Filler-induced failure mechanism in plastic-encapsulated microelectronic packages

Based on empirical data, the present work provides a model to prevent filler-induced reliability degradation in plastic-encapsulated LOC (lead-on-chip) packages. According to the model, the maximum size of the silica fillers included in the plastic package body should be smaller than one half of the inter-distance between the device and its overlying lead-frame. In particular, it is shown in the model that the spherical silica particles, which are sometimes trapped in the space between the top surface of the device and the bottom of the lead-frame during the encapsulating process, can induce huge compressive stress on a specific site of the integrated circuit pattern due to the thermal shrinkage of the plastic package body. Further, the present model suggests that tiny fillers squeezed beneath a large trapping filler might directly attack the brittle layer of the device pattern because the compressive force from the large filler particle can develop into huge compressive stress due to the reduced load-carrying area.     

Reliability and stability of executive functioning in older adults.

A number of methodological questions have been raised about the reliability and validity of measuring executive functioning (EF) across multiple time points. In this study, correlational and latent-variable analyses were used to examine test-retest reliability of 5 common measures of EF and the stability of a latent EF construct. One hundred eighteen nondemented older adults were tested twice over a 4- to 8-week period. Findings demonstrated modest reliability of individual EF measures but very high stability of a latent EF construct. Relative contributions of each measure to the latent EF factor did not change across measurement trials. In addition, age-related effects on EF were similar at the 2 time points and were within the expected range. Implications for future studies of EF are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

LC4L-20增压中冷柴油机的研制

介绍了LC4L-20增压中冷柴油机的性能与结构特点，着重分析了增压中冷技术，及各主要运动件的可靠性设计。     

Using rainbow net simulation to measure fault tolerance in a multiprocessor

The Rainbow net simulation technique is applied to modelling the impact of system load and fault handling on the availability of a fault-tolerant multiprocessor architecture. Rainbow nets are described along with the motivation for creating this modelling technique. A Rainbow net fault-handling model is created for the fault-tolerant multiprocessor architecture and the topology is shown to remain constant in size, independent of the number of processor, memory and I/O elements configured in the system. Simulation is performed with a varying load in terms of the number of active jobs the system must support. Results are given showing how the fault-tolerant capability varies with load. Two new metrics for evaluating fault tolerance are introduced; namely full fault-tolerability and partial fault-tolerability. They are based on simple observations in the model.     

Structural reliability optimization using an efficient safety index calculation procedure

The objective of this paper is to conduct reliability-based structural optimization in a multidisciplinary environment. An efficient reliability analysis is developed by expanding the limit functions in terms of intermediate design variables. The design constraints are approximated using multivariate splines in searching for the optimum. The reduction in computational cost realized in safety index calculation and optimization are demonstrated through several structural problems. This paper presents safety index computation, analytical sensitivity analysis of reliability constraints and optimization using truss, frame and plate examples.     

用于ABS粘接的UV固化胶粘剂

研究了用于低表面能材料ABS的UV固化胶粘剂的组成,及各组分对胶粘剂性能的影响。结果表明,配比为:双酚A环氧丙烯酸酯、脂肪族聚氨酯丙烯酸酯的混合物为预聚物(占50%~55%),混合单体40%~45%,光引发剂3%~7%,流平剂BYK 307占0.1%~0.2%的胶粘剂,对ABS的湿润性及粘接强度最好。     

ULSI中的铜互连线RC延迟

随着ULSI向深亚微米特征尺寸发展，互连引线成为ULSI向更高性能发展的主要限制因素。由互连引线引起的串扰噪音及RC延迟限制了ULSI的频率性能的提高，同时考虑到电迁移和功率损耗，人们开始寻找新的互连材料；低电阻率的铜互连材料和低介电常数介质的结合可以有效地发送互连线的性能，主要讨论了互连延迟的重要性以及发送和计算延迟的方法。     

Evaluate the performance of a stochastic-flow network with cost attribute in terms of minimal cuts

This paper proposes a performance index to measure the quality level of a stochastic-flow network in which each node has a designated capacity, which will have different lower levels due to various partial and complete failures. The performance index is the probability that the maximum flow of the network equals the demand d without exceeding the budget b. A simple algorithm in terms of minimal cuts is first proposed to generate all upper boundary points for (d, b), and then the probability that the maximum flow is less than or equal to d can be calculated in terms of such points. The upper boundary point for (d, b) is a maximal vector representing the capacity of each arc such that the maximum flow of the network under the budget b is d. The performance index can be calculated by repeating the proposed algorithm to obtain all upper boundary point for (d−1, b). A benchmark example is shown to illustrate the solution procedure.     

2197铝锂合金的组织和性能

通过力学性能测试和显微组织观察研究了2197合金组织和性能之间的关系。结果表明,2197合金具有中等强度,小的各向异性,强的热稳定性。该合金在T8状态下能获得最佳的强度和塑性配合,在T6峰时效状态以析出少量δ′相、θ′相和T_1相联合强化为主。在2197合金的相组成中,T_1相析出数量不占主导地位,Al_6Mn弥散质点的析出有利于减小各向异性。2197合金中Li含量较低,使其呈现较强的热稳定性。     

童亭矿锚杆支护安全可靠性控制

简要介绍了煤巷锚杆支护技术在童亭煤矿的应用推广情况 ,重点介绍了童亭煤矿在安全可靠性控制方面强化管理、优化设计、提高工艺水平和质量保证体系建设的一些经验和做法 ,并对今后发展煤巷锚杆支护技术提出了看法。