IC基板传输机器人末端执行器结构拓扑优化设计

在半导体封装基板检测的传输过程中,末端执行器对其快速稳定高效率的传输起着关键作用。在满足设计强度、刚度的条件下,以末端执行器轻量化为目标,建立了末端执行器的三维模型,利用有限元分析软件ANSYS对基板传输机器人末端执行器进行静力学和模态分析,得到末端执行器在最大载荷情况下的应力、应变特性和对应的振型,并对其进行拓扑优化设计,根据拓扑优化结果建立新的末端执行器结构,对新的结构进行强度校核,验证设计方案的有效性。研究结果表明,优化后末端执行器的前四阶固有频率都大于伺服电动机的回转频率(50Hz),质量减少了26.7%,较好地实现了轻量化的目标,同时为后续的相关产品研制提供了一种新的技术方案。     

影响微小零件可靠操作的粘附力及其影响因素

分析了末端执行器的拾取与释放过程，零件和末端执行器材料以及环境湿度对粘附力的影响，利用微力传感器，按 “接触－分离”的运动方式，测量了末端执行器和3种不同材料零件之间的粘附力.即最大的分离力。结果表明:分离速度和拾取时的加载时间增加，都会导致粘附力增大，不同的拾取加载力对粘附力几乎不会产生影响，不同材料的末端执行器与不同材料零件之间的粘附力差异明显，随着环境湿度的增加，表面粘附力明显增大，因此采用表面能较低材料的末端执行器、减小环境湿度等措施，可减小装配过程中的粘附力，提高操作的可靠性。     

冗余并联机构的刚度分析

本文给出了并联机构刚度的定义和物理意义,求出了刚度矩阵的度量指标。对非冗余并联机构,在靠近电机和工作空间的两个顶点位置时刚度很大,末端执行器失去了其原有自由度而使得机构刚化,在奇异点位置时,因为末端执行器获得了自由度使刚度趋于零;对冗余并联机构,在靠近三个顶点位置时,刚度突然增大,末端执行器失去了其原有自由度而使得机构刚化。驱动冗余可以明显提高并联机构的刚度,完全可以消除奇异性对刚度的影响。     

苹果采摘装置的研究与探讨

苹果采摘装置适用于苹果成熟后的苹果采摘,智能化机械化的采摘模式解放了劳动力,提高了采摘效率,本装置利用无线遥控技术,搭载移动平台,安装末端执行装置即机械手,实现了苹果采摘过程中的机械化,利于农业机器人的研发应用。     

加强科学数据汇交安全保障

当今,科学数据的管理与共享在科学发现与社会经济发展中的作用尤为凸显。科研项目实施过程中产生的数据,既是项目研究成果的重要组成部分,又是科技创新的重要基础。经过十几年的不断探索,数据汇交工作在科研管理工作中越来越受到重视。数据汇交过程步骤较多,如何在汇交过程中做好数据安全和涉密数据保密工作,更好地服务国家科技发展,是科研工作需要重点关注的问题。     

一种快速响应双稳态热执行器的结构设计

利用ANSYS有限元分析软件并结合工艺条件,就其中的热执行按照快速响应的特点,对各结构参数与热执行器部件的驱动力、驱动位移、电阻、响应时间等驱动性能的影响进行了分析与仿真,从而得到了优化结构设计。此设计所要达到的目标是,热执行器驱动电压为5V,响应时间为2ms,末端最大位移为3.16×10-4m,末端位移20μm时的驱动力为4.94×10-3N。     

传感器和传动器

能确保精确定位的外直线执行器HSI 的size11 混合式外直线执行器采用了集成到电机转子上的、可旋转的不锈钢acrme螺杆结构,避免了轴-螺杆连轴器的采用。该执行器可以取代4种不同的部件:电机、连轴器、螺杆和螺帽。外直线执行器上的螺帽采用了与HIS的约束式和非约束式设计的转子驱动螺帽相同的工程热塑料。这确保了高精度应用中的无故障、长寿命工作。分辨率范围从0.000125~0.002/步,推进力达到25lbs。标准的size 11外直线执行器有4条可见的螺杆。螺杆长度、线圈端子和负载螺帽可以根据用户的具体要求定制。螺杆的末端可以采用特殊加工,以…     

双向横向热执行器结构设计

在传统非对称冷热梁结构横向热执行器的基础上,提出了一种能实现双向横向运动的热执行器.采用对称结构设计,主要由折叠柔性梁、直柔性梁、宽梁和连接梁构成,通过选择加热臂,可以控制结构的偏转方向,实现双向推挽运动.在典型尺寸下,仿真结果显示,在20 mW驱动作用下,产生的末端位移9.55 μm,驱动力9.4μN,其性能与单向横向执行器相当.同时还进行了结构优化分析.     

基于AMAMS/View六自由度串联机器人运动学仿真

采用ADAMS建立机器人的运动学模型,设定一直线为机器人末端执行器的行走轨迹,通过在ADAMS环境下添加约束和运动,完成机器人的运动学仿真。调用独立的后处理模块ADAMS/PostProcessor,获得机器人的各种运行曲线。     

基于六维机械手的硅片传输系统

详细介绍了如何选择满足CMP抛光机硅片传输系统要求的六维机械手,并基于所选择的六维机械手配合换枪盘、末端执行器构建了硅片干进湿出式传输系统,最终利用示教盒示教出一条无碰撞、姿态合理的运动路径。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Call for Papers

正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its