PCB电镀锡工艺及添加剂的研究进展

镀锡层具有抗腐蚀性、无毒性和可焊性,被广泛应用于印制板制造领域。概述了应用于PCB镀锡过程中的电镀锡工艺种类和添加剂的发展状况。对各种镀锡的工艺和特点进行了归纳和总结。介绍了不同添加剂在镀锡中的作用,指出添加剂将由单一型向多样型发展,并对甲基磺酸盐镀锡的应用进行了展望。     

最新专利文摘

金属化的层状结构及制备方法本专利涉及一种金属化层状结构,这种层状结构适合生产有金属化外观的刚性容器。这种层状结构含有一个金属化薄膜和一个热塑性片材。有一部分热塑性片材通过层压工艺和金属化薄膜结合在一起。金属化薄膜包括一层金属层、一层密封层     

超声波化学镀锡及其性能研究

将超声波与化学镀锡工艺相结合,研究了镀液温度对超声镀锡层微观形貌、表面成分和耐腐蚀性能的影响.结果表明:超声波化学镀锡的沉积速度较常规化学镀锡提高了近30％,获得的超声镀锡层表面比较平整致密,表现出良好的耐腐蚀性能.随着镀液温度升高,超声镀锡层的耐腐蚀性能先增强后减弱,与表面状况发生明显变化有关.超声镀锡层成分未随着镀液温度升高而发生明显改变.镀液温度为80℃时获得的超声镀锡层表面平整性和致密性最佳,具有相对较好的耐腐蚀性能.     

层状硅酸钠的制备及插层性能的研究进展

从晶体结构、制备工艺、插层改性和应用的角度,对层状硅酸钠的研究进行较全面阐述。介绍了层状硅酸钠存在的多种晶相及结构特点;指出了喷雾干燥结晶法或水热合成工艺在制备结晶层状硅酸钠中存在的技术问题;从反应类型的角度详细介绍了层状硅酸钠的插层改性技术和赋予改性层状硅酸钠丰富的功能性;分析了层状硅酸钠的不同晶相或改性技术在实际应用中的研究思路和存在问题,为层状硅酸钠的深度研究与开发指出方向。     

酸性硫酸盐镀锡工艺(二)

介绍了酸性镀锡液的维护与调整,杂质对镀锡液的影响,常见故障及其排除方法,不同基材上镀锡层的去除方法,镀锡层表面防氧化方法,以及从镀锡泥渣与回收槽液中回收锡的工艺。     

化学还原法制备镀锡铜粉

采用硼氢化钠还原氢氧化锡,在铜粉表面进行化学镀锡,得到镀锡铜粉。用两面粗糙度不同的铜箔替代铜粉进行模拟试验,以研究锡层在铜粉表面的包覆情况和微观结构以及高温处理和制备方法对镀锡层显微结构的影响。结果表明,铜粉表面完整地包覆了一层均匀致密的镀锡层;采用还原法制备的镀锡层比采用置换法制备的镀锡层更为均匀致密,高温处理可进一步提高镀锡层的均匀性和致密性。     

印制线路板中化学镀锡研究现状与发展

综述了PC B化学镀锡的发展现状及历史。介绍了现阶段化学镀锡工艺的优点及硫酸盐体系与烷基磺酸盐体系2种化学镀锡液的组成。分别介绍了主盐、硫脲、络合剂、还原剂及其它添加剂的作用。对化学镀锡的机理做了探讨。提出了比较合理的改进化学镀锡液的方案,尤其是在提高镀速和改善镀厚性等方面。同时提出了防止镀锡层表面变色和锡须生成的一些有效方法。     

酸性光亮镀锡工艺的研究

1　前言金属锡具有无毒、易焊接、柔软和延展性好、导电性好等特点 ,在食品和电子工业有着广泛的用途。近年来 ,对有些零件在外观上要求锡层具有像银层一样光亮。但是光亮镀锡层易变色 ,长晶须。为了适应市场的需求 ,我们对酸性光亮镀锡工艺进行了研究 ,并投入生产应用。2　工艺流程化学除油光亮腐蚀光亮镀锡中和除氢涂防变色剂干燥3　主要工序说明3.1　化学除油由于目前需光亮镀锡的基体材料均为铜合金 ,故只允许采取化学除油 ,不允许电解除油。其工艺规范如下 :ＮａＯＨ ,ｇ/Ｌ 10～ 15Ｎａ2 ＣＯ3,ｇ/Ｌ 5 0Ｎａ3ＰＯ4 ,ｇ/Ｌ 5 0Ｎａ2 …     

化学沉积法制备功能性化学镀锡层的研究

在紫铜表面制备了功能性化学镀锡层。用扫描电镜观察了化学镀锡层的表面形貌,用X射线衍射仪分析了化学镀锡层的物相,并用电化学工作站对化学镀锡层的耐蚀性进行了测试。结果表明:化学镀锡层表面比较致密,呈不规则的柱状结构;化学镀锡层的XRD图谱中出现了六个明显的锡衍射峰;化学镀锡层能为紫铜提供有效的保护,提高紫铜在质量分数为3.5%的氯化钠溶液中的耐蚀性。     

电镀古锡新工艺

介绍了一种金属钮扣电镀古锡的工艺,其主要工序包括除油、卤化物镀锡、氧化发黑、抛光、罩清漆等。给出了各工序的配方及操作条件。该镀锡工艺配方简单,镀液稳定,操作简便,着色后的膜层深黑,牢固。     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。