, the frequency and temperature modified coffin Manson equation. The results of numerical analysis provide a theoretical basis for improving the reliability and optimization design of CCGA package. Specific content is as follows:
A CCGA finite element model is established to simulate load and thermal cycling conditions of CCGA package under thermal cyclic loading conditions of stress deformation analysis, view stress and strain nephogram, carries on the analysis to the reason and the principle of deformation of CCGA, to predict the thermal fatigue life.
Research and design of the structure and solder joints of CCGA package. The main factors that affect the structure of the structure are the size of the ceramic carrier and the substrate and the size of the solder column.. Effect of the study of the ceramic carrier length and the thickness of substrate on the reliability, through calculation analysis, wait until the following conclusion: extended the length of the ceramic carrier, can prolong the fatigue life of CCGA device, is conducive to improving the reliability of the device and reduce the package size and the chip area ratio, on the package; increase substrate thickness is equivalent to increasing the volume of the substrate, the thermal cycling process, device structure of equivalent stress increase and reduction of fatigue life. Joint optimization considering the influence on the reliability of solder joint height, diameter and spacing, results are as follows: welding column diameter, with the increase of the height of the solder joint, increase CCGA package thermal fatigue life; welding column height, spot diameter becomes larger, the thermal fatigue life decreased as; solder joint height factors influence the reliability is greater than the diameter; at the same time fatigue life and welding column spacing and array distribution.