时钟信号竞争型三值CMOS边沿触发器

本文利用时钟信号的竞争冒险现象,提出了CMOS时钟信号竞争型三值D型边沿触发器的逻辑设计.通过PSPICE程序模拟,证实了该设计具有正确的逻辑功能,而且与传统的三值D型维持阻塞触发器相比,它具有更简单的结构和更低的功耗.     

热超声倒装键合换能系统多模态振动与有限元分析

研究了热超声倒装键合设备的核心执行机构——换能系统的动力学特性.利用激光多谱勒测振仪测试系统末端各方向的振动速度,发现系统以轴向振动为主,但受到其他非轴向振动的干扰.非轴向振动对芯片造成芯片倾斜、键合强度降低等负面影响.采用有限元方法对换能系统建模,仿真计算发现换能系统振动是各方向振动的耦合结果,且工作模态附近存在多种干扰模态.最后分析了系统多模态产生的根源并提出抑制方法.     

Morphological stability of solder reaction products in flip chip technology

We have studied two kinds of solder reactions between eutectic SnPb and Cu. The first is wetting reaction above the melting point of the solder, and the second is solid state aging below the melting point of the solder. In wetting reaction, the intermetallic compound (IMC) formation has a scallop-type morphology. There are channels between the scallops. In solid state aging, the IMC formation has a layer-type morphology. There are no channels but grain boundaries between the IMC grains. Why scallops are stable in wetting reactions has been an unanswered question of fundamental interest. We have confirmed that the scallop-type morphology is stable in wetting reaction by re-wetting the layer-type IMC by molten eutectic SnPb solder. In less than 1 min, a layer-type Cu₆Sn₅ is transformed back to scallops by the molten solder at 200 C. In analyzing these reactions, we conclude that the scallop-type morphology is thermodynamically stable in wetting reaction, but the layer-type morphology is thermodynamically stable in solid state aging, due to minimization of interfacial and grain boundary energies.     

确定非正常触发主从JK触发器次态的一种简单方法

通过对非正常触发时主从JK触发器可能出现的工作波形的详细分析,归纳出了非正常触发时确定主从JK触发器次态的简单方法。     

Periodic solutions and flip bifurcation in a linear impulsive system

In this paper, the dynamical behaviour of a linear impulsive system is discussed both theoretically and numerically. The existence and the stability of period-one solution are discussed by using a discrete map. The conditions of existence for flip bifurcation are derived by using the centre manifold theorem and bifurcation theorem. The bifurcation analysis shows that chaotic solutions appear via a cascade of period-doubling in some interval of parameters. Moreover, the periodic solutions, the bifurcation diagram, and the chaotic attractor, which show their consistence with the theoretical analyses, are given in an example.     

双面电镀在先进封装中应用的可行性研究

在晶圆双面及孔的侧壁用一种简单的工序电沉积金属的能力,在先进封装和某些工艺中提供了一些基本的优势。双面电镀样机硬件已经过用配置垂直电镀槽的生产型ECD装置的试验。这种工艺已经成功地在几种不同的金属和多种应用中得以展示。     

具有轨道翻转和倾斜翻转的退化异维环分支

本文研究4 维系统中一类具有轨道翻转和倾斜翻转的退化异维环分支问题. 通过在未扰异维环的小管状邻域内建立局部活动坐标系, 本文建立Poincaré 映射, 确定分支方程. 由对分支方程的分析,本文讨论在小扰动下, 异宿环、同宿环和周期轨的存在性、不存在性和共存性, 且给出它们的分支曲面以及共存区域, 推广了已有结果.     

关于反中心对称矩阵的某些性质探讨

利用反中心对称矩阵的定义以及翻转矩阵等技巧,给出了反中心对称矩阵的伴随矩阵、特征值及特征向量的一些新结论.     

Codimension-4 resonant homoclinic bifurcations with orbit flips and inclination flips

The paper studies a codimension-4 resonant homoclinic bifurcation with one orbit flip and two inclination flips, where the resonance takes place in the tangent direction of homoclinic orbit.Local active coordinate system is introduced to construct the Poincar′e returning map, and also the associated successor functions. We prove the existence of the saddle-node bifurcation, the perioddoubling bifurcation and the homoclinic-doubling bifurcation, and also locate the corresponding 1-periodic orbit, 1-homoclinic orbit, double periodic orbits and some 2n-homoclinic orbits.