激光微细熔覆快速制造厚膜热敏传感器的研究

采用激光微细熔覆技术，利用钌系厚膜热敏电阻浆料，在质量分数为96％的Al2O3陶瓷基板上成功地制作出热敏电阻器。热敏电阻图形的极限线宽线距能达到60 μm。元件的电阻温度特性(TCR)值为2.33×10-3 /℃，热响应时间2.3 s,线性度达到0.6 ℃，有着良好的重复性、热稳定性和迟滞性。通过实验得出了激光处理工艺中参数对元件性能的影响规律。对所制作热敏电阻元件的各项电性能进行测量，并与传统工艺制作的元件进行了比较，测试结果证实新工艺制作的元件具有相对优良的特性，有较强的实用前景。     

Organic Light‐Emitting Diode Sensing Platform: Challenges and Solutions

The organic light‐emitting diode (OLED)‐based sensing platform is gaining momentum due to unique attributes of the compact OLEDs that are used as excitation sources. This paper, however, points to issues related to this sensing platform that will affect many (bio)chemical sensing applications, in particular in photoluminescence (PL)‐based sensors operated in the advantageous time domain, where pulsed OLEDs are utilized. The issues are related to the post‐pulse electroluminescence (EL) profile, i.e., transient EL, which depends on the OLED materials and structure, and to the long‐wavelength tail of the typically broad‐band EL spectrum. Depending on materials and device structure, the transient EL may exhibit spikes peaking at ～100–200 ns and μs‐long tails. As shown, these interfere with the determination of PL decay times (that are related to analyte concentrations) of sensing elements. The results also indicate that the long‐wavelength tail of the EL spectrum contributes to the interfering post‐pulse μs‐long EL tail. Hence, it is shown that the choice of OLED materials, the use of microcavity (μC) OLEDs with tunable, narrower EL bands, and the use of UV OLEDs alleviate these issues, resulting in more reliable data analysis. Furthermore, a 2‐D uniform 2 μm‐pitch microlens array that was previously used for improving light extraction from the OLEDs (J.‐M. Park et al., Optics Express 2011 , 19, A786) is used for directional PL scattering toward the photodetector, which leads to a ～2.1–3.8 fold enhancement of the PL signal. This behavior is shown for oxygen sensing, which is the basis for sensing of bioanalytes such as glucose, lactate, ethanol, cholesterol, and uric acid.     

一种磁吸附式微小型惯性粘滑运动平台研究

在显微操作领域中,要求运动平台能在狭小空间中实现高精度的位姿调整,因此,该文提出了一款整体尺寸仅10 mm×10 mm×10 mm的惯性粘滑精密跨出度定位运动平台。该结构的设计采用将惯性部分与滑块部分集成为一体的设计方案,摩擦力使用磁铁来提供。对惯性粘滑运动平台中的柔性铰链进行尺寸优化,并使用有限元分析软件进行校核,验证理论分析的正确性。测试样机性能结果表明,水平方向最大运动速度为4.966 mm/s,竖直方向上运动速度可达2.1 mm/s,正、反向最大单步位移分别为2.984μm和2.349μm,步长重复性良好。实验证明,该样机具有体积小,运动速度快,步长重复性稳定等特点,适用于狭小空间内的高精度运动。     

铒镱共掺铋磷酸盐玻璃光谱性能的研究

基于光通信技术发展对光放大器材料的带宽要求,研究了掺铒铋磷酸盐玻璃的结构、熔制性能,以及其光谱性能,并且用Judd-Ofelt理论进行了光谱计算分析。得到了一种以铋磷酸盐为基质的光放大器玻璃材料,其折射率为1.778,荧光半峰全宽为54nm,发射截面为0.61×10-20cm2,其荧光寿命达到了8ms。结果表明,铒镱共掺铋磷酸盐玻璃是一种良好的宽带放大器材料。     

一种大容性负载的压电陶瓷驱动电源设计

压电陶瓷作为微定位系统的动能器件,可达到纳米级的位移精度。针对位移驱动型压电陶瓷的大容性负载特点,基于PA92设计了一种高精度、大电流的动态驱动电源。通过电容超前反馈、隔离电阻结合反馈及相位补偿等方式提高了电源的稳定性。分析结果表明,该电源能有效应用于纳米级定位系统中,在大容性负载时具有良好的动态性能,输出电压精度可达0.5 mV。     

Mechanical strength of Sn-3.5Ag-based solders and related bondings

The tensile strengths of bulk solders and joint couples of Sn-3.5Ag-0.5Cu, Sn-3.5Ag-0.07Ni, and Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge solders and the shear strengths of ball grid array (BGA) specimens, solder-ball-attached Cu/Ni/Au metallized substrates were investigated. The tensile strength of the bulk is degraded by thermal aging. The Ni-containing solder exhibits lower tensile strength than Sn-3.5Ag-0.5Cu after thermal aging. However, the Ni-containing solder joints show greater tensile strength than the Cu/Sn-3.5Ag-0.5Cu/Cu joint. Fracture of the solder joint occurs between the intermetallic compound (IMC) and the solder. The shear strength and fracture mechanism of BGA specimens are the same regardless of solder composition.     

On the Feasibility of Growing Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 Single Crystals

Pb[(Zn_1/3Nb_2/3)_0.91Ti_0.09]O₃ (PZNT91/9) single crystals were grown by two methods: from solution using PbO as a self‐fluxing agent (SC method) and directly from the melt without fluxing (MC method). In both growth methods, an allomeric Pb[(Mg_1/3‐Nb_2/3)_0.69Ti_0.31]O₃ (PMNT69/31) single crystal was used as a seed. X‐ray diffraction patterns of ground crystals showed that phase‐pure perovskite PZNT91/9 single crystals were successfully fabricated by the above two methods. The composition of the crystals obtained by both the SC and MC methods was analyzed using X‐ray fluorescence, which confirmed that the crystal composition is close to the nominal value, although volatilization of PbO and segregation during crystal growth are inevitable. The MC PZNT91/9 crystals exhibit excellent piezoelectric properties, with the piezoelectric constant, d₃₃, in the range of 1800–2200 pC N^–1. This value is comparable to that of the SC crystals. However, the MC crystals show an abnormal dielectric behavior. In contrast with the SC crystals, in the MC crystals a much broader dielectric peak appears in the dielectric response curves, accompanied by a much lower peak temperature of around 105 °C. Furthermore, frequency dispersion is apparent over a much wider temperature range (even more apparent than in pure relaxors), where a large, i.e., about 70 °C, full width at half maximum (FWHM) for the dielectric peaks is observed in the dielectric response. It is speculated that such an unusual phenomenon correlates with defects, microinhomogeneities, and polar regions in the as‐grown MC crystals. The origins of this abnormality have not been interpreted in detail until now. However, optical observation of the domain structure confirms that both the SC and MC crystals possess complex structural states.     

限流用BaTiO3系PTC陶瓷的制备及影响因素

介绍了以钛酸四丁酯和自制高纯醋酸钡为主要原料,采用溶胶–凝胶一步法(sol-gel)制备限流用BaTiO3系PTC陶瓷材料的工艺路线,用正交实验法研究了Ti/Ba,Pb,Ca,Y,Mn等组分因素对PTC陶瓷材料性能的影响。优化确定了PTC陶瓷材料的较佳组成。在基方固溶体化学组成,原材料选择和复合添加物的改性,特别是烧结工艺等方面做了细致的工作。最终获得了居里温度(tC)100℃,室温电阻率(r25) ≤20 ·cm,升阻比(Rmax / Rmin)>105,温度系数(aR)≥15% /℃,耐电压(Vb)≥190 V·mm1的PTC陶瓷材料。     

利用固相反应法在硅片上制备硅酸锌发光薄膜及表征

采用与硅集成工艺相兼容的固相反应方法在硅衬底上制备了未经掺杂及掺锰的硅酸锌薄膜 .XRD测试和UV - Vis吸收谱测试证明在高于 880℃的温度下热处理 ,可以获得结晶状态很好的硅酸锌薄膜 .光致发光光谱分析表明 ,未掺杂的薄膜在紫外波段有较弱的发射 ,而掺锰的硅酸锌薄膜在可见光波段有很强的光致发射 .由于硅酸锌薄膜在高温下非常稳定 ,可以与硅集成电路工艺兼容 ,而且发光强度高 ,因此在制作硅基光电集成器件方面有非常大的应用前景