Factors affecting the long-term stability of Cu/Al ball bonds subjected to standard and extended high temperature storage

This paper presents the findings of work performed on 20-μm diameter copper wire of five different wire types from three suppliers. Gold wire is the control. The test die was mounted on BT (B (Bismaleimide) and T (Triazine)) resin substrates. The bonding parameters were optimized for each wire used. Part of the optimization process involved monitoring the flatness of the bonded ball and the amount of aluminum remaining under the bond. The crystal structure of each type of interconnect was examined using composite imaging techniques. Visual data such as ball size, thickness, and shape were collected. First and second bonds were subjected to destructive testing, such as ball shear and wire pull, throughout the preparation process. The samples were then subjected to an industry-standard, high temperature stress test to determine the long-term stability of the interface of each wire type. Data for all read points are presented on all tests performed and provide useful information on the material and process set best suited for long term reliability.     

通过改进TFT-LCD生产工艺提高光透过率降低生产成本和能耗

很多人都把注意力集中在TFT液晶显示器的面板技术上,例如LED背光源、120/240Hz帧频、宽视角以及其它一些能提高显示性能的技术。在这个背景下,通过不断改进TFT液晶显示器的制造工艺,提高了生产效率,降低了成本,同时亦提高了能源利用率。最新的技术进展涉及滤光片、液晶配向、TFT设计等方面。     

Multimodal acting in mixed reality interactive storytelling

In this paper, an experimental mixed reality using a multimodal approach is introduced which lets users play characters in interactive narratives as though acting on a stage. Users interact with characters through speech, attitude, and gesture, enhancing their immersion in the virtual world. This system provides a small-scale but complete integration of multimodal communication in interactive storytelling. It uses a narrative's semantic context to focus multimodal input processing-that is, the system interprets users' acting (the multimodal input) in the mixed reality stage in terms of narrative functions representing users' contributions to the unfolding plot.     

Impact of ambient temperature set point deviation on Arrhenius estimates

A least squares model is developed that takes ambient temperature set point error into account when making predictions with the Arrhenius equation. Complete data following a lognormal distribution is assumed. According to the model, the regression can be performed assuming the temperatures are at their desired levels (fixed temperature case). Random variation of the actual ambient temperature about the set point value will inflate the variance or mean squared error but will not bias the estimates. This increases the width of confidence intervals on the parameter estimates and predictions like the MTTF compared to the fixed temperature case. The amount of inflated variance depends chiefly on the extent of set point deviation and activation energy but is also influenced by choice of experimental design.     

Towards Using Scientific Publications to Automatically Extract Information on Rare Diseases

A small percentage of the population is afflicted by what is called an orphan or a rare disease. All over the world, there are about several thousand of these diseases. When adding up together all the individuals who are affected, it amounts for up to 10% of the US population. Scientific works on these diseases are often poorly financed due to the lack of potential markets for a treatment, which means for patients and clinicians a very limited and scattered access to vital information. To contribute addressing this issue, we present in this paper a new software tool for automating the extraction of information related to rare diseases from scientific publications. More precisely, our contribution consists in a new method of extracting automatically symptoms of these diseases from research papers exploiting a Named Entity Recognition (NER) algorithm based on the numerical statistic Term Frequency - Inverse Document Frequency (TF-IDF). The proposed tool has been tested using PubMed Central (PMC) database.

     

Modulation of Mechanical Interactions by Local Piezoelectric Effects

Piezoelectricity is a well‐established property of biological materials, yet its functional role has remained unclear. Here, a mechanical effect of piezoelectric domains resulting from collagen fibril organisation is demonstrated, and its role in tissue function and application to material design is described. Using a combination of scanning probe and nonlinear optical microscopy, a hierarchical structuring of piezoelectric domains in collagen‐rich tissues is observed, and their mechanical effects are explored in silico. Local electrostatic attraction and repulsion due to shear piezoelectricity in these domains modulate fibril interactions from the tens of nanometre (single fibril interactions) to the tens of micron (fibre interactions) level, analogous to modulated friction effects. The manipulation of domain size and organisation thus provides a capacity to tune energy storage, dissipation, stiffness, and damage resistance.     

用输入滤波器防止仪表放大器射频整流误差

仪表放大器用于需要从大共模噪声或干扰中提取微弱差分信号的各种设备.但是,设计师常常会忽视仪表放大器内存在的潜在射频整流问题.放大器的共模抑制通常能大大减小仪表放大器输入端的共模噪声.但遗憾的是,射频整流仍然会发生,这是因为即使最好的仪表放大器在频率高于20kHz时实际上也不能抑制共模噪声.放大器的输入级可能会对强信号进行整流,然后以直流偏移误差的形式出现.     

Accelerated life test calculations using the method of maximum likelihood: an improvement over least squares

Reliability calculations from failure time data are often performed using least squares regression of the log of the mean time to failure (MTTF) vs. inverse temperature. It is demonstrated that this method produces estimates of relevant parameters like E_a and MTTF with confidence limits that are larger and more variable than necessary. In comparison, the method of maximum likelihood makes more efficient use of the data and as a result, does not suffer from the above difficulties. A previously published dataset is used to compare the two techniques and the maximum likelihood approach is shown to be superior.     

边缘接入智能化

MMAP(多功能、多业务接入平台)集成了光纤传输和接入技术,使接入网和城域网(MAN)融合在一起。     

The properties of MOVPE grown 1.3 μm DFB MQW lasers infilled with semi-insulating InP fabricated on semi-insulating substrates

The use of optoelectronic integrated circuits (OEICs) is now emerging as a practical technology for a variety of applications, particularly in advanced telecommunications. OEICs consist of a range of devices such as lasers, waveguides, modulators, amplifiers, transistors, detectors, etc. fabricated on the same substrate. When a semi-insulating substrate is used, these devices can be electrically isolated by channel etching, resulting in a low capacitance structure with reduced electrical interference between the subcomponents. One of the devices which is particularly advantageous for this type of integration scheme is the distributed feedback (DFB) laser. The laser can be made to function more efficiently by minimizing the current flowing outside the active region. This can be achieved by surrounding the active region with semi-insulating iron doped InP. This work describes for the first time, the MOVPE growth, fabrication, and device characterization of 1.3 um buried heterostructure DFB MQW lasers, which combine the advantages of using both a semi-insulating substrate and a semi-insulating infill region in the same device structure. The potential advantage of this design scheme is improved OEIC performance as a result of, reduced capacitance and electrical crosstalk, enhanced laser output power, higher speed, increased efficiency, wider operating temperature and reduced threshold current. The laser active region consists of 8 x 140 Å quantum wells of GalnAsP (λ = 1.3 μm) and 110 Åbarriers of GalnAsP (λ= 1.07 μm). Single mode 1.3 urn devices of length 250 μm operating at room temperature produced threshold currents of 8 mA, efficiencies of up to 25%, output powers of 18 mW at 80 mA (pulsed), and a frequency response greater than 12GHz. The parasitic capacitance was estimated to be less than 3 pF.