球栅阵列——更适合多端子LSI的表面安装式封装

塑封球栅列（ＢＧＡ）是一各新型表面安装多端子型ＬＳＩ封装。与塑封四方扁平封装（ＱＦＰ）相比，前者外形更小，设备与操作较为简单可靠性民提高。ＢＧＡ替代ＱＦＰ的尝试从美国开始，并正在各国展开。     

球栅阵列封装

本叙述了球栅阵列（ＢＧＡ）封装的概况，与ＱＦＰ相比的优点以及ＢＧＡ的多种变种．     

超细间距方形扁平封装与球栅阵列封装的比较及其发展趋势

本文主要论述了超细间距QFP封装与BGA封装的比较，以及BGA封装的检查、返修、清洗及其各种类型，并简述了它们的利用率和发展趋势。     

球栅阵列──更适合多端子LSI的表面安装式封装(续)

球栅阵列──更适合多端子ＬＳＩ的表面安装式封装（续）田民波，冯晓东（清华大学材料科学与工程系，北京，１０００８４）。１．２ＢＧＡ采用二维布置的球形焊接端子如图２所示，在一种小尺寸两面布线塑料基板上带有球形焊盘的表面安装型ＬＳＩ封装引起了人们的很大兴趣...     

塑料球栅阵列封装的热应力模拟

电子封装使用多种性能各异的材料,这些材料的热膨胀系数各不相同.把其组合成一个整体后,当温度变化时,在不同的材料界面会产生压缩或拉伸应力.建立了完全焊点阵列形式的模型,采用局部温度加载方式,对塑料球栅阵列封装的热应力进行了数值模拟.     

球栅阵列(A)封装器件与检测技术

介绍了A封装器件的特点,重点讨论了A封装的检测技术,并建议在A组装过程中采用断层剖面或"倾斜式”X光检测仪.     

球栅阵列技术及其应用

本文简要介绍了最新的球栅阵列封装技术,包括表面技术的发展,球栅阵列技术的特点，球栅阵列器的类型和制作工艺及其应用前景等。     

倒装陶瓷球栅阵列电子封装的热模型研究

针对倒装陶瓷球栅阵列(flip chip ceramic ball grid array,FC-CBGA)封装,采用有限元数值方法,建立三维有限元的详细热模型.在5W热负荷下,分析裸芯式、平板式和盖板式三种形式,不同芯片尺寸(5mm×5 mm、15 mm×15 mm和20 mm×20 mm)以及不同润滑剂材料对系统热阻...     

倒装陶瓷球栅阵列电子封装的热分析

建立了倒装陶瓷球栅阵列(flip chip ceramic ball grid array,FC-CBGA)封装的三维热模型。在5 W热负荷下,比较了裸芯片式、盖板式和盖板加装热沉三种情况下芯片的热性能,进而分析了有无热沉和不同空气流速下,盖板式封装的具体热流分配情况。结果表明:在自然对流下,与裸芯片式相比,采用盖板式能使芯片结点温度降低约16℃,盖板加装热沉能使芯片结温降低47℃。芯片产生的热量大部分向上流向盖板,且随着空气流速的增加比例增大;由芯片流向盖板的热量有相当大一部分经过侧面流向基板,且随着流速增大比例较小。     

一种毫米波BGA封装低成本测试方法

提出一种可应用于毫米波BGA(Ball Grid Array)封装器件的低成本无损测试方法.该测试方案主要由毛纽扣及两块单层基板组成.其中,毛纽扣作为封装焊球与基板之间的垂直互联媒介,实现信号传输.同时,毛纽扣具有较小的弹性接触力,在测试过程中能够保护焊球不受损伤.毛纽扣与基板形成的介质填充类同轴结构和基板上的高低阻抗...     

PBGA封装的可靠性研究综述

通过传统BT类型的PWB材料与独特的PWB材料来PBGA封装的可靠性。相关的研究结果表明,后者同样具有相同的热循环稳定性和回流焊期间的疲劳强度,并具有较低的封装翘曲特点;模塑料的低吸湿性及粘片材料的高粘附强度和高断裂强度特性,有利于提高回流焊期间的疲劳强度和防止剥离现象的扩散。     

Failure Morphology after the Drop Impact Test of the Ball Grid Array Package with Lead-Free Sn-3.8Ag-0.7Cu on Cu and Ni Under-Bump Metallurgies

High strain-rate drop impact tests were performed on ball grid array (BGA) packages with lead-free Sn-3.8Ag-0.7Cu solder (in wt.%). Plated Ni and Cu under-bump metallurgies (UBMs) were used on the device side, and their drop test performances were compared. Failure occurred at the device side, exhibiting brittle interfacial fracture. For Ni UBM, failure occurred along the Ni/(Cu,Ni)₆Sn₅ interface, while the Cu UBM case showed failure along the interface between two intermetallics, Cu₆Sn₅/Cu₃Sn. However, the damage across the package varied. For Cu UBM, only a few solder balls failed at the device edge, whereas on Ni UBM, many more solder bumps failed. The difference in the failure behavior is due to the adhesion of the UBM and intermetallics rather than the intermetallic thickness. The better adhesion of Cu UBM is due to a more active soldering reaction than Ni, leading to stronger chemical bonding between intermetallics and UBM. In our reflow condition, the soldering reaction rate was about 4 times faster on Cu UBM than on Ni UBM.     

等离子清洗工艺对PBGA组装可靠性的影响

文章主要论述了PBGA组装的等离子清洗评定,包括抗界面剥离。研讨了通过射频和微波能量施加功率的两种不同的等离子体系。通过测量表面接触角获得最佳的等离子清洗工艺参数通过扫描电子显微镜、抗拉及剪切力试验来鉴定等离子清洗结果,试验样品为27 mm×27mm的292个焊球的PBGA。陈述了密封剥离试验、芯片和密封剂拉力试验、焊线拉力试验和C-模式SAM(C-SAM)检查的结果,证明了最佳的等离子清洗工艺会增强PBGA封装的定性等级,并提高工艺效率和生产率。     

机载预警雷达海杂波的抑制方法

大型阵列因阵元数目多,具有增益高、波束窄的特点而得到广泛应用。针对大型阵列阵元数目较大的特点,在工程应用中通常采用2D-FFT算法快速估计波达方向。但是2D-FFT算法仅适用于天线阵元矩形栅格排布情况。若2D-FFT用于三角形栅格排布的阵列,则会出现栅瓣。针对这一问题,提出一种基于2D-FFT的相位补偿算法用于三角形栅格阵列的波达方向估计。该算法将2D-FFT分为行变换和列变换两步,对行变换的结果相位补偿后再进行列变换。理论分析和计算机仿真证明了该算法的有效性。     

A Probabilistic Approach to Predict Thermal Fatigue Life for Ball Grid Array Solder Joints

Numerous studies of the reliability of solder joints have been performed. Most life prediction models are limited to a deterministic approach. However, manufacturing induces uncertainty in the geometry parameters of solder joints, and the environmental temperature varies widely due to end-user diversity, creating uncertainties in the reliability of solder joints. In this study, a methodology for accounting for variation in the lifetime prediction for lead-free solder joints of ball grid array packages (PBGA) is demonstrated. The key aspects of the solder joint parameters and the cyclic temperature range related to reliability are involved. Probabilistic solutions of the inelastic strain range and thermal fatigue life based on the Engelmaier model are developed to determine the probability of solder joint failure. The results indicate that the standard deviation increases significantly when more random variations are involved. Using the probabilistic method, the influence of each variable on the thermal fatigue life is quantified. This information can be used to optimize product design and process validation acceptance criteria. The probabilistic approach creates the opportunity to identify the root causes of failed samples from product fatigue tests and field returns. The method can be applied to better understand how variation affects parameters of interest in an electronic package design with area array interconnections.     

陶瓷球栅阵列焊点连接改进措施分析

针对陶瓷球栅阵列封装的焊点连接问题,提出一种相对比较完善的改进措施,并进行了理论分析、仿真和试验验证,为陶瓷球栅阵列封装的合理选型提出了建议。