镍层耐硝酸腐蚀性测试——一种简单的预先探测ENIG镍层“黑盘”现象的测试方法

随着更加精细的SMT、BGA等表面贴装技术的运用,化学沉镍金(ENIG)作为线路板最终表面处理得到了越来越广泛的应用,同时可怕的“黑盘”现象也随之更广泛地“流行”起来,直接导致贴装后元器件焊接点不规则接触不良。为了贯彻执行最好的流程控制和采取有效的预防措施,了解这种焊接失败的产生机理是非常重要的,及早的观测到可能发生“黑盘”现象的迹象变得同样关键。本文介绍了一种简单的预先探测ENIG镍层“黑盘”现象的测试方法-镍层耐硝酸腐蚀性测试,这种测试可以用于作为一种常规的测试方法监测一般化学沉镍溶液在有效使用寿命范围内新鲜沉积的镍层的质量。利用Weibull概率统计分析在不同的金属置换周期(MTO)下镍层的可靠性能表现。结合试验结果得出了一个镍层耐硝酸腐蚀性的判定标准。     

Studies on the corrosion behavior of cerium-implanted zircaloy-4 with GAXRD

In order to study the influence of cerium ion implantation on the aqueous corrosion behavior of zircaloy-4, specimens were implanted by cerium ions with a fluence range from 1×10¹⁶ to 1×10¹⁷ ions/cm² at maximum 150°C, using MEVVA source at an extracted voltage of 40 kV. The valence and elements penetration distribution of the surface layer were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES) respectively. Glancing angle X-ray diffraction (GAXRD) was employed to examine the phase transformation due to the cerium ion implantation in the oxide films. Three-sweep potentiodynamic polarization measurement was employed to value the aqueous corrosion resistance of zircaloy-4 in a 1 N H₂SO₄ solution. It was found that a significant improvement in the aqueous corrosion behavior of zircaloy-4 implanted with cerium ions compared with that of the as-received zircaloy-4. The improvement effect will declined with raising the implantation fluence. The bigger is the fluence, the less is the improvement. Finally, the mechanism of the corrosion behavior of the cerium-implanted zircaloy-4 is discussed.     

Effect of chloride ions on immersion plating of copper onto porous silicon from a methanol solution

The effect of chloride ions (Cl⁻) during the immersion plating of copper onto porous silicon (PS) from a methanol (MeOH) solution has been studied. The presence of Cl⁻ in the Cu²⁺ solution was found to slow down the rate of copper deposition, as confirmed by inductively coupled argon plasma emission spectroscopy and X-ray photoelectron spectroscopy measurements. The threshold concentration of Cl⁻ at which the deposition of copper is very severely diminished was found to be 0.1 M. The inhibition effect is discussed on the basis of the rest potential values of PS and polarization curve measurements. They revealed that the rest potential of PS upon dipping in these solutions appears to direct the metal deposition. Current density-potential curves show that at Cl⁻ concentrations higher than 0.1 M, the reduction of Cu ions proceeds in two steps; the reduction of Cu(II) to Cu(I) followed by the reduction of Cu(I) to Cu(0). This suggests that Cu(I) species in MeOH solution can be stable over a certain potential range and this stability of Cu(I) is responsible for the inhibition of metal deposition. Fourier transform infrared spectroscopy and scanning electron microscopy (SEM) were also performed to investigate the structural changes and characterizations of PS samples after the plating process.     

等离子体湮没离子注入

本文扼要地介绍了等离子体湮没离子注入的基本原理，特点，应用效果及发展趋向。     

Modelling of marine immersion corrosion for copper-bearing steels

The non-linear phenomenological model previously proposed for the ‘general’ corrosion loss of mild and low alloy steels under fully aerated ‘at-sea’ near-surface immersion conditions is applied to provide a new interpretation of literature data for copper-bearing steels. The data is examined to extract the parameters required for the model as a function of average seawater temperature. On the basis of the expectation of consistency, the data is then used to calibrate the parameters. All are generally consistent with the parameters derived earlier for mild and low alloy steels. The calibrated parameters are used to predict a consolidated plot of expected corrosion loss-time-temperature for copper-bearing steels. This compares favourably with a similar plot derived earlier from observed data alone.     

Corrosion and mechanical behavior of fusion bonded epoxy (FBE) in aqueous media

In recent years there have been many reported cases of corrosion failure in cement concrete pipelines. In the majority of cases, the failures have been attributed to rebar corrosion which is caused by the permeability of chloride from low resistivity soil and subsequent attack on a passive layer on an iron bar in the structure. As a possible alternative to cementitious materials, some organic coatings based on olefin, vinyl or epoxy-based polymers have been considered. However, due to a paucity of data on the behavior of these coatings in aqueous media— particularly product water—the possibility of their application in water transmission systems in the Kingdom has not been fully exploited. This paper deals with the studies carried out on the corrosion and mechanical behavior of fusion bonded epoxy (FBE) coating on steel in aqueous media which include product water, distilled water and saline water. The mechanical testings on coating include adhesion, bending and cathodic disbondment testings. The corrosion studies include immersion testing under static and dynamic conditions, autoclave tests and accelerated (salt-fog) tests. The analysis of results indicates chemical inertness of FBE coating in either of the aforementioned water used during testing, good adhesion and no damage to the coating during bending. Cathodic disbondment tests indicate that FBE coating sustains under cathodic protection (CP) conditions. In general, the results of mechanical and corrosion tests indicate that FBE is a promising material for internal coating on steel in water transmission systems.     

浸液复合磁化探伤装置产生的磁场分析

分析了浸液复合磁化探伤装置产生的合成磁场。结果表明,该合成磁场是个平面旋转磁场,故与受检工件侧面圆柱面同心的弧状裂纹无法用穿棒法检出,而工件的退磁因子与复合磁化法中所用的磁化方式无关。     

关于虚拟现实—核心概念与工作定义

本文秀彻地论述了虚拟现实的若干重要方面，并首次提出了虚拟实现的工作定义。此外，文中还介绍了一些采用虚拟现实技术的应用实例。     

改进缺陷,套刻和聚焦性能的第五世代浸没式曝光系统

论述了第五世代双扫描平台浸液式扫描曝光机的性能和进展。表明了在高速扫描状态下有生产价值的套刻和聚焦性能的实现。浸液式设备更多的关键部分与缺陷有关,而且该机的改进是通过有生产价值的缺陷水平方面来体现的。为了保持这种缺陷水平的改进效果,需要在圆片应用中进行专门稳定的测量。特加是边缘空泡除去(EBR)设计和圆片斜面良流线性是很重要的。     

预分绞无浸压式上浆设备的设计及应用

探讨预分绞无浸压式上浆设备的工作原理及其应用效果。针对传统浸压式上浆方法存在的压浆力大、耗费浆料多、易破坏纱线结构、上浆率不匀、易产生分绞毛羽等缺陷,改变传统的浸压上浆方法,采用预分绞后再上浆的模式,利用浆液喷嘴循环喷淋对纱线进行上浆,应用红外线对纱线进行烘燥,开发出了无浸压上浆设备,并对长丝进行了上浆。认为该设备不破坏原纱的特性,浆液成膜性好,浆纱性能稳定,且避免了分绞劈纱产生的二次毛羽,烘燥效率高,节约能源,后续织机效率和织造质量较好。