多层板层压过程中的尺寸收缩分析

内短作为多层板层压制作过程中的一种常见的失效形式,一直严重的影响了电子产品的性能。而芯板的涨缩是导致层偏内短的主要原因之一。本文通过分析多层板层压过程中内层收缩的两大主要影响因素:残留内应力和热涨系数不匹配,然后以线路/PP/线路芯板结构的六层板为例,分别建立内应力完全释放与不释放两种数学模型,各自进行求解,得出两种情况下的菲林补偿系数,分别为-0.37和4.79,这与相关制造厂商提供的线路菲林补偿系数的测量数据2~3.5十分接近。另外,计算结果还验证了内应力对内层收缩的影响。     

In基复合半导体氧化物Cl2敏感特性的研究

Aiming at detecting Cl2 gas, this study was made on how to make In-based compound semiconductor oxide gas sensor. The micro-property and sensitivity of In-based gas sensing material were analyzed and its gas sensitive mechanism was also discussed. Adopting constant temperature chemical coprecipitation, the compound oxides such as In-Nb, In-Cd and In-Mg were synthesized, respectively. The products were sintered at 600 ℃ and characterized by the Scanning Electron Microscope （SEM）, showing the grain size almost about 50-60 nm. The test results show that the sensitivities of In-Nb, In-Cd and In-Mg materials under the concentration of 50 × 10^-6 in Cl2 gas are above 100 times, 4 times and 10 times, respectively. The response time of In-Nb, In-Cd and In-Mg materials is about 30, 60 and 30 s, and the recovery time less than 2, 10 and 2 min, respectively. Among them, the In-Nb material was found to have a relatively high conductivity and ideal sensitivity to Cl2 gas, which showed rather good selectivity and stability, and could detect the minimum concentration of 0.5 × 10^-6 with the sensitivity of 2.2, and the upper limit concentration of 500 × 10^-6. The power loss of the device is around 220 mW under the heating voltage of 3 V.     

PCB内层芯板补偿系数预估:实验和统计学方法

内层芯板补偿系数的准确性是保证PCB产品实现高密度互连的重要因素之一。文章从生产实际出发,确定影响补偿系数的三个主要因素:残铜率、芯板铜厚和芯板厚度,并且在此基础上采用正交试验的方法制定九组实验。通过分析实验数据得到各因素的主效应图与交互作用图,并根据分析结果提出四种回归模型,从而得到适合芯板不同方向上的补偿系数回归公式。     

一种用于电镀成本核算及资源优化的计算方法

以几种常见的电镀线生产设备为例,介绍了一种可以广泛应用于PCB生产过程中水平及类水平设备的生产时间计算方法,以此精确计算出产品在生产过程中所消耗的设备折旧成本,为销售人员报价提供参考。推导出同时适用于不同生产批量大小的产能计算公式,为生产管理提供理论依据,以达到资源优化,提高设备利用率,降低成本的目的。     

有机基板中埋入无源元件概述

介绍了埋入无源元件在减小基板面积和提高基板高频特性的优点,总结了目前正在应用和研究的埋入电阻和埋入电容技术的实现方法.并提出基于埋入平面薄膜电阻和埋入薄芯介质材料形成平面电容技术的混合埋入技术将成为未来埋入无源元件PCB的主流技术.最后阐述了埋入无源元件技术在产业化过程中遇到的困难.