CBGA组件热变形的2D-Plane42模型有限元分析

本文介绍有限元中的2D-Plane42模型在CBGA组件热变形中的应用，利用有限元的模拟CBGA组件的应变、应力的分布，通过模拟表明有限元法是研究微电子封装中BGA焊点、CBGA组件的可靠性的方法。     

焊接与连接工艺

0316936CBGA组件热变形的2D-Plane42模型有限元分析〔刊〕/杨玉萍//电子工艺技术。-2003,24(2).-67～70(C) 介绍有限元中的2D-Plane42模型在CBGA组件热变形中的应用,利用有限元的模拟CBGA组件的应变、应力的分析,通过模拟表明有限元法是研究微电子封装中BGA焊点、CBGA组件的可靠性的方法。参8 0316937倒装芯片凸点制作方法〔刊〕/李福泉//电子工艺技术。-2003,24(2).-62～66(C)     

CBGA组件热变形的3-D SOLID模型有限元分析

利用有限元中的3-DSOLID模型分析CBGA组件的热变形、应变和应力的分布，表明有限元法是研究微电子封装中BGA焊点、CBGA组件的可靠性的方法。     

印制板组件回流焊表面温度场的建模仿真技术

采用有限元分析方法，基于材料实际参数建立印制板组件的三维模型。对照回流炉实际温度设置方式，通过研究炉体结构、加热方式和空气流动，然后以传热学中的射流模型估算得到的对流系数值作为有限元模型的边界条件，通过模拟仿真得出组件表面各个位置在再流焊过程中的温度变化情况和温度场的分布情况。在印制板组件表面设置测温点，测量实际回流曲线，与模拟仿真结果进行对比，验证了仿真的有效性。     

微波组件用pin梁式引线管热元模型分析研究

在微波组件中,有源器件是主要热源,它们对微波组件的热性能具有决定性的作用。基于ANSYS有限元分析软件,采用有限元分析法,针对某型号微波组件用pin梁式引线管热元模型进行了模拟和分析。模拟结果与实际样品的红外热像测试结果基本一致,表明热元模型正确地反映了pin管在组件中的热性能状况情况。热元模型的建立能快速、简便地获得缉件中单个管芯的温度分布情况,可缩短热设计与测试周期。     

CBGA植球在线质量检测与控制技术

文章主要阐述了CBGA（陶瓷焊球阵列封装）植球过程中焊球、锡膏的选择,基板上焊盘镀金层厚度的控制,植球网板与印刷网板的制作,回流工艺的设定,焊球与陶瓷基板黏附质量的无损检测和破坏性检测方法。介绍了CBGA产品植球过程中的在线质量检测与控制,对提高CBGA产品的植球质量、成品率、一致性以及剔除焊球互连中的缺陷,提高产品的可靠性有帮助。     

基于ANSYS的电子组件有限元热模拟技术

随着电子组件集成化程度越来越高，单位何种内的热耗散程度越来越高，导致发热量和温度急剧上升，由于热驱动引起的机械，化学、电气等可靠性问题越来越严重，严重影响了产品的质量和可靠性，本文以大功率电子组件DC/DC电源变换器为例，提出了基于通用的大型有限元分析软件ANSYS进行热模拟分析方法，并利用实验结果对模拟结果进行了验证。     

CBGA植球工艺成熟度提升方法的研究

随着陶瓷球栅阵列(CBGA)封装形式产品被广泛应用,对其植球工艺质量的可靠性和一致性要求也越来越严格,焊球的位置度是检验CBGA产品质量的重要参数之一,其直接影响该产品表面贴装的质量和可靠性。以CBGA256产品为例,针对CBGA产品在批生产过程中出现的局部助焊剂聚集而引起焊球位置偏移的问题,通过对陶瓷外壳质量、焊膏印刷工艺和回流焊工艺的研究,优化CBGA产品的植球工艺,解决局部焊球位置度较差的问题,进而提高产品的一致性和可靠性,提升CBGA植球工艺的成熟度。     

陶瓷外壳质量对CBGA植球工艺质量的影响

随着陶瓷球栅阵列(CBGA)封装形式的产品被广泛应用,对其产品植球工艺质量的可靠性和一致性的要求也越来越严格,对原材料特别是对陶瓷外壳质量的控制是影响CBGA植球工艺质量的重要因素之一。以CBGA256和CBGA500封装形式的电路产品为例,通过焊盘的共面性、位置度和陶瓷表面的平面度三个方面来研究陶瓷外壳的质量对CBGA植球工艺质量的影响。     

基于CBGA技术的双频段四通道变频SiP

在现代雷达系统中,相控阵雷达以其得天独厚的优势依然占据着强势的地位,其中作为核心器件的收发组件发挥重要的作用。伴随着组件高集成、小型化和轻量化的需求,系统级封装（SiP）的技术得以迅猛的发展。本文设计完成了一种基于陶瓷球栅阵列（CBGA）封装的集成S波段和P波段的四通道变频SiP模块,共集成4路S波段变频和1路P波段双向放大芯片,可切换4种工作模式。四通道的带内发射高、低增益值约为30 dB和14 dB,带内接收高、低增益值约为48 dB和35 dB,满足设计要求。此外,变频SiP通过CBGA方式组装在印刷电路板（PCB）上,器件通过100次-55~125 ℃的温度循环试验,板级可靠性较高。     

温度试验条件下柱栅阵列仿真失效分析

陶瓷柱栅阵列(CCGA)封装是陶瓷球栅阵列(CBGA)封装的衍生技术,能有效缓解CBGA因热失配而引起的失效问题。对CCGA1140封装的材料和结构进行建模,针对焊接过程和热环境试验仿真条件下柱栅阵列焊点的应力应变分布情况和薄弱环节进行重点论述。仿真结果表明,在焊接和热环境中,CCGA封装最薄弱环节是柱栅阵列最外侧四角的焊点处。     

Finite element modeling of thermal fatigue and damage of solder joints in a ceramic ball grid array package

A nonlinear finite element model is presented for analyzing the cyclic and thermal fatigue loading and for viscoplastic damage characterization of the lead-tin (Pb-Sn) solder joints in a ceramic ball grid array (CBGA) surface mount package. An approach using a Δ ∈ _eq ⁱⁿ -modified Coffin-Manson equation is proposed to estimate the fatigue life of the solder joints. The Δ ∈ _eq ⁱⁿ represents a saturated equivalent inelastic strain range as determined by the finite element model. The present study shows that the predictied fatigue life and the associated damage mechanism of the solder joint agree reasonably well with the test data for the 18,25, and 32 mm CBGA packages run at a cyclic temperature load of 0°C/100°C with a frequency of 1.5 cycles per hour. Analysis also shows that a preferred failure site is expected to occur in and around the Pb37-Sn63 solder attachment of the solder joint. A time-dependent (creep induced) damage mechanism is found to be more pronounced than the time-independent (plastic deformation) mechanism.     

Modified micro–macro thermo-mechanical modelling of ceramic ball grid array packages

The ceramic ball grid array (CBGA) packages are typically used for high I/O count area array assemblies. As the package size is large, the distance to neutral point is also high resulting in a large thermal deformation mismatch between the CBGA package and the printed circuit board (PCB). In order to cope with this problem, a special solder joint connection is used. As CBGA assemblies are used for high pin count assemblies, a full 3D thermo-mechanical modelling of an assembly to an FR4 board is not possible anymore. Therefore, a modified micro–macro methodology is proposed where only the critical solder joint is modelled in detail, while the other connections are replaced by equivalent connections. For several CBGA configurations, simulation results are correlated to thermal cycling test results. Finally, a parameter sensitivity study shows that the PCB properties have a significant influence on the solder joint reliability.     

Modeling and simulation of core switching noise for ASICs

This paper presents simulation and analysis of core switching noise for a CMOS ASIC test vehicle. The test vehicle consists of a ceramic ball grid array (CBGA) package on a printed circuit board (PCB). The entire test vehicle has been modeled by accounting for all the plane resonances using the cavity resonator method. The models included both the on-chip and off-chip decoupling capacitors. Using both time domain and frequency domain simulations, the role of plane resonances on power supply noise for fast current edge rates has been discussed. The models have been constructed to amplify certain parts of the test vehicle during simulations     

有限元数值模拟在BGA/QFP/CCGA器件焊点可靠性研究中的应用

有限元数值模拟方法因其可以有效研究IC封装中无铅焊点的可靠性,被国内外专家学者所青睐,使得无铅焊点可靠性数值模拟成为IC封装领域的重要研究课题。综述了有限元法在球珊阵列封装(BGA)、方型扁平式封装(QFP)、陶瓷柱栅阵列封装(CCGA)3种电子器件无铅焊点可靠性方面的研究成果。浅析该领域国内外的研究现状,探究有限元方法在无铅焊点可靠性研究方面的不足及解决办法,展望无铅焊点可靠性有限元模拟的未来发展趋势,为IC封装领域无铅焊点可靠性的研究提供理论支撑。     

PBGA封装热可靠性分析

对PBGA封装体建立了有限元数值模拟分析模型。模型采用无铅焊点,完全焊点阵列形式。研究了封装体在经历IPC9701标准下的五种不同温度循环加载后,受到的热应力、应变,以及可能的失效形式。结果表明,焊点是封装体结构失效的关键环节,焊点所受应力大小与焊点位置有关。比较了不同温度循环下封装体的疲劳寿命。其结果为提高封装体的可靠性和优化设计提供了理论依据。     

Impact of flip-chip packaging on copper/low-k structures

Copper/low-k structures are the desired choice for advanced integrated circuits (ICs). Nevertheless, the reliability might become a concern due to the considerably lower strength and greater coefficient of thermal expansion (CTE) of the low-k materials. To ensure successful integration of the new chips within advanced packaging products, it is essential to understand the impact of packaging on chips with copper/low k structures. In this study, flip-chip die attach process has been studied. Multilevel, multiscale modeling technique was used to bridge the large gap between the maximum and minimum dimensions. Interface fracture mechanics-based approach has been used to predict interface delamination. Both plastic ball grid array (PBGA) and ceramic ball grid array (CBGA) packages were evaluated. Critical failure locations and interfaces were identified for both packages. The impact of thin film residual stresses has been studied at both wafer level and package level. Both PBGA and CBGA packaging die-attach processes induce significantly higher crack driving force on the low-k interfaces than the wafer process. CBGA die-attach might be more critical than PBGA die-attach due to the higher temperature. During CBGA die-attach process, the crack driving force at the low-k/passivation interface may exceed the measured interfacial strength. Two solutions have been suggested to prevent catastrophic delamination in copper/low-k flip-chip packages, improving adhesion strength of low-k/barrier interface or adding tiles and slots in low-k structures to reduce possible area for crack growth.     

Lead-free ceramic ball grid array: Thermomechanical fatigue reliability

Flip-chip carriers have become the preferred solution for high-performance, application-specific integrated circuit and microprocessor devices. Typically, these are packaged in organic or ceramic ball grid array (BGA) packages, which cover a wide range of package input/output (I/O) capabilities required for high-performance devices, typically, between 300 to more than 1,600 I/O. Recently, there has been a move toward Pb-free solders as replacement alloys for standard, eutectic Sn/Pb and other Pb-based BGAs. The leading solder that has emerged from various Pb-free solder evaluations by industry and academic consortia is the Sn/Ag/Cu (SAC) alloy. One of the primary issues with changing solders is the reliability of the joints when these are subjected to thermomechanical fatigue (TMF). This evaluation has previously been conducted on SAC ceramic ball grid array (CBGA) assemblies in a 1.27-mm pitch.¹ However, with the need to shrink the I/O pitch to accommodate higher wiring density, it has become increasingly important to conduct TMF reliability assessments in a 1-mm pitch format. This paper describes such an evaluation conducted using SAC BGA assemblies. The results show that, for a 1-mm pitch, the Pb-free SAC CBGA solution provides superior reliability as compared to the standard Sn/Pb CBGA solutions. This finding is an added incentive for a new CBGA offering employing the new Pb-free, SAC, single-alloy, self-aligning system.