NiAl对激光熔凝Ni-P-Al2O3复合镀层性能的影响

利用CO2激光熔凝NiAl/Al2O3化学复合镀层,研究NiAl金属间化合物的加入对复合镀层的性能影响.借助SEM、XRD、摩擦摩损试验机等对激光强化后的复合镀层的成分、组织、结构以及耐磨性能进行了分析.NiAl金属间化合物的加入明显提高复合镀层的表面平整度,对显微组织的细化也起到了一定的作用.激光熔凝后产生的金属间化合物对提高复合镀层的硬度和耐磨性起到重要的作用.复合镀层硬度提高近3倍,而其耐磨性提高50%左右.     

电场力显微镜不同探针对表面电荷注入的影响

在电场力显微镜(EFM)下利用不同金属镀层微探针,在微纳米尺度下对聚酰亚胺薄膜的表面电荷生成特性进行研究。采用电场力显微镜导电探针在聚酰亚胺薄膜表面注入电荷,并对微纳米区域产生的电荷进行表征,结果表明不同金属镀层的微探针对聚酰亚胺薄膜上电荷注入效果不同。铂铱合金镀层具有比钴铬合金镀层更高的功函数fm,因此前者在金属-电介质接触中产生更大肖特基势垒,进而降低了电荷的注入程度。该研究为微纳米尺度下探索聚合物绝缘材料表面电荷生成、发展机理提供了一个新的研究方法和途径。     

激光熔凝NiAl/纳米Al2O3化学复合镀层抗高温氧化性能

采用大功率连续横流CO2激光对化学复合镀NiAl/纳米Al2O3复合镀层进行激光熔凝处理,并对熔凝层的抗高温氧化性能进行研究。采用X射线衍射仪(XRD)、扫描电镜(SEM)和能谱仪(EDS)等分别对高温氧化前后的表面形貌、物相组织和元素组成进行表征分析。与复合镀层和基体试样相比,激光熔凝后表面抗高温氧化性能明显提高,这一方面与激光熔凝镀层中的金属间化合物NiAl2O4、Ni0.77AlFe0.23在800℃时具有良好的抗高温氧化性有关,另一方面是由于激光熔凝后镀层表面形成了连续致密的氧化膜。     

激光辅助复合电沉积加工速率及表面质量研究

为了解决纳米复合电沉积加工速率慢、颗粒易团聚以及沉积层表面质量差等问题,采用构建高能脉冲激光辅助纳米复合电沉积的方法,利用激光辐照产生定域微区搅拌,缓解颗粒团聚现象,加速电化学反应速率,提高沉积层表面质量,并对加工过程进行了有限元仿真和实验验证。结果表明,激光与电化学复合能够明显的提高复合沉积速率,且激光的冲击作用能够提高晶粒的结合性,进而促进镀层的致密化;同时此冲击作用也能降低纳米粒子的团聚几率,细化镀层晶粒。此研究结果对电解加工技术的发展具有一定帮助。     

基于MEMS工艺的碳纳米管(碳纳米纤维)铜微异型触点

一类为保护MEMS微继电器、提高它们使用寿命,而设计生产的微异型触点.该类微异型触点利用MEMS工艺,对铜基碳纳米管及碳纳米纤维复合电镀层进行细微图形化加工而成.一系列测试表明,铜基碳纳米管及碳纳米纤维复合电镀层本身具有良好的电接触性能,而利用MEMS工艺表面细微图形化加工后的微异型触点,比未经图形化加工的复合电镀层及纯铜触点具有更好耐电弧磨损性能.     

激光感应聚酰亚胺薄膜表面电镀金属的研究

本文介绍了用电镀的方法提高激光感应聚酰亚胺薄膜电导率的实验结果。实验证实,激光感应聚酰亚胺薄膜表面产生的物理和化学变化对金属镀膜的形成和镀层与衬底的结合性有积极的影响。文中讨论了在整个过程中一些电镀条件,如电流密度等对金属镀层的均匀性、晶粒的大小等性质所起的作用。实验证明电流密度越小,镀层越均匀,晶粒也越小。该实验将激光技术与电镀这一传统工艺相结合,从而提高了有机复合薄膜的电导率。这一结果有可能在     

复合镀层的新进展

用电镀方法,使溶液中不能溶解的固体微粒与金属在阴极上共沉积,可形成各种各样的复合镀层(也可称为分散镀层)。它是材料科学中的一支新军。最近十几年来,获得了极其广泛的应用。它能如此引人注意和高速发展的原因是复合镀层的生产方法,与其他制备新型材料的方法相比,有很多优点。例如,制备复合镀层的材科种类很多,可根据需要形成各种不同性质的镀层;不需要高温,操作简单,     

新型柔性毫米波材料导电布的制备与测试

提出一种新型柔性毫米波材料导电布的制备方法,采用真空磁控溅射复合镀膜技术在涤纶基布表面沉积金属镀层。检验导电布的导电性能和镀层附着力,并应用毫米波辐射计测试系统测试导电布与金属铝板的3 mm波段毫米波辐射特性。结果表明,导电布镀覆均匀,质地柔软轻薄,有良好的镀层结合强度及较强的导电性能。导电布在3 mm波段的毫米波辐射与金属板的性能相当。     

MPVD涂层微钻在PCB钻孔领域的应用

本文介绍了一种新型微钻涂层—MPVD涂层在PCB钻孔领域的应用。通过刀面磨损试验、孔壁粗糙度实验和钻孔寿命试验对MPVD涂层微钻与常用的未涂层微钻进行了比较。试验证明,应用MPVD涂层微钻在钻孔12000后,微钻刀面未见明显磨损痕迹。其钻孔孔壁粗糙度满足质量标准情况下,孔限达到12000,是未涂层微钻寿命的3-4倍。应用MPVD涂层微钻可以有效地延长微钻使用寿命、提高机台工作效率和降低钻孔成本。     

微粒与基质金属在复合镀层中的作用

简要地论述了复合镀层常用的分类方法外,并在做了大量研究的基础上,提出了另一种新的分类法,即根据微粒和基质金属在镀层中所处的地位来分类。     

PCB用微型钻针及其检测技术的发展解析

通过对微钻的损耗机理进行分析,介绍了目前业内常用的微钻性能改善方法,对微钻的检测技术进行展望。     

纳米技术在PCB用微钻中的应用

本文论述了随着印制线路板(PCB)向高密度互连方向的发展,PCB导通孔急速走向直径0.1mm的微小化,对钻头的要求越来越高,介绍了纳米技术在线路板用微钻中的发展前景和国内外趋势,以及纳米技术提高钻头性能的机理、制备方法。     

提高准分子激光打孔质量的方法研究

为了提高准分子激光打孔质量,分析了影响现行加工系统打孔质量的因素,在此基础上提出利用钻孔法改进打孔效果的解决方案。根据此方案设计了加工光路,进行了微孔加工实验。实验结果表明,采用248nm准分子激光加工有机材料聚甲基丙烯酸甲酯,微孔形状规则,孔径锥度可减小至0.055。该加工系统和方法提高了微孔加工的速度和质量,在微加工领域具有很好的实际应用价值。     

毫米波辐射图像目标定位技术研究

针对毫米波辐射图像中目标定位的问题,提出了一种基于区域标记的毫米波辐射图像金属目标定位算法.该算法通过分析金属的毫米波辐射特性以及毫米波辐射图像的特点,利用区域标记算法对图像中金属目标进行分割,并引入基于面积的虚假目标去除准则,采用计算重心的方法实现了金属目标的定位.实验表明,该算法既能对图像中单个金属目标又能对图像中多个金属目标实现准确定位,且不论目标的外形如何,都能得到其精确的中心坐标,为下一步目标的选择与跟踪提供了依据.     

Advanced RF/baseband interconnect schemes for inter- and intra-ULSI communications

Future inter- and intra-ULSI interconnect systems demand extremely high data rates (up to 100 Gbps/pin or 20-Tbps aggregate) as well as bidirectional multiI/O concurrent service, re-configurable computing/processing architecture, and total compatibility with mainstream silicon system-on-chip and system-in-package technologies. In this paper, we review recent advances in interconnect schemes that promise to meet all of the above system requirements. Unlike traditional wired interconnects based solely on time-division multiple access for data transmission, these new interconnect schemes facilitate the use of additional multiple access techniques including code-division multiple access and frequency-division multiple access to greatly increase bandwidth and channel concurrency as well as to reduce channel latency. The physical transmission line is no longer limited to a direct-coupled metal wire. Rather, it can be accomplished via either wired or wireless mediums through capacitor couplers that reduce the baseband noise and dc power consumption while simplifying the fabrication process by eliminating vertical metal studs needed in three-dimensional ICs. These new advances in interconnect schemes would fundamentally alter the paradigm of ULSI data communications and enable the design of next-generation computing/processing systems.     

Standing‐Wave‐Assisted Creation of Nanopillar Arrays with Vertically Integrated Nanogaps for SERS‐Active Substrates

An optical method is used to create multi‐dimensional metal structures with three distinct periodicities for surface‐enhanced Raman scattering (SERS). Periodic arrays of nanopillars are formed by phase‐shift interference lithography on sub‐micrometer length scales. With the help of a standing wave, each nanopillar is made to be a disk‐stacking structure consisting of a series of 20‐nm‐thick metal nanogaps; the nanopillars consequently resemble a pagoda. The vertically integrated metal nanogaps of the metal‐deposited pagoda‐like nanopillars enable strong localization of an electromagnetic field and effective enhancement of Raman signals for molecules adsorbed on the metal surface. Moreover, the nanopillars are arranged in a regular lattice, which results in a low spatial variation of the SERS intensity and provides high reproducibility in measurements. Arrays of the nanopillars can be further micropatterned to have a periodicity ranging from tens of micrometers to a millimeter by subsequently employing photo‐lithography. The nanopillar arrays promote the wetting of sample fluids, which enables the selective confinement of fluids on the array regions of the micropatterns without spreading. Consequently, numerous fluid samples can be separately deposited, enabling SERS‐based analysis of multiple samples using a single substrate.     

3D金属打印天线技术研究综述

近年来, 随着通信用户量的迅速增加和通信设备市场的快速发展, 数据速率高于10 Gbit/s的高速通信系统要求多种功能集成在天线上, 天线的制造要求趋于高精度、低成本和微型化. 3D打印或增材制造(additive manufacturing, AM)是一种直接从数字模型到零件制造的新兴产业技术, 可在短时间内生产出高精度和复杂的天线零件, 该技术已经成为了当前天线设计的研究热点.制造天线的AM技术主要有粉床熔合、材料挤压和材料喷射.文章首先简要介绍3D金属打印技术的基本原理、操作流程和分类, 接着重点分析几种3D金属打印天线技术的研究成果, 然后浅析3D金属打印天线技术的发展趋势, 最后对3D金属打印天线技术做了总结.     

Silicon nitride processing for control of optical and electronic properties of silicon solar cells

Thin films of SiN are well suited as antireflection (AR) coatings for Si solar cells because their optical properties, such as refractive index and absorption coefficient, can be tailored during deposition to match those of Si solar cells. The SiN layers, particularly those deposited by a plasma-enhanced chemical vapor deposition (PECVD) process, can serve other functions in Si solar-cell fabrication. They can be excellent buffer layers through which the front metal contact can be fired. The PECVD nitridation also introduces H into the Si surface, which diffuses deep into the solar cell and passivates residual impurities and defects during metal-contact firing. The optimization of SiN properties and processing conditions may have conflicting demands based on its multifunctional role. To fully exploit these multiple functions, the SiN processing sequence must be optimized based on the properties of the nitride, the diffusion behavior of H, and the interactions of metal with the SiN/Si composite substrate.     

380‐nm Ultraviolet Light‐Emitting Diodes with InGaN/AlGaN MQW Structure

In this paper, we demonstrate the capabilities of 380‐nm ultraviolet (UV) light‐emitting diodes (LEDs) using metal organic chemical vapor deposition. The epi‐structure of these LEDs consists of InGaN/AlGaN multiple quantum wells on a patterned sapphire substrate, and the devices are fabricated using a conventional LED process. The LEDs are packaged with a type of surface mount device with Al‐metal. A UV LED can emit light at 383.3 nm, and its maximum output power is 118.4 mW at 350 mA.     

Photoinduced Colossal Magnetoresistance under Substantially Reduced Magnetic Field

The colossal magnetoresistive insulator to metal switching of almost nine orders of magnitude under the significantly reduced magnetic field is achieved by illumination for the low bandwidth manganite thin films. Similarly, by changing the measuring bias voltage through the sample the required magnetic field for insulator–metal transition can be further fine‐tuned. By applying a magnetic field of suitable strength, the samples can also be tuned to be extra sensitive to the illumination having colossal effect on the resistivity at low temperatures. This kind of utilizing of multiple external stimulants, which together change the properties of the material, could have significant impact on the new generation of phase‐change memories working under affordable conditions.