共查询到19条相似文献,搜索用时 78 毫秒
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球栅阵列封装(BGA)综合性能好,广泛应用于表面贴装.采用电子散斑干涉(ESPI)离面位移光路,在简单机械加栽情况下,对板级组装BGA器件的离面位移进行测量,比较了完好BGA、焊球分层BGA与焊球脱落BGA器件的测量结果.发现焊球有缺陷样品的条纹形状与完好样品相比有明显的差别,ESPI条纹在失效焊点附近发生突变.通过计算ESPI的位移测量值后,可判断BGA焊点的失效位置.结合有限元(FEM)模拟,对位移异常的BGA焊点进行分析.通过将计算结果与ESPI的位移测量值比较,可判断BGA焊点的失效模式. 相似文献
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采用双面贴装回流焊工艺在FR4基板表面贴装Sn3.0Ag0.5Cu(SnAgCn)无铅焊点BGA器件,通过对热应力加速实验中失效的SnAgCu无铅BGA焊点的显微结构分析和力学性能检测,研究双面贴装BGA器件的电路板出现互连焊点单面失效问题的原因,单面互连焊点失效主要是由于回流焊热处理工艺引起的.多次热处理过程中,NiSnP层中形成的大量空洞是导致焊点沿(Cu,Ni)6Sn5金属间化合物层和Ni(P)镀层产生断裂失效的主要因素.改变回流焊工艺是抑制双面贴装BGA器件的印制电路板出现互连焊点单面失效问题的关键. 相似文献
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集成化与微型化是芯片集成电路产业发展的特点,其中芯片封装热振失效是影响其可靠性的重要原因。为进一步优化BGA焊点结构并提高可靠性,运用ANSYS将TOPLINE的BGA器件建成了3D模型,进行了数值模拟仿真后,利用田口正交稳健设计进行了BGA焊点结构优化。数值分析表明:芯片边角焊点为热失效关键焊点,距封装中心最远焊点为随机振动失效关键焊点;经田口正交优化热设计,焊点阵列为12×12,焊点径向尺寸为0.42 mm,焊点高度为0.38 mm,焊点间距为0.6 m;随机振动设计焊点间距为0.46 mm,焊点径向尺寸为0.42 mm,焊点阵列为10×10,焊点高度为0.30 mm。本研究中的分析成果对优化球珊阵列芯片封装焊点结构的设计,提升芯片封装器件结构稳定性具有重要意义,所提出的优化设计将对封测产业的生产具有一定的影响和价值。 相似文献
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无铅BGA封装可靠性的力学试验与分析 总被引:4,自引:0,他引:4
着重研究了机械冲击和应力对无铅BGA封装焊点可靠性的影响,介绍了BGA封装的可靠性力学试验(跌落、弯曲试验)及其分析方法.通过对力学试验中失效焊点的分析以及借助ANSYS模拟工具,找出引起失效的根本原因,为开发性能更好、高可靠性的无铅材料、改进无铅工艺提供依据. 相似文献
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采用自由跌落的试验方法,研究了BGA(球栅阵列)封装自由跌落到不同材质基板后的可靠性,对比分析焊点裂纹产生、扩展直至断裂的机理。对失效封装芯片进行了染色处理,观察BGA封装中焊点的失效位置和焊点内部裂纹的形貌。结果表明,不同接触面上焊球裂纹都经历稳态-扩展-失效的过程,石质接触面上裂纹出现最早,裂纹扩展最快,失效最快,钢质接触面次之,最后是木质接触面。木质接触面的焊点失效模式主要是焊盘失效;钢质和石质接触面的焊点的失效模式以金属间化合物失效为主。比例风险模型(PHM)估计得到的寿命值与试验结果误差较小,能有效预测焊点自由跌落条件下的寿命。 相似文献
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阐述了在实际工作中遇到的混装BGA焊点空洞问题;介绍了常用的混装BGA焊接方法并对其利弊进行了分析;介绍了BGA焊点空洞的检验标准;通过对无铅BGA焊点与有铅BGA焊点的对比,分析了BGA焊点空洞的成因;从管理措施、工艺手段和操作经验等多个角度总结了控制BGA焊点空洞形成的诸多要素. 相似文献
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本文以某著名电脑主板的BGA贴装失效为例,介绍了对BGA贴装失效的分析过程与分析方法,同时找到了导致该BGA贴装失效的机理与原因,为有关各方进行工艺质量控制提供了及时的改进依据。 相似文献
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Solder joint fatigue failure under vibration loading has been a great concern in microelectronic industry. High-cycle fatigue failure of lead-free solder joints has not been adequately addressed, especially under random vibration loading. This study aims to understand the lead-free solder joint behavior of BGA packages under different random vibration loadings. At first, non-contact TV Laser holography technology was adopted to conduct experimental modal analysis of the test vehicle (printed circuit board assembly) in order to understand its dynamic characteristics. Then, its first order natural frequency was used as the center frequency and narrow-band random vibration fatigue tests with different kinds of acceleration power spectral density (PSD) amplitudes were respectively carried out. Electrical continuity through each BGA package is monitored during the vibration event in order to detect the failure of package-to-board interconnects. The typical dynamic voltage histories of failed solder joints were obtained simultaneously. Thirdly, failed solder joints were cross-sectioned and metallurgical analysis was applied to investigate the failure mechanisms of BGA lead-free solder joints under random vibration loading. The results show that the failure mechanisms of BGA lead-free solder joint vary as the acceleration PSD amplitude increases. Solder joint failure locations are changed from the solder bump body of the PCB side to the solder ball neck, finally to the Ni/intermetallic compound (IMC) interface of the package side. The corresponding failure modes are also converted from ductile fracture to brittle fracture with the increase of vibration intensity. 相似文献
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It has been well established that lead-free solder underperforms conventional leaded solder in reliability under dynamic impact. Common failures observed on ball-grid-array (BGA) solder balls on chip under board level impact include bulk solder ductile failure, intermetallic (IMC) layer crack and pad-lift. In this work, a finite element modeling approach was proposed to model bulk solder ductile failure and intermetallic layer crack. The use of beam elements and connector elements to represent the bulk solders and board/component side intermetallic layers, respectively, offers the advantage of simplicity over the use of continuum elements and cohesive elements for solder joints. This approach enables the modeling of assembly level impact with significantly less computational resources. The model was verified by comparing its prediction of BGA solder reliability against actual test results in a dynamic four-point bend test. The physical tests consist of ball impact at varying heights on a board with a mounted chip, and the subsequent analysis of the failure modes of the BGA solder joints. Simulation results were in good agreement with test results. The study shows that it is feasible to model BGA solder joint ductile failure and intermetallic layer crack under impact with simple elements with reasonable accuracy. 相似文献
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本文以企业实际生产中出现的一个非典型性BGA焊接失效案例为素材,详细介绍了不良原因分析的过程与方法,在可制造性设计方面提出具体建议,为产品设计和工艺技术人员提供经验借鉴. 相似文献
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The subject of this paper is a 14×22 mm ball grid array (BGA) integrated circuit assembly containing two or three chips. Three failure modes came to light in the reliability testing of this BGA package: delamination of solder resist from the top copper layer occurred in moisture resistance testing; cracking of the top layer solder resist and consequent cracking of the top copper layer occurred in temperature cycling; and cracking of the bottom layer solder resist which propagated into the bottom copper layer occurred in thermal shock. The failure analysis techniques used to disclose these failures are presented. Finite element analysis of thermomechanical stress within the multichip structure was carried out. The purpose was to find the root cause of one of the failure modes and to explore possible means of overcoming the stress damage. The characteristics of the original and modified substrate layout designs are detailed. The improved performance in reliability testing is compared with the original. All failure modes were eliminated in the final design, and the product was qualified to greatly improved reliability standards. 相似文献
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Iver E. Anderson Adam Boesenberg Joel Harringa David Riegner Andrew Steinmetz David Hillman 《Journal of Electronic Materials》2012,41(2):390-397
Pb-free solder alloys based on the Sn-Ag-Cu (SAC) ternary eutectic have promise for widespread adoption across assembly conditions
and operating environments, but enhanced microstructural control is needed. Micro-alloying with elements such as Zn was demonstrated
for promoting a preferred solidification path and joint microstructure earlier in simple (Cu/Cu) solder joints studies for
different cooling rates. This beneficial behavior now has been verified in reworked ball grid array (BGA) joints, using dissimilar
SAC305 (Sn-3.0Ag-0.5Cu, wt.%) solder paste. After industrial assembly, BGA components joined with Sn-3.5Ag-0.74Cu-0.21Zn solder
were tested in thermal cycling (−55°C/+125°C) along with baseline SAC305 BGA joints beyond 3000 cycles with continuous failure
monitoring. Weibull analysis of the results demonstrated that BGA components joined with SAC + Zn/SAC305 have less joint integrity
than SAC305 joints, but their lifetime is sufficient for severe applications in consumer, defense, and avionics electronic
product field environments. Failure analysis of the BGA joints revealed that cracking did not deviate from the typical top
area (BGA component side) of each joint, in spite of different Ag3Sn blade content. Thus, SAC + Zn solder has not shown any advantage over SAC305 solder in these thermal cycling trials, but
other characteristics of SAC + Zn solder may make it more attractive for use across the full range of harsh conditions of
avionics or defense applications. 相似文献
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High Cycle Cyclic Torsion Fatigue of PBGA Pb-Free Solder Joints 总被引:1,自引:0,他引:1
Haiyu Qi Qian Zhang Tinsley E.C. Osterman M. Pecht M.G. 《Components and Packaging Technologies, IEEE Transactions on》2008,31(2):309-314
In this study, a comprehensive experimental and numerical approach was used to investigate high cycle cyclic torsion fatigue behavior of lead-free solder joints in a plastic ball grid array (PBGA) package. The test vehicle was a commercial laptop motherboard. The motherboard was subjected to torsional loading and life tests were conducted. Using finite element analysis (FEA), the test assembly was simulated as a global model and the BGA component was simulated as a local model. Strains measured on the motherboard surface near by the BGA were used to calibrate the FEA models. By combining the life test results and FEA simulations, a high cycle fatigue model for the lead-free solder joints was generated based on the Coffin-Manson strain-range fatigue damage model. This model can now be used to predict the cycles to failure of BGA interconnects for new electronic product design under cyclic torsion loading. 相似文献