A surface mounted device （SMD） microwave ceramic band-pass filter for mobile communication with a new coupling structure is reported in this paper. In this filter, the external and internal coupling structures are f...A surface mounted device （SMD） microwave ceramic band-pass filter for mobile communication with a new coupling structure is reported in this paper. In this filter, the external and internal coupling structures are fabricated on an alumina substrate and both resonators and coupling structures are placed into a metal house to cut off its radiation. The relationship between the coupling structures and the performance of the filter is analyzed by high frequency structure software （HFSS） and the filter with a center frequency of 836.5 MHz, bandwidth of 40.0 MHz, pass-band ripple of 0.1 dB and insertion loss of 1.5 dB has been successfully designed and fabricated. The measured results show a good agreement with the simulation results.展开更多
The relationship between the photometric, electric, and thermal parameters of light-emitting diodes（LEDs） is important for optimizing the LED illumination design. Indium gallium aluminium phosphide（InGaAlP）-based ...The relationship between the photometric, electric, and thermal parameters of light-emitting diodes（LEDs） is important for optimizing the LED illumination design. Indium gallium aluminium phosphide（InGaAlP）-based thin-film surface-mounted device（SMD） LEDs have attracted wide attention in research and development due to their portability and miniaturization. We report the optical characterization of InGaAlP thin-film SMD LED mounted on FR4, 2 W, and 5 W aluminum（Al） packages. The optical and thermal parameters of LED are determined at different injection currents and ambient temperatures by combining the T3ster（thermal transient tester） and TeraL ED（thermal and radiometric characterization of power LEDs） systems. Analysis shows that LED on a 5 W Al substrate package obtains the highest luminous and optical efficiency.展开更多
针对贴片机中表面贴装器件(Surface Mount Device,SMD)的视觉测量问题,研究了SMD的图像识别和测量算法.基于视觉飞行对中技术获取SMD图像.根据SMD的几何特征,提出了用于其图像处理流程的高斯滤波、迭代算法和最小面积外接矩形算法,并分...针对贴片机中表面贴装器件(Surface Mount Device,SMD)的视觉测量问题,研究了SMD的图像识别和测量算法.基于视觉飞行对中技术获取SMD图像.根据SMD的几何特征,提出了用于其图像处理流程的高斯滤波、迭代算法和最小面积外接矩形算法,并分别在Halcon和OpenCV两大机器视觉平台上进行对比分析与验证.展开更多
Fluxless soldering can solve a series of problems caused by side-effects afflux essentially. Feasibility research on vacuum fluxless laser soldering and mechanism analysis on fluxless action of vacuum were carried out...Fluxless soldering can solve a series of problems caused by side-effects afflux essentially. Feasibility research on vacuum fluxless laser soldering and mechanism analysis on fluxless action of vacuum were carried out. Fluxless soldering succeeded in spreading and wetting on Cu pad with laser heating source in vacuum surroundings. What' s more, this fluxless technology was applied in surface mounting of chip resistance successfully.展开更多
基金Supported by Sino-British Excellent Youth Scholar Foundation (2005362)the Natural Science Foundation of Hubei Province (2008CDB315)
文摘A surface mounted device （SMD） microwave ceramic band-pass filter for mobile communication with a new coupling structure is reported in this paper. In this filter, the external and internal coupling structures are fabricated on an alumina substrate and both resonators and coupling structures are placed into a metal house to cut off its radiation. The relationship between the coupling structures and the performance of the filter is analyzed by high frequency structure software （HFSS） and the filter with a center frequency of 836.5 MHz, bandwidth of 40.0 MHz, pass-band ripple of 0.1 dB and insertion loss of 1.5 dB has been successfully designed and fabricated. The measured results show a good agreement with the simulation results.
文摘The relationship between the photometric, electric, and thermal parameters of light-emitting diodes（LEDs） is important for optimizing the LED illumination design. Indium gallium aluminium phosphide（InGaAlP）-based thin-film surface-mounted device（SMD） LEDs have attracted wide attention in research and development due to their portability and miniaturization. We report the optical characterization of InGaAlP thin-film SMD LED mounted on FR4, 2 W, and 5 W aluminum（Al） packages. The optical and thermal parameters of LED are determined at different injection currents and ambient temperatures by combining the T3ster（thermal transient tester） and TeraL ED（thermal and radiometric characterization of power LEDs） systems. Analysis shows that LED on a 5 W Al substrate package obtains the highest luminous and optical efficiency.
文摘针对贴片机中表面贴装器件(Surface Mount Device,SMD)的视觉测量问题,研究了SMD的图像识别和测量算法.基于视觉飞行对中技术获取SMD图像.根据SMD的几何特征,提出了用于其图像处理流程的高斯滤波、迭代算法和最小面积外接矩形算法,并分别在Halcon和OpenCV两大机器视觉平台上进行对比分析与验证.
基金This project is subsidized by Natural Science Funds of Naion.The authorized number is 59671063.
文摘Fluxless soldering can solve a series of problems caused by side-effects afflux essentially. Feasibility research on vacuum fluxless laser soldering and mechanism analysis on fluxless action of vacuum were carried out. Fluxless soldering succeeded in spreading and wetting on Cu pad with laser heating source in vacuum surroundings. What' s more, this fluxless technology was applied in surface mounting of chip resistance successfully.
