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碱性镀锌试验总结 总被引:1,自引:0,他引:1
一、试验目的电镀就是金属的电结晶过程.金属晶体的形成包括两个过程,即晶体核的生成和成长.如果在电镀过程中晶核生成的速度大于晶核成长的速度,就能获得结品细致、排列紧密的镀层.要达到此目的必须提高阴极极化作用.为了改善电镀溶液的性能和镀层的质量,就要在电镀溶液中加入少量的有机添加剂.根据添加剂在碱性镀锌溶液中的作用,其本身必须符台下述要求:1.有机胺类-环氧氯丙烷系列添加剂,必须反应完全,以防止因长期贮存或使用过程中继续缩聚或分解.2.添加剂的分子量要适中,使镀液有较大的极化度.3.分子结构最好是线型结构,有较好的亲水性,以提高镀液的极化度.4.添加剂的补加周期要长,镀液老化要慢. 相似文献
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酸性电镀铜是重要的电子互连制造技术之一。为解决其工业生产过程中,聚二硫二丙烷磺酸钠(SPS)和3-巯基-1-丙烷磺酸钠(MPS)稳定性欠佳,导致镀液老化,使添加剂监控失效、镀液均镀能力下降和镀层结瘤等问题,通过电化学实验、定量分析实验和电镀实验,研究了巯基丙烷磺酸络二铜(MA)作为电子互连中酸铜电镀加速剂的特性。结果表明,MA能够直接替代原配方中的SPS和MPS,作为酸铜加速剂使用,且工作浓度更低,具有更宽的CVS分析线性区间,能够提供更准确的定量分析结果,在微通孔保型电镀中表现出良好的均镀能力,并能实现微盲孔的超级填充,不改变铜镀层的金相织构等,展现出广阔的应用前景。 相似文献
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研究添加剂对电沉积的作用机理及添加剂用量对镀层结构的影响,有利于开发一种更好效果的添加剂。为了获得良好的镀层,硫脲及其衍生物作为添加剂已经广泛应用于电镀工业中,脒基硫脲(GTU)作为电镀添加剂,采用循环伏安法(CV)和电化学石英晶体微天平(EQCM)技术,考察GTU在酸性溶液中对铜沉积机理的影响。CV结果表明,脒基硫脲对铜电沉积有抑制作用;QCM分析表明,当镀液中含有GTU时,铜阴极沉积和阳极溶出过程的M/n分别为61.50,64.12 g/mol,表明电极反应过程中,Pt/Cu电极表面的铜离子沉积从二电子过程过渡到单电子过程,添加剂的最佳浓度为10 mmol/L。 相似文献
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前言在印制电路板(PCB)制造过程中,常常遇到退除铅锡镀层的问题.如插头镀金时,需将插头部位的铅锡镀层退除,以便在露出的铜层上镀镍、镀硬金.最近在欧美市场上流行的裸铜上复盖阻焊膜,或称裸铜上黑化后复盖阻焊膜,即SMOBC工艺,需要在图形电镀蚀刻后,再去掉电镀的铅锡合金,成为裸铜的印制电路,以防止波峰焊接时阻焊膜皱裂的现象发生.有时,要脱除PCB上的毛刺或整块不要的镀层,都需要采用退除工艺.国内普遍采用氟化氢铵溶液退除铅锡镀层.但此种溶液在组成含量控制不当,如氟化氢铵含量偏低,或过氧化氢偏高时,均对层压板有严重的腐蚀作用.氟化氢铵本身易潮解,系无机有毒品,在PCB生产中逐渐被其它药剂所取代.现将有关先进退镀方法评述如下: 相似文献
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通过赫尔槽试验与直流电解试验,研究了添加剂在焦磷酸盐溶液体系无氰电镀铜-锡合金(低锡)工艺中的作用。该体系镀液组成与工艺条件为:Cu2P2O7·3H2O25g/L,Sn2P2O71.0g/L,K4P2O7·3H2O250g/L,K2HPO4·3H2O60g/L,温度25℃,pH8.5,电流密度1.0A/dm2。采用扫描电镜(SEM)、X射线衍射(XRD)、能谱(EDS)、中性盐雾试验等方法研究了添加剂对镀层组成结构、外观、耐腐蚀性能及微观形貌的影响。结果表明,焦磷酸盐溶液体系无氰电镀铜-锡合金(低锡)时使用有机胺类添加剂可抑制Sn的析出,使合金镀层致密均匀,耐蚀性能好。镀层结晶主要为Cu13.7Sn结构,镀层中Sn含量为9%~11%。镀液中添加剂的使用量增加,则合金镀层中的Sn含量降低。 相似文献
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The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion. 相似文献
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Investigation of the effects of fatty acids on the compressive strength of the concrete and the grindability of the cement 总被引:1,自引:0,他引:1
In cement industry, a great energy consumption has been observed during grinding of clinker. To reduce this consumption, some waste products have been used as grinding aids.In this investigation, the effects of sunflower oil (SO), oleic acid (OA), stearic acid (SA), myristic acid (MA) and lauric acid (LA) on the fineness and strength of the cement have been examined. These aids were added into clinker in certain ratios based on the cement clinker weight and the grinding has been done for a definite time at the same condition.All of the fatty acids used increased the fineness as compared with the cement without the grinding additives. SO and OA decreased the strength significantly, LA decreased it to a lesser extent and SA increased it definitely according to the common cement. But MA did not alter the strength of the cement as much as SA. In addition, the covering of the balls influences the grinding of cement clinker unfavourably. 相似文献
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Polyurethaneureas (PUU), which were synthesized from 4,4′-diphenylmethane diisocyanate (MDI), poly(ethylene glycol) (PEG), and 3,5-diaminobanzoic acid (DABA), were used as polyelectrolytes in this study. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were used to monitor the effect of the various kinds of PEG on the changes in morphology of PUU electrolytes corresponding to the concentration of lithium perchlorate (LiClO4) dopants. The results of DSC and FT-IR indicate the Li+ ions coordinate with the soft and hard segments. Additionally, the crystallinity of the PEG soft segment and the ordered hydrogen-bonded urea carbonyl groups decreased with increasing salt concentration. Impedance spectroscopy (IS) measurements show that the PUU electrolyte with the high phase separation degree has the high ionic conductivity. The hard-segment Tg and the soft-segment Tm influence the conductivity behavior of polyelectrolytes with increasing measurement temperature. 相似文献
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组合凹模的应力分析是一个非常复杂的问题,对其进行精确分析是解决模具寿命的关键。本文采用有限元分析软件Ansys对转子的组合凹模进行了分析,为转子组合凹模的优化设计提供了依据。 相似文献
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In spinning basalt fibres, the drafting force is in the same range as in spinning of glass fibres. The effect of the drafting
force can not be considered in the calculation for the strength and rigidity of the bottom of the spinneret.
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Translated from Khimicheskie Volokna, No. 5, pp. 47–50, September–October, 2007. 相似文献