功率电子器件用AlN陶瓷基板的研制

阐述了AlN陶瓷的烧结原理 ,分析了烧结工艺参数对大面积AlN基板性能的影响 ,成功研制出了高热导率(190W /m·K)、大面积 (14 0mm× 90mm)、翘曲度为 2 0 μm/5 0mm的AlN陶瓷基板。     

管接头类冲压件模具调整过程中有关问题的解决

以出水管接头为例，说明了管接头类冲压件在多次拉深过程中的工艺特点，并提出了模具调试过程中拉深颈缩、法兰平面度超差等问题的解决措施。     

西门子平坦度检测系统在冷轧中的应用

结合西门子平坦度检测系统在冷轧厂的应用实例，通过对其检测原理的分析，从系统的硬件构成到软件实现，较详细地介绍了西门子新一代平坦度检测系统。最后对该检测系统的特点进行了总评。     

五机架UCMW冷连轧机板形平坦度自动控制系统

板形平坦度自动控制系统是板带材冷连轧机过程控制系统的重要组成部分。从国外成套引进的某1550UCMW冷连轧机组装备了具有国际先进水平的板形平坦度自动控制系统。本文通过对此系统的深入消化研究,从预设定控制、弯辊力-轧制力前馈控制和闭环反馈控制三个方面,分别总结介绍了系统的扳形控制策略和控制模型设计思想。     

基于IGA的板形板厚神经网络分散解耦PID控制

针对板带材轧制是一个复杂的非线性过程，板形控制(AFC)和板厚控制(AGC)又是相互耦合的一个综合系统等特点．该文首先采用神经网络分散解耦方法，对此板形板厚多变量耦合系统进行解耦，而后再应用基于免疫遗传算法的PID控制对解耦后的已近似成为两个独立的SISO系统的广义对象进行控制。从而建立了基于免疫遗传算法的板形板厚神经网络分散解耦PID控制系统。仿真结果证明了此AFC—AGC控制系统具有良好的自适应跟随和抗扰性能，其控制效果优于传统的解耦PID控制。     

Improvement of Heater Surface Flatness and Uniformity of TiN Film Deposition

The deposition rate and the thickness uniformity of chemical vapor deposition (CVD) titanium nitride films depend on wafer temperatures. The heater surface conditions, such as flatness, roughness, and surface imperfections, can greatly affect heat transfer efficiency from the heater surface to the wafer, and the process performance. Because heater surface imperfections or “hot spots” that caused poor uniformity had to be eliminated, the origin of “hot spots” was identified by a detailed study of heater surface profiles. A better visualization of “hot spots” could be obtained by comparing wafer-chucking patterns with deposition patterns. Thus, the time needed to locate “hot spots” could be shortened. The manufacturing process was revised to prevent “hot spots” and improve heater performance.     

A Genetic Algorithm for Assessing Flatness in Automated Manufacturing Systems

The measurement of flatness for manufactured parts is one of the most frequently used procedures in automated manufacturing systems. Measuring instruments are commonly utilized in taking measurement data from manufactured surfaces for inspection purposes. The measurement data is then used to evaluate the geometric information, from errors associated with its surface. The study proposes the computational approaches for flatness with respect to ASME Y14.5M-1994 standard. The proposed methods consider the trade-off between the accuracy of flatness and the efficiency of inspection. Two approaches of computational metrology based on genetic algorithms are proposed to explore the optimality of flatness measurement and the flatness feasibility analysis. The results show that the optimization algorithms provide exact flatness errors and adequate tolerance size. Received: February 2004 / Accepted: September 2005     

Flatness tolerance evaluation: an approximate minimum zone solution

This paper is concerned with the problem of flatness tolerance evaluation. First, we introduce the concepts of width and inner radius of point sets, and establish the equivalence between the width of a point set and the inner radius of the convex hull of the self-difference of the set. On this basis, we present an algorithm for calculating the exact minimum zone tolerance of flatness. Second, we prove that an approximation of the inner radius of a convex set can be obtained from the inner radius of the set in fixed direction. On this basis, we present an algorithm for calculating the ‘almost exact’ minimum zone solution. This algorithm is implemented by solving a single linear programming problem, of which the computational complexity is O(n). Numerical examples are given to validate the proposed algorithms.     

公差为7μm的工作台平面度的检定方法

通过误差分析与计算，论证了０．０１ｍｍ／ｍ合象水平仪不能满足公差为７μｍ的机床工作台平面度检定精度要求，采用０．００５ｍｍ／ｍ自准直仪或电子水平仪可获得满意的检定精度结果。因此正确选择检定仪器，对于保证机床工作台检定质量尤为必要。