A device transfer process "selectively occupied repeated transfer (SORT)" for resource-saving integration of polymer micro optics fabricated by "built-in mask" method

The device transfer process known as selectively occupied repeated transfer, which integrates thin-film device elements into a substrate with desired arrangement at one time using all-photolithographic methods, is demonstrated here. As the elements, 300-/spl mu/m-diameter polymer waveguide lenses made of acrylic photo-definable material are formed on a poly-vinyl-alcohol (PVA)-coated glass substrate in a two-dimensional array with 450-/spl mu/m pitch by UV light exposure through a "built-in mask." The lenses are transferred to a supporting substrate by solving the PVA in water, and are further transferred to a final substrate, on which catch-up sites that have stronger adhesion strength than the surrounding area are formed with a pitch of 1800 /spl mu/m. Selective transfer of the lens to the catch-up site is observed.     

Ultrasonic bonding for multi-chip packaging bonded with non-conductive film

System-on-Chip and System-on-Package technologies have advantages depending on application needs. As a number of electrical and electronic equipment manufacturers have an interest in increasing CMOS technology densities, a range of two- and three-dimensional silicon integration technologies are emerging which will support next-generation high-end semiconductors such as high speed microprocessors and high speed memories. However, there are many issues regarding process integration, thermal management, and reliability of 3D stacked package.In this study, the printed circuit board (PCB), silicon carrier and silicon chip are integrated with ultrasonic vibration. Die shear tests of the joints were carried out with increasing bonding time and input power to optimize the bonding condition. The integrated chips were successfully bonded to the PCB with and without NCF using a transverse ultrasonic bonding. Electrical resistance of multi-chip bonded with NCF (10 mΩ) measures lower than that bonded without NCF (28.9 mΩ). The voids and delamination were easily found on the joint bonded without NCF that caused lower shear strength.     

Aluminium-based packaging platform for led using selectively anodising method

An aluminium-based packaging platform with microreflector and electrical via for an interconnection electrode is first proposed for a package component of a light-emitting diode (LED). The electrode-guided interconnection with 180 mum thickness has been successfully fabricated by using the selectively anodising process, and not by either the plating or the solder paste technique. The reflector was formed during the isotropic etching process. By mainly a two-step chemical process, the LED packaging platform integrated microreflector and electrical via in one body was developed in a low-cost process.     

A scalable design of multigranularity optical cross-connects for the next-generation optical Internet

This paper proposes a scalable design for next-generation optical cross-connects (OXCs). We present a novel strategy for dimensioning the switching capability as a long term planning. Switching fabrics in OXCs have to be expanded according to traffic growth, which may incur a scalability problem due to the exponentially increasing cost in manufacturing and maintenance. The proposed scheme expands the switching capacity of OXCs with waveband- and fiber-switching components (or, equivalently, expands the network capacity with waveband- and fiber-switching tiers). To minimize the number of extra fibers for waveband- and fiber-switching tiers required to satisfy a given traffic matrix, we formulate the problem of routing and wavelength assignment (RWA) with tunnel allocation (RWAT) into a constraint programming (CP) process. The CP is simplified as two integer linear programming (ILP) processes that are performed sequentially. Experiments are conducted on four examples to compare the throughput and the number of switching points when different switching architectures are adopted under different traffic increase. The benefits of our approach are demonstrated. Finally, we conclude that the proposed optimization scheme can dimension the networks with expandability and scalability to the growing traffic demand.     

Characteristic study of anisotropic-conductive film for chip-on-film packaging

Chip-on-film (COF) is a new technology after tape-automated bonding (TAB) and chip-on-glass (COG) in the interconnection of liquid crystal module (LCM). The thickness of the film, which is more flexible than TAB, can be as thin as 44 μm. It has pre-test capability, while COG does not have. It possesses great potential in many product fabrication applications.In this study, we used anisotropic-conductive film (ACF) as the adhesive to bind the desired IC chip and polyimide (PI) film. The electric path was formed by connecting the bump on the IC and the electrode on the PI film via the conductive particles in the ACF. In the COF bonding process experimental-design method was applied based on the parameters, such as bonding temperature, bonding pressure and bonding time. After reliability tests of (1) 60 °C/95%RH/500 h and (2) −20 to 70 °C/500 cycles, contact resistance was measured and used as the quality inspection parameter. Correlation between the contact resistance and the three parameters was established and optimal processing condition was obtained. The COF samples analyzed were fabricated accordingly. The contact resistance of the COF samples was measured at varying temperature using the four points test method. The result helped us to realize the relationship between the contact resistance and the operation temperature of the COF technology. This yielded important information for circuit design.     

An optical multi-mesh hypercube: a scalable optical interconnectionnetwork for massively parallel computing

A new interconnection network for massively parallel computing is introduced. This network is called an optical multi-mesh hypercube (OMMH) network. The OMMH integrates positive features of both hypercube (small diameter, high connectivity, symmetry, simple control and routing, fault tolerance, etc.) and mesh (constant node degree and scalability) topologies and at the same time circumvents their limitations (e.g., the lack of scalability of hypercubes, and the large diameter of meshes). The OMMH can maintain a constant node degree regardless of the increase in the network size. In addition, the flexibility of the OMMH network makes it well suited for optical implementations. This paper presents the OMMH topology, analyzes its architectural properties and potentials for massively parallel computing, and compares it to the hypercube. Moreover, it also presents a three-dimensional optical design methodology based on free-space optics. The proposed optical implementation has totally space-invariant connection patterns at every node, which enables the OMMH to be highly amenable to optical implementation using simple and efficient large space-bandwidth product space-invariant optical elements     

Multipath routing with topology aggregation for scalable inter-domain service provisioning in optical networks

In this paper, we propose to use static virtual topology for a scalable inter-domain optical service provisioning, while addressing the resource efficiency issue by using multipath routing. To this end, we discuss methods for virtual topology aggregation with consideration of inter-domain routing, and propose two heuristic algorithms for two representative applications, referred to as real-time streaming and bulk data transfer. We consider specific requirements of each application, including transmission deadline and jitter, and evaluate the impact of differential delay issue of multipath routing on the performance of proposed algorithms. Numerical results show that the proposed multipath routing algorithms yield a low blocking ratio of inter-domain connections even on the static virtual topology, which is known for poor blocking performance otherwise. The resulting differential delay is sufficiently small for the studied applications, and can be compensated with relatively small buffers. We show that a scalable inter-domain service provisioning in optical networks can be achieved by using a combination of static virtual topology and multipath routing.     

Compact packaging of optical and electronic components for on-board optical interconnects

An optical interconnection plate was developed in order to achieve a compact and cost-effective interconnection module for an optical data link between chips on printed circuit boards. On the silica substrate, transmission lines and solder bumps are formed on the top surface of the substrate, and polymer waveguide array with 45/spl deg/ mirror planes is formed on the back side. This optical interconnection plate technique makes the alignment procedure quite simple and economical, because all the alignment steps between the optical components can be achieved in wafer processes and a high accuracy flip-chip bonding technique. We confirmed the sufficiently high coupling efficiency and low optical crosstalk using the simplified experimental setup. Flip-chip bonding of the vertical-cavity surface-emitting laser and photodiode arrays on the top surface of the optical interconnection plate was performed using indium bumps in order to avoid thermal damage of the polymer waveguide. The fully packaged optical interconnection plate showed an optical data link at rates of 455 Mb/s. Improvement of the mirror surface roughness and the mirror angle accuracy could lead to an optical link at higher rates. In addition, the interconnection system can be easily constructed by inserting the optical interconnection plate between the processing chips or data lines requiring optical links.     

Glass waveguides on silicon for hybrid optical packaging

Work on deposited glass waveguides on silicon to form waveguides and filters is reviewed. The choice of these particular waveguides makes sense only as part of a consistent approach to optoelectronic packaging. Hybrid optical packaging on silicon (HOPS) is described and briefly compared with other techniques. For these packages, two waveguides were developed: a tight mode waveguide with a silicon nitride rib core for matching a semiconductor laser and a loose mode waveguide with a phosphosilicate glass core for matching an optical fiber     

A bandwidth scalable OFDM passive optical network for future access network

In order to reduce the cost for delivering the ever increasing broadband services, network providers need to simplify their network architectures and have a better control of the bandwidth. In this article, we propose a simple and cost-effective bandwidth scalable passive optical network (PON) based on orthogonal frequency division multiplexing (BSOFDM-PON). We report performance analysis in terms of the signal-to-noise ratio (SNR), bit-error-rate (BER), and error vector magnitude (EVM) of a PON system accommodating 32 optical network units (ONUs). Our simulations have successfully demonstrated that throughputs of 35.5 and 53.2 Gbps can be achieved using 16 and 64 QAM, respectively, within a total distance ranging from 20 to 30 km. It gives throughputs of 1.10 and 1.66 Gbps per ONU.     

Transport parameters and optical properties of selectively doped Ga(Al)As/Zn(Mn)Se heterovalent structures with a two-dimensional hole channel

The growth of III–V/II–VI:Mn heterostructures with a high hole concentration in the AlGaAs:Be/GaAs/AlGaAs 2D channel situated in the immediate vicinity of the AlGaAs/Zn(Mn)Se heterovalent interface by molecular-beam epitaxy is reported. Despite the decrease in the hole concentration in the GaAs channel upon a decrease in the distance between the channel and the heterovalent interface, the hole concentration reaches a value of 1.5 × 10¹³ cm^?2 at a temperature of 300 K even at the minimum distance of 1.2 nm. Deep profiling by dynamic secondary-ion mass spectrometry confirmed the back diffusion of Mn from ZnMnSe into the III–V part. High hole concentration and the presence of magnetic manganese ions in the GaAs conduction channel determine the interest in the structures as possible objects in which the effect of magnetic ordering in heterogeneous semiconductor systems can be studied.     

A framework of scalable optical metropolitan networks for improvingsurvivability and class of service

The issues of scalability and class of service have been among the most important research focuses in design of the control plane for wavelength-routed WDM networks. We introduce a framework for achieving a scalable design in metropolitan area networks with WDM as the core technology (called optical metropolitan networks). The framework is summarized with the topics of survivability, scalability and class of service. A novel design concept, called interarrival planning, which aims to achieve scalable control and management in optical metropolitan networks, is addressed     

光学膜厚监控方法

光学膜厚监控方法是光学镀膜过程中用以控制光学薄膜光学厚度的主要方法,也是实现镀膜自动化的关键技术之一.了解光学膜厚监控方法的工作原理、特点及误差来源,有助于在实际应用中根据所镀产品的要求选择合适的光学监控方法及监控参数.文中针对最常用的两种光学膜厚监控方法一单波长法和宽光谱法,分别介绍其工作原理,给出了单波长下根据薄膜的透射率或反射率推算膜层厚度的计算方法以及宽光谱法所常用的3种评价函数,总结出影响单波长法测量的8种因素和宽光谱法的11种因素,并根据这些因素分析了这两种方法的特点和适用范围.     

Design and fabrication of thin film resistive heaters for hybrid optoelectronic packaging

This paper presents the technology for the design and fabrication of planar resistive heaters made from vacuum deposited nichrome thin films on a quartz substrate. These heaters are suitable as isolated local heat sources for melting solder to attach discrete components on a hybrid optoelectronic integration platform. Numerical simulations are performed using the Finite Element Method (FEM) to determine the geometry of the heaters in order to deliver adequate thermal performance. Multiple heater elements are batch processed on a 3.0 in polished fused quartz wafer using standard photolithographic techniques. Use of polyimide as a reliable insulation layer between the nichrome thin film and the solder has improved the thermal uniformity over the heater surface. Individual heaters can reach temperatures close to 300/spl deg/C drawing 7.1 W of power on an uncooled alumina platform and 12.0 W on an uncooled copper platform. This temperature is high enough to melt gold-tin (AuSn) solder (with eutectic melting point of 280/spl deg/C), typically used for attaching different optoelectronic components on a substrate.     

Efficient and scalable side pumping scheme for short high-power optical fiber lasers and amplifiers

A new and simple method of pumping short high-power optical fiber lasers and amplifiers is described. In our approach, several passive coreless optical fibers are brought into direct contact alongside a single rare-earth doped active fiber which constitutes the active medium of the laser (amplifier). Pump light is delivered through the passive coreless fibers and penetrates into the active fiber via evanescent field coupling. To enhance the pump absorption in the gain medium, high-order spatial modes are excited in the pump delivery fibers, and an active fiber with high concentration of the dopant ions is used. As a demonstration of the viability of our approach, test results are reported on a 12-cm-long Er/sup +3/-Yb/sup +3/ codoped phosphate glass fiber laser. The laser output reaches 5 W using 23-W pumping into six coreless fibers. Above threshold, the laser has /spl sim/24% optical-to-optical conversion efficiency (with /spl sim/64% being the theoretical maximum). The linearity of the input-output characteristic for the laser suggests that the output power can be scaled up by applying higher pump power.     

Highly scalable ballistic injection AND-type (BiAND) flash memory

An AND-type split-gate Flash memory cell with a trench select gate and a buried n/sup +/ source is proposed. This cell, programmed by ballistic source side injection (BSSI), can provide high programming efficiency with a cell size of 5F/sup 2/. Furthermore, both the programming speed and the read current are enhanced by the shared select gate configuration.     

Reflective digital optical switch (RDOS) for DWDM optical networkapplications

A novel, high-performance, reflective digital optical switch for use in dense wavelength-division-multiplexed (WDM) network applications is presented. Highly reliable Ti-LiNbO₃ devices show high-speed polarization-independent reflection modulation with 30-dB ON-OFF ratios over a wavelength range from 1520 to 1570 nm     

Growth of metanitroaniline film crystal with controlled orientation for optical waveguide second-harmonic generation

The use of organic molecular crystals with large second-order nonlinear optical susceptibilities for implementing compact waveguide second-harmonic generation devices is addressed. The growth of metanitroaniline film crystal in a planar capillary with a channel/taper structure for single seed formation by zone melting recrystallization using a ridge heater is presented. Single-crystal film (5*15 mm/sup 2/, approximately 2- mu m thickness) was obtained with reproducible crystallographic orientation control. Cerenkov-radiation-type waveguide second-harmonic generation is demonstrated.<>     

Lifting-based invertible motion adaptive transform (LIMAT) framework for highly scalable video compression

We propose a new framework for highly scalable video compression, using a lifting-based invertible motion adaptive transform (LIMAT). We use motion-compensated lifting steps to implement the temporal wavelet transform, which preserves invertibility, regardless of the motion model. By contrast, the invertibility requirement has restricted previous approaches to either block-based or global motion compensation. We show that the proposed framework effectively applies the temporal wavelet transform along a set of motion trajectories. An implementation demonstrates high coding gain from a finely embedded, scalable compressed bit-stream. Results also demonstrate the effectiveness of temporal wavelet kernels other than the simple Haar, and the benefits of complex motion modeling, using a deformable triangular mesh. These advances are either incompatible or difficult to achieve with previously proposed strategies for scalable video compression. Video sequences reconstructed at reduced frame-rates, from subsets of the compressed bit-stream, demonstrate the visually pleasing properties expected from low-pass filtering along the motion trajectories. The paper also describes a compact representation for the motion parameters, having motion overhead comparable to that of motion-compensated predictive coders. Our experimental results compare favorably to others reported in the literature, however, our principal objective is to motivate a new framework for highly scalable video compression.     

Characteristics of solderable electrically conductive adhesives (ECAs) for electronic packaging

This study investigated the effect of the viscosity of the ECAs using a low-melting-point alloy (LMPA) filler on its bonding characteristics. The curing behaviors of the ECAs were determined using Differential Scanning Calorimetry (DSC), and ECA temperature-dependant viscosity characteristics were observed using a torsional parallel rheometer. The wetting test was conducted to investigate the reduction capability of ECAs and the flow-coalescence-wetting behavior of the LMPAs in ECAs. Electrical and mechanical properties were determined and compared to those with commercial ECAs and eutectic tin/lead (Sn/Pb) solder. In the metallurgically interconnected Quad Flat Package (QFP) joint, a typical scallop-type Cu–Sn intermetallic compound (IMC) layer formed at the upper SnBi/Cu interface after curing process. On the other hand, a (Cu, Ni)₆Sn₅ IMC layer formed on the SnBi/ENIG interface. In addition, the fracture surface exhibited by cleavage fracture mode and the fracture was propagated along the Cu–Sn IMC/SnBi interface. The extremely low-level viscosity of ECAs had a significant influence on the flow-coalescence-wetting behavior of the LMPAs in ECAs and also on the interconnection properties. Stable interconnected assemblies showed good electrical and mechanical properties.