玻璃、陶瓷表面Ni-P化学镀研究

在普通平板玻璃和空心陶瓷基材表面沉积Ni-P合金。对镀液成分及用量、温度、pH值、施镀时间等工艺参数用均匀设计进行组合筛选,获得可沉积光亮Ni-P镀层的中低温酸性玻璃基体Ni-P化学镀工艺:NiSO4.7H2O30gL-1,NaH2PO2.H2O22gL-1,琥珀酸36gL-1,添加剂A2mgL-1,温度48～50℃,pH值5.8～6.0;对玻璃表面化学镀镍进行改进获得了空心陶瓷表面高温酸性Ni-P化学镀工艺:NiSO4.7H2O29gL-1,NaH2PO2.H2O38gL-1,琥珀酸36gL-1,添加剂A2mgL-1;,温度90±1℃,pH值5.5～6.0。玻璃表面镀层表面质量良好、光亮、平整,有较好结合力;有效沉积时间达到15min时,空心陶瓷表面镀层表面质量良好,与陶瓷表面有较好结合力。     

不锈钢化学镀Ni-P合金镀层的性能研究

讨论了不锈钢上化学镀Ni-P合金镀层的工艺,重点是不锈钢基体的前处理工艺、镀液温度和PH值.对镀层成分和结构的分析、结合力测试表明,用文中提出的前处理工艺对不锈钢基体处理后,再进行化学镀能获得性能可靠的Ni-P合金镀层.     

PCB基材上化学镀Ni-P合金层用于埋置电阻的工艺方法研究

文章研究了在PCB基材上化学镀Ni-P合金层用于埋置电阻的工艺方法。基于埋入电阻在挠性及刚性PCB板中的应用,分别研究了Ni-P合金在无卤的FR-4、无卤的PI两种PCB基材上镀层厚度与试验时间之间的关系,初步得出了在两种不同基材上化学沉积Ni-P合金的规律,该规律对后期的试验具有重要的指导作用。     

螺旋形碳纤维结构吸波材料的制备及性能研究

用基板法以乙炔为碳源,镍板为催化剂,PCI,为助催化剂,通过化学气相沉积制备了螺旋形碳纤维手性吸收剂,并研究了其在2～18GHz的微波电磁特性：具有较高的介电损耗,电磁参数随频率的增大有减小的趋势,有利于实现宽频吸波。以螺旋形碳纤维作为吸收剂制备了Nomex蜂窝夹芯结构吸波材料,复合材料的厚度为9．5mm时,在3．76～18GHz反射率R小于-10dB,反射率小于-10dB的频宽为14．24GHz;最大吸收峰在10．4GHz,反射率R为-21．62dB。探讨了螺旋形碳纤维的吸波机理,螺旋形碳纤维是一种非常有发展前景的手性吸收剂和吸波材料。     

化学镀Ni-P在纯锡凸点的应用及界面研究

采用化学镀Ni-P作UBM阻挡层,利用电镀的方法制备了面阵列和周边排布的无铅纯锡凸点,凸点高度为85±2μm,一致性良好。研究了不同回流温度下纯锡焊球的剪切强度、断裂模式和与Ni-P层反应生成的金属间化合物。结果表明,纯锡凸点回流时与Ni-P生成针状Ni3Sn4,凸点剪切强度达到92MPa以上。剪切断裂为韧性断裂,随着回流温度提高及回流时间延长,Ni3Sn4相由针状向块状转变,Ni-P层与Ni3Sn4层间生成层状Ni3P相,粗化的Ni3Sn4相受压应力向焊球内部脱落。     

具有电磁防护功能的吸波吊顶制备及性能研究

制备了以矿棉板、石膏板和PVC板为吊顶面板,吊顶腔体厚度分别为6 mm和3 mm的吸波吊顶,研究了吊顶面板材质和吊顶腔体厚度对吊顶吸波性能的影响。结果表明:面板为矿棉板和截面多孔的PVC板吸波性能明显好于石膏板和截面孔径大的PVC板,前两者吸波性能在1.7~18 GHz范围内均优于-10 dB,这种差异主要来自于面板对电磁波的透射性能以及多孔结构对吸波性能的影响。在一定范围内,吊顶腔体厚度越厚,吊顶吸波性能越好。     

电磁超表面在隐身技术中的应用研究进展

电磁超表面能够利用散射调控和电磁波吸收2种主要机理进行隐身是隐身技术中一种极具潜力的新型技术途径。对电磁超表面在隐身技术中的应用与研究进展进行综述,首先介绍了超表面散射调控机理进行隐身设计的基本原理与实现方法,介绍了相位梯度超表面、编码超表面和超表面隐身套的发展历程和研究成果;其次介绍了基于吸波机理的超表面隐身技术研究进展,包括完美吸波结构、多频带吸波结构、宽频带吸波结构、宽角域吸波结构;再次介绍了超表面雷达隐身与其他功能的复合设计研究,包括超表面隐身强度复合设计、超表面吸波透波散射一体化、雷达红外兼容隐身等内容;最后总结了一些超表面在隐身技术应用中存在的问题和未来的研究方向。     

金属衬底多层吸波材料表面等效电磁流的研究

基于Maxwell方程的一阶状态矢量微分方程描述。推导出均匀平面波入射下金属衬底多层各向异性材料表面上等效电磁流的一般解析表达式及其相互关系。以此为基础给出了两层涂覆电大尺寸平板导体的散射结果，为我层各向异性材料涂覆导体目标电磁散射的近信计算提供了理论基础。     

Fe-Ni-P合金改性空心微珠及吸波性能研究

采用化学镀的方法制备了表面包覆Fe-Ni-P合金的空心微珠,研究了制备方法及条件对空心玻璃微珠表面改性的影响,并对其吸波性能进行了测试.实验结果表明,空心玻璃微珠表面镀层中铁、镍的质量分数分别为30.1%和63.2%,在频率为16.80 GHz处,涂层的反射衰减可达-18.20 dB,且在12.5 ～18.00 GHz频段范围内,反射衰减皆低于-10.00 dB.     

吸波材料基体的应用与研究现状

在介绍吸波材料分类与原理的基础上,归纳了目前吸波材料中基体的应用与研究进展,总结了基体材料研究中的问题,指出提高高分子基体的耐温耐候性能、提高无机吸波材料的韧性及增加吸收剂的填充量是今后吸波材料的重要研究方向.     

Effects of phosphorus content on the reaction of electroless Ni-P with Sn and crystallization of Ni-P

The reaction between electroless Ni-P and Sn and the crystallization behavior of Ni-P were investigated to better understand the effect of P content on the Ni-P layer. Electroless Ni-P specimens with three different P contents, 4.6 wt.%, 9 wt.%, and 13 wt.%, were used to study the effect of the P content and the microstructure of Ni-P on the subsequent crystallization and intermetallic compound (IMC) formation during the reaction between Ni-P and electroplated Sn. Ni₃Sn₄ was the major phase formed in all samples heated up to 300°C, which totally transformed into Ni₃Sn₂ when samples were heated up to 450°C and the Sn layer was 0.5-μm thick. The IMC formed on the nanocrystalline Ni-P showed stronger texture compared to that formed on the amorphous Ni-P. Both the IMC thickness and density decreased with P content in the Ni-P layer, and Ni₃Sn₄ morphologies varied with P content. Dissolution of Ni into Sn increased with P content, which made IMC size in the bulk Sn increase with P content.     

超细铜粉的化学镀锡及其抗氧化性能研究

以水合肼还原法制备出平均粒径约1μm的超细铜粉,并对其进行化学镀锡。研究了镀锡层对复合粉末微观形貌及抗氧化性能的影响。结果表明:镀覆质量分数50%的锡后,复合粉末平均粒径有所减小,但在空气中的氧化起始温度从120℃提高到220℃,与镀银层相比,镀锡层在较低温度区间对铜粉抗氧化具有优势。     

pH对化学镀镍-磷法制作的埋嵌电阻方块电阻影响的研究

文章主要介绍了pH对通过化学镀镍-磷法制作埋嵌电阻时镍-磷合金层方块电阻的影响。在温度相同的条件下,当镀液的pH不同时,探究了两种基材表面上镍-磷合金层方块电阻与反应时间的关系,并分析了适合用于制作埋嵌电阻的镍-磷合金层方块电阻值,以及最佳的化学镀镍-磷反应pH值。从实验结果可知,当反应时间相同时,随着pH的减小两种基材表面上镍-磷合金层的方块电阻将会逐渐大;适合用于埋嵌电阻制作的化学镀镍-磷反应pH为3.4~3.7,反应时间为3min~8min,方块电阻为15Ω/□～200Ω/□。     

Interfacial reactions and compound formation of Sn-Ag-Cu solders by mechanical alloying on electroless Ni-P/Cu under bump metallization

Electroless Ni-P under bump metallization (UBM) has been widely used in electronic interconnections due to the good diffusion barrier between Cu and solder. In this study, the mechanical alloying (MA) process was applied to produce the SnAgCu lead-free solder pastes. Solder joints after annealing at 240°C for 15 min were employed to investigate the evolution of interfacial reaction between electroless Ni-P/Cu UBM and SnAgCu solder with various Cu concentrations ranging from 0.2 to 1.0 wt.%. After detailed quantitative analysis with an electron probe microanalyzer, the effect of Cu content on the formation of intermetallic compounds (IMCs) at SnAgCu solder/electroless Ni-P interface was evaluated. When the Cu concentration in the solder was 0.2 wt.%, only one (Ni, Cu)₃Sn₄ layer was observed at the solder/electroless Ni-P interface. As the Cu content increased to 0.5 wt.%, (Cu, Ni)₆Sn₅ formed along with (Ni, Cu)₃Sn₄. However, only one (Cu, Ni)₆Sn₅ layer was revealed, if the Cu content was up to 1 wt.%. With the aid of microstructure evolution, quantitative analysis, and elemental distribution by x-ray color mapping, the presence of the Ni-Sn-P phase and P-rich layer was evidenced.     

石墨衬底多晶硅籽晶层制备及性质

采用磁控溅射技术在石墨衬底上制备多晶硅籽晶层,系统研究了不同衬底温度、不同快速热退火(RTA)温度和时间对籽晶层结构性质的影响。通过X射线衍射(XRD)仪测试分析,发现溅射过程中衬底温度对于结晶质量有着至关重要的影响,即衬底温度为700℃是形成Si(220)晶面择优取向的临界温度,当衬底温度高于700℃时,Si(220)晶面衍射峰峰高随衬底温度的增加显著增大。在RTA过程中,提高退火温度和延长退火时间均能够提高薄膜多晶硅籽晶层Si(220)晶面的择优取向。     

无铅石墨导电浆料的制备和性能

以导电石墨粉、低熔无铅玻璃和乙基纤维素松油醇溶液制备了无铅石墨导电浆料。分析了浆料中玻璃粉含量对烧结膜表面电阻、威氏硬度和附着力的影响,给出了石墨导电浆料的配方。研究了浆料的流变性、触变性和粘弹性。用玻璃转变温度为476℃的无铅低熔玻璃配制的浆料在520~580℃烧结后,外观致密光洁;当烧结膜厚度为(25±3)μm时,方阻为80~135?/□,硬度为12.3 N/mm2,附着力为45.6 N。     

化学镀工艺在微电子材料中的研究和应用

简要综述了化学镀工艺在微电子材料中的应用,讨论了影响化学镀镍、铜、锡、钴和贵金属等的主要因素,阐述了化学镀微电子材料的特性、存在问题及研究动态。     

Phenomena of electroless Ni-P and intermetallic-compound stripping and dissolving in Sn-Bi and Sn-Pb solder joints with Au/EN/Cu metallization

Electroless Ni-P (EN) has been popularly adopted and used as a diffusion barrier in the under-bump metallurgy (UBM) for flip-chip application. The EN with different P contents was first deposited on activated Cu/Al₂O₃ substrates. To prevent the EN from oxidation, a thin Au coating was further plated on the EN/Cu/Al₂O₃ substrates. Two types of solder alloys (63Sn-37Pb and 42Sn-58Bi) and two compositions of EN (Ni-5.5wt.%P and Ni-12.1wt.%P) were employed to investigate the interfacial reaction in the joint of solder/Au/EN/Cu. Occurrence of EN and intermetallic compound (IMC) stripping and dissolving was revealed. After annealing, Ni₃Sn₄ and Ni₃P formed between the solder and the EN in all joints. However, some of the Ni₃Sn₄ IMCs stripped into the solder for a longer annealing time. The stripped EN was first observed in the Sn-Bi/Au/Ni-5.5wt.%P/Cu/Al₂O₃ joints annealed at 185°C for 180 min. The stripped IMCs and the EN then dissolved in the solder and formed the Ni-P-Cu-Sn-Pb solid solution in the Sn-Pb/Au/Ni-5.5wt.%P/Cu/Al₂O₃ joints annealed at 200°C or 240°C. The phenomenon of IMC stripping was found in all joints. However, both the stripping and dissolving of EN was only observed in joints with Ni-5.5wt.%P. The tendency of IMC stripping was related to the amount of IMCs, while the EN stripping corresponded to the surface condition of the EN.     

频率选择表面谐振特性在吸波材料中的应用

利用等效电路法(ECM)及时域有限差分(FDTD)算法分析了频率选择表面(FSS)在2.0～18.0GHz的传输特性,并进行自由空间法测试;同时对含FSS复合吸波材料进行了仿真分析与弓形法反射率测试。结果表明,利用FSS谐振特性与吸波材料吸收特性相互作用,反射率小于–10.0dB的合格带宽可达到7.2GHz(5.0～12.2GHz),有效展宽了反射率曲线的合格带宽,实现了吸波材料吸收性能的宽频化设计。     

Morphology and kinetic study of the interfacial reaction between the Sn-3.5Ag solder and electroless Ni-P metallization

This work summarizes the interfacial reaction between lead-free solder Sn-3.5Ag and electrolessly plated Ni-P metallization in terms of morphology and growth kinetics of the intermetallic compounds (IMC). Comparison with pure Ni metallization is made in order to clarify the role of P in the solder reaction. During reflow, the IMCs formed with the Ni-P under-bump metallization (UBM) exist in chunky crystal blocks and small crystal agglomerates, while the ones with the sputtered Ni UBM exhibit uniformly scallop grains with faceted surfaces. The IMC thickness increases with reflow time following approximately a t^1/3 power law for both systems. The IMC growth rate is higher with the Ni-P UBM than the Ni UBM. The thickness of the Ni₃Sn₄ layer increases linearly with the square root of thermal aging time, indicating that the growth of the IMCs is a diffusion-controlled process. The activation energy for Ni₃Sn₄ growth in solid-state reaction is found to be 110 kJ/mol and 91 kJ/mol for the Ni-P and sputtered Ni UBMs, respectively. Kirkendall voids are detected inside the Ni₃P layer in the Sn-3.5Ag/Ni-P system. No such voids are found in the Sn-3.5Ag/Ni system.