平行缝焊机的阵列焊设计

在电子设备的使用中,会遇到各种苛刻环境条件,如潮湿、酸雨和盐雾等.在这种情况下,器件可能因电化学腐蚀而缓慢失效,也可能因水汽渗入而性能劣化.因此,对器件进行性能优良的气密性封装,有效保护器件免受外界环境的影响至关重要.平行缝焊是最常用的气密性封装方法之一,属于电阻焊.传统的平行缝焊设备单个焊接效率低下,为了提高焊接效率,提出了带阵列焊功能的平行缝焊机.     

微波混合电路铝合金封装外壳电镀锡铋技术

混合集成电路中，封装一般采用表面电镀镍金可伐外壳。但是可伐表面镀金在实用中也有其固有的缺点，表面镀金层与电路焊接时，镀层金与焊料中的锡，电位差较大，存在原电池腐蚀的不利因素。铝合金上采用无铅锡铋镀层是一种较好的替代方案。本文采用盐雾试验法，对铝合金表面化学镀镍做底层及电镀光亮锡铋层做表层的样品进行抗腐蚀性研究，结果表明采用化学镀镍14微米和光亮锡铋7微米组合镀层的具有良好的抗腐蚀效果，可以承受72小时的盐雾试验。此外采用扫描电镜、X射线能谱仪对锡铋光亮镀层的成分进行分析，结果表明铋含量为1％，锡含量为99％。     

平行缝焊工艺抗盐雾腐蚀技术研究

抗盐雾腐蚀是提高集成电路封装可靠性的重要手段之一.根据金属腐蚀机理,通过优化封焊工艺和AuSn合金焊料平行缝焊封盖工艺,以及在封盖后再次进行电镀修复损伤等措施,提高了平行缝焊集成电路的杭盐雾腐蚀能力.     

提高多芯片微波模块气密性的研究

伴随着现代微电子技术的高速发展,在一些特殊环境条件下使用的各种微波模块,需要进行密封封装,以防止器件中的电路因潮气、大气中的离子、腐蚀气氛的浸蚀等引起失效,采用气密性封装以延长器件的使用时间。密封的实现方式根据具体要求采取不同的措施,对于密封要求相对较低,可以采用锡封的方式实现;对于密封要求相对较高的,可以采用平行封焊的方式实现。影响平行缝焊质量的有诸多因素,盖板与平行缝焊的关系是相当重要的,在壳体性能稳定的情况下,盖板质量的好坏直接影响着器件的气密性,盖板和管壳之间的匹配、工艺参数的设置、电极表面的状态等对平行缝焊的质量都起着重要的作用。     

平行缝焊焊缝质量的评判

平行缝焊是微电子单片集成电路及混合电路气密封装的一种关键密封工艺,其中焊缝质量的优劣对平行缝焊产品的密封质量、可靠性影响较大。虽然平行缝焊只是在盖板边缘进行局部加温,对外壳的整体升温比较低,但如果工艺控制不当的话,缝焊过程中同样会引入较大的热应力,导致焊环与陶瓷结合部位开裂,最终造成筛选、鉴定试验过程中的气密性失效。针对平行缝焊工艺中焊点、焊缝质量的评判方法进行了讨论。     

浅谈电极对平行缝焊质量的影响

伴随着现代微电子技术的高速发展,对温度较敏感的电子元器件在设计中被普遍采用,为了满足这种电子元器件的封装要求,平行缝焊技术应运而生。平行缝焊是一种温升小、气密性高的高可靠性封装方式,普遍用于对水汽含量和气密性要求较高的集成电路封装中。影响平行缝焊质量的有诸多因素,如盖板和管壳之间的匹配、工艺参数的设置、电极表面的状态等。我们通过在SSEC(Solid State Equipment Company)M-2300型平行缝焊机上进行实验,总结出电极的状态对于平行缝焊的成品率有着直接的影响。     

镀金层盐雾试验机理及方法探讨

本文从盐雾试验的方法和目的着手，探讨盐雾试验是如何显示金镀层质量，并结合微电池腐蚀原理提出盐雾试验机理。根据剖析的盐雾试验的机理，作者从微电池腐蚀的两个微观因素糙度等。结合这些宏观条件，作者探讨了金镀层耐盐雾试验的有效方法。     

声表面波延迟线器件用高频三腔体金属外壳的研制

本文详细介绍了一种高频三腔体金属外壳的研制,该外壳是声表面波器件专用封装的典型之作：三腔体单面密封结构,上腔体内腔的钎焊卡槽用来装配隔板,从而满足电磁屏蔽要求;采用金锡焊工艺钎焊高频引线组件,确保了信号输入输出端的高频阻抗要求;平行缝焊工艺设计,确保产品气密封接;镀层满足抗盐雾要求。     

AZ91D化学镀Ni-P结构耐蚀性研究

利用金相、SEM、TEM、XRD、盐雾、电化学测量系统研究了镁合金AZ91D的化学镀Ni-P镀层组织结构及耐蚀性能,结果表明,化学镀镍层为胞状致密结构,镀层厚度均匀,与基体结合良好.P的质量分数为6.68%,为中P镀层,镀层阻抗为0.6 Ω,镀层组织为非晶加少量微晶;镀层耐腐蚀性能良好,连续盐雾8 h未出现腐蚀斑点.盐雾腐蚀速率明显低于基体的腐蚀速率.化学镀镍磷层的最小腐蚀电流密度为4.52μA/cm2,腐蚀电位为-250 mV.低于200℃退火,镀层的耐腐蚀性能有所提高,而高于200℃退火,其耐腐蚀性能随温度提高而降低.     

平行缝焊壳体温升影响研究

在微电子器件密封工艺中,平行缝焊气密性焊接过程的热冲击导致器件质量问题是一种比较常见的现象。为了量化分析缝焊温度与焊接参数、封装外壳形式的关系,提出了一种采用AD590温度传感器芯片定量测试器件内腔温度变化情况的新方法。针对测试的温度数据,根据其规律性开展工艺优化试验,降低产品在焊接过程中生产的热应力损伤,避免产生质量问题。     

可伐合金气密封接的预氧化

可伐合金和硅硼硬玻璃是通过可伐合金表面的氧化物与玻璃互溶而紧密结合在一起的,所以可伐合金的预氧化是金属外壳制造的一个非常重要的工艺环节,是直接影响气密封接的一个重要因素。为实现气密封接,可伐合金预氧化需要得到的氧化物应是Fe_3O_4和FeO,而不希望得到Fe_2O_3。同时,氧化膜的厚度要控制在一定的范围内;氧化膜过薄则氧化物完全溶于玻璃,造成玻璃与金属基体表面的直接封接,使封接强度下降;氧化膜过厚则造成金属表面氧化物较粗糙疏松,封接件容易漏气。为达到上述两个目的,可以从可伐合金氧化的热力学和动力学出发,通过控制氧化气氛,氧化温度和时间来实现。     

The coupled effects of salt-spray corrosion,electrical current and mechanical load on the electrical and fatigue properties of COG assembly

It is well-known that chip-on-glass (COG) assembly working in the coastal areas is often subjected to the coupled effects of salt-spray corrosion, electrical current and cyclic mechanical loading in service. Therefore, the fatigue life and electrical property of COG assembly undergoing the coupled loads of salt-spray corrosion, electrical current and cyclic mechanical loading have been studied in the present work. It is found that the relative resistance of COG assembly increases with the increase of salt-spray corrosion time. Moreover, the salt-spray corrosion time has a great influence on the resistance variation during the fatigue process. Simultaneously, the fatigue life of the COG assembly decreases with the increasing corrosion time. Finally, Miner's linear damage rules could be used to define the damage of COG assembly caused by the salt-spray corrosion.     

密封胶粘剂在高可靠微电子封装中的应用

阐述了高可靠微电子封装对密封胶粘剂的性能要求.通过试验优选出一种能实现高可靠、高气密粘接封帽的环氧树脂胶粘剂,用该胶粘剂封帽的外壳通过了严苛的可靠性考核.详细介绍了胶粘封帽工艺过程,并对影响封帽质量及可靠性的因素进行了探讨.     

Methodology for studying the impact of intrinsic stress on thereliability of the electroless Ni UBM structure

A methodology for evaluating the reliability and the impact of intrinsic stresses on the electroless Ni under bump metallurgy (UBM) structure is presented. The first part of this work will address the testing methodology, which uses a pressure sensing device to determine the intrinsic stress in Ni due to the plating process. An optical method is used to capture deformation in the sensing device due to the Ni plating process. A finite element model is then used to calculate the intrinsic stress in the Ni film using the deformation output from the optical measurements. The second part of this work will address a predictive model used to determine the reliability of applying intrinsic stress values to a low cost electroless Ni UBM structure during the bump formation and solder reflow process. The combined work of the testing and predictive methodology provides a more effective and accurate method of predicting the Ni UBM reliability     

Thermo-mechanical reliability analysis of a RF SiP module based on LTCC substrate

The RF SiP module based on LTCC substrate has attracted considerable attention in wireless communications for the last two decades. However, the thermo-mechanical reliability of this 3D LTCC architecture has not been well-studied as common as its traditional ceramic package structure. A practical RF SiP module based on LTCC substrate was presented and its thermo-mechanical reliability was analyzed in this paper, with emphasis on the reliability of heat reflow process, the operating state and fatigue of second-level solder joints. The configuration and assembly process of the SiP module were briefly introduced at first, and qualitative analysis was made according to the reliability problem that may occur in the manufacturing process and the operating state. Through FEM simulation, this paper studied the warpage and stress variation of the RF SiP module, as well as parametric studies of some key package dimensions. Solder joint reliability under temperature cycling condition was also analyzed in particular in this paper. The results show that for the heat reflow process and operating state, the maximum warpage is both on the top LTCC substrate, but the maximum stresses are on the outermost solder ball and the kovar column at the corner, respectively. There is a large residual stress on the critical solder ball at the end of the reflow process and the key package dimensions has little effect on it. The thickness of top LTCC substrate has a significant impact on the thermal deformation and thermal stress, followed by the height of kovar columns. The reason for the considerable thermal stress on the kovar column is the non-uniform of temperature distribution. The key to reducing thermal deformation and stress in the operating state is the employment of effective cooling measures. It is found by comparison that the reliability of critical solder joints can be greatly improved by adding suitable underfill.     

合金焊料盖板选择与质量控制

在平行缝焊、储能焊、玻璃熔封、激光焊、合金焊料熔封等密封工艺中,合金焊料密封是高可靠密封的优选工艺。文章针对合金焊料密封工艺中常遇到的密封强度、密封内部气氛、焊缝及盖板耐腐蚀、薄形封装易短路等问题,介绍了通过合金焊料盖板的选择,从而控制密封强度、密封内部气氛、耐蚀性能和电性能等的质量。     

气密性平行缝焊技术与工艺

气密性封焊的产品因其杰出的可靠性被广泛应用于军事应用。与储能焊、激光焊相比,平行缝焊具有可靠性高、密封性能优越、运行成本低及生产率高等特点,是微电子器件最常用的气密性封装方法之一。主要阐述了气密性平行缝焊技术与工艺,并对焊接工艺参数进行了详细分析,同时给出了气密性检测要求及针对性措施。     

长短板边插头渗金改善方法研究

由于在电镀镍金过程中均会发生析氢反应,在镀镍金过程中,氢气的释放会攻击抗蚀材料的侧面位置,导致抗镀层侧蚀位疏松,容易出现渗镀问题。本文通过采用DOE试验优化设计以改善上述不良问题。     

钕铁硼永磁材料电镀锌镍合金工艺

钕铁硼磁材因其特殊的疏松和多孔结构,导致抗蚀性能差,表面镀覆又会引起磁性能降低。为提高其耐蚀性,降低磁损失,采用新型工艺进行表面处理,包括前处理工艺、电镀Zn-Ni合金和后处理工艺。性能测试表明:该工艺极大地提高了钕铁硼表面处理后的耐蚀能力,同时又降低了磁损失。