铅锡合金镀层的控制

电镀铅锡合金是最简单的合金电镀之一，铅和锡两种金属的标准电极电位相近，仅差１０毫伏，可以从简单的电解质溶液中实现共沉积。一般，印制板理想的铅锡层为３７％铅，６３％锡，因其共熔点为１８３℃，此为合金中共熔点最低值。要获得理想的铅锡合金镀层：必须严格控制金属离子浓度，电流密度、温度、搅拌及有机污染等条件。本文就铅锡合金镀层的工艺控制问题，作一简单阐述，仅供参考。     

半导体硅片清洗工艺发展方向

对半导体硅片传统的RCA清洗办法中各种清洗液的清洗原理、清洗特点、清洗局限以及清洗对硅片表面微观状态的影响进行了详细的论述,同时在此基础上,对新的清洗办法(改进的RCA清洗办法)进行了一定的说明,指出了硅片清洗工艺的发展方向。     

氧对铅锡碲薄膜电阻率的影响

氧吸收或氧化对金属电阻膜、合金电阻膜及金属陶瓷膜的影响及作用机理差别很大。淀积不同厚度的铅锡碲合金膜暴露在氧气或大气中, 其电阻随时间发生明显的变化,电阻的变化是随着膜厚的增加、基片温度的增加呈下降趋势,比较了金属氧化膜、合金电阻膜及金属陶瓷膜中的氧对电阻值的不同影响。铅锡碲氧吸收模型解释了其电阻变化机理,并进一步得到XPS光电子色谱分析的支持。     

高温工艺中硅片的翘曲

通过硅片高温热处理实验研究了热自理工艺和表面状态对硅片高温弯曲度变化的影响，高温工艺中坚直装片引起的形变较小，研磨硅片经过适当化学腐蚀可明显降低高温翘曲。     

Au—Sn合金电镀

概述了改善的Ａｕ－Ｓｎ合金镀液,可以稳定地形成组成为８０ｗｔ％Ａｕ,２０ｗｔ％Ｓｎ的Ａｕ－Ｓｎ合金镀层,适用于具有抗蚀剂图形的半导体等电子零件上形成Ａｕ－Ｚｎ合金微细焊料图形。     

电镀Au-Sn合金的研究

Au-Sn(质量分数为20%)共晶焊料有着优良的导热和导电特性,已被广泛应用在光电子和微电子的器件封装工业中.对微氰和无氰电镀Au-Sn合金的两种电镀方法进行了研究,概述了镀液组分和电镀工艺条件,用扫描电镜的方法测试不同电流密度下Au-Sn合金组分,用测厚仪测试镀层厚度,计算出镀速,最终确定电镀Au-Sn(质量分数为20%)合金的电镀条件,并对微氰和无氰电镀液优缺点进行了对比分析.     

超薄硅片倒角工艺研究

在硅片加工的前期工程中,由于切割成型的硅片存在着边缘崩口、裂纹、应力集中等物理特性差的现象,需用倒角机来对硅片进行边缘磨削加工,以改善硅片的物理性能,随着硅片厚度的减小,硅片边缘越来越容易出现崩边,碎片率也逐渐提升,砂轮寿命也在逐渐降低,硅片的倒角技术逐渐变为一个难题。本文通过对砂轮转速、吸盘转速的改变来开展工艺试验,当加工超薄硅片时适当减小砂轮转速,可明显提高硅片边缘倒角质量;吸盘转速一般稳定在15 mm/s左右时,加工速率相对比较高,边缘质量也会得到最大程度的保证。     

新颖型弹性膜硅加速度传感器芯片的设计

介绍了最新设计的双E型硅传感器芯片的制作工艺。通过控制不同敏感硅芯片弹性膜的厚度,即可制得不同量程的双E型敏感硅芯片和加速度传感器。     

太阳能硅片双束激光划槽方法与装置

本文提出一种太阳能硅片双束激光划槽方法和装置,它利用Z型谐振腔的Nd:YAG激光器,声光Q开关调制,经直角棱镜发射双束激光,扩束聚焦输出到太阳能硅片表面,划槽最小线宽:20μm,最大划片速度:120mm/s、使生产率提高100%,节约能源30%。     

Effects of pattern characteristics on the copper electroplating process

The non-planarity of a surface post electroplating process is usually dependent on variations of key layout characteristics including line width,line spacing and metal density.A test chip is designed and manufactured in a semiconductor foundry to test the layout dependency of the electroplating process.By checking test data such as field height,array height,step height and SEM photos,some conclusions are made.Line width is a critical factor of topographical shapes such as the step height and height difference.After the electroplating process,the fine line has a thicker copper thickness,while the wide line has the greatest step height.Three typical topographies, conformal-fill,supper-fill and over-fill,are observed.Moreover,quantified effects are found using the test data and explained by theory,which can be used to develop electroplating process modeling and design for manufacturability (DFM) research.     

版图图形特征对铜电镀工艺的影响

铜电镀工艺后表面的不平整度通常取决于版图关键特征,包括线宽,线间距和金属密度。本文设计了一款测试芯片并在一家半导体厂加工制造。版图特征效应被真正的测试数据所检查和验证。通过分析金属蝶形、介质腐蚀、金属厚度和SEM照片,得出一些结论。线宽是决定表面形貌及产生铜金属蝶形和介质层腐蚀的最关键因素。经过铜电镀工艺发现,铜线越细铜生长的越厚,铜线越宽铜金属蝶形越大,发现了3种典型表面形貌。而且,通过测试数据,量化版图特征的影响并用曲率增强加速剂覆盖率的理论解释,这可以用于开发铜电镀工艺模型和开展可制造性设计研究。     

通孔电镀铜填孔浅析

电子产品朝更轻、更薄、更快方向发展的趋势,使印制电路板在高密度互连技术上面面临挑战。微堆叠孔技术是一种用来产生高密度互连的方法。通孔的填充介质目前主要有三种,分别为导电膏、树脂、纯铜。比较此三种填充方式,纯铜填孔技术工艺流程短,可靠性高。该文介绍了通孔填孔的反应机理,并论述了通孔填孔电镀技术的优势。     

微结构传感器芯片划切工艺优化

MEMS传感器技术的发展,伴随着新结构、新材料、新工艺应用在晶圆制造中[1]。这对封装核心工序的划片工艺提出了很大挑战。主要通过芯片划切过程中容易出现的几个异常现象对微结构敏感芯片划切过程中的破片进行分析,提出了一些解决微结构芯片划切过程中存在问题的办法,并进行了划切参数的优化。     

稳健的MRLS码片均衡算法

码片均衡是提高第三代移动通信系统性能的关键技术之一。为了增强码片均衡器抗突发干扰的能力，本文将应用数学中的“稳健估计(RE)”应用于MRLS算法中，得到稳健的MRLS算法(RMRLS)。理论分析与计算机模拟结果都证明了RMRLS算法在保持MRLS算法的优点的同时，提高其抗突发干扰的能力，使MRLS算法更加稳健。     

The characteristics of vibration fracture of Pb-Sn and lead-free Sn-Zn eutectic solders

This work investigated the fatigue fracture characteristics of Sn-7∼11wt.%Zn and Sn-30∼50wt.%PPb solder alloys under resonant vibration. For the alloys containing proeutectic Sn-rich grains, the results show stratum appearance on the deformation of coarse proeutectic grains. This stratum-type deformation will reduce the vibration resistance of Pb-Sn solder by inducing cracks. For the Sn-Zn system, fine eutectic structure will cause cracks to form and coalesce easily in the regions concentrated with small fibrous deformation grains, whereas hypereutectic structure shows coarse proeutectic Zn-rich particles as the crack initiation sites. Sn-t-Zn solders have better damping capacity than Pb-Sn solders. With hypoeutectic composition to induce stratum-type deformation and under lower vibration strain, these lead-free solders tend to exhibit superior crack propagation resistance, and, in that respect, are possible to replace Pb-Sn solders.     

Residual stress and interfacial reaction of the electroplated Ni-Cu alloy under bump metallurgy in the flip-chip solder joint

Pure Ni, the Ni-Cu alloy, and pure Cu layers as the under bump metallurgy (UBM) for a flip-chip solder joint were deposited by electrolytic plating. For the pure Ni layer, residual stress can be controlled by adding a wetting agent and decreasing current density, and it is always under tensile stress. The Ni-Cu alloys of different Cu compositions from ∼20wt.%Cu to 100wt.%Cu were deposited with varying current density in a single bath. The residual stress was a strong function of current density and Cu composition. Decreasing current density and increasing Cu content simultaneously causes the residual stress of the metal layers to sharply decrease. For the pure Cu layer, the stress is compressive. The Cu layer acts as a cushion layer for the UBM. The residual stress of the UBM strongly depends on the fraction of the Cu cushion layer. Interfacial reaction of the UBM with Sn-3.5 wt.% Ag was studied. As the Cu contents of Ni-Cu alloys increased, the dissolution rate increased. Several different intermetallic compounds (IMCs) were found. The lattice constants of alloys and the IMC increase with increasing Cu contents because the larger Cu atoms substitute for the smaller Ni atoms in the crystallites. The Cu content of the IMC are strongly dependent on the composition of the alloys. Ball shear tests were done with different metal-layer schemes. The failure occurs through the IMC and solder.     

印制线路板电镀均匀性概述

电镀生产实践中,电镀均匀性是检验镀层质量的一个重要指标。本文总结归纳了对表面及孔内镀铜均匀性进行改善的一般性思路与方法,并结合应用实例进行了说明,以期对实际生产提供一定的借鉴与指导意义。