共查询到19条相似文献,搜索用时 125 毫秒
1.
工业级FPGA空间应用器件封装可靠性分析 总被引:1,自引:1,他引:0
分析了工业级和宇航级FPGA(Field Programmable Gate Array)在封装结构上的差别。用Ansysworkbench有限元软件对热循环、随机振动和外力载荷下封装的变形和应力以及焊点的塑性应变进行了仿真。依据剪切塑性应变变化范围预测了焊点热疲劳寿命。结果表明,FCBGA(Flip-Chip Ball Grid Array)封装内部倒装芯片焊点可靠性低于CCGA(Ceramic Column Grid Array)封装,其外部焊点的热疲劳寿命、随机振动等效应力均优于CCGA封装;在外力载荷下,其热疲劳寿命下降速率也明显小于CCGA封装。 相似文献
2.
对比封装体不同的热疲劳寿命预测模型,选择适用于微弹簧型陶瓷柱栅阵列(CCGA)封装的寿命预测模型,并对焊点的热疲劳机制进行分析。利用Workbench对焊点进行在温度循环载荷作用下的热疲劳分析。对比不同热疲劳寿命预测模型的结果,表明基于应变能密度的预测模型更适用于微弹簧型CCGA。随后对等效应力、塑性应变、平均塑性应变能密度和温度随时间变化的曲线进行分析,结果表明,在温度保持阶段,焊柱通过发生塑性变形或积累能量来降低其内部热应力水平,减少热疲劳损伤累积;在温度转变阶段,焊柱的应力应变发生剧烈变化,容易产生疲劳损伤。 相似文献
3.
针对LCCC封装器件在温度循环载荷下焊点开裂的问题,首先分析其失效现象和机理,并建立有限元模型,进行失效应力仿真模拟。为降低焊点由封装材料CTE不匹配引起的热应力,提出了两种印制板应力释放方案,并分析研究单孔方案中不同孔径和阵列孔方案中不同孔数量对热疲劳寿命的影响。之后,为降低对PCB布局密度的影响,提出一种新型的叠层焊柱应力缓冲方案,进行了不同叠层板厚度和焊柱间距的敏感度分析。结果表明,更大的开孔面积、更小的叠层板厚度、更密的焊柱可有效降低焊点应力,提高焊点热疲劳寿命,使得LCCC封装器件焊点热疲劳可靠性得到有效提高。 相似文献
4.
PCBA结构参数与振动谱型对BGA焊点疲劳寿命的影响 总被引:1,自引:1,他引:0
为获得印制电路板组件(PCBA)的板厚、芯片布局等结构参数和随机振动谱型(功率谱密度,PSD)变化对球栅阵列(BGA)封装芯片焊点振动疲劳寿命的影响,利用HYPERMESH软件建立了带BGA封装芯片的PCBA三维有限元网格模型,并采用ANSYS软件对PCBA有限元模型进行了随机振动响应分析。结果表明,随着PCB厚度增加,BGA焊点振动疲劳寿命呈现明显提升的趋势,当PCB厚度由1.2 mm增加到2.2 mm时,BGA焊点振动疲劳寿命N由45363大幅增加到557386;合理的芯片安装间距能够明显增加焊点振动疲劳寿命,特别是当芯片安装在靠近固定约束并处于两个约束对称中间位置时;当PCBA的第一阶固有频率位于随机振动谱最大幅值对应的频率区间时,BGA焊点的振动疲劳寿命会明显降低。 相似文献
5.
6.
7.
8.
9.
10.
针对三维芯片封装技术的需求,设计了一种基于高温共烧陶瓷(HTCC)的接收前端3D封装结构,通过有限元模型模拟分析了其可靠性。首先通过恒定加速度加载分析研究了焊盘结构可靠性;然后通过预应力模态分析研究了3D封装整体结构模态频率,通过疲劳可靠性分析研究了寿命预测模型;最后通过热模拟研究了稳态热分析以及热应力分析。结果表明:焊盘的应力应变以及位移满足其材料特性;3D封装整体结构谐振频率均在30 kHz以上;50%载荷作用下寿命为106次循环,150%载荷作用下寿命为74561次循环;稳态热分析最高温度为54.2℃;热应力模拟最大应力为33.84 MPa。最终证明了该接收前端3D封装结构是可靠的,可应用在3D射频微系统封装结构设计中。 相似文献
11.
温度循环是考核封装产品板级可靠性的重要试验之一。陶瓷四边引脚扁平封装(CQFP)适用于表面贴装,由于陶瓷材料与PCB热膨胀系数的差异,温循过程中引线互联部分产生周期性的应力应变,当陶瓷壳体面积较大时,焊点易出现疲劳失效现象。CQFP引线成形方式分顶部成形和底部成形两类。针对CQFP引线底部成形产品在板级温循中出现的焊接层开裂现象,采用有限元方法对焊接层的疲劳寿命进行了预测分析。采用二次成形方法对引线进行再次成形以缓解和释放热失配产生的应力。仿真和试验结果显示,引线二次成形有利于提高焊接层的温循疲劳寿命。与引线底部成形相比,当引线采用顶部成形时,焊接层的温循疲劳寿命显著提高。 相似文献
12.
Effect of substrate flexibility on solder joint reliability. Part II: finite element modeling 总被引:1,自引:1,他引:0
Solder joint fatigue failure is a serious reliability concern in area array technologies, such as flip chip and ball grid array packages of integrated-circuit chips. The selection of different substrate materials could affect solder joint thermal fatigue life significantly. The mechanism of substrate flexibility on improving solder joint thermal fatigue was investigated by thermal mechanical analysis (TMA) technique and finite element modeling. The reliability of solder joints in real flip chip assembly with both rigid and compliant substrates was evaluated by accelerated temperature cycling test. Finite element simulations were conducted to study the reliability of solder joints in flip chip on flex assembly (FCOF) and flip chip on rigid board assembly (FCOB) applying Anand model. Based on the finite element analysis results, the fatigue lives of solder joints were obtained by Darveaux’s crack initiation and growth model. The thermal strain/stress in solder joints of flip chip assemblies with different substrates were compared. The results of finite element analysis showed a good agreement with the experimental results. It was found that the thermal fatigue lifetime of FCOF solder joints was much longer than that of FCOB solder joints. The thermal strain/stress in solder joints could be reduced by flex buckling or bending and flex substrates could dissipate energy that otherwise would be absorbed by solder joints. It was concluded that substrate flexibility has a great effect on solder joint reliability and the reliability improvement was attributed to flex buckling or bending during temperature cycling. 相似文献
13.
板厚影响通孔再流焊点抗热疲劳性能的试验研究 总被引:1,自引:0,他引:1
针对不同板厚的通孔再流焊点进行了热冲击的可靠性测试,以非破坏性和破坏性的试验方式,对比分析了板厚对通孔再流焊点的抗热疲劳能力的影响。结果表明,热膨胀系数(CTE)失配是焊点产生裂纹的主要原因,使得板厚严重影响着焊点的抗热疲劳性能:厚板焊点断裂程度重于薄板焊点,其循环后的强度下降也快于后者,但二者的电性能变化差异不大。 相似文献
14.
15.
本文通过用于焊点形态预测软件SURFACE EVOLVER的输入数据文件,得到倒装焊焊点形态.参考模板开口指导说明(IPC-7525),拟定模板开口方案,得到相应的焊点形态.通过建立有限元模型,运用ANSYS软件对含铅焊点在热循环加载条件下的应力应变和疲劳寿命进行分析.根据预测得到的热疲劳寿命,找出了适合本文模型的模板结构参数,同时分析了其它设计与工艺参数和焊点可靠性之间的关系. 相似文献
16.
陶瓷阵列封装的两种形式及其接头可靠性 总被引:1,自引:0,他引:1
介绍了CBGA及CCGA的基本结构,对它们的优缺点进行了对比,分析了在热循环过程中,CBGA、CCGA封装结构产生的热应变及接头的热疲劳寿命,对目前接头热疲劳失效机理的分析进行了对比,总结了影响接头热疲劳寿命的几种因素。 相似文献
17.
This investigation examines how the number of chips affects the reliability of solder balls for wire-bonded stacked-chip ball grid array packages under thermal cycling tests. The studied objects were packages with one, two, three and four stacked chips. Three-dimensional finite element analysis was utilized to simulate the stress/strain behavior of all studied packages. Two kinds of properties of 63Sn/37Pb eutectic solder were employed individually in the finite element analyses. One property of the solder was assumed to exhibit the elastic–plastic–creep behavior. Temperature-dependent stress/strain curves and Norton’s steady creep equation were used in the analysis. Another property of the solder governed by the Anand’s viscoplastic model was also employed to describe the behavior of solder balls. The simulation results in the elastic–plastic–creep analyses and viscoplastic analyses reveal that the von Mises stress, the non-linear strain, and the inelastic strain energy density of the critical solder balls increase with the number of stacked chips, but the increments become gradually stable as the number of chips increases. Three fatigue life prediction models—Darveaux’s model, the modified Coffin–Manson model and the creep-fatigue model—were applied to evaluate the fatigue life of the studied packages. Prediction results indicate that the fatigue life of the solder balls decreases as the number of stacked chips increases, and the decrease in predicted life shows stable behavior as the number of chips increases. The stable trend is consistent with experimental observation in the thermal cycling tests. By comparing with the experimental data, it is shown that the Darveaux’s model gives better prediction than the other two models. 相似文献
18.
Thermal fatigue damage of flip chip solder joints is a serious reliability concern, although it usually remains tolerable
with the flip chip connections (of smaller chips) to ceramic boards as practiced by IBM for over a quarter century. However,
the recent trend in microelectronics packaging towards bonding large chips or ceramic modules to organic boards means a larger
differential thermal expansion mismatch between the board and the chip or ceramic module. To reduce the thermal stresses and
strains at solder joints, a polymer underfill is customarily added to fill the cavity between the chip or module and the organic
board. This procedure has typically at least resulted in an increase of the thermal fatigue life by a factor of 10, as compared
to the non-underfilled case. In this contribution, we first discuss the effects of the underfill to reduce solder joint stresses
and strains, as well as underfill effects on fatigue crack propagation based on a finite element analysis. Secondly, we probe
the question of the importance of the effects of underfill defects, particularly that of its delamination from the chip side,
on the effectiveness of the underfill to increase thermal fatigue life. Finally, we review recent experimental evidence from
thermal cycling of actual flip chip modules which appears to support the predictions of our model. 相似文献
19.
When an electronic package encounters thermal fluctuations, cyclical shear strain is imposed on the solder joint interconnections.
The thermal cycling leads to a condition of thermal fatigue and eventual solder joint failure. This study was performed in
order to understand the microstructural mechanisms that lead to solder joint failures in thermal fatigue. Thermal cycling
tests were performed on 60Sn-40Pb joints using a -55° C to 125° C cycle and 19% imposed shear strain. A heterogeneously coarsened
region of both Pb and Sn-rich phases develops within the 60Sn-40Pb solder joints. Cracks initiate in the heterogeneously coarsened
Sn-rich phase at the Sn-Sn grain boundaries. Heterogeneous coarsening and failure occurs in both high (35 to 125° C) and low
(-55 to 35° C) thermal cycles. The elevated temperature portion of the thermal cycle was found to be the most significant
factor in the heterogeneous coarsening and failure of the solder joints. 相似文献