焊膏技术及其进展

本文详细介绍了焊膏的组成、特性及使用要求。作为一种重要的电子耗材,焊膏的性能对SMT生产有着举足轻重的影响,优良的焊膏是综合性能达到完美平衡的体现。但是,品质优良的焊膏,还要结合匹配的工装,才能保证SMT高良品率、高品质的要求。     

复合电镀层应用的新动向

介绍了复合电镀层应用的新动向，如电解工业用电极的制备，铝发动机气缸的应用，重点介绍Sn-Ag纳米微粒复合镀层做为无铅可焊镀层的溶液，pH值，霍氏槽及可焊性试验的结果，还介绍了具有装饰和优良憎水性的镍－聚四氟乙烯微粒复合镀层，简述了其工艺过程，溶液组成和操作条件，镀层特性及应用。     

助焊剂系列化合物专利信息

一种SnZn系无铅钎料用助焊剂及其制备方法;一种用于无铅焊的低固含量免清洗助焊剂;无铅软钎焊料丝用无卤素助焊剂及制备方法;无铅软钎焊料丝用助焊剂及制备方法;     

欧胜微电子股份有限公司过渡到无铅焊

欧胜微电子股份有限公司日宣市将只采用无铅焊模式提供所有的新产品，此模式和常规的SnPh及无铅焊工艺都兼容，使得它可以方便地整合到任何PCB装贴者的无铅发展规划中去。“我们将成为一个纯粹的无铅供应商”，欧胜微电子的首席技术官JimReid官称。     

环保型晶雕堆花装饰在高档骨质瓷中应用的研究

文中简要介绍了高档骨质瓷晶雕堆花装饰的特点,通过实验研究获得了适合晶雕堆花装饰的骨质瓷无铅坯釉配方,开发出了用于骨质瓷晶雕堆花装饰的无铅干粒釉和釉膏,介绍了高档骨质瓷晶雕堆花装饰的加工工艺过程。     

钛酸钡系无铅压电陶瓷的研究进展

钛酸钡（BaTiO3）压电陶瓷具有优异的电性能和低污染性，长期以来是人们重点研究的对象。本文综述了近年来BaTiO3系无铅压电陶瓷研究开发的几种体系与进展，着重介绍了BT--BNT和BT-BKT二元系无铅压电陶瓷的结构及性能。同时对BaTiO3系无铅压电陶瓷的发展趋势作了评述。     

热塑性复合材料及其焊接

本文主要介绍了热塑性复合材料的若干种焊接方法，如热板焊、红外焊、感应焊、振动焊、超声波焊等。     

SnAgCu无铅焊膏用活性剂的优化研究

以SnAgCu无铅焊膏铺展性能、接触角和焊点形貌作为评价的主要指标,通过回流焊接实验,对常用于焊膏的5种活性剂进行了单一活性剂优选,并对三种性能较好的活性剂进行复配优化研究。结果表明:丁二酸、苹果酸、硬脂酸作为单一活性剂时助焊剂的润湿性较好,并且其焊点铺展良好、焊点光滑;通过组合方法,对筛选出来的三种活性剂进行接触角测试,得到比例为6:2:2(丁二酸:苹果酸:硬脂酸)润湿性能最好,并且焊点圆润光滑,铺展性能良好。     

耐盐耐高温隔离液的研制与评价

随着深水盐下油气藏勘探开发加速，钻遇复杂盐膏层和高压盐水层日益增多，常规隔离液体系存在抗盐、抗高温、悬浮稳定性差等问题。为此，研制出一套由抗盐黏土、抗盐降失水剂、悬浮稳定剂、流型调节剂组成的耐盐耐高温隔离液体系。该抗盐隔离液体系抗温可达160℃，流变性能调节自由，失水量可控，与钻井液、水泥浆相容性好，对水泥石强度和水泥浆稠化时间影响小，沉降稳定性优良，满足复杂盐膏层固井作业技术需求。     

膏霜类化妆品配方设计原理

本文根据乳化理论和亲水亲油平衡（HLB）值的计算,详细论述了膏霜类化妆品配方的设计原理。为工程技术人员研究和开发膏霜类新产品,提供了一种比较方便快捷的设计方法。     

聚酰胺改性氢化蓖麻油在无铅锡膏中的应用研究

通过试验，在免洗松香型无铅锡膏中添加聚酰胺改性氢化蓖麻油，考察其对焊锡膏流变性能及应用性能的影响。其中，测试方法包括粘度、粘着力和抗热塌性测试。聚酰胺改性氢化蓖麻油用量为5g时的焊锡膏的粘度适中、粘着力最大及其抗热塌性最好，会有一个较好的印刷性能。     

Synthesis and characterization of ceramic nanoparticles reinforced lead-free solder

Sn-0.7Cu is among the least expensive types of lead-free solders available. However, its poor mechanical properties have limited its application. In this study, Sn-Cu lead-free solder reinforced with amorphous silica (SiO₂) nanoparticles was synthesized through powder metallurgy route. Desired mixtures of raw materials was mechanically milled, compressed, sintered and extruded to prepare bulk solder samples. The samples were characterized by optical and electron microscopy as well as mechanical tests. The results showed that mechanical properties were increased by addition of SiO₂ nanoparticles to the solder matrix. Addition of 1.5 wt% ceramic reinforcement to the composite increased tensile, yield and compressive strengths up to 27%, 23% and 41%, respectively, compared to those of the monolithic sample. In addition, the ceramic nanoparticles caused an up to 50% decrease in the wetting angle between the substrate and the nanocomposite solder.     

Electroless Co-P for diffusion barrier in Pb-free soldering

Lead-free solders with high tin content and high melting temperature limit the reliability of electroless nickel/immersion gold finish on copper as diffusion barrier. Autocatalytic cobalt-phosphorus is proposed as a barrier metallization for copper in lead-free soldering. Autocatalytic deposition of cobalt is carried out in hypophosphite containing electrolytes at 95 °C and pH 8. Autocatalytic Co-P/Au finish with about 4 wt% P content strongly limits interdiffusion and intermetallic compounds formation with respect to the Ni-P/Au finish with Sn-Pb and Sn-Ag-Cu solder alloys. Contact angle of Sn-Pb solder alloy with Ni-P/Au and Co-P/Au layers is comparable, while in the case of Sn-Ag-Cu alloy contact angle is much lower for Co-P/Au than for Ni-P/Au layers. Mechanical strength of lead-free joints for Ni-P/Au and Co-P/Au finishes is evaluated with shear test on BGA coupons, obtaining higher joint strength values for autocatalytic cobalt.     

Adhesion of underfill and components in flip chip encapsulation

The underfill material is a polymeric adhesive used in flip chip packaging. It encapsulates the solder joints by filling the gap between a silicon die and an organic substrate or board. Within a typical flip chip structure, there are interfaces between the various components, namely, substrate, solder mask, flux residue, underfill encapsulant and die passivation layer, etc. Maintaining a good adhesion condition, both as-made and after temperature/humidity aging, is vital for these interfaces because of the expected performance of the flip chip device, where the underfill material is employed to enhance the reliability of the flip chip interconnect. We have studied the adhesion strength between the various components for different process variables as measured with the lap shear and die shear test configurations. The effects of the assembly factors, i.e. solder mask, flux residue, underfill, and die passivation, etc., were evaluated and the adhesion strength was found to depend greatly on these factors. The die shear strength of a passivated die assembled onto an organic board coated with a solder mask was much higher after using a no-clean flux on the solder mask than for the assembly without such a no-clean flux. The influence of some accelerated aging tests on the adhesion durability was also investigated. A die passivation layer of benzocyclobutene exhibited better capability in retaining the die shear strength than a passivation layer of silicon nitride or polyimide, especially for the initial aging period. The knowledge obtained in this study should provide insights into the interfacial adhesion in the flip chip assembly structure.     

Development of a high curing latency no-flow underfill with self-fluxing ability for lead-free solder interconnects

Tin-lead solders have been used as joining materials in the electronics industry for many years. As present there are great concerns about the potential harm of lead-containing solders to human beings and many efforts have been made to remove the lead from the electronics packages. However, there is no no-flow underfill currently on the market that is compatible with the lead-free solder. In this study, a new no-flow underfill for flip chip bumped with lead-free solder has been developed based on a curing agent and catalysts with high curing latency. The curing agent itself has the fluxing ability, so the need of extra flux is eliminated. Compared with the underfill for lead-containing solder, the new underfill has a higher curing temperature, compatible with the melting profile of lead-free solder. The wetting compatibility of the underfill with the lead-free solder has been studied by wetting experiments. The material properties of the underfill have been investigated using DSC, TGA, TMA and DMA. The results show that the newly developed underfill material has the potential to be used in lead-free interconnects.     

一种无铅晶硅太阳电池背场铝浆

文章介绍了一种无铅玻璃粉配制而成的可用于太阳能电池背场的无铅铝浆。该无铅玻璃粉在500℃左右软化,550℃左右流平,与铝粉、有机载体混合轧制成铝浆。定性I-V特性测试、X-射线粉末衍射及差热分析表明此铝浆在烧结过程中能与硅形成Si-Al合金,有良好的重掺杂欧姆接触性能。     

无铅化微电子互连技术与导电胶

介绍了电子互连用导电胶(ECA)的组成和基本性能,综述了ECA在电学性能、力学性能和稳定性等方面的研究进展。随着世界范围内含铅材料的限制和禁止使用,电子制造过程中的无铅化已成为该领域的发展方向和必须面对的挑战。ECA是替代含铅钎料、实现微电子互连技术无铅化的重要发展方向。虽然目前ECA仍存在着电阻率偏高、易老化失效和电流通过能力偏低等问题,但是高性能树脂和新型导电填料的不断涌现,将为ECA性能的提高提供新的解决途径和方法。     

Effect of joint sizes of low-temperature sintered nano-silver on thermal residual curvature of sandwiched assembly

Residual bending could be formed in sandwiched assembly as a result of coefficients of thermal expansion (CTEs) mismatch and temperature difference. An optical measurement system was developed to study the residual curvature of sandwiched assembly bonded by three different kinds of die-attachment materials, i.e., nano-silver paste, Pb/Sn solder, and SAC 305, in this paper. We found that all the sandwiched assemblies at ambient temperature concave toward the alumina side and the residual bending was relieved as the temperature rose. It also turned out that the residual curvature in the assembly grew as the joint size increased. The residual bending in nano-silver assembly fell in between those of Pb/Sn solder and lead-free solder, SAC 305 (Sn96.5Ag3.0Cu0.5). Finite element analysis (FEA) was also introduced to simulate the bending behavior of the assemblies. It was shown that the FEA results agree well with the experimental one. In addition, a one-dimension theoretical model was developed and could characterize the relation between the residual curvature and the joint size.     

Electrodeposition and characterisation of Sn-Ag-Cu solder alloys for flip-chip interconnection

A pyrophosphate and iodide based bath was investigated for the electrodeposition of near-eutectic Sn-Ag-Cu alloys, which are promising lead-free solder candidates for electronics interconnection. Near-eutectic Sn-Ag-Cu electrodeposits (2.5-4.2 wt.% Ag and 0.7-1.5 wt.% Cu) were achieved from the system as measured by wavelength dispersive X-ray spectroscopy (WDS). Electroplating such near-eutectic ternary alloys at higher deposition rates was possible with the application of electrolyte agitation. Different morphologies of deposited Sn-Ag-Cu films were analysed using scanning electron microscopy (SEM). X-ray diffraction (XRD) data indicated that Sn, Ag₃Sn and Cu₆Sn₅ were present in the “as-electrodeposited” Sn-Ag-Cu film. The microstructure of the deposits and the morphology of Ag₃Sn and Cu₆Sn₅ intermetallics were characterised from cross-sectional images produced from a focused ion beam scanning electron microscopy and then imaged from transmission electron microscopy (TEM) micrographs. The proposed bath proved capable of producing fine pitch near-eutectic Sn-Ag-Cu solder bumps as demonstrated on a glass test wafer.     

无铅水基热风整平助焊剂的研究

使用水溶性载体、活化剂、抗氧剂、表面活性剂和去离子水,制备出一种无铅水基热风整平助焊剂。探讨组分配比对无铅热风整平焊接后,印制板焊盘、孔上铅锡的饱满度、腐蚀性以及单产率等的影响。结果表明,助焊剂的最佳组成为水溶性载体75%,活化剂1.5%,抗氧剂0.3%,表面活性剂0.01%,其余为去离子水。该助焊剂粘度低、助焊效果好、腐蚀性小、耐高温,可适用于新的无铅焊料体系。