The use of failure analysis as a preventative quality tool

The materials and processes used to fabricate electronic components have significant effects on their ul-timate reliability. By examining a small number of samples, high risk types of materials and poor work-manship can be flagged, either excluding them from production use,or using them to drive corrective actions. The tools of failure analysis are well suited to this approach, even though the sample components have technically not failed at all. Both nondestructive and destructive types of analysis can be used. By focusing on comparative device analysis between available suppliers, it is possible to find the best in class components for use in high- reliability applications such as automotive electronic modules.     

基于ABB IRB120型机械臂的手机SIM卡装配工艺研究

以3C行业中装配手机为例,采用自动化程度高、可靠性好、工作效率高的6自由度机械臂,针对基于工业机器人的自动装配线,对小型电子产品手机SIM卡的安装进行了装配规划研究,分析了该工序的难点,分解了装配的路径轨迹,阐明了工具姿态及示教点对装配质量的影响,并给出了解决方法,极大地提高了生产效率。同时针对提高以机械臂为核心的生产线开发效率提出了一些建议。     

微电子封装低温Sn-xBi-yM合金钎料研究现状与展望

小型化、多功能电子产品的发展使器件在封装和组装过程中面临热损伤和基板翘曲等问题。为了减小电子封装和组装过程对芯片和器件的热影响,需要研究和开发低熔点的互连材料。锡铋（Sn-Bi）合金钎料由于低熔点、低成本、良好的润湿性和机械强度等特性受到了广泛关注,但是其中脆性Bi相的偏析却不利于器件的长期服役可靠性。通过在Sn-Bi钎料中添加合金元素构成Sn-xBi-yM形式的合金钎料可以有效改善Sn-Bi合金钎料及其焊点的服役可靠性。本文从钎料合金化的角度出发,分析并总结了不同合金元素对Sn-Bi钎料的熔点、润湿性、微观组织、机械性能、界面反应及可靠性的影响。并根据现有的研究成果,展望了锡铋合金钎料未来的发展方向。     

Reconfiguring flexible machine modules of a PCB assembly line

Assembly of electronic components to Printed Circuit Boards (PCB) is a complicated manufacturing process and therefore its control is usually divided into several subtasks which are handled separately. We consider the combined task of determining a machine configuration and line balancing for a single assembly line of interconnected, reconfigurable machine modules and one PCB type in production. The modules can be tailored to the needs of each PCB type by suitable assignments for placement heads, nozzles and feeders. Out of these, the component-to-machine assignment appears to be most difficult and we propose five different solution methods for it; brute force, random, greedy, local search and genetic algorithm. The genetic algorithm outperformed the other methods in practical test.     

Autonomous Processes in Assembly Systems

Today's assembly systems have to be flexible to adapt quickly to an increasing number and variety of products and changing demand volume. To manage these dynamics, flexible, reconfigurable, and autonomous assembly systems were proposed and partly realised in the last two decades. The flexibility and adaptability is realised by clustering the assembly system into subsystems and modules which get a certain degree of autonomy and control themselves in a decentralised way. This keynote paper will present the general principles of autonomy and the proposed concepts, methods and technologies to realise autonomous processes in assembly systems. Different approaches for design and autonomous operation of assembly will be explained and future trends towards fully autonomous components of an assembly system as well as autonomous parts and products will be discussed.     

Sizing up the Efficiency of Induction Heating Systems for Soldering Electronic Modules

The efficiency of induction ring-type heating systems and on an unclosed magnetic circuit, as applied to soldering parts and electronic components, is sized up during assembly of electronic modules. For inductors on the magnetic circuit, owing to the concentration of the electromagnetic field in a working gap, the efficiency of heating of parts increases and the heating zone is localized. Simulation of the parameters of both the electric and magnetic fields in COMSOL gives the temperature profiles of heating of surfacemounted components over a frequency range of 22–100 kHz. The highest heating rate of 12–15°С/s is attained at lower frequencies, where the penetration of the electromagnetic field is deeper.     

枕簧智能组装机器人系统方案设计与分析

目前，铁路货车转向架检修过程中的枕簧组装均采用人工作业模式，存在作业强度大、操作空间狭窄、有安全隐患和效率低等问题，迫切需要自动化和智能化组装设备。基于转向架枕簧的组装工况分析，研发一种智能组装机器人系统，代替人工实现枕簧的自动组装。机器人系统包括顶升装置、中转机器人、中转平台、组装机器人和斜楔支撑机器人等5个模块，通过模块的交互与协同控制完成枕簧的自动组装。介绍了机器人系统的总体方案和各模块方案设计。利用ADAMS软件对六轴机器人进行轨迹仿真分析，得到机器人系统工作的最优轨迹。     

航天电子产品CCGA加固工艺可靠性分析

航天电子产品大量应用陶瓷柱栅阵列封装(ceramic column grid array, CCGA)器件,其装焊质量与器件本体尺寸和加固工艺息息相关.文中通过试验和数值仿真方法,研究印制电路板(primted circurt board, PCB)约束、器件加固工艺对大尺寸CCGA焊点可靠性的影响. 仿真与试验结果表明,优化CCGA周围印制电路板约束方式、使用EC-2216环氧胶加固CCGA均可大幅降低随机振动过程中焊点受力. 使用少量环氧胶加固CCGA提高焊点抗振性能的同时,对焊点抗热疲劳性能影响较小,满足QJ 3086A—2016高可靠装焊要求;随着环氧胶点胶量的增多,焊点抗热疲劳性能显著下降,焊点在温差变化较大的服役环境下存在失效风险;在充分优化PCB约束以降低板级振动响应的情况下,使用GD414硅橡胶加固器件也满足航天电子产品高可靠装配要求.     

A multi-dimensional measure for determining the complexity of manual assembly operations

A key to solving the discrepancies of deterministic and static assembly sequences at manual work places is seen in situation-oriented and cognitive methodologies in assembly. These provide means for efficient and ergonomically feasible worker guidance. An accurate and detailed technique of adjusting the instructional content is seen as a prerequisite. In this context the authors present factors for a multi-dimensional measurement of the degree of detail and complexity of manual assembly tasks. It extends the concept and application of common systems of predetermined times. It includes dimensions of actual human performance and attention allocation, as well as learning effects based on the product and its reference levels. It is assumed that identifying global attributes that contribute to assembly difficulty will provide means for predicting assembly complexity more effectively.     

层状复合材料周期结构的超声传播频散特性及均匀化模拟

首先采用改进全局矩阵算法,研究了层状复合材料周期结构的频散特性。当层数足够大时,在特定方向上结构表现出类似均匀各向异性材料的性质,可采用均匀化方法求解频散曲线。其次,给出了层状复合材料周期结构均匀化的计算方法,并研究了其适用范围。发现在低频段和高频高相速度段范围内可以采用等效模量计算频散特性;而高频低相速度范围内不能采用均匀化方法,该范围内波的性质有待进一步研究。     

基于小位移旋量公差建模和蒙特卡洛模拟的装配体公差优化设计方法北大核心

提出一种基于小位移旋量(SDT)公差建模和蒙特卡洛模拟的装配体公差优化设计方法,通过分析装配精度链、装配结合面和结合面公差3个对装配精度具有重要影响的核心要素之间的关系,利用SDT理论和蒙特卡洛模拟法建立公差模型,再利用齐次变换理论建立结合面误差模型和装配精度模型,进而推导出装配体装配精度与结合面公差相关的映射模型;结合公差制造成本、装配精度可靠度原则,建立装配体装配精度的公差优化模型,并以顶尖装配体为例完成公差优化分析。研究发现:在满足装配精度可靠度的前提下,可使顶尖装配体加工成本降低9.02%,而装配精度可靠度提高至97.81%,验证了所提方法的有效性。     

Open-architecture products

This paper defines open-architecture products (OAPs), a new class of products comprising a fixed platform and modules that can be added and swapped. Customers can adapt OAPs to their needs by integrating modules into the platform. Manufacturers will produce these platforms, while new small companies and customers will develop the modules, thus increasing employment and causing the economy to flourish. At the same time OAPs will provide consumers with the product they desire. Challenges include developing new OAP design software for non-professional designers and new assembly systems to facilitate economical assembly of a large number of product variants.     

模块化虚拟装配系统的开发和研究

文章从装配的概念及发展现状阐述了产品虚拟装配的过程和重要性，给出了模块化虚拟装配系统的构想。系统模块包括基础模型的建立、装配模型的生成、装配路径和顺序的规划、装配过程仿真和演示；举例给出了利用Pro／E和Autodesk Inventor来实现各模块的功能；建立了系统流程图，分析了系统中各模块之间的联系，以及系统在生产过程中的作用。具有一定参考价值。     

临床试验辅助管理系统的设计与初步实践

在临床试验的实施过程中,电子化管理可有效实现规范有效的管理以及质量控制并提高工作效率和水平,但国内目前相关电子管理系统的应用较少。为此,本临床试验机构自主研发了一个“临床试验辅助管理系统”,应用计算机网络和数据库技术初步实现临床试验的电子化管理。本文阐述了该系统中研究者信息管理、项目管理、标准操作规程管理等三大功能模块的设计要点及其应用,并就系统的深入开发利用进行了探讨。     

Mechanical Bus for Modular Product Design

Modular products consist of detachable modules that can be manufactured, assembled, and serviced separately and may be reusable, recyclable, or remanufacturable upon product retirement. Thus, modular design can provide benefits to many aspects of product life cycle. To realize these benefits, the connections between modules must be designed to facilitate operations for parallel manufacturing, assembly as well as post product life activities. This paper presents a new concept of Mechanical Bus for facilitating modular and platform product design. The characteristics and features of Mechanical Buses have been identified including bus functions, locking and release mechanisms, positioning and locating features and so on. A design method for modular platform design using Mechanical Buses has also been developed. Examples and a case study will be included to illustrate the Mechanical Bus and modular platform product design method.     

Reconfigurable handling system

The demand for more versatile assembly and handling systems to facilitate customized production is gaining in importance, especially with regard to the constantly-increasing cost pressure, to expansion of the range of product versions and the shortening of innovation cycles. As a cost-effective approach for frequently changing assembly tasks, a novel manipulation concept has been developed by combining given robot technologies. This new handling system has a modular and adaptable layout, which consists of several mobile arms to manipulate the object in six-dimensional Cartesian space. After grasping, when the arms are attached to the object, the mechanical architecture is similar to parallel manipulators or cooperating robots. As the mounting and gripping points of the arms can easily be changed, the manipulator can be reconfigured so as to match the user’s preferences and needs. In addition to the kinematic adaption the regarding task, the hardware and new functions can be reconfigured as well. Contact elements, measurement and assembly devices as well as testing modules can easily be in integrated in the concept. A modular automatic control concept combined with a self-optimizing planning tool helps the user to find the optimal configuration and realize it in an economic way.     

三维钢网装配机械的模块化设计与应用

以产品装配工艺和装配机械的功能分析为基础,将模块化原理应用于三维钢网系列装配机械的设计上。对三维钢网装配机械进行了功能模块的划分与创建,并对主要功能模块的结构进行了阐述。最后给出了一种装配机械模块的典型配置方案。     

Innovative Assembly Concepts with Reel-To-Reel Transfer

Mechatronic solutions are progressively influencing innovative products from the most diverse range of applications. To ensure the optimum integration of mechanical, electronical and software components to form complete systems, modules are increasingly being based on flexible circuit carriers. Despite technological advantages, the use of foil based electronic circuits in main stream manufacturing has not arisen due to the absence of suitable production technologies. This article presents various concepts and prototype solutions to realize an economic process with the main focus on automated reel-to-reel manufacturing. The substrates are rigidly coupled in a panel during the paste application, assembly and reflow process steps and are separated at the end of the complete process sequence. This procedure requires both innovative systems and processes and new concepts for controlling the whole line.     

Automated assembly of electro-optical components onto printed circuit boards with integrated optical waveguides

The performance of information- and communication-systems will be defined in the future increasingly by their interior capacity of signal transmission. The feasible bandwidth of the conventional electrical signal transmission is limited because of physical properties like wave propagation and length of conductors. Due to the different nature of optical signal transmission inside printed circuit boards, those effects are avoided and therefore with this technology, a significant increase in data transfer rates can be achieved. For this reason, optical signal transmission finds its way into conventional electronic systems and substitutes electrical based high frequency transmission lines. This type of assembly results in hybrid systems where electrical and optical technology coexist. In view of promising system solutions, increased research and development activities take place with a focus especially on assembly and packaging technologies. This article describes the conceptual design and implementation of a continuous process chain for manufacturing electro-optical packages, which makes it possible to interlink the so far incompatible technologies of electrical and electro-optical assembly.     

Development of micro assembly processes for further miniaturization in electronics production

Steady increase of functionality and concurrent reduction of the package size are one of the key driving forces in electronics production. In this paper we will present solutions developed at the institute for the automated assembly of highly miniaturized flip-chips with pitches down to 100 μm. In particular the present and future influences of miniaturization on the main process steps wafer bumping, component placement, reflow soldering and inspection are examined as well as the influences on complementary materials used. Results regarding the achievable yield after assembly and the reliability of the structures will be presented in addition to an analysis of the failure mechanisms.