浅析集成电路封装发展对封装材料的性能要求

主要从半导体工业器件的可靠性、成形性出发,分别对塑封料的纯度、机械性能、射线含量和焊接性能等几个方面提出要求。同时介绍了目前国内外塑封料的发展现状,并提出了环氧塑封料的发展方向。     

扇出型晶圆级封装中圆片翘曲研究

在扇出型晶圆级封装工艺中,由于芯片材料与塑封料之间的热膨胀系数差异,晶圆塑封过程中必然会形成一定的翘曲.如何准确预测晶圆的翘曲并对翘曲进行控制是扇出型晶圆级封装技术面临的挑战之一.在讨论圆片翘曲问题时引入双层圆形板弯曲理论与复合材料等效方法,提出一套扇出型晶圆级封装圆片翘曲理论模型,并通过有限元仿真与试验测试验证了该翘...     

扇出封装设备和材料市场销售收入预测

相比其他常见封装平台,扇出封装市场规模较小,但它覆盖了高端的高密度扇出应用和低端的核心扇出应用。过去,扇出封装对于电源管理集成电路、射频收发器、连接模块、音频/编解码器模块、雷达模块和传感器等应用至关重要。苹果的应用处理器引擎(APE)采用了台积电的InFO-PoP平台,推动了扇出封装的普及,并实现了高密度扇出封装。     

一种基于扇出晶圆级封装技术的控制模块设计

随着摩尔定律放缓,各种先进封装技术成为半导体产业的重要研究内容.同时,这些技术也为系统工程师们如何实现定制电路小型化提供了更多样的选择.在对已有SiP技术研究的基础上,基于国内工艺线,尝试使用扇出晶圆级封装技术实现一款控制模块,为该技术在数模混合系统小型化中的应用提供参考.     

用于5G通信的射频微系统与天线一体化三维扇出型集成封装

本文研究了一种用于5G通信的射频微系统与天线一体化三维扇出型集成封装技术.通过在玻璃晶圆上使用双面布线工艺,实现毫米波天线阵列的制作.将TSV转接芯片与射频芯片倒装焊在玻璃晶圆上,再用树脂材料进行注塑,将玻璃晶圆与异构芯片重构成玻璃与树脂永久键合的晶圆.减薄树脂晶圆面漏出TSV转接芯片的铜柱,在树脂表面上完成再布线.把控制、电源管理等芯片倒装焊在再布线形成的焊盘处,植上BGA焊球形成最终封装体.利用毫米波探针台对射频传输线的损耗进行测量,结果表明,1 mm长的CPW传输线射频传输损耗在60 GHz仅为0.6 dB.在玻璃晶圆上设计了一种缝隙耦合天线,天线在59.8 GHz的工作频率最大增益达到6 dB.这为5G通信的射频微系统与天线一体化三维扇出型集成提供了一个切实可行的解决方案.     

环氧塑封料用热潜伏型固化促进剂的研究与应用进展

环氧塑封料（EMC）是集成电路（IC）芯片封装的关键材料之一,而固化促进剂又是影响EMC在IC封装应用中的可靠性的重要成分之一。综述了近年来国内外EMC用热潜伏型固化促进剂（TLC）在基础与应用领域中的研究进展。从IC封装用EMC的发展趋势、EMC的发展对TLC的性能需求以及当前IC封装应用中的主流EMC相关TLC材料的研究现状等几个方面进行了阐述。重点阐述了有机磷系络合型本征型TLC的研究与发展状况,对先进EMC用TLC组分的未来发展趋势进行了展望。     

环氧塑封料的性能和应用研究

介绍了环氧塑封料的国内外发展概况,着重论述了其物理性能、机械性能、热性能、导热性能、电性能、化学性能、阻燃性能、贮存性能、封装性能,以及应用中封装工艺、缺陷的解决办法,并就发展前景发表了自己的看法.     

基于硅基扇出(eSiFO?)技术的先进指纹传感器晶圆级封装工艺开发

传统的晶圆级芯片封装(WLCSP)是一种标准的扇入式封装结构。随着I/O数的增加,无法为重布线层(RDL)提供足够的区域。近年来,在芯片周围形成扇出区域的嵌入式封装技术发展起来,其具有I/O数目高、成本低、集成灵活、体积小等优点。晶圆扇出型封装(FOWLP)通常采用环氧塑封复合料(EMC),其面临翘曲、各层热膨胀系数(CTE)不匹配、成本高昂等难题。报道了一种全新的晶圆级嵌入式硅基扇出技术,名为eSiFO^?,其用于实现电容式指纹传感器封装。在这个创新的集成器件中,一个5.6 mm×1.0 mm的ASIC芯片被减薄到90μm,然后嵌入到硅基槽中重建一个新的晶圆。在整个工艺过程中,金属的覆盖面积达80%以上,但晶圆的翘曲小于2 mm。整个晶圆级封装工艺使用了10个掩模版,其产品良率达到98%。该产品通过了包括预处理测试、温度循环(TCT)测试、高加速温湿度应力试验(u-HAST)和高温贮存试验(HTST)在内的标准可靠性测试。     

The relationship between moisture resistance and epoxy molding compounds in integrated circuits

The influence of epoxy molding compounds on metallized aluminum corrosion in a Pressure Cooker Test (P.C.T.) was investigated by a monitor chip encapsulated in a dual in-line package (D.I.P.). The monitor chip is composed of a leakage current measuring part which has opposite metallized aluminum tracks and an aluminum corrosion measuring part which has metallized fine aluminum tracks. The formulation of the epoxy molding compound was changed for the average particle size of fillers, the internal release agents, and the coupling agents. The relationships between the stress of the epoxy molding compounds and moisture resistance was also investigated by using epoxy molding compounds which had different characteristics of stress.     

电子封装用环氧树脂基复合材料的优化

研究了593固化剂不同用量加入电子封装用环氧树脂E-51中的效果,以及在E-51,Al2O3复合材料中硅烷偶联剂不同用量的效果,结果显示:593固化剂与环氧树脂质量比为1:4时,复合材料的致密度高,气孔少,成型效果好;当硅烷偶联剂KH-560质量分数为8%时,复合材料的热导率达到0.75 W/(m·K).     

复合陶瓷颗粒/环氧模塑料的制备与性能

选用SiO_2、Al_2O_3、Si_3N_4三种陶瓷颗粒的复合填充环氧模塑料(EMC),研究了不同填料种类、含量对EMC导热系数、热膨胀系数(CTE)、介电常数等性能的影响随着填料百分含量的增加,EMC的热导率、介电常数也随之增加,而其热膨胀系数显著下降相同体积百分含量下,Al_2O_3、Si_3N_4复合体系EMC热导率和介电常数高于SiO_2、Si_3N_4复合体系,而其热膨胀系数比后者低。百分含量为60%时,前者热导率达到2．254 W(m·K)~(-1)、后者达到2．04w(m·K)~(-1)。百分含量为65%时,其CTE分别为1．493×10~(-5)K~(-1)、1．643×10~(-5)K~(-1),同时两体系复合材料的介电常数可以维持在较低水平     

灌封用环氧树脂的制备与力学性能研究

灌封用环氧树脂除了要具备较强的抗冲击过载能力外,固化后还必须具有较小的内应力。通过控制环境温度,制备了灌封用环氧树脂,并对其力学性能进行了测量,分析了不同固化时间对材料弹性模量、抗压模量和屈服强度的影响。结果表明:固化90天的环氧树脂弹性模量比固化30天的环氧树脂下降了近23%,抗压强度增加了近24%。通过延长环氧树脂的固化时间能够有效减少材料内部的应力集中,从而降低对被灌封电路模块的影响。     

Accelerated popcorn testing of high solder-reflow crack resistant molding compounds

In testing the resistance of a molding compound to popcorn failures after solder reflow, there are two basic options for shortening the moisture absorption phase: varying the severity of moisture exposure by varying the temperature and percent relative humidity or maintaining a constant humidity/temperature profile and varying the length of time the compounds are exposed. In addition, the total testing time can be accelerated by the choice of test method. There are three major measurement techniques for evaluating the extent of popcorn cracking: SAM testing; bubble chamber testing; and visual crack inspection. In this paper we will explore the effects of differing lengths of exposure time and the merits of different measurement techniques.A variety of epoxy resins, filler mixtures and adhesion additives were examined in semiconductor molding compounds for solder-reflow crack resistance (popcorn crack resistance). A limited comparison of molding compound high-temperature strength properties and extent of popcorn cracking suggests no strong positive correlation. On the other hand, factors that might have an impact on adhesion properties of the molding compound, such as low melt viscosity resins and putative adhesion additives, appear to have the greatest impact. A molding compound developed with these factors showed no internal or external cracks on 84 lead QFPs (29.2 × 29.2 × 3.68 mm) after 72 h of 85°C/85% R.H. and one 10 s solder dip at 260°C. Nor were any external cracks observed after 168 h of 85°C/85% R.H. and one solder dip. However, minor internal cracks were observed.The most data can be obtained by using bubble chamber testing for large numbers of parts and evaluating a smaller sample of the best of those compounds via SAM testing with crack extension analysis. The length of exposure time affected the parts as expected, with longer times being more severe. There did not appear to be a gradient effect or a threshold level. In general, 72 h allowed the greatest differentiation among the compounds tested for internal defects; external defects were not fully developed until 168 h of moisture exposure.     

Effect of spin coating on the curing rate of epoxy adhesive for the fabrication of a polymer optical waveguide

Spin coating is a simple process for rapidly depositing thin, solid polymeric films onto relatively flat substrates. Evaporation occurs during spinning of the relatively volatile species in any solution. The curing behavior of spin-coated polymeric film is influenced by the evaporation of any reactive component. An investigation was carried out on a silicon substrate to study the effects of spin coating on the curing behavior of the epoxy adhesive. The degree of curing for both spin and without spin-coated epoxy adhesive was measured by Fourier-transform infrared spectroscopy (FTIR). A slower curing reaction rate was observed for the spin-coated epoxy adhesive. The composition gradient established by solvent evaporation during spinning is responsible for the slower curing reaction rate of the spin-coated epoxy adhesive. From this study, it is proposed to use solvents that are less volatile and allow a greater part of the thinning behavior to occur without significant changes in the fluid properties during the spinning process.     

芯片冷却技术中的微/纳米材料与结构的研究进展

分析和讨论了芯片冷却技术中应用到的微/纳米材料和结构方面的进展,并对其应用前景作了一定展望。这些内容对于发展新的芯片冷却技术及相关高热流密度器件的冷却应用具有重要的参考价值。     

Fine structural tuning of diketopyrrolopyrrole-cored donor materials for small molecule-fullerene organic solar cells: A theoretical study

Two novel strategies to tune diketopyrrolopyrrole and its derivatives by lactam-lactim and alkoxy-thioalkoxy exchange were theoretically presented for improving the efficiency of bulk heterojunction solar cells. The structural tunings could synergistically reduce the HOMO level and the energy gap of donors due to the disrupted aromaticity of the linked pyrrole derivatives. Compared with the parent molecule, the new designed donors not only create a more red-shift of absorption spectrum but also show better hole transport rates, larger fill factor, higher open circuit voltage and more favorable solar cell efficiency. Moreover, the arrangements at the interface and the optical properties of the donor-PCBM complexes were computationally investigated to get insight into the absorption of charge transfer states. Consequently, the strategies are judicious approaches to enhance their intrinsic properties of donors and can be used for further improving the performance of other DPP-based molecules in bulk heterojunction solar cells.     

Effect of temperature on elastic properties of woven-glass epoxy composites for printed circuit board applications

The effect of temperature on the elastic properties of woven-glass epoxy substrates for printed circuit board applications was investigated. Three common commercially pressed boards (1080, 2116, and 7628 woven-glass fabrics and FR4 epoxy) were used for this study. The elastic properties were identified by means of a combined theoretical and experimental vibration method. Vibration experiments were performed under reduced air pressure to reduce the influence of mass, stiffness, and damping of the surrounding air and inside an environmental chamber with varying temperature and constant humidity. Above the glass-transition temperature (Tg) of the epoxy, the in-plane shear moduli (G₁₂) were decreased by 33–37% and the out-of-plane shear moduli (G₁₃, G₂₃) were decreased by 48%, whereas the Young’s moduli in the warp (E₁) and fill (E₂) directions were much less affected.     

温度梯度法生长Nd:YAG晶体的1200 W激光输出

用温度梯度法（TGT）生长了大尺寸的Nd：YAG激光晶体，测试了室温下的吸收谱并利用吸收谱研究了Nd离子在YAG晶体中的分布。比较了温度梯度法与提拉法生长晶体的区别。根据热容激光的原理，利用生长的Nd：YAG激光晶体片设计了热容激光器，利用侧面抽运，获得了1200w的激光输出，工作时间为2s，光-光转换效率为30％。