28nm IC封装系统的多物理域优化设计

发布时间：2018-05-06 18:50

本文选题：微电子封装 + 多物理域　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：随着微电子封装系统日益轻薄化,性能要求越来越高,功率密度越来越大,其面临的热-机械可靠性和热、电性能问题也越来越突出。同时,微电子封装系统的热-机械可靠性和热、电性能容易同时受到多个外界环境因素的共同作用,具有显著的多物理域特征,因而如何有效进行多物理域优化设计已成为微电子封装领域研究的热点和难点。本文采用仿真分析方法研究采用28纳米工艺技术节点的(Flip Chip-Chip Scale Package,FCCSP)封装的热-机械可靠性和热、电性能。重点实现多物理场耦合分析与优化,将仿真分析技术真正渗透到产品设计开发的各个阶段,便于提高产品的设计技术水平、产品性能与可靠性。本文主要从以下3个方面开展研究工作:(1)基于热-机械可靠性仿真分析平台ANSYS Workbench,采用实验设计方法系统研究塑封体厚度、芯片厚度、基板厚度等结构参数和塑封料类型等材料参数对FCCSP封装的翘曲大小和应力分布的影响,并进行翘曲和应力最小化的优化设计。研究发现不同封装设计方案下芯片的应力水平无明显变化,而封装和芯片的翘曲则明显不同。得到了使封装的翘曲和应力同时最小的封装设计方案,有效提升了封装的热-机械可靠性。(2)采用基于计算流体力学的Flotherm热仿真软件,首先研究封装尺寸、芯片尺寸、封装基板内层铜厚、封装基板BT材料热导率和封装基板Solder Mask层开窗大小对FCCSP封装封装级热性能的影响,然后研究PCB方向散热器翅板数目和塑封体方向散热器翅板数目对FCCSP封装系统级热性能的影响,得到了合理的散热器翅板数目和排布方式。通过仿真分析,实现了FCCSP封装的散热性能优化设计,得到了封装级和系统级的最优散热方案。(3)基于ANSYS HFSS电性能仿真平台,采用频域分析法,对FCCSP封装的信号完整性和电源完整性进行仿真分析,研究无源通道各功能部件对信号质量的影响,并将信号完整性进行一体化建模研究。研究发现:增加电源平面面积,不但可以降低直流压降,而且可以起到分散电流密度,避免了因个别线路上电流过大,造成线路熔断等影响可靠性等问题。
[Abstract]:With the increasing thinning of microelectronic packaging systems, the performance requirements are becoming higher and higher, and the power density is increasing. The thermal mechanical reliability, thermal and electrical performance of microelectronic packaging systems are becoming more and more prominent. At the same time, the thermal mechanical reliability and thermal properties of the microelectronic packaging system are easily affected by many external environmental factors at the same time. Therefore, how to effectively carry out multi-physical domain optimization design has become a hot and difficult point in the field of microelectronic packaging. In this paper, the thermal mechanical reliability and thermal and electrical properties of Flip Chip-Chip Scale package Chip-Chip package with 28 nanoscale technology nodes are studied by simulation analysis. The multi-physical field coupling analysis and optimization are realized, and the simulation analysis technology is really infiltrated into every stage of product design and development, which is convenient to improve the level of product design technology, product performance and reliability. Based on the thermal-mechanical reliability simulation platform ANSYS Workbench, the thickness of plastic seal and chip is systematically studied by experimental design method. The effects of structural parameters such as substrate thickness and type of plastic seal on the warpage size and stress distribution of FCCSP packaging were investigated and the optimum design of warpage and stress minimization was carried out. It is found that there is no significant change in the stress level of the chip under different package design schemes, but the warpage between the package and the chip is obviously different. A package design with minimum warping and stress is obtained, and the thermal-mechanical reliability of the package is improved effectively. The Flotherm thermal simulation software based on computational fluid dynamics is used to study the package size and chip size. The influence of the inner copper thickness of the packaging substrate, the thermal conductivity of the packaging substrate BT material and the window size of the Solder Mask layer on the thermal performance of the FCCSP package is discussed. Then, the influence of the number of fin plates in PCB direction and the number of fin plates in plastic body on the thermal performance of FCCSP packaging system is studied, and the reasonable number and arrangement of fin plates of radiators are obtained. Through simulation analysis, the optimization design of heat dissipation performance of FCCSP package is realized. The optimal heat dissipation scheme at package level and system level is obtained. Based on ANSYS HFSS electric performance simulation platform, frequency domain analysis method is used. The signal integrity and power integrity of FCCSP package are simulated and analyzed, and the influence of various functional components of passive channel on signal quality is studied. The integrated modeling of signal integrity is carried out. It is found that increasing the plane area of the power supply can not only reduce the DC voltage drop, but also disperse the current density, and avoid the problem that the over-large current on some lines will affect the reliability of the circuit, such as circuit breakage and so on.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN405

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