TiB2掺杂对316L不锈钢厚膜电阻抗氧化性能的影响

目的厚膜电阻在电热膜方面的应用越来越广,而对于多孔陶瓷基体表面的厚膜电阻抗氧化性能的研究尚不多见。方法通过恒温氧化实验研究了TiB_2掺杂对不锈钢厚膜电阻在400、500、600、700℃下抗氧化性能的影响,采用XRD、SEM和EDS等方法分析了未掺杂及TiB_2掺杂两种厚膜电阻的相组成和显微组织。结果两种厚膜电阻的氧化动力学曲线均符合类抛物线模型,即(Δw)n=kt。在400℃下,两种厚膜电阻的指数n均为4,掺杂TiB_2电阻膜的氧化速率常数K1为1955.8 g4/(m8·h),而未掺杂TiB_2电阻膜的氧化速率常数K2为4694.9 g4/(m8·h),这是由于掺杂TiB_2厚膜电阻的致密度较高,使得厚膜电阻的抗氧化性能得以提高。高于500℃时,两种厚膜电阻的指数n均为2,掺杂TiB_2厚膜电阻的氧化速率常数大于未掺杂厚膜电阻。这是由于TiB_2氧化致使膜层内部出现间隙,膜层内部氧化严重(氧化产物主要为TiO_2、B_2O_3、Fe_2O_3以及(Fe_(0.6)Cr_(0.4))_2O_3),厚膜电阻抗氧化性能降低。结论不锈钢厚膜电阻中掺杂TiB_2可在400℃下提高膜层的抗氧化性能,而在500℃以上的高温环境下却有损于膜层的抗氧化性能。     

3D laser trimming technology for regulating embedded thick-film carbon resistors on a random access memory module

This study presents a novel solution for regulating embedded thick-film carbon resistors on random access memory (RAM) modules using 3D laser trimming technology. The embedded passive components, which are printed on a substrate using liquid-polymer ink, are employed due to their rapid response time. The original resistance of such resistors, however, is less than the target value. Hence, a 3D laser trimming technology is proposed for etching thick-film resistors and reaching a target resistance value with online assistance of a four-wire resistance measurement device. A laser beam deflection path with a spiral cycle is manufactured on the printed thick-film to superficially thin the resistor using a wobble-grinding function in a layer-by-layer manner. Resistance material was removed by each laser pulse until the target resistance was obtained. Twelve RAM modules were tested. Experimental results demonstrate that the resistance value of the trimmed resistors was an averaged accredited percentage of 88.54% with a tolerance of 5%. All trimmed resistors with a tolerance of 10% were obtained. Furthermore, 144,000 embedded thick-film carbon resistors on 1800 RAM modules were trimmed in a factory using the proposed scheme. Measurement results indicate that an average accredited rate of 95.67% with tolerances of 5–20% was obtained for industrial applications. Therefore, the proposed technology is a practical and efficient solution for regulating thick-film carbon resistors on RAM modules and other related products.     

低温共烧用可焊浆料用银钯合金粉特性研究

银钯合金粉末制备的电子浆料以其优异的导电、抗银离子迁移、可焊耐焊性,成为低温共烧陶瓷工艺(LTCC)配套用关键电子浆料之一。比较研究两种不同特性的银钯合金粉制备的浆料与Ferro A6生瓷带共烧后的匹配性、电学性能、附着力、可焊性与耐焊性等性能。高振实、大粒径的银钯合金粉制备的浆料与Ferro A6生瓷带共烧平整,电极膜层平整光滑,各项性能表现出优异。粒径较小的银钯合金粉,与瓷料烧结收缩率不匹配,基板翘曲严重,膜层起皱,导电性及可焊耐焊性相对较差。     

RuO2厚膜电阻器的传导模型

ＲｕＯ２基厚膜电阻器的电阻温度系数ＴＣＲ取决于ＲｕＯ２的含量，存在ＲｕＯ２含量的临界点（Ｗｃ），该临界点的ＴＣＲ近似为零。当ＲｕＯ２含量低于Ｗｃ时，电阻有负温度系数，系数值随ＲｕＯ２含量的减少单调增大。当ＲｕＯ２含量高于Ｗｃ时，电阻有正温度系数，其系数值随ＲｕＯ２含量的增加单调增大。用Ｐｉｋｅ和Ｓｅａｇｅｒ提出的隧道效应模型计算电阻器的热电阻温度系数（ＨＴＣＲ）和冷电阻温度系数（ＣＴＣＲ），计算结     

Fibre laser micro-cladding of Co-based alloys on stainless steel

Laser micro-cladding by powder injection has been used to produce Co-based alloy clad strips with geometrical characteristics in the micrometer range (width: 45 µm, height: 15 µm). A new experimental set-up based on the use of a single mode fibre laser and a powder microfeeder was used to produce such coatings. A systematic study on the influence of several processing parameters (laser power, processing speed, mean precursor particle size) on the geometric features of the clad strips was carried out. Moreover Young's modulus and hardness measurements of the micro-clad strips allow affirming that these micro-cladding coatings maintain the mechanical properties typical from this hardfacing alloy.Reparation of defective microparts, surface functionalisation of small areas, or rapid fabrication of prototypes are areas of application of this rapid one step microcoating technique.     

Improved Ag-Si interface performance for Si solar cells using a novel Te-based glass and recrystallization process of Ag

In order to prove that the Te-based glass frit could be applied to Ag pastes to fabricate Ag electrode and elucidate the reactions among Ag,the frit,and the Si wafer,the Te-based glass and Ag pastes with different contents of glass frit(0 wt%,1 wt%,3 wt%,5 wt%,and 7 wt%) were prepared.The microstructures of Ag electrodes and the phase analysis of interface between Ag electrodes and the Si wafer were investigated using scanning electron microscopy(SEM) coupled with energy-dispersive X-ray spectroscopy(EDX) and X-ray diffraction(XRD).When the content of glass frit is 3 wt%,the Ag electrode has good adhesion with Si wafer.What's more,Ag crystallites and metallic Te could be found on the Si wafer.These results suggest that the TeO_2 in the glass frit could react with SiNx anti-reflecting coating(ARC) and Si to serve as a medium for forming Ag crystallites.     

Laser solidification of conductive composites on a fabric surface

Selective laser solidification of conductive composites on rough fabric surfaces for electric circuit boards was carried out. This process has been used for flat, smooth, heat resistant surfaces, such as glass or silicon. However, there are currently numerous applications of printed or fabricated conductive lines for circuit boards on flexible and rough surfaces, and many of them have not been investigated for selective laser solidification. In our study, conductive paste containing nanoparticles that become a conductive layer when solidified was applied to a fabric substrate, and a laser beam was irradiated on the surface to fabricate a conductive line. Conductive lines with low electrical resistance were successfully achieved on the fabric surface. An experimental study and theoretical analysis of solidifying pastes with conductive nanoparticles is presented, and its process characteristics are discussed.     

微连接和纳连接的研究新进展

微连接和纳连接是微/纳级机械、电子和医疗等器件或系统结构制造的关键技术,综述其最新研究进展.针对电子封装,阐述无铅钎料的研制现状和铜引线键合新技术.针对医疗器件和铋系超导带材,分别介绍细丝、薄片连接的典型方法如微电阻焊、微激光焊和钎焊以及一步法扩散焊.对于碳纳米管,介绍电子束辐照连接、双壁碳纳米管薄膜卷覆法连接及钎焊....     

电场增强的阴极弧放电TiCN薄膜结构及性能研究

采用一种新型的电场增强阴极弧沉积技术在304不锈钢表面制备了TiCN涂层。研究了附加电极电流对阴极弧放电特性、涂层相结构、截面形貌、耐磨性以及结合力的影响。结果表明:附加电极的引入显著增加真空室内等离子体密度,工件偏流提高近100%;只有超过一定阈值,附加电极电流才能有效减小晶粒尺寸、提高膜层致密性,同时也提高膜基结合力。附加电极电流为30 A时,膜基结合力达到HF1,相对于无附加电极情况样品表面摩擦系数降低了33%,磨痕宽度最小,耐磨性最好。可见电场增强阴极弧放电是一种非常有效的TiCN制备方法。     

CVD金刚石薄膜的微机械加工技术研究进展

金刚石薄膜是一种蕴涵巨大应用潜力的新型电子功能材料，但是它极高的硬度和化学稳定性使其难以被加工成型，因此，金刚石薄膜的微机械加工技术是其MEMS应用的关键技术问题之一，本文介绍了近年来国内外在选择性生长，模型复制，激光刻蚀和等离子体刻蚀等金刚石微机械加工技术方面的研究进展，着重探讨了可以直接对金刚石薄膜进行微细加工的反应离子刻蚀技术，提出了改善微机械加工效果的金属掩膜侧壁钝化概念，为MEMS器件的金刚石微结构集成制造开辟了更为精确有效的技术途径。     

角位移传感器膜电阻全自动激光修刻系统试验研究

导电塑料角位移传感器中的膜电阻是其核心结构,直接影响传感器的各种输出性能,必须依靠修刻才能满足要求。激光修刻技术是近几年出现的膜电阻修刻新技术,利用了激光微加工精准、非接触并快速的优势,能达到非常高的修刻精度和效率。激光修刻系统主要由带自动调焦激光器、工件自动装卸机构、回转修刻台、阻值在线检测电路和工控机等组成。膜电阻修刻算法是实现快速高精度修刻的关键,依据离散逼近修正理论,通过采用反馈电压算法实现系统的自动修刻控制,试验结果表明:激光修刻系统能达到0.1%的电阻修刻精度和3 min/个的修刻速度。     

Fabrication of concave micro lens array using laser patterning and isotropic etching

Micro lens arrays are widely used in optical communication and laser-fiber coupling applications. In this paper, a technique to fabricate concave micro lens arrays on glass substrate using a third harmonic Nd:YAG laser direct patterning and followed by chemical wet isotropic etching is presented. The patterning process was done on gold film, which was coated on a glass substrate by using a NC controlled laser ablation tool paths. The glass substrate is then etched by using hydrofluoric acid (HF) solutions whereby the exposed area will be dissolved away by chemical reaction with HF. The type of etching process is an isotropic etching which the etching rate is equal at all direction thus produce hemispherical concave profile on glass. The optimum laser patterning parameters is obtained and the effect of different types of HF solutions on etching efficiency is studied. The surface morphology, 2D and 3D profiles are also measured. Various micro lens diameters are fabricated with different values of lens sag.     

新型电阻焊电极材料——弥散强化铜

本文详细介绍了弥散强化铜（ＯＤＳＣ）的组织结构、物化性能、机械性能及制造工艺性，并与铬锆铜进行全面的对比分析。     

LTCC钌系厚膜电阻电性能影响因素研究综述

钌系厚膜电阻具有阻值精度高、稳定可靠性高、工艺重复性好等优点,在厚膜混成电路制造中占据重要的地位。综述了钌系厚膜电阻电性能的影响因素,阐述导电相、粘接相、改性剂及有机载体与共烧电阻体电性能的关系,并针对国内高品质钌系厚膜电阻浆料面临的主要问题,提出原料粉体性能可控性制备,浆料制备工艺的优化设计与表征,浆料与生瓷带共烧匹配以及浆料无铅化等研究方向。     

纳米银填充导电浆料的研究进展

导电浆料是发展电子元器件的基础及封装、电极和互联的关键材料。随着电子元器件向微型化、精密化和柔性化等方向发展,国内外正在开展金属导电填料纳米化的研究。其中,纳米银填充导电浆料成为该领域的研究热点。纳米银作为导电填料对银浆性能影响是正面还是负面影响还没有一个统一的结论。一般认为纳米银填充到基体中,由于粒子间的接触点面积小,填料粒子数目增多导致接触电阻增加。只有当纳米银间距离在一定范围内时,由于隧道效应等使导电性增强。这主要与其颗粒大小和形貌、表面性质和烧结行为等密切相关。本文从纳米银填充导电浆料的导电机理、纳米银低温烧结、表面处理、填量、形貌和原位添加等方面综述了国内外研究者近年来在纳米银填充导电浆方面的研究进展,并对未来的发展方向进行了展望。     

17-4PH不锈钢基体激光熔覆制备球形WC/Ni基复合涂层

为了制备高性能耐磨带,提高工件的使用寿命,利用激光宽带熔覆技术在17-4PH不锈钢表面沉积镍基合金做为过渡层,然后熔覆球形WC/Ni基复合涂层。对激光熔覆层分别采用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射(XRD)等检测分析手段进行形貌观察、成分分析、物相表征等,并使用MMG-10型摩擦磨损试验机进行涂层耐磨性能测试。研究结果表明,采用激光熔覆技术可制备高质量WC/Ni基复合涂层,碳化钨质量分数达到65%,涂层冶金质量、裂纹尺寸、稀释率等满足技术要求。复合涂层的耐磨性为镍基合金的15倍,但其平均摩擦系数(0.926)高于镍基合金(0.762)。     

热式MEMS流量传感器的设计及测试

根据已有的热式MEMS气体微流量传感器芯片的各部分热敏电阻热串扰现象严重,造成很大的测量误差,改进设计了一种MEMS热式流量传感器,将加热电阻和上下游测温电阻采用悬臂梁隔离结构,并相互隔离,有效的避免了热膜流量传感器各部分热敏电阻间相互热串扰现象。基于改进的MEMS热式流量传感器,设计了流量传感器的测试系统,包括恒温差电路、桥式测量电路及放大、滤波电路,所采集的流量信号经过滤波放大后输入AD模块进行模数转换,最后经过单片机处理,利用单片机与计算机串口通信功能,在不同流速下打印出不同的电压值;通过Matlab对所测出的数据进行拟合,完成对传感器性能的检测。测量结果表明:在一定的流量范围内,该流量传感器具有测量精度高、响应速率快、输出信号平滑等特点,能够广泛应用于工业、医疗领域的流量测量。     

Stencil printing behavior of lead-free Sn-3Ag-0.5Cu solder paste for wafer level bumping for Sub-100 μm size solder bumps

Stencil printing for flip chip packaging using fine particle solder pastes is a low cost assembly solution with high throughput for fine pitch solder joint interconnects. The manufacturing challenges associated with both solder paste printing increases as electronic device size decreases due to trend of miniaturization in electronic components. Among multiple parameters, the two most important stencil printing parameters are squeegee pressure and printing speed. In this paper, the printing behavior of Pb free Sn-3Ag-0.5Cu solder paste with a particle size distribution of 2–12 μm for wafer level bumping using a stencil printing method (stencil opening dimension ?30 μm) was evaluated by varying the printing speed and squeegee pressure to fabricate solder bumps with a sub 100 μm size. The optimal squeegee pressure and print speed for the defect free printing behavior and fairly uniform size distribution of reflowed paste were found to be 7 kgf and 20 mm/s, respectively. The average size of the reflowed printed paste decreased with the increasing squeegee pressure.     

金铂钯合金粉末的特性对低温共烧电子浆料性能的影响

以金铂钯粉末作为导电相的电子浆料由于其优异的可焊性、耐焊性与可靠性,成为低温共烧工艺配套用关键电子浆料之一。采用2种不同特性的金铂钯合金粉末调制出相应的浆料,比较研究了2种浆料与Ferro A6生瓷料带实施共烧后的匹配性、电学性能、可焊性与耐焊性、附着力等性能。结果表明,高密度、亚微米级球形粉制备的浆料具有更好的综合性能。     

The formation of diamond-like carbon film at atmospheric pressure by the pulsed laser/plasma hybrid deposition method

A pulsed laser/plasma hybrid deposition method has been developed to produce the diamond-like carbon (DLC) film at atmospheric pressure in this work. A plasma torch was used to heat up the carbon particles which were simultaneously ablated by a pulsed laser, thus the kinetic energy of the carbon particle can be increased to form the carbon atoms with amorphous bonding structure of the DLC film by this proposed hybrid deposition method.The influences of the plasma flow have been examined numerically and experimentally. In the numerical analysis, the temperatures of the plasma flow at various inlet pressures and electrode currents have been predicted. According to the experimental results of the carbon film inspected by the Raman spectroscopy, it reveals that the intensity ratio of the D-band to G-band of the carbon film can be reduced to 0.5 by the implementation of plasma flow. Therefore the DLC film was solidly formed. The adhesive strength of the DLC film was also characterized by the scratch test, it can be found that the critical loading of the film is up to 19 N.