Laser-assisted deposition of Cu bumps for microelectronic packaging

Cu bump was transferred using a focused laser pulse for microelectronic packaging.An Nd:YAG laser pulse (maximum energy of 500 mJ;wavelength of 1064 nm;fluences of 0.4-2.1 kJ/cm2) was irradiated on a sacrificial absorption layer with copper coating.The focused laser beam induced plasma between the semi-transparent donor slide and the sacrificial layer,causing a shock wave.The shock wave pressure pushed the Cu layer and transferred material to deposit a bump on substrate.A beam-shaper was used to produce uniform pressure at the interface to reduce fragmentation of the transferred material on the substrate.The calculated shock wave pressure with respect to laser fluence was 1-3 GPa.A Cu bump of diameter of 200 μm was successfully deposited at laser fluence of 0.6 kJ/cm 2.The pressure control at the sacrificial layer using a laser pulse was critical to produce a bump with less fragmentation.The technique can be applied to forming Cu bump for an interconnecting process in electronics.     

Comparison of antioxidant activities and bioactive compounds between Bokbunja (Rubus coreanus Miq.) and other berries

The physicochemical properties and antioxidant properties of bokbunja, a Korean black raspberry, were clarified and compared with blueberry, cranberry, raspberry, and strawberry. The amount of soluble solids was significantly (p<0.05) lower in bokbunja than in other berries, whereas the pH of bokbunja was significantly (p<0.05) higher. Analysis of the total phenolic, flavonoid, and anthocyanin contents found that bokbunja had the highest, while the others were ranked in the order of raspberry>blueberry>cranberry>strawberry. The content of ellagic acid (147.3 mg/100 g of FW) also was highest in bokbunja. The antioxidant activities of bokbunja, assessed based on DPPH, ABTS, and ferric reducing antioxidant power (FRAP) assays, were higher than for other berries. Bokbunja is a healthier antioxidant source than other berries.     

Molecular Structure and Functionalities of Protein Isolates Prepared from Defatted Cottonseed Flour Succinylated at Various Levels

Protein isolates were prepared from glandless cottonseed flour succinylated at various levels. Succinylation levels of the resultant proteins followed first order kinetics with respect to succinic anhydride concentration added. Succinylation decreased the amount of free sulfhydryl, as well as ξ-amino groups of proteins, but did not change intermolecular disulfide bonds. Protein isolate prepared from highly succinylated flour consisted of one homogeneous protein agglomerate, while isolate from unmodified flour contained several heterogeneous proteins. Water solubility of the isolates increased logarithmically with respect to degree of succinylation, with the sharpest increase at 95% succinylation or higher. Heat coagulability had an inverse-linear relationship with amounts of negative charges on protein molecules. Emulsion capacity and oil absorption capacity were not significantly changed at less than 60% succinylation. However, these increased markedly at greater than 60% succinylation. Emulsion capacity had a positive, but not linear correlation with water solubility of proteins.     

电子束表面工程的技术发展水平（下）

四、第一代表面工程方法 １．固态淬火（硬化） 加热的各项工艺参数、材料的初始组织和机件的具体几何形状,都对材料的组织和性能、淬硬的深度和机件的表面质量有很大的影响。在我们的试验研究中,对各种不同的结构钢和工具钢以及某些铁进行了研究,采用的加热方式为将需要淬硬的整个表面同时加热等。对于退火状态的和整体淬硬的多,硬化度分别达到３．６～３．７和１．５～１．７。钢的硬度达到ＨＲＣ６５～６８,显微硬度为１０～１１ＧＰａ,硬化的深度为 １．５－２．０ｍｍ。 在各种钢中,会产生残余的压缩应力,还会形成细粒组织,并…     

专业铸就品牌

第八届国际公路水运交通技术与设备展览会（CHINA TRANSPO 2006）将于2006年9月26-29日在北京全国农业展览馆举行。截至目前．参展企业已近300家，包括徐工、柳工、三一重工、中联重科、西筑等筑路机械厂家．中海油、壳牌等道路材料生产企业．中国重型汽车集团、宇通客车、厦门金龙等商用车辆制造企业，尤其引人注目的是，本届展会有十余家省市交通厅局单位设台参展，这是历年来同类展会中不多见的。据悉，目前预订的展位面积已达38000平方米，一场交通行业的国际展览盛宴正在徐徐拉开帷幕。     

Adaptive Step Size Control of LMS-based Interference Cancellationfor ICS Repeater in Wibro Environment

The use of repeater for the support of high rate data transmission and the extension of cell coverage is imperative for the Wibrc system,which based on the IEEE 8M.16e standardization.Generally,if the separation between transmitting and receiving antennas isnot sufficient,the oscillation of repeater and the interference due to the feedback signals from original transmitted signal may be ocerur.Hence,the Interference Cancellation System(ICS)should be implemented as the important part of the repeater system far the mobile cellular systems in order to eliminate unwanted signals from the corruptW signals in the receiver.In this paper,we propose an adaptive technique for the Least Mean Square(LMS)-based interference cancellation methods by changing the step size according to the variation of channel environment in order to improve the performance degradation which oceuurs by using the fixed step size approach.Simrlatim results show that the proposed sclxme attains a little lower Berafor Rate(BER)performance and much faster convergence speed compared to the conventional LMS-based interference cancellation techniques.The proposed scheme can be applied to other Orthogonal Frequency Division Multiple(OFDM)-based cellular systems and also be expected to achieve a similar performance improvement to W17-advanced system,which is called as the next generation mobile communication standards.     

Measuring IP Performance Metrics on Mobile Network with Heterogeneous Wireless Technologies

The new measurement scheme of IP performance metrics is proposed for the mobile network in heterogeneous wireless network environment. In the proposed scheme, when Mobile Nodes (MNs) inside the mobile network needs to understand the condition of multiple communication paths outside the mobile network, they can get IP performance metrics, such as delay, jitter, bandwidth, packet loss, etc., irrespective of the presence or absence of measurement functionality. At the same time, the proposed scheme does not require the MN to be involved in measuring IP performance metrics. The Multihomed Mobile Router (MMR) with heterogeneous wireless interfaces measures IP performance metrics on behalf of the MNs inside the mobile network. Then, MNs can get measured IP performance metrics from the MMR using L3 messages. The proposed scheme can reduce burden and power consumption of MNs with limited resource and battery power since MNs don't measure IP performance metrics directly. In addition, it can reduce considerably traffic overhead over wireless links on multiple measurement paths since signaling messages and injected testing traffic are reduced.     

Low Phase Noise VCO using Novel Harmonic Control Circuit Based on Quad-band Composite Right/Left-handed Transmission Line

In this paper,a novel Voltage-Controlled Oscillator(VCO)using the harmonic control circuit based on the quad-band Composite Right/Left-Handed(CRLH)Transmission Line(TL)is presented to reduce the phase noise without the reduction of the frequency tuning range and miniaturizing the circuit size.The phase noise has been reduced by the quad-band harmonic control circuit which has the short impedance for the second-and third-and fourth-and fifth-harmonic components.The CRLH TL with two Left-Handed(LH)(backward)and two Right-Handed(RH)(forward)pass bands are used to design the quad-band harmonic control circuit.The high-Q resonator has been used to reduce the phase noise,but it has the problem of the frequency tuning range reduction.However,the frequency tuning range of the proposed VCO has not reduced because the phase noise has reduced without the high-Q resonator.The miniaturization of the circuit size is achieved by using the quad-band CRLH TL instead of the conventional RH TL.The phase noise of VCO is-124.43～-122.67 dBc/Hz at 100 kHz in the tuning range of 5.729～5.934 GHz.     

LOW-VELOCITY IMPACT RESPONSE OF COMPOSITE LAMINATES CONSIDERING HIGHER-ORDER SHEAR DEFORMATION AND LARGE DEFLECTION

SUMMARY

Low-velocity impact responses of composite laminates are investigated analytically and experimentally. In analytical research, the finite element analyses based on various plate theories and three-dimensional thoeory are performed. For experimental research, a drop weight type impact test system is used. In geometrical non-linear analysis, a displacement field considering higher-order shear deformation and large deflection of the laminate is assumed and the finite element formulation is derived. The modified Hertzian contact law is incorporated into the finite element program to evaluate contact force. Numerical results including impact force histories, deflections, dynamic strains in the laminate from the impact response analysis are presented and compared with the experimental results from impact test. The results of the investigation indicate that higher-order shear deformation and large deflection effects should be considered to accurately describe the low-velocity impact response including interlaminar shear stress of the laminate.