A Single Mode Hybrid Ⅲ-Ⅴ/Silicon On-Chip Laser Based on Flip-Chip Bonding Technology for Optical Interconnection

A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.

A two-step transient liquid phase diffusion bonding process of T91 steels

In this study, a two-step heating process is introduced for transient liquid phase （ TLP） diffusion bonding fo r sound joints with T91 heat resistant steels. At first, a short-time higher temperature heating step is addressed to melt the interlayer, followed by the second step to complete isothermal solidification at a low temperature. The most critical feature of our new method is producing a non-planar interface at the T9／ heat resistant steels joint. We propose a transitional liquid phase bonding of T91 heat resistant steels by this approach. Since joint microstructures have been studied, we tested the tensile strength to assess joint mechanical property. The result indicates that the solidified bond may contain a primary solid-solution, similar composition to the parent metal and free from precipitates. Joint tensile strength of the joint is not lower than parent materials. Joint bend＇s strengths are enhanced due to the higher metal-to-metal junction producing a non-planar bond lines. Nevertheless, the traditional transient liquid phase diffusion bonding produces planar ones. Bonding parameters of new process are 1 260 °C for 0. 5 min and 1 230 °C fo r 4 min.

Mechanism of Wafer Bonding Process

The basic force and bonding energy in wafer bonding have been revealed in this study. The basic cause for bonding contributes to the interatomic attractive forces between surfaces or the reduction of surface energies. The amplitude of roughness component can not exceed the criterion if wafer pair is bondable. The bonding behavior and challenge during annealing have been investigated.

Electrochemical and Reaction Bonding Processing of Thick ZrO_2/Al_2O_3 Composite Coatings

A novel technique combining electrophoretic deposition (EPD) and reaction bonding process (RBP) is developed to fabricate thick ZrO2/Al2O3 composite coatings. Mixed organic solvents are used here to make suspension containing yttria stablised zirconia (YSZ) and aluminium (Al). The results show that densely packed green form coatings are deposited using a mixture of ethanol and acetylacetone as suspension medium and ball milling for 48 hours. On subsequent heat treatment, melting and oxidation of aluminium in the green forms promote densification during sintering. By these means, thick, uniform and crack-free ZrtVA^Oa composite coatings have been fabricated on metal substrate.

Reliability of flip-chip bonded RFID die using anisotropic conductive paste hybrid material

A reliability of flip-chip bonded die as a function of anisotropic conductive paste (ACP) hybrid materials, bonding conditions, and antenna pattern materials was investigated during the assembly of radio frequency identification(RFID) inlay. The optimization condition for flip-chip bonding was determined from the behavior of bonding strength. Under the optimized condition, the shear strength for the antenna printed with paste-type Ag ink was larger than that for Cu antenna. Furthermore, an identification distance was varied from the antenna materials. Comparing with the Ag antenna pattern, the as-bonded die on Cu antenna showed a larger distance of identification. However, the long-term reliability of inlay using the Cu antenna was decreased significantly as a function of aging time at room temperature because of the bended shape of Cu antenna formed during the flip-chip bonding process.

Recent advances and trends in roll bonding process and bonding model:A review

This review presents a thorough survey of the roll bonding process with a focus on the bimetallic bars/tubes as well as the bonding models and criteria.The review aims to provide insight into cold,hot and cryogenic bonding mechanisms at the micro and atomic scale and act as a guide for researchers working on roll bonding,other joining processes and bonding simulation.Mean-while,the shortcomings of roll bonding processes are presented from the aspect of formable shapes,while bonding models are shown from the aspect of calculation time,convergence,interface behav-ior of dissimilar materials as well as hot bonding status prediction.Two well-accepted numerical methodologies of bonding models,namely the contact algorithm and cohesive zone model(CZM)of bonding models and in simulations of the bonding process are highlighted.Particularly,recent advances and trends in the application of the combination of mechanical interlocking and metallurgical bonding,special energy fields,gradient structure,novel materials,green technology and soft computing method in the roll bonding process are also discussed.The challenges for advancing and prospects of the roll bonding process and bonding model are presented in an attempt to shed some light on the future research direction.

Indium bump array fabrication on small CMOS circuit for flip-chip bonding

We demonstrate a novel method for indium bump fabrication on a small CMOS circuit chip that is to be flip-chip bonded with a GaAs/A1GaAs multiple quantum well spatial light modulator. A chip holder with a via hole is used to coat the photoresist for indium bump lift-off. The 1000 μm-wide photoresist edge bead around the circuit chip can be reduced to less than 500 μm, which ensures the integrity of the indium bump array. 64 - 64 indium arrays with 20 μm-high, 30 μm-diameter bumps are successfully formed on a 5 - 6.5 mm^2 CMOS chip.

Effects of intermixing process on bonding strength of IBED CrN coatings

The coating substrate bonding strengths under different intermixing processes were evaluated by scratch and spherical rolling contact fatigue methods. The results show that for low bombarding energy of N ions dynamic recoiling at 10 keV and 20 keV, the coating layers are of excellent bonding strengths. The bonding strength of CrN coating with 40 keV static recoiling is higher than that of low energy(20 keV). On the other hand, the bonding strength of coating with 40 keV dynamic recoiling is much lower than that of static recoiling at the same energy and even less than that of dynamic recoiling intermixings at 10 keV and 20 keV energy. The results of scratch and spherical rolling contact fatigue methods exhibit the same trend for each group of recoiling methods, yet the results of the scratch and fatigue tests for two groups do not agree with each other.

基于视觉技术的Wire Bonding中焊点质量的自动检测方法

用WireBonder(引线键合机)进行键合后的芯片,其焊点可能会出现位置偏移、断线和线尾(Pigtail)过长等缺陷。该文针对上述几种质量问题,利用WireBonder现有的硬件,运用图象处理及模式识别技术,提出了一套自动视觉检测的方法。实验表明,该方法所需硬件低廉,操作方便,能很好地检测WireBonding中焊点的质量。

Portfolio optimization of credit risky bonds: a semi-Markov process approach

This article presents a semi-Markov process based approach to optimally select a portfolio consisting of credit risky bonds.The criteria to optimize the credit portfolio is based on l_(∞)-norm risk measure and the proposed optimization model is formulated as a linear programming problem.The input parameters to the optimization model are rate of returns of bonds which are obtained using credit ratings assuming that credit ratings of bonds follow a semi-Markov process.Modeling credit ratings by semi-Markov processes has several advantages over Markov chain models,i.e.,it addresses the ageing effect present in the credit rating dynamics.The transition probability matrices generated by semi-Markov process and initial credit ratings are used to generate rate of returns of bonds.The empirical performance of the proposed model is analyzed using the real data.Further,comparison of the proposed approach with the Markov chain approach is performed by obtaining the efficient frontiers for the two models.

The Effect of HDDR Process on Magnetic Properties in NdFeB Type of Bonded Magnets

The present paper describes the effect of alloy composition,homogenization and dehy-drogenization procedures on magnetic properties of NdFeB type of HDDR powders and the bonded magnet.The results showed that the powders prepared by HDDR process possesses useful magnetic proper- ties and a better thermal stability than the sintered NdFeB magnet does.

A Statistical Theory for Hydrogen Bonding Networks: One Component Case

The theory of reversible gelation is shown to be applicable to the hydrogen bonding system by analyzing their similarities in statistical viewpoint.The size distribution of hydrogen bonding clusters,the gelation condition and the generalized scaling law can be obtained directly.These results show that such a system can undergo phase transition process.Furthermore,a relationship between Gibbs free energy of forming hydrogen bond and conversions of groups is given.As an example,the chemical shift of OH groups is considered.

Process monitoring of the Au-S bond conversion in acetylene hydrochlorination

The continuous expansion of vinyl chloride production increases environmental pollution caused by mercury catalysts,which is an issue that urgently needs to be solved.Green and stable catalysts should be researched to alleviate this issue.In this research,Thiolactic acid acts as a ligand where sulfhydryl groups form a stable complex with Au on the surface of a spherical activated carbon(SAC).An Au-thiolactic acid/SAC catalyst was designed with a Au theoretical loading of 0.5%(mass)to overcome the disadvantages of traditional Au-based catalysts,such as a low conversion rate and poor life cycle.The ratio of Au to ligand was screened,and the activity was best when Au/S=1:8.The formation of the Au-S bond was proven by FT-IR and UV-vis.The longevity test of the Au1 S8/SAC catalyst was carried out at 1200 h^(-1) for 50 h.Samples with reaction times of 0 h,5 h,10 h,20 h,and 50 h were taken to monitor the catalyst status.The XPS and TPR tests proved that the Au-S bond broke as the acetylene hydrochlorination reaction proceeded,The DFT calculation proved that the Au-S bond is the active site,and the sulfur atom promotes the adsorption of C_(2)H_(2) by the catalyst.

Demagnetization Process and Coercivity for Anisotropic HDDR NdFeB Bonded Magnets

The demagnetization process and the coercivity mechanism for amsotropic HDDR Nd(Fe,Co)B bonded magnets were studied by comparing the dependence of coercivity on the alignment field applied while the powders were pressed. The results showed that both the remanence and the coercivity of magnet increased with increasing alignment field. The demagnetization process of the magnet can be classified as the nucleation process inside the grains and the domain-wall motion between the grains. The combined effect of two processes determines the coercivity of HDDR NdFeB bonded magnets.

STUDIES ON PROCESS AND STABILITY OF BONDED Sm_2TM_(17)MAGNETS WITH HIGH COERCIVITY AND HIGH ENERGY PRODUCT

The process of the epoxy-bonded Sm_2TM_(17) magnets includes:(1)after melting,the ingots are treated by solid soluiion,and then aged and pulverized;(2)the obtained alloy powder is mixed with epoxy resin bind- er;(3)the mixture is pressed in a magnetic field;(4)the compacts are cured.When the SmCo_(4.9)Fe_(2.7)Cu_(0.54)Zr_(0.13) alloy is heat treated and pressed with optimum pressing parameters,the high quality bonded magnets with B_r=8250 G,_iH_c=13000 Oe,and(BH)_(max)=16MGOe can be obtained.The stability of the magnets is studied also.The irreversible loss of O.C.(open circuit)remanence B_r in the temperature range between 25 and 150℃,is less than 4%.The average temperature coefficient at temperatures between 25 and 70℃ is-0.03%/℃.The magnets obtained have heat resistance up to 130℃ even in long-term service, and have good corrosion resistance in acid,alkali and salt solutions.

轨道减振器双底模注射硫化成型工艺的研究与应用

对轨道减振器双底模注射硫化成型工艺进行研究,并与传统高压模硫化成型工艺进行对比。结果表明:双底模注射成型工艺缩短了硫化时间,实现了轨道减振器的连续化生产,同时提高了型腔内压,促进了金属与橡胶的有效粘接;双底模注射硫化成型轨道减振器疲劳后垂向静刚度和动静刚度比变化率小,垂向静刚度波动范围在10%以内,产品性能更稳定。

杨树刨花尺寸对定向刨花板性能的影响研究

将5种不同宽度的杨木刨花按不同比例混合并制备定向刨花板(OSB),考察了不同刨花宽度组合对板材内结合强度(IB)、弹性模量(MOE)、静曲强度(MOR)的影响。结果表明:不同宽度、不同比例的刨花可显著影响OSB的制备过程和板材质量。研究揭示了刨花宽度组合对OSB性能的影响机制,对进一步提高OSB产品质量,提高资源利用率,减少人造板生产碳足迹和降低生产成本具有一定的参考意义。

树脂渗透剂的制备及其后处理对3DP成型件抗压性能的影响

在利用三维粉末黏结(3DP)工艺成型标准圆柱件时,为了制备3DP工艺后处理环节所需的树脂渗透剂,以抗压强度为指标,利用响应面法中的Box-Behnken设计了实验方案,确定了优化配比方案。以此为后处理剂扫描电子显微镜(SEM)、能谱仪(EDS)和抗压强度测试讨论了渗透参数(渗透次数、渗透方式以及渗透间隔时间)对3DP工艺成型件的抗压性能的影响。结果表明,制备的树脂渗透剂可有效改善成型件的抗压性能。在渗透处理时,采用浸润的渗透形式,通过多次浸润、渗透间隔时间逐次递增的方式,可以有效提高成形件的抗压性能。

非晶合金铁芯粘接-冲裁-叠压工艺研究

针对非晶合金在室温状态下冷加工性能不佳导致难以对其进行常规冲裁加工,严重限制其在电机领域的应用的问题,提出了一种粘接-冲裁-叠压工艺,以提高非晶合金的室温冲裁能力。首先,将多片非晶合金叠压粘结成具有一定厚度的坯料,然后对非晶合金坯料进行冲裁,最终将冲裁后的成品叠压成铁芯产品。试验证明,该工艺生产的非晶合金成品断面光洁,毛刺高度低于5μm,表面质量满足叠压要求,叠压后的成品满足电机铁芯的制造要求,解决了非晶合金在室温下冲裁质量较差、毛刺较高等问题。

基于机理模型与深度学习的密炼工艺预测控制方法

针对轮胎生产中密炼工艺的时变特性以及生产多要素对过程控制的要求,采用键合图和深度学习算法设计了一种模型预测控制方法,形成了对密炼过程生产多要素的有效控制。通过状态空间方程模型加反馈校正的方式,减小线性预测模型与非线性过程间误差;通过卷积神经网络(CNN)提取密炼工艺过程数据特征,通过长短期神经网络(LSTM)提取数据前后的时序关系;提出基于CNN-LSTM网络结构的系统参数辨识方法,实时更新状态空间预测模型参数,实现了预测模型与密炼过程的精准匹配。仿真结果验证了所提方法的有效性。