基于门延时的数字TDC电路设计

为了扩大时间数字转换(Time to Digital Converter,TDC)的测量范围并提高其分辨率,确保测量结果的正确有效,提出了一种数字TDC电路的设计方法.采用与工艺无关的环形门延时单元的设计方法,缩小了电路规模,且可以方便地移植到其它系统中.通过Verilog HDL语言对该设计进行了RTL级的描述,最后通过了时序仿真和FPGA验证.该设计方法与现有设计方法相比,使用较少的逻辑资源达到了大量程高精度的测量要求,计数结果正确稳定.     

2.5D转接板封装高频互连结构设计、分析与测试

An interposer test vehicle with TSVs(through-silicon vias) and two redistribute layers(RDLs) on the top side for 2.5D integration was fabricated and high-frequency interconnections were designed in the form of coplanar waveguide(CPW) and micro strip line(MSL) structures. The signal transmission structures were modeled and simulated in a 3D EM tool to estimate the S-parameters. The measurements were carried out using the vector network analyzer(VNA). The simulated results of the transmission lines on the surface of the interposer without TSVs showed good agreement with the simulated results, while the transmission structures with TSVs showed significant offset between simulation and test results. The parameters of the transmission structures were changed,and the results were also presented and discussed in this paper.     

一种三维立体传输结构的分段式设计方法

随着信号频率以及芯片集成密度的持续增长,三维集成系统内部面临严重的耦合噪声问题。针对三维集成技术中广泛使用的硅通孔(TSV)和水平重布线层(RDL)构成的三维互连结构,提出了一种基于分段传输线(STL)的三维互连结构优化设计方案。通过将三维互连结构传输线按STL模式划分为数个传输线片段生成复数反射波,并运用基因算法(GA)筛选片段特征信息,从而优化反射波叠加效果,实现对传输过程中产生的信号损失进行补偿。仿真结果表明,该方法可以有效改善三维互连结构中由于耦合噪声造成的信号反射问题,提升系统传输性能。     

Analysis and comparison of cloning methods for the preparation of repetitive polypeptides

Repetitive polypeptides, defined as a protein consisting primarily of tandemly repeated blocks of amino acid sequence, are widely used biomaterials. These repetitive polypeptides can be used in diverse biological fields including tissue engineering scaffolds, drug delivery systems, biomaterials, and DNA separation systems. The physical/chemical properties of the repetitive polypeptides can be improved by changing the composition of the repeated amino acid sequence. In this study, we introduced genetic methods for the production of repetitive polypeptides. By using recursive directional ligation (RDL) and controlled cloning method (CCM), multimerized genes were cloned and identified. Also, we compared the characteristics of recursive directional ligation (RDL) with those of controlled cloning method (CCM). This work was presented at 13 ^th YABEC symposium held at Seoul, Korea, October 20–22, 2007.     

玻璃通孔技术研究进展

近年来,随着5G、可穿戴设备、智能手机、汽车电子、人工智能等新兴领域蓬勃兴起,集成电路应用正向着多元化应用方向发展,先进三维封装技术也逐渐成为实现电子产品小型化、轻质化、多功能化的重要手段.玻璃通孔(TGV)互连技术具有高频电学特性优异、成本低、工艺流程简单、机械稳定性强等应用优势,在射频器件、微机电系统(MEMS)封...     

基于RDL的桥梁结构安全监测系统数据报表的研究

针对传统数据报表方案数据分析灵活性低或数据错误率高等弊端,文章转化问题为多模板报表模式,提出了一种基于报表定义语言的报表设计方案。工程应用结果表明,该方案具有灵活性高、一体化程度高和可操作性强的优点,因而能够有效地对桥梁结构安全监测系统数据进行分析。     

圆片级封装工艺简介及其最新发展趋势

圆片级封装(Wafer Level Package)是近期快速崛起的创新性先进封装工艺。因其适应消费性电子产品对轻薄短小特性的需求,故而被市场广泛接受和推崇。本文将会介绍WLP的工艺流程和工艺控制,在可靠度上的挑战,和探讨圆片级封装的最新发展趋势。     

基于SQL2005的企业报表系统的研究与实现

介绍了SQL Server报表服务2005的特点,结合企业报表的需求,采用对RDL文件的修改和对报表服务的数据处理进行扩展的方法,给出了一个在VS环境下利用SQL Server2005中的Reporting Service实现动态显示Web自定义报表的例子。     

Investigation of electromigration reliability of redistribution lines in wafer-level chip-scale packages

Wafer-level chip-scale packages (WLCSPs) have become subject to the same drive for miniaturization as all electronic packages. The I/O count is increasing and ball pitch is shrinking at the expense of trace pitch and in turn, current densities are increasing. This leads to current crowding and Joule heating in the vicinity of solder joints and under bump metallurgy (UBM) structures where resistance values change significantly. These phenomena are responsible for structural damage of redistribution line (RDL)/UBM and UBM/solder interconnects due to ionic diffusion or electromigration. In this work, sputtered Al and electroplated Cu RDLs were examined and quantified by three-dimensional electrothermal coupling analysis. Results provide a guideline for estimating maximum allowable currents and electromigration lifetime.