电镀法制备汇流电极的研究

汇流电极是等离子体显示板(PDP)中的必要结构。本文首次提出了制备汇流电极的电镀法,分析了电极电位、电流密度以及电流在阴极上的分布对电镀过程的影响,研究了汇流电极的电镀工艺,包括基板的预处理、电镀液的选择与配制和汇流电极的电镀。本文用电镀法实际制备了汇流电极,测试了它的导电性和均匀性。实验结果证明,本文研究的制备技术能够制备汇流电极,并因此技术的设备低廉、生产效率高而为降低PDP的成本开辟了一条新途径。     

元器件纯锡镀层表面晶须风险评估与对策

讨论了各种锡晶须的形态以及其长度的具体测量方法,并在试验研究的基础上进一步分析抑制非光滑(哑光)纯锡镀层上锡晶须生长的对策.研究结果表明,增加锡镀层厚度(＞7 μm),或通过使用添加剂来产生更加粗糙的表面以适当增大晶粒尺寸,电镀完成后及时进行退火程序是进一步减轻雾锡镀层上锡晶须困扰的有效手段.如果引入Ni作为中间镀层,则需要达到一定的厚度(估计＞0.7 μm),方可达到预期的效果.     

ITO薄膜制备及RTA处理对发光器件特性的影响

采用射频反应磁控溅射生长铟锡氧化物(ITO)薄膜,通过X射线衍射(XRD)、透射光谱、四探针法及原子力显微镜(AFM)研究了生长条件、快速热退火(RTA)温度等对薄膜的晶化、透过率、电导率以及表面形貌的影响.以ITO/NPB/AlQ/Al结构的器件为例,讨论了不同的制备条件下ITO薄膜的表面效应对电致发光(EL)的影响,通过EL光谱表征发现,对ITO退火处理后,器件的相对发光强度明显增加,衰减速度减慢,器件的EL光谱有明显的变化.通过进一步分析认为,这是由于ITO薄膜表面的变化引起功函数的改变,从而引起电场重新分布造成的.     

Indium and tin oxide nanowires by vapor-liquid-solid growth technique

Regular three-dimensional (3-D) arrays of crystalline SnO₂-In₂O₃ nanowires were produced on m-sapphire using a gold catalyst-assisted vapor-liquid-solid growth process. The growth characteristics at multiple growth conditions were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), x-ray photoemission spectroscopy (XPS), and Rutherford backscattering spectroscopy (RBS) to evaluate the functional dependence of nanowire structure and composition on growth parameters such as temperature and source composition. The results indicate that nanowires of mixed composition are not possible from the catalytic clusters; rather, a mixture of indium and tin oxide wires are formed in the range of conditions investigated here.     

Pb/Sn凸点的制备

介绍了用电镀法制备Pb / Sn凸点的工艺,包括:凸点的设计,圆片的准备,溅射UBM(凸点下金属层),厚膜光刻,电镀Cu柱, Pb / Sn凸点,回流凸点等。结果表明:采用电镀法可以得到球形Pb / Sn凸点,50μm的厚胶工艺是可行的。     

Self‐Compensation in Transparent Conducting F‐Doped SnO2

The factors limiting the conductivity of fluorine‐doped tin dioxide (FTO) produced via atmospheric pressure chemical vapor deposition are investigated. Modeling of the transport properties indicates that the measured Hall effect mobilities are far below the theoretical ionized impurity scattering limit. Significant compensation of donors by acceptors is present with a compensation ratio of 0.5, indicating that for every two donors there is approximately one acceptor. Hybrid density functional theory calculations of defect and impurity formation energies indicate the most probable acceptor‐type defects. The fluorine interstitial defect has the lowest formation energy in the degenerate regime of FTO. Fluorine interstitials act as singly charged acceptors at the high Fermi levels corresponding to degenerately n‐type films. X‐ray photoemission spectroscopy of the fluorine impurities is consistent with the presence of substitutional F_O donors and interstitial F_i in a roughly 2:1 ratio in agreement with the compensation ratio indicated by the transport modeling. Quantitative analysis through Hall effect, X‐ray photoemission spectroscopy, and calibrated secondary ion mass spectrometry further supports the presence of compensating fluorine‐related defects.     

Novel Percolation Mechanism in PMMA Matrix Composites Containing Segregated ITO Nanowire Networks

Poly(methyl methacrylate) (PMMA)/indium tin oxide (ITO) nanocomposites were prepared by mechanical mixing and compression molding in order to study the properties and microstructure of the composites. The composites were examined by optical and scanning electron microscopy, impedance spectroscopy, and UV‐VIS spectrophotometry. It was observed that upon compaction of the powders above the glass‐transition temperature of the matrix, the PMMA transforms from spherical to polyhedral‐shaped, and develops sharp edges and flat faces. The ITO nanoparticles do not penetrate the polymer particles, resulting in a novel segregated network microstructure. Excellent correlation between the electrical, optical, and microscopy data also provide good insight about the behavior of the filler as the content is increased in the nanocomposites. There is strong evidence that the ITO nanoparticles are extensively displaced during compaction as the PMMA powders become polyhedral‐shaped. Our results indicate that percolation occurs due to the ITO forming a continuous network along the edges of the faceted PMMA particles. The ITO nanoparticles do not appear on the faces of the PMMA particles until after a percolation path has formed and a marked increase in electrical conductivity has occurred. This behavior significantly diverges from previous models for segregated network microstructures which proposed that percolation occurred as the result of limited displacement of the filler during compaction of the mixed powders.     

双面电镀在先进封装中应用的可行性研究

在晶圆双面及孔的侧壁用一种简单的工序电沉积金属的能力,在先进封装和某些工艺中提供了一些基本的优势。双面电镀样机硬件已经过用配置垂直电镀槽的生产型ECD装置的试验。这种工艺已经成功地在几种不同的金属和多种应用中得以展示。     

The effects of bath composition on the morphologies of electroless nickel under-bump metallurgy on Al input/output pad

The electroless nickel plating on an aluminum input/output (I/O) pad was investigated. The aluminum pad was pretreated in a zincate solution prior to electroless nickel plating. Zinc particles on the aluminum pad gave a good adherent nickel layer. The adhesion and uniformity of zinc on the aluminum is the key factor in under-bump metallurgy (UBM). The electrode potential changes with and without zinc ions in the bath were measured to analyze the sequence of two competing reactions: zinc deposit and hydrogen evolution. The relationship between aluminum dissolution and the ratio of zinc and NaOH was investigated. The electroless nickel deposition rate was dependent on bath composition. The effects of complexing ligand and additive on the nickel deposit were analyzed. Electrode potential changes were measured with time to confirm nucleation and grain growth. Adhesion of the UBM was related to zinc-particle dissolution and nickel nucleation. The uniform nickel UBM was fabricated on a real Al I/O pad.