Atomic diffusion properties in wire bonding

1 Introduction Ultrasonic bonding was applied primarily to wire bonding in microelectronic packaging industry, while the mechanism of ultrasonic bonding has not been understood very well. HARMAN[1] observed that the peeling underdeveloped bonds simulate a…     

轴承-转子系统模态参数时域识别的研究

轴承－转子系统模态参数时域识别对于回转机械的状态监测与故障诊断具有重要意义。然而，一般时域识别方法通常存在对系统定阶的困难，因此本文提出一种逐步扩阶的ＳＴＤ方法，并在双跨转子实验台上进行了模态参数识别实验，结果表明，该方法较好地解决了对系统定阶的困难，可以取得良好的识别结果     

磁悬浮球的H∞控制研究

设计了一种磁悬浮球实验系统，建立了磁悬浮球的控制模型。基于H∞混合灵敏度控制理论，研究了加权阵的选取规律和方法，设计了磁悬浮球的H∞鲁棒控制器。开发了功率驱动系统和光电位置检测系统，并用DSP系统实现了H∞控制算法。仿真分析和实验结果表明：该磁悬浮系统具有较高的控制精度和鲁棒性，解决了磁悬浮系统中的建模精度低，外界干扰难以避免等棘手问题。     

裂纹转子的重力响应模拟

基于JEFFCOT裂纹转子的模型，分析其重力响应，并给出了裂纹振动响应的模拟结果，可供裂纹在线诊断参考。     

改善银阳极有机发光二极管空穴注入特性研究进展

介绍了采用金属银作阳极的特殊结构有机电致发光技术,阐述了利用表面处理和增加缓冲层方法提高阳极空穴注入的原珲,分析了各种技术的优缺点,并提出了利用蒸镀有机薄膜改善载流子注入的方法.     

The relationship between IR characteristic peak and microstructure of the glass used as optical fiber

Based on the harmonic vibration equation, the relationship between IR characteristic peak of fiberglass and Si-O-Si bond angle was deduced, and 1 100 cm^-1 characteristic peak was specifically studied. It is found that 1 100 cm^-1 characteristic peak shifts to higher wave number when Si-O-Si bond angle increases. Taking fused biconical taper （FBT） coupler as an example, the microstructures of the fiber coupler manufactured at different draw- ing speeds were tested with micro infrared spectrum. According to the test results, it is found that the bond angle at the taper region is the largest, the one at the fused region is the second largest, and the one of bare fiber is the smal- lest. The characteristic peaks of fused-taper region shift to higher wave number when drawing speed increases.     

Structure analysis of optical fiber coupler with infrared spectrometry

To obtain excellent performance optical fiber couplers, the structural difference of SiO2 in couplers with different manufacturing techniques was investigated. With 740-FT-IR infrared spectrometric analyzer, the infrared absorption spectrum of SiO2 in couplers at different drawing velocities was measured, and two characteristic peaks in the wavenumber range of 650 - 2000 cm^-1 were observed. One characteristic peak is at about 943 cm^-1 , which is attributed to Si--O Si bond asymmetric stretching vibration, the other is at about 773 cm^-1 , which is attributed to Si--O--Si bond symmetric stretching vibration. From the infrared spectrum, it is found that the intensity and wavenumber of the characteristic peaks are related to the manufacturing technique of couplers. The characteristic peak atabout 943 cm^-1 becomes steeper when increasing the drawing velocity. At the drawing velocity of 150μm/s, the distance between the two characteristic peaks is maximum, and then the optical fiber coupler has excellent performance, indicating that the performance of the optical fiber coupler has a close relationship with the wavenumber of the two characteristic peaks.     

熔融拉锥光纤耦合器波长响应研究

基于变分理论,分析了常规对称单模熔融拉锥光纤耦合器的腰部区域和梯度区域的耦合行为,得出了耦合器耦合比与波长的关系,并在熔融拉锥机的实验平台上进行了相应的波长响应实验,理论和实验结果都表明:在一定波长范围内,耦合比不但对波长敏感,且响应具有单调性。利用此特性,光纤耦合器有望作为光波长敏感元件,开发出结构简单、造价低廉的光波长探测器。     

Micro scale design and experimental research of rolling interface

1　ＩＮＴＲＯＤＵＣＴＩＯＮＲｏｌｌｉｎｇｉｎｔｅｒｆａｃｅｉｓｏｆｃｏｍｐｌｉｃａｔｅｄａｎｄｓｅｎｓｉｔｉｖｅｌｉｎｋ ,ａｌｓｏｉｓｔｈｅｋｅｙｏｆｖａｒｉｏｕｓｐｒｏｂｌｅｍｅｘｉｓｔｉｎｇｉｎｒｏｌｌｉｎｇｓｙｓｔｅｍ .Ａｓｗｅｋｎｏｗ ,ａｌｏｔｏ     

硅微半球陀螺频率裂解修调工艺规律仿真分析

频率裂解是影响半球谐振陀螺性能的主要因素之一.硅微半球陀螺谐振子球壳的厚度为μm量级,半径为mm量级,小而脆弱的谐振子导致修调难度大,针对此问题,文中通过有限元仿真的方法分析了在硅半球壳谐振子唇边进行打孔对频率裂解的影响规律.得到了"应该在低频模态上打孔以减小频率裂解"、"修调的加工精度需要在微米级甚至是亚微米级"、"...