SMT虚拟样机可视化建模与仿真

探讨SMT虚拟样机可视化建模与仿真,利用三维建模软件AutoCAD、SolidWorks、Pro/Engineer、3D MAX,对SMT生产流水线中的丝印机、贴片机、回流焊、波峰焊等设备进行建模及动画模拟仿真。同时在VC平台上,将3D MAX与OpenGL相结合,实现动态3D仿真。     

堆叠(PoP)组装的挑战

提出了一种大批量堆叠(PoP)组装方法,这种方法利用了倒装芯片组装中已有的电子封装技术,讨论了多个挑战和考虑因素;演示了怎样使用自动贴装机和倒装芯片组装使用的选项、堆叠和组装这些模块。为适应底部CSP较大的球体尺寸及使用焊膏和助焊剂,必须进行某些改动,堆叠要求的精度要高于标准SMT贴装,某些现有的SMT贴装机可以进行改进,采用相应的改动精确地高速贴装堆叠的CSP,这种方法在成本上非常有竞争力。     

贴片机可视化运动仿真系统设计与实现

贴片机在制造过程中,需要进行贴装测试工作,进行这项工作不仅需要消耗基板、元件而且费时费力,对贴片机的调试工作也很麻烦。为了解决以及更多的了解这方面的技术问题,从可视化动态仿真的角度提供新的思路,通过建立贴片机三维模型、实现贴片机可视化运动仿真、对仿真系统进行测试与优化几个方面对贴片机技术进行研究设计,实现了贴片机的可视化运动仿真,使贴片机的工作流程清晰形象的展现出来。     

并行多机调度问题的一种基于组合规则的遗传算法

本文对最小化完工时间并行多机调度问题提出了一种基于组合规则的遗传算法.用遗传算法来优化调度策略,使得在不同的调度阶段,可采用不同的调度规则以提高算法性能,并用计算实例表明了该遗传算法优于基于机器编码的模拟退火算法和遗传算法,并能适用于大规模并行多机调度问题,算法计算量小,鲁棒性强.     

如何提高SMT设备运行效率

SMT设备运行效率的主要指标有贴装正确率与故障停机率，如何保持和提高SMT设备贴装正确率及降低故障停机率，以创造最大限度的效益，是设备在使用过程中所面临的首要课题，以松下高速贴片机为例，从多方面详细阐述影响设备贴装率的原因，并详细介绍了SMT设备故障的诊断方法及其常见故障的解决方案。     

An approach for grouping circuit cards into families to minimize assembly time on a placement machine

This paper addresses a difficult problem that often arises in printed circuit card assembly systems: how should circuit cards be grouped into families to decrease total assembly time? Traditional approaches to this problem focus on setup time, without considering the possible impacts on processing time. A new approach for selecting card families to be processed on an assembly machine is developed to minimize total assembly time through the joint consideration of setup time and processing time. The overall approach for addressing the card grouping problem involves capturing the lower level machine configuration decisions through an empirical estimator function and incorporating this function with the higher level card grouping problem. The card grouping problem is solved using a branch-and-bound algorithm supplemented by techniques to improve the solution time. An industrial case study is conducted for a turret style placement machine, a Panasonic MV150 machine. The results demonstrate the positive impact of including the lower level decisions on the total assembly time and system throughput for certain types of assembly machines. In addition, this research provides insight on other process planning problems, such as line assignment and card sequencing, by demonstrating the importance of incorporating the related lower level decision problems.     

Hybrid genetic-paired-permutation algorithm for improved VLSI placement

This paper addresses Very large-scale integration (VLSI) placement optimization, which is important because of the rapid development of VLSI design technologies. The goal of this study is to develop a hybrid algorithm for VLSI placement. The proposed algorithm includes a sequential combination of a genetic algorithm and an evolutionary algorithm. It is commonly known that local search algorithms, such as random forest, hill climbing, and variable neighborhoods, can be effectively applied to NP-hard problem-solving. They provide improved solutions, which are obtained after a global search. The scientific novelty of this research is based on the development of systems, principles, and methods for creating a hybrid (combined) placement algorithm. The principal difference in the proposed algorithm is that it obtains a set of alternative solutions in parallel and then selects the best one. Nonstandard genetic operators, based on problem knowledge, are used in the proposed algorithm. An investigational study shows an objective-function improvement of 13%. The time complexity of the hybrid placement algorithm is O(N²).     

层叠封装(PoP)组装的挑战

本文提出了一种大批量层叠封装(PoP)组装方法,这种方法利用了倒装芯片组装中已有的电子封装技术。本文讨论了多个挑战和考虑因素。许多文章[1、2、3]详细介绍了这一新型封装的要求和实例。本文将演示怎样使用自动贴装机和倒装芯片组装使用的选项,堆叠和组装这些模块。为适应底部CSP较大的球体尺寸及使用焊膏和助焊剂,对上述技术必须进行某些改动。堆叠要求的精度要高于标准SMT贴装。某些现有的SMT贴装机可以进行改进,采用相应的改动精确地高速贴装堆叠的CSP。这种方法在成本上非常有竞争力。我们还将他细分析部分测试工具的设计问题。这些测试工具是为了深入考察工艺和组装问题而研制的。     

生产数据准备软件CircuitCAM的特点及应用

CircuitCAM是我们在生产过程中能用到的一个非常有用的工具,用户可通过直观的方式为印制电路板（PCB）和表面贴装技术（SMT）制造中使用的100多种设备类型生成程序。该脱机软件包可将30多种CAD、Gerber及材料单数据快速转换为设备方案,而不必中断SMT生产线的运行。它不但可以生成设备程序,还可为装配员和检验员提供用于创建视像辅助资料的文档工具。文章对这个软件的一些基本功能进行了介绍,例如文件的输入输出等,使大家能在实际工作中应用,并带来方便。     

Korean Morphological Analysis for Korean-Vietnamese Statistical Machine Translation

This paper describes the experiments with Korean-to-Vietnamese statistical machine translation (SMT). The fact that Korean is a morphologically complex language that does not have clear optimal word boundaries causes a major problem of translating into or from Korean. To solve this problem, we present a method to conduct a Korean morphological analysis by using a pre-analyzed partial word-phrase dictionary (PWD). Besides, we build a Korean-Vietnamese parallel corpus for training SMT models by collecting text from multilingual magazines. Then, we apply such a morphology analysis to Korean sentences that are included in the collected parallel corpus as a preprocessing step. The experiment results demonstrate a remarkable improvement of Korean-to-Vietnamese translation quality in term of bi-lingual evaluation understudy (BLEU).     

SMT质量检测中的AOI技术及应用

随着电子制造业中印刷电路板元器件安装普遍采用表面贴片技术,产品的集成度更高,元器件体积更小,安装密度更大,传统的检测技术在技术和速度上都不能适应新的电子检测技术。而基于机器视觉的检测技术（AOI）可以快速、准确地实现对贴片安装产品缺陷的自动检测,是提高电子制造业自动化水平和产品质量的重要技术。对AOI的技术原理进行了阐述,通过分析AOI在工艺中放置位置和最终需要实现目标及其在SMT工序中的应用,充分表明AOI在SMT工艺中的优点。     

SMT生产线配置与粘接剂涂覆工艺

主要论述了对于不同的PCB产品，可采用的不同的组装工艺、生产线配置方案及不同的粘接剂涂覆工艺，并针对粘接剂涂覆这一重要工艺进行了重点讨论。     

一种多语言机制英语在线翻译辅助系统

文中通过对以词组为本的统计式机器翻译系统(Statistical machine translation system,SMT)进行词对应方法的优化和筛选来建立多语言机制的英语在线翻译辅助系统.通过M1模型来计算平行语料库中语言字与字之间可能的配对几率,以EM演算法求取未知资料状况下的参数最大值.通过设置条件值参数作为...     

生产数据准备软件CircuitCAM的特点及应用

CircuitCAM是我们在生产过程中能用到的一个非常有用的工具,用户可通过直观的方式为印刷电路板（PCB）和表面贴装技术（SMT）制造中使用的100多种设备类型生成程序。该脱机软件包可将30多种CAD、Cerber及材料单数据快速转换为设备方案,而不必中断SMT生产线的运行。它不但可以生成设备程序,还可为装配员和检验员提供用于创建视像辅助资料的文档工具。本文对这个软件的一些基本功能进行介绍,例如文件的输入输出等,使大家能在实际工作中应用,并带来方便。     

Optimizing the performance of a surface mount placement machine

Process planning is an important and integral part of effectively operating a printed circuit board (PCB) assembly system. A PCB assembly system generally consists of different types of placement machines, testing equipment, and material handling equipment. This research develops a new solution approach to determine the component placement sequence and feeder arrangement for a turret style surface mount-placement machine often used in PCB assembly systems. This solution approach can be integrated into a process planning system to reduce assembly time and improve productivity. The algorithm consists of a construction procedure that uses a set of rules to generate an initial component placement sequence and feeder arrangement along with an improvement procedure to improve the initial solution. An industrial case study conducted at Ericsson, Inc., using a Fuji CP4-3 machine and actual PCB data, is presented to demonstrate the performance of the proposed solution approach. The solutions obtained using the proposed solution approach are compared to those obtained using state of the art PCB assembly process optimization software. For all PCBs in the case study, the proposed solution approach yielded lower placement times than the commercial software, thus generating additional valuable production capacity. This research is applicable for both researchers and practitioners in printed circuit board assembly systems     

贴片工艺技术概述

贴片工艺在SMT生产中起着非常重要的作用,其控制直接影响着组装板的质量和效率。介绍了贴片设备的结构、视觉系统和元件供料系统,同时还介绍了贴片程序的编辑、生产线平衡和程序优化的方法和经验,希望对从事SMT技术工作的工程技术人员有一定参考作用。     

Processing of fluxing underfills for flip chip-on-laminate assembly

Fluxing underfill eliminates process steps in the assembly of flip chip-on-laminate (FCOL) when compared to conventional capillary flow underfill processing. In the fluxing underfill process, the underfill is dispensed onto the board prior to die placement. During placement, the underfill flows in a "squeeze flow" process until the solder balls contact the pads on the board. The material properties, the dispense pattern and resulting shape, solder mask design pattern, placement force, placement speed, and hold time all impact the placement process and the potential for void formation. A design of experiments was used to optimize the placement process to minimize placement-induced voids. The major factor identified was board design, followed by placement acceleration. During the reflow cycle, the fluxing underfill provides the fluxing action required for good wetting and then cures by the end of the reflow cycle. With small, homogeneous circuit boards it is relatively easy to develop a reflow profile to achieve good solder wetting. However, with complex SMT assemblies involving components with significant thermal mass this is more challenging.     

SMT中印刷电路板设计工艺

伴随无铅化高密度电子组装技术的发展,印刷电路板设计工艺变得越来越重要,相应地对基材选择、元器件布局、焊盘设计以及布线等要求也变得越来越高。针对以上问题,给出了详细的设计工艺要求,并对设计不当而造成的缺陷加以归纳与分析。     

SMT／THT混装焊接技术综述

电子组装的高密度给传统波峰焊接技术提出了新挑战。为了应对挑战,新的混装焊接技术不断涌现。与传统波峰焊情况不同,这些新型焊接技术可以保护表面贴装元件来实现对通孔元件焊接,大幅度降低生产工序和周期时间,印刷线路板的焊接质量也被提升。新的焊接工艺允许充分有效利用SMT贴装设备,免除对点胶机的使用。本文主要介绍了几种新型混装焊接技术的特点,可以确信这些新型焊接技术将会被更多地应用于电子组装上,并将非常具有竞争力。