折衍混合单透镜的色球差校正研究

分析研究了小视场折射混合单透镜的设计中，当衍射面同时用于消色差和球差时光焦度分配的最优方案，得到了改进的光焦度分配公式，通过设计实例表明，由该改进公式可得到了较好的初始结构，能够有效地克服了衍射光学透镜校球差时产生的较大的色球差，验证了此改进公式的正确性和有效性，此改进公式对折衍混合系统的设计具有指导意义。     

DOE技术在低电压CMOS晶体管中的质量控制

采用DOE(Design of Experiment)试验方法进行了CMOS晶体管工艺流片的分卡操作,研究18个样品的Vt区注入Dvt、N场注入DNF、TEMP注入DP这3种注入剂量变化的情形下阈值电压Vtn和Vtp的调控优化值。通过最大跨导法测试阈值电压Vtn和Vtp,考查3种注入剂量对Vtn和Vtp的影响趋势,发现Dvt和DNF直接决定Vtn,Dvt和DP直接决定Vtp。结果表明,Vtn为0.082 V~0.600 V,关系式为Vtn=0.15791Dvt+0.12320DNF+0.11433;Vtp为0.0535 V~0.6300 V,关系式为V2tp=-0.03077D2vt-0.01688D2P+0.71899。     

衍射器件实现单模光纤与光波导低损耗耦合

提出了一种集成化衍射光学模式转换器。利用衍射光学器件(DOE)实现模式转换，消除模式失配，实现单模光纤(SMF)与光波导的低损耗耦合。DOE的相位分布由数值迭代相位恢复算法优化得到。在迭代算法中引入一种新的混和远场约束，达到很高的模式转换质量。此方案适用于任何波导结构。分别针对不同尺寸及不同折射率对比度的方形波导、薄膜波导和脊形波导进行了设计，耦合损耗均降至0.12dB以下。     

Assessing the MALDI-TOF MS sample preparation procedure to analyze the influence of thermo-oxidative ageing and thermo-mechanical degradation on poly (Lactide)

Multiple processing by means of successive injection cycles was used to simulate the thermo-mechanical degradation effects on the oligomeric distribution of PLA under mechanical recycling. Likewise, an accelerated thermal ageing over PLA glass transition was performed in order to simulate its service life. MALDI-TOF MS was used for the analysis and the sample preparation procedure was assessed by means of a statistical Design of Experiments (DoE). The quality effects in use for the analysis were signal-to-noise ratio and Resolution. Different matrixes, analyte/matrix proportions and the use of NaTFA as cationization agent were considered. A deep inspection of the statistical results provided a better understanding of the influence of the different factors, individually or in combination, to the signal. The application of DoE for the improvement of the MALDI measurement of PLA stated that the best combination of factors (levels) was the following: matrix (s-DHB), proportion analyte/matrix (1/5 V/V), and no use of cationization agent. Degradation primarily affected the initially predominant cyclic [LA_C]_n and linear H[LA_L]_nOH species, where LA stands for a PLA repeating unit. Intramolecular and intermolecular transesterifications as well as hydrolytic and homolytic reactions took place during the formation and disappearance of oligomeric species. In both degradation mechanisms induced by thermal ageing and thermo-mechanical degradation, the formation of H[LA_L]_nOCH₃ by intermolecular transesterifications was highlighted.     

印制板翘曲品质改善研究

随着电子产品向轻、薄、小的方向发展。印制板的封装方式也在不断的改变,这就对PCB的制造提出了更高的要求,特别是印制板的平整度要求,只有保证PCB在PCBA过程中有很高的平整度,才能保证SMD引脚与板面焊盘的焊接,才能保证SMT过程的质量(包括网印焊膏、贴片、等工序)。分析了造成翘曲问题的主要原因,从分析中可以看出,其原因是多方面的,可以说是从供应商的基板来料开始,一直到做成成品的印制板,还有在客户的SMT过程中,都有机会造成翘曲问题,就引起翘曲问题的主要原因进行研究,通过对印制板的排板结构的设计、压合工序的影响及FQC翻压工序分别进行了DOE实验研究,共进行了70多个工艺实验,对试验结果进行统计分析,找出影响翘曲的主要影响因素,并进行参数优化,达到改善翘曲品质的目的。     

无铅BGA枕头缺陷的研究

BGA枕头焊点的锡膏和锡球完全没有融合成为一体,倒过来看就像头压在枕头上面。介绍了四种有效的检测方法。从设计、材料和工艺三方面分析了枕头缺陷的潜在影响因素。选取PCB玻璃态转化温度、钢网厚度、BGA贴装偏移量和回流焊炉链条速度四个因素进行两水平全因子实验设计,在成功复制枕头缺陷的基础上,分析了各因素的影响作用,得出了链条速度是最显著的影响因素。     

Combination of CFD and DOE to analyse solid particle erosion in elbows

Solid particle erosion is a major concern in the engineering industry, particularly where transport of slurry flow is involved. Such flow regimes are characteristic of those in alumina refinement plants. The entrainment of particulate matter, for example sand, in the Bayer liquor can cause severe erosion in pipe fittings, especially in those which redirect the flow. The considerable costs involved in the maintenance and replacement of these eroded components led to an interest in research into erosion prediction by numerical methods at Rusal Aughinish alumina refinery, Limerick, Ireland, and the University of Limerick. The first stage of this study focused on the use of computational fluid dynamics (CFD) to simulate solid particle erosion in elbows. Subsequently an analysis of the factors that affect erosion of elbows was performed using design of experiments (DOE) techniques. Combining CFD with DOE harnesses the computational power of CFD in the most efficient manner for prediction of elbow erosion. An analysis of the factors that affect the erosion of elbows was undertaken with the intention of producing an erosion prediction model.     

基于衍射光学元件色散特征的三维建模系统

为了重建复杂形状的三维物体,在此提出了一种便捷的基于衍射光学元件（DOE）色散成像特性的三维建模算法,该算法在一种新型的三维建模系统中实现,它充分利用了DOE在红外波段的模式投影和探测.给出了重建复杂形状的三维物体的仿真试验结果,证明该算法及系统的有效性和可行性.     

衍射光学元件车削补偿技术的研究

超精密单点金刚石车削加工是高精度衍射光学元件制造的重要方法,但是以往的加工方法是直接一次车削加工成型,无法实现具有加工-检测-补偿加工-检测的闭环控制特点的超精密加工,从而导致零件精度较低。针对这种加工技术的缺陷,通过研究衍射光学元件金刚石车削过程和面形状误差补偿,对表面轮廓仪实际测量的轮廓数据进行处理,计算出实际车削曲线与理想曲线之间的法向残余误差,以此获得新的金刚石车削加工轨迹,实现衍射光学元件的超精密闭环控制加工。利用单点金刚石车床对口径78的衍射光学元件进行补偿加工试验,最终使其PV值由10.4 m经过一次补偿加工后降为4.3 m。     

DOE在SMT丝网印刷中质量改进的应用

影响丝网印刷质量的主要因素有焊膏的特性、模版与PCB的制造质量、印刷机的工艺参数和性能以及操作工艺流程是否规范等。当前,由于无铅焊膏的使用,焊膏物理性能变化,需要重新摸索调整无铅焊膏的印刷参数,以获得最好的焊膏印刷质量。文章借助质基改进中DOE质量工具的理论,结合实际工艺参数特性建立了相应的正交表,并采用了极差分析法和MINITAB软件分析法。通过建立最优响应模型,选出了最优参数的近似值,并得到了实际生产中的验证,明显提高了SMT良率。