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This paper presents an experimental investigation into various aspects of epoxy-bonded polymethylmethacrylate (PMMA) and PMMA-to-aluminium joints. The effects of adhesive thickness, overlap area, surface roughness, and environmental exposure on the joint strength were studied. Results indicated that the joint strength was not directly proportional to the overlap area, while sanding had a positive effect on the joint strength. A negative effect was observed when adhesive thickness was increased. The fatigue behaviour of adhesively-bonded joints under dynamic loading was found to be independent of frequency, for the range of values tested; however, it was dependent on the test temperature with greater reduction in fatigue life observed in PMMA-to-aluminium joints at higher temperature. Empirical equations from which the fatigue life of joints can be predicted were obtained by regression analysis. Intermittent fatigue testing of the joints was also performed. The epoxy adhesive tested proved to be a satisfactory choice for outdoor exposure. The rate of degradation of the adhesive was slow with the adherend itself degrading at a faster rate than the adhesive or the bondline. 相似文献
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在ATM机和纸币清分机中,钞票的厚度检测是必须的功能,通过钞票的厚度特征可以识别钞票上粘贴的胶带和折角等,从而剔除不合格钞票。本文论述了一种电涡流式钞票厚度检测传感器,采用并列的结构相同的多路厚度传感器,通过每路独立的厚度传感器检测出来的信号,拼接成整张钞票的厚度特征,从而识别钞票是否有异常。本传感器具有电路简单、成本低、检测范围大等优点。 相似文献
25.
This work studies the relation between the residual layer thickness and the patterned area size, fill factor and stamp thickness for identical stamps with opposite polarity (positive and negative) made in silicon and nickel. Important and different variations in the homogeneity of the residual layer are obtained in comparison with the values predicted by the theory. This will help to optimize stamp designs and choose appropriate process setups and parameters for nanoimprint with improved pattern transfer capability. 相似文献
26.
YongXia JerryLiu 《电子工业专用设备》2004,33(9):78-82
应用高速度、高点密度熏覆盖全晶圆的薄膜检测仪得到的膜厚均匀图像来对CMP工艺进行快速评定。高点密度、全晶圆的膜厚均匀图像能即时显现出CMP工艺中的非对称性膜厚均匀问题并为根源分析和工艺改进提供快速反馈。对一些用常规的稀疏抽样点薄膜测量方法难以检测到但常见的CMP工艺中导致非对称性膜厚均匀问题熏例如垫片异常熏抛光机头安装不当熏空白晶圆nanotopography等进行比较分析和探讨。 相似文献
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We report on the effects of back channel etch depth and etchant chemistry on the electrical characteristics of inverted staggered advanced amorphous silicon thin-film transistors. We found that the optimum amorphous silicon film thickness in the channel is about 800-1100 Å. Three dry etch, HBr + Cl2, C2F6, and CCl2F2 + O2, and one wet etch, KOH, chemistries are used for the back channel etch processing. We established that dry etch can be used for the back channel etch of amorphous silicon transistor without degrading its electrical characteristics. 相似文献
30.
D. Windover E. Barnat J. Summers T. -M. Lu A. Kumar H. Bakhru S. L. Lee 《Journal of Electronic Materials》2002,31(8):848-856
In this work, we employed a fixed-angle, energy-dispersive x-ray reflectivity technique to obtain the thickness of thin tantalum
films (examples <9 nm) within seconds using a conventional, low-energy x-ray copper or chromium source (20 kV/20 mA/400 W).
We compared this fixed-angle, energy-dispersive result with more conventional fixed-energy (monochromatic source), angular-dispersive
x-ray reflectivity to establish the validity of the energy-dispersive method. This x-ray technique may be particularly useful
for the metrology of growing thin-barrier layers, atomic-layer passivation, and seed-layer measurements in future microelectronics
applications. Currently, thickness precision is limited by modeling assumptions and the energy discrimination available from
x-ray detectors. 相似文献