基于CAN总线电子系统在车辆底盘控制中的应用

对于军用特种车辆底盘控制系统使用的点对点控制方式所造成的车体底盘布线复杂、布局不合理、维修更换难等一系列技术问题进行了分析研究.设计了基于CAN总线的电子综合控制系统,各测控模块进行多点控制,同时各测控模块采用基板印制电路板加功能印制电路板的组合,可随时根据现场车体被控设备的要求进行添加或精简,各测控模块通过CAN总线...     

基于LASAR的印制电路板故障诊断系统研究

介绍了应用LASAR软件开发印制电路板故障诊断程序的流程 ,并进行了详细的探讨 ,在此基础上提出了一种新型的印制电路板通用故障诊断系统 ,即基于LASAR的印制电路板故障诊断系统     

A solution technique for placing digital integrated circuitry on printed circuit boards

A mathematical formulation of the problem is presented using the concepts and terminology of graph theory. This formulation includes both stages of the placement problem wherein the vertices of the circuit graph are partitioned into several subsets (representing integrated circuit packages) which are, in turn, assigned to geometric positions corresponding to the printed circuit board specifications. Utilizing the manhattan metric, a heuristic procedure is described which provides minimum length placements on two-sided printed circuit boards consistent with the requirements of PC board designers. Computational results from problems arising in actual design efforts are discussed.     

低成本微反应槽PCR芯片阵列双重控制系统

设计了内部不含温度传感元件、加热元件的低成本微反应槽聚合酶链式反应（PCR）芯片．研制了宏观集中控制与微观分散控制有机结合的双重控制系统,该系统具备对PCR芯片的批量处理能力;宏观集中控制装置以水为传热媒质通过特制换热器给芯片提供聚合酶反应所需的基本温度;在柔性印刷电路板上形成与芯片阵列对应的微型加热器阵列,针对各芯片进行分散的温度补偿。     

基于IMAQ的印刷电路板电子元件缺件检测

提出了基于IMAQ Vision Assistant的印刷电路板上电子元件缺件检测方法。该方法首先对被检测的印刷电路板图像进行校正,然后主要利用IMAQ Vision Assistant的模板匹配函数实现对印刷电路板上电子元件缺件的检测。文中给出了应用实例,结果表明该方法能有效地检测出印刷电路板上电子元件缺件缺陷。     

Automated visual inspection: A tutorial

This article introduces the topic of automated visual inspection (AVI) as a subset of machine vision. The components of a generic AVI system will be presented and current applications of AVI systems will be discussed. Specifically, the applications of automated dimension verification, bare printed circuit board inspection, stuffed printed circuit board inspection and component identification using color technology will be covered in some detail.     

列车用高速数字PCB电路板抗干扰设计（EMS）

详细阐明了高速数字印制电路板在设计时应该注意的问题,阐明了在列车车载系统中高速数字电路将会受到哪些方面的影响,以及产生这些影响的原因,针对具体问题提出设计高速电路时应该采取的几种方法。实践证明,采取这些方法设计的电路能够极大提高产品的抗干扰性能。     

Mechanics of flexible interconnect in lateral tape open drives

A mechanics modeling is presented in this paper with focus given to understanding effect of flexible printed circuit cable’s dynamic effect on tape head actuator’s lateral motion in advanced, high capacity tape drives. The flexible printed circuit cable which connects the actuator to printed circuit board is first examined through establishment of analytical model to predict its profile with considerations of boundary conditions and mechanical design parameters. Secondly, equivalent stiffness produced by the flexible printed circuit cable when the linear tape head actuator is positioned along its lateral positions is examined. Finally, effect of tape head actuator’s voice coil motor is studied and modeled as a magnetic suspension, contributing to stability and controllability of the actuator lateral motion dynamics. Validated by calibrated laboratory experiments, the work presented in this paper can add to the literature regarding dynamics and control of LTM in modern LTO drives.     

基于Protel99SE的电路板设计

阐述了使用印制板设计软件Protel99SE进行印制板设计的流程和注意事项,在电路设计中遵循这些原则和应用技巧会给电路设计带来很大的方便,为工作组的设计人员提供设计规范,并且可以在电路设计和印制电路板中减少错误,有利于设计人员之间进行交流和相互检查。     

Three-axis pneumatic tactile display with integrated capacitive sensors for feedback control

In this paper, we propose a three-axis pneumatic tactile display that is precisely controlled by using integrated capacitive displacement sensors. The proposed tactile display consists of a core body with a 3 × 3 balloon array on its top surface, four lateral balloons made of latex rubber, and inner and outer frames that include capacitive displacement sensors based on a flexible printed circuit board. The 3 × 3 balloon array on the core body is designed to apply normal haptic stimulation to a human fingertip. In addition, the lateral motions of the core body and each frame produce haptic stimulation in a tangential direction. Precise control of lateral motion was achieved by feedback control using the capacitive displacement sensors. The size of the fabricated tactile display was 26 × 26 × 18 mm³. We experimentally performed manipulation of the proposed device with a custom control system, thereby demonstrating accurate control of displacement.     

A system for PCB automated inspection using fluorescent light

Research was performed on the detection of faults such as shorts, cuts, and nicks in a printed circuit board pattern. The possibility was investigated of detecting a pattern by illuminating a printed circuit board with violet or ultraviolet rays and detecting the pattern using the (yellow or other) fluorescent light emitted by the base material consisting of glass-epoxy or glass-polyimide, etc. It was found that the pattern could be detected clearly by selecting an optical fiber that would separate the emitted fluorescent light from the illumination and using a detector consisting of a high-sensitivity TV camera that produces a silhouette image in which the base material is bright and the pattern is dark. A printed-circuit-board pattern inspector using this approach was developed. Test operation of the inspector in a plant demonstrated that it performs consistently good pattern inspections     

基于控件和XML的可定制软件开发方案

为降低软件维护上的难度，适应不断变化的用户需求，提出了一种基于控件和XML配置技术的可定制的软件开发方案，一定程度上解决了面向Windows应用程序的可定制问题。该方案利用XML存储软件设计中的关键信息，将部分设计信息与开发平台分离，降低了和其它模块的耦合度，使得使用该方案开发的软件系统具有较高的可扩展性。该方案已经在一个电子元器件库存系统和一款印刷电路板的设置软件上得以应用。     

Parametric study of flip-chip packaging for an MEMS device with diaphragm

A backside-etched silicon chip with a polysilicon diaphragm flip-chip attached on a printed wiring board and globally bumped on a FR4 printed circuit board was investigated through a finite element analysis for determining three key parameters of flip-chip chip size packaging, namely, the size of solder bump, and the thickness of the printed wiring board with/without U8437-3 underfill. Four kinds of thermal-induced stresses and deformations in the diaphragm, solder bump, and printed wiring board were evaluated for the parametric study. As the simulation results show, the thermal-induced stresses in the diaphragm and solder bump can be reduced effectively if the printed wiring board is thinner. However, the printed wiring board is still required to be sufficiently thick to prevent warping. In addition, the underfill material also can reduce the induced stress occurring at the interface between the solder joint and the chip and improve reliability. In general, the parametric study can provide a basis for the flip chip package of a MEMS device with a diaphragm, such as a MEMS microphone, MEMS pressure sensor, etc.     

基于卷积神经网络的PCB缺陷检测

印刷电路板(PCB)在生产制造中由于生产工序等问题易导致电路板存在瑕疵缺陷,为提高对电路板缺陷的检测效率,提出了一种基于卷积神经网络(CNN)的电路板缺陷检测网络.该检测网络基于YOLO v4网络进行优化改造,针对于PCB制作精密、复杂,各类缺陷不易检测的难点,在优化后的网络中加入了基于细粒度空间域的长距离全局注意力机...     

Laser speckle reduction by a hybrid MEMS diffuser device with continuous height profile

Microsystem Technologies - The hybrid MEMS diffuser device based on Si wafer and fire resistant 4 printed circuit board (FR-4 PCB) was designed in order to obtain a low-cost device with large...     

Evaluation of complex and dynamic safety tasks in human learning using the ACT-R and SOAR skill acquisition theories

This paper provides a human-centered analytical approach to learning dynamic and complex tasks using the Adaptive Control of Thought-Rational (ACT-R) and the State, Operator And Result (SOAR) models by comparing the task times of the model and the subjects. Twenty-one full time assembly line workers at a local computer company (14 men and 7 women) from ages 18-32 (Mean = 19.86 years, SD = 0.96 years) were randomly selected for this analysis. The task involved the placement of printed circuit board (PCB) components on the flow line of the desktop computer mother board manufacturing process. The overall timed performance of the subjects indicated that the match between the model and the subjects was good, resulting in an R² - value of 0.94. At the unit task level performance, and R² - value of 0.96 for placing the PCBs on the flow line. For tasks involving picking and searching of PCBs, the obtained R² - value was 0.76 and R² of 0.68 at the keystroke level. Findings revealed that the model already started out with a complete strategy of performing the task, whereas the human participants had to acquire additional learning information during the trials. Efforts will be made in the future to determine how the performance of the human subjects could be enhanced to meet or the same level as the model performance.     

一种基于模板和DCT变换的柔性电路板配准方法

针对柔性印刷电路板（FPC）生产检测过程中的效率、精度等要求,提出一种基于模板与离散余弦变换（DCT）描述子的配准方法。首先,为了解决配准的精度问题,由电路板文件工程图解析得到对应图像,为后续处理提供更好的模板图,再利用离散余弦描述子的频域能量聚集特点,在模板与被检测图像之间建立对应关系,从而计算出对齐参数。其次,使用mipmap技术处理模板,为配准阶段提供不同精度的模板图片,从而有助于精度及效率的提升。实验结果表明：该改进算法的最大误差和平均误差均比原方法小;对于电路板这种大分辨率的图像,在mipmap采样的模板条件下,可以获得较高的精度,且处理速度有较大的提升。     

A compact UWB‐MIMO with dual grounded CRR for isolation improvement

In this article, a compact half‐hexagonal ultra‐wide band multiple‐input‐multiple‐output (MIMO) antenna is presented. The key feature of the antenna is its novel isolation improvement technique which includes grounded stub along with dual grounded circular ring resonator. The antenna contains two counter facing half‐hexagonal monopoles having hybrid isolation circuit. The antenna has a compact size of 20 × 34 mm², with operating frequency band of 3‐11 GHz where port isolation is better than 20 dB in most of the band. The MIMO performance is ensured by calculating envelop correlation coefficient and mean effective gain ratio for isotropic, indoor, and outdoor environment. The performance of the antenna with multilayer printed circuit board having large dual ground plane and device housing is also studied. Results show that the proposed MIMO antenna is a good candidate for handheld devices for wireless personal‐area networks application.     

多根贯通导线对屏蔽体内电路电磁干扰影响的仿真研究

仿真研究了两根贯通导线对屏蔽体内印制电路板终端负载的影响。研究表明,贯通导线与屏蔽体外的电磁脉冲波耦合,可使传入屏蔽体内印制电路板终端负载上的电压增大很多;当双线连接时,不仅存在着空间辐射干扰波通过导线吸收传导进入电路而产生的干扰电压,而且还存在着两线间串扰电压。实验结果可知,随着频率的增加,线间串扰增大,在终端负载产生的总干扰电压,比只有通过线吸收传导进入电路产生的电压要大。这些工作对电子系统的设计和安装具有指导意义。     

Data clustering and fuzzy neural network for sales forecasting: A case study in printed circuit board industry

In order to obtain a better control of market trend and profit for the company, timely identification of sales is very important for businesses. Upward and downward trends in sales signify new market trends and understanding of sales trends is important for marketing as well as for customer retention. This research develops a hybrid model by integrating K-mean cluster and fuzzy neural network (KFNN) to forecast the future sales of a printed circuit board factory. Based on the K-mean clustering technique, the historical data can be classified into different clusters. The accuracy of the forecasted model can be further improved by referring the new data to be forecasted from a more focused region, i.e., a smaller region after clustering. Numerical data of various affecting factors and actual demand of the past 5 years of the printed circuit board (PCB) factory are collected and input into the hybrid model for future monthly sales forecasted. The experimental results derived from the proposed model show the effectiveness of the hybrid model when compared with other approaches.