混合聚合物光纤光栅封装元件的温敏实验

用两种不同聚合材料按一定比例均匀混合后对光纤光栅进行封装处理,并对其进行了温敏实验.实验表明,光纤光栅封装元件在20℃～80℃常温区,具有良好的线性温敏性;而在100℃～300℃高温区,则具有较好的温度不敏感性,与裸光纤光栅的温敏性接近.     

大功率LED的电流老化特性分析

基于一体化封装技术,先将铝基板进行硬质阳极氧化处理使其绝缘,后将蓝光LED芯片直接封装到铝基板上,分别制成大功率白光和蓝光LED,其中白光LED由蓝光芯片涂覆YAG∶Ce荧光粉制成。将白光和蓝光LED分别用500 mA和700 mA电流加速老化1 000 h,平均每间隔24 h测试其各种光学参数,对比蓝光LED与白光LED的衰减情况。白光LED的光通量衰减比蓝光严重,但白光光功率的衰减比蓝光慢。LED的衰减分为两个阶段:第一阶段芯片与荧光粉同时衰减;第二阶段主要是芯片的衰减,荧光粉衰减较慢。     

Experimental and theoretical analyses of package-on-package structure under three-point bending loading

<正>High density packaging is developing toward miniaturization and integration,which causes many difficulties in designing,manufacturing,and reliability testing.Package-on-Package(PoP) is a promising three-dimensional highdensity packaging method that integrates a chip scale package(CSP) in the top package and a fine-pitch ball grid array (FBGA) in the bottom package.In this paper,in-situ scanning electron microscopy(SEM) observation is carried out to detect the deformation and damage of the PoP structure under three-point bending loading.The results indicate that the cracks occur in the die of the top package,then cause the crack deflection and bridging in the die attaching layer.Furthermore,the mechanical principles are used to analyse the cracking process of the PoP structure based on the multi-layer laminating hypothesis and the theoretical analysis results are found to be in good agreement with the experimental results.     

小尺寸数字闭环光纤陀螺信号处理电路

数字闭环光纤陀螺信号处理电路通常由分立的器件构成,其体积较大,限制了光纤陀螺的体积。为了缩小光纤陀螺的体积。设计了一种通用型小尺寸数字闭环光纤陀螺信号处理电路,该电路采用一体化陶瓷外壳,不需要使用基板,通过系统级封装(SIP)的方式,把国产的前级放大器、数模转换器(DAC)、模数转换器(ADC)、后级放大器以及串口收发器的裸芯片封装在外壳里,电路体积仅为14.6mm?14.6mm?2.5 mm,与采用分立的器件相比,光纤陀螺体积缩小了四分之一。电路可以实现光纤陀螺信号的采集以及调制波形的输出,实验结果表明,电路可以实现0.01(°)/h的光纤陀螺精度。     

基于VSP2的液体有机过氧化物不稳定性分级研究

本文通过对国内外危险化学品不稳定性分级进行研究,提出了一种新的有机过氧化物不稳定性分级方法(OPIC),此方法基于泄放尺寸包绝热量热仪(VSP2)测量数据,将反应初始温度(Tonset)作为反应可能性指数(RPI),最大功密度(MPD)(包含反应热(ΔH)和最大反应速率max(dr/dt))、绝热温升(ΔTad)、最大压力上升速率max(dp/dt)和总压力变化(ΔP)等参数通过层次分析法综合为反应严重度指数(RSI),并将前人统计的采用这些参数准确分级的次数代入层次分析法(AHP)中,得到这些参数在反应严重度指数(RSI)中的权重。将RPI指数与RSI指数采用风险矩阵的方法得到最终的有机过氧化物不稳定分级,能更加全面的表征有机过氧化物的不稳定性。根据VSP2实验和计算结果分析证明:利用本文提出的有机过氧化物分级方法(OPIC)对液体有机过氧化物进行分级更符合实际情况,该方法为化学品的本质安全筛选提供了可靠的技术支持。     

高效液相色谱法检测溴化丁基胶塞中11种抗氧剂及游离硫的浸出量及迁移量

采用Inertsil ODS-SP C18(250×4.6 mm,5μm)色谱柱,以0.1%乙酸水-甲醇-乙腈为流动相,进行梯度洗脱,流速为1.0 mL/min,检测波长为277 nm。胶塞提取溶剂分别为无水乙醇和模拟药液。11种抗氧剂及游离硫的分离度均大于1.5;在2.47~54.51μg/mL浓度范围内,线性关系良好(R^2均大于0.999);检出限为0.021~0.403μg/mL;以无水乙醇为提取溶剂时,加标回收率为82.8%~115.3%,相对标准偏差为1.1%~6.1%;以模拟药液为提取溶剂时,加标回收率为62.9%~103.2%,相对标准偏差为1.4%~5.6%。该方法可用于包材相容性试验中实际样品的检测。     

纤维素假性乳胶在药物包衣上的应用

用乳化溶剂蒸发法和相反转法制造纤维假性乳胶及在胃溶型，肠溶型及控释制药物包衣上的应用。     

The response of clamped-clamped microbeams under mechanical shock

We present modeling, simulation, and characterization for the dynamic response of clamped-clamped microbeams under mechanical shock. A Galerkin-based reduced-order model is utilized and its results are verified by comparing to finite-element results. The results indicate that the response of a microbeam to mechanical shock is inherently non-linear because of the dominating effect of mid-plane stretching. The effect of the shock pulse shape is investigated. It is concluded that the shape of the shock pulse can result in significant dynamic amplification in the response of the microbeam even in cases where the shock load is considered quasi-static.The combined effect of the electrostatic force and mechanical shock is investigated. The results show that this combined effect can lead to early instability in microelectromechanical systems (MEMS) devices through dynamic pull-in. This could explain some of the reported experimental evidences for the existence of strange modes of failure of MEMS devices under mechanical shock and impact. These failures are characterized by overlaps between moving microstructures and stationary electrodes, which cause electrical shorts. The shock-electrostatic interaction is shown to be promising to design smart MEMS switches triggered at predetermined level of shock and acceleration. Finally, the mechanical shock combined with the packaging effect of MEMS devices is analyzed. A single-degree-of-freedom model representing the motion of the package, which is mounted over a printed circuit board, coupled with the continuous beam model is utilized. Our results reveal that neglecting the effect of the package motion on the response of microbeams can overestimate or underestimate their response. It is concluded that a poor design of the package may result in severe amplification of the shock effect leading to a device failure.     

基于VxWorks的PCI设备驱动程序设计

 阵列天线控制系统采用实时操作系统VxWorks,为了实现控制系统计算机与单元天线的通信,在控制系统计算机中采用PCI设备与单元天线通信,并且基于VxWorks实时操作系统开发了PCI设备的驱动程序。主要完成了板级支持包的修改、PCI设备的初始化,以及功能函数的设计。经试验验证,该驱动程序工作稳定可靠,可以应用于控制系统中。     

Effects of packing materials on the sensitivity of RadFET with HfO2 gate dielectric for electron and photon sources

The radiation sensing field effect transistor (RadFET) with SiO₂ gate oxide has been commonly used as a device component or dosimetry system in the radiation applications such as space research, radiotherapy, and high-energy physics experiments. However, alternative gate oxides and more suitable packaging materials are still demanded for these dosimeters. HfO₂ is one of the most attractive gate oxide materials that are currently under investigation by many researchers. In this study, Monte Carlo simulations of the average deposited energy in RadFET dosimetry systems with different package lid materials for point electron and photon sources were performed with the aim of evaluating the effects of package lids on the sensitivity of the RadFET by using HfO₂ as a gate dielectric material. The RadFET geometry was defined in a PENGEOM package and electron–photon transport was simulated by a PENELOPE code. The relatively higher average deposited energies in the sensitive region (HfO₂ layer) for electron energies of 250?keV–20?MeV were obtained from the RadFET with the Al₂O₃ package lid despite of some deviations from the general tendency. For the photon energies of 20–100?keV, the average amount of energy deposited in RadFET with Al₂O₃ package was higher compared with the other capped devices. The average deposited energy in the sensitive region was quite close to each other at 200?keV for both capped and uncapped devices. The difference in the average deposited energy of the RadFET with different package lid materials was not high for photon energies of 200–1200?keV. The increase in the average deposited energy in the HfO₂ layer of the RadFET with Ta package lid was higher compared with the other device configurations above 3?MeV.