废旧电路板物理拆解方法及其试验验证

在废旧电路板的资源化途径中,物理拆解方法正日益受到重视.在对废旧电子电器产品的典型电路板的组装与结构特点进行分析的基础上,对废旧电路板拆解分离的加热解焊方法和施力方法进行定性比较和分析,分别针对典型电子产品电路板和典型电器产品电路板提出两种不同的物理拆解分离工艺,并依据这两种工艺研制两种不同的拆解原型装备.分别以废旧计算机主板和废旧电视机主板为拆解对象,在这两种拆解原型装备上进行拆解试验.结果表明,采用上述物理拆解分离工艺,在适当的拆解工艺控制参数下,对于废旧电子产品电路板,插装元器件、体积较大的贴片元器件和体积微小的片式元件的拆解分离率分别达到91.6%、100%和99.1%,对于废旧电器产品电路板,电路板上的插装元器件引脚焊点去除率达到94.9%,有效实现元器件的拆解和焊料的分离,这对研发具有实际应用价值的废旧电路板拆解工艺和装备具有重要指导意义.     

废旧电路板钎料吹扫去除试验研究

废旧电路板拆解不但是旧元器件重用的必要步骤,而且有利于废旧电路板上不同材料物质的分类收集.现有废旧电路板拆解工艺和拆解设备难以有效拆卸插装元器件,为了实现废旧电路板的自动化拆解,提出一种基于钎料吹扫去除的废旧电路板拆解工艺,并研制了相应的钎料吹扫去除试验设备,用于辅助拆解以插装电子元器件为主的电路板.为了提高钎料去除率和焊点脱钎率,以废旧电视机主板为例,在钎料吹扫去除试验设备上进行钎料去除的正交试验,并在试验条件下确定最优的预热功率、喷嘴缝宽、压缩热气体吹扫角度和电路板运行速度等工艺参数.试验结果表明,基于钎料吹扫去除的拆解工艺能有效拆解插装元器件,焊点脱钎率可达98.1%;试验结果还表明,在采用基于钎料吹扫去除的拆解工艺中,电路板运行速度是影响钎料去除效果的最重要因素,应该适当取值以优化拆解工艺.     

印制电路板拆解技术与拆解工艺综述

综述了电路板拆解单元技术、工艺和设备等方面的研究现状与进展。按照电路板拆解的过程顺序,分别从元器件的识别与定位、电路板解焊技术、拆解施力方式、元器件与焊锡的分离、收集与分类等5项单元技术方面描述了近年来的技术现状与发展;在分析各种拆解工艺和设备的基础上,根据拆解目的和拆解方法的不同,分选择性拆解工艺与设备、面向材料回收的同时性拆解工艺与设备、面向元器件功能重用的同时性拆解工艺与设备、混合拆解工艺与设备等4个方面对当前的各种拆解工艺和设备进行了综合与分类。最后指出,电路板拆解在采用新方法的拆解单元技术、电路板拆解机理分析、更加经济实用、环保、快速的拆解工艺和装备等方面有待进一步研究与开发。     

废旧电路板元器件分离位移模型研究

在焊料加热熔化的前提下,电子元器件拆解取决于在拆解外力作用下元器件相对电路板基板产生的位移即元器件分离位移。首先建立水平拆解和垂直拆解两种方式下不同元器件的分离位移模型;然后重点针对3种典型类型元器件引脚下的焊料在垂直拆解时的断裂高度进行分析,基于牛顿静压力方程和拉普拉斯方程建立了焊料断裂高度的数学模型,并通过实验验证了模型的正确性。废旧电路板上元器件分离位移模型对于确定拆解工艺参数具有重要价值。     

应用遗传算法的线路板拆解加热参数优化

为了优化线路板拆解加热参数,保证元器件有较高的拆除率和合格率,通过正交试验和BP神经网络技术,建立了加热参数与元器件拆除率和合格率之间的映射关系,并验证了网络的稳定性和可靠性;用遗传算法对无数学表达式、多目标、离散值的线路板拆解问题进行多次优化,均收敛到同一个解,说明最优解的稳定性与正确性;按照优化参数得到的元器件拆除率和合格率的网络预测值和试验值都很高,说明加热参数优化效果良好.     

印刷线路板振动拆解模型及其拆解过程分析

废弃印刷线路板(Printed circuit boards,PCB)上的元器件具有较高的重用价值,而元器件的重用是基于合理的线路板拆解工艺的。目前相关研究多关注拆解力的分析和计算,然而由于拆解时元器件与线路板间存在熔融状态的焊料,即便提供足够大的拆解力也难以保证元器件被拆解。在基于已建立的拆解力模型,提出综合考虑拆解力和元器件分离位移的拆解能作为拆解准则,并基于这一准则研究了垂直振动激励下元器件的拆解分离过程,分析了废弃线路板在对边简支对边自由的边界条件下强迫振动的模态,基于薄板振动理论建立PCB的运动微分方程,获得PCB的加速度及位移响应;分析了垂直振动拆解中贴片元器件和插装元器件的不同分离过程,并且采用拆解能模型对不同拆解激振频率、位于线路板不同位置、具有不同最小拆解加速度的元器件进行拆解分析;提出以拆解能图来比较元器件实际获得的拆解能与所需的最小拆解能,为拆解工艺参数的确定提供依据。最后在试验中验证拆解能模型的正确性。     

废弃电路板插装件的自适应磨削拆解方法

将废弃印制电路板(Printed circuit board,PCB)上的元器件拆解之后再分类,能有效提高后续材料分选和回收的效率。PCB上的插装式元器件由于引脚弯曲等原因,所需拆解力很大,常用的方法难以做到有效拆解。为解决这一困难,提出自适应磨削拆解方法,利用弹簧的自适应调节能力,在处理挠曲不平的PCB时提供较为平稳的法向磨削力。对自适应磨削系统的力学特性进行分析,结论显示在采用合理的磨削参数时,能够快速去除引脚并且不会过多地降低基板的刚度,证明了自适应磨削拆解方法的可行性。基于此自适应磨削系统的原理研制废弃PCB插装式元器件的引脚磨削拆解原型设备,并进行验证试验研究。试验结果表明此方法能够在轻微磨削基板的条件下高效地去除引脚,磨削后元器件的自动脱落率达到90%以上,并且未脱落的元器件与基板的连接强度大幅降低。     

元器件再利用的废旧印制电路板拆解技术研究

将元器件从废旧PCB上无损拆卸,既可以实现元器件的回收再利用,易于处理含有有毒有害物质,又便于拆卸后的PCB实现贵重金属回收和非金属材料的再生利用。在总结国内外对废旧PCB处理方法的基础上,根据电子产品中元器件组装与焊接特点,提出了能实现元器件重用的低成本无损拆解方案,分析讨论了钎料加热熔焊技术、风力吹扫分离技术和拆除力施加技术。试验表明,本方案实现了废旧PCB资源化拆解。     

废旧印刷电路板振动拆除装置设计及其动力学仿真

开发废旧印刷电路板上电子元件和基板的拆除分离设备,一直是电子电器产品回收的难点问题。在分析比较国内外现有废旧印刷电路板电子元件拆除方法的基础上,文章介绍了一种废旧印刷电路板元器件无损拆除装置的设计原理和结构模型。然后采用虚拟样机技术对废旧电路板元器件振动拆除过程中产生的接触—碰撞问题进行动力学仿真,确定了不同激振力下电路板与振动头之间的碰撞力(即拆除力)的大小的关系,从而优化设备结构参数、缩短设备开发周期、降低了开发成本。     

印制电路板组装工艺决策系统研究

研究了CAPP系统读取印制电路板装配工艺信息的方法;对三种元器件描述方法进行了比较,选用了物料清单与元件库相结合的元器件描述方法,建立了元器件库;建立了印制电路板装配工艺参数库,并在此基础上实现了印制电路板装配工艺决策系统。     

带元器件废旧电路板拆卸技术研究

介绍了一种拆卸废旧电路板的设备.在国内外,研究废旧电路板上的元器件拆卸成为一个热门话题,本文介绍的拆卸装置保证了能基本全面的拆卸下电路板上的元器件,并从理论上和实践上证明了此拆卸装置的可行性.     

电热激发的主动拆卸结构设计

基于ADSM的主动拆卸驱动部件及其产品,传统的热激发方法(如水浴或空气浴加热)均为加热整个产品,能耗较高,加热时间长,而且加热时可能损害产品的零部件。电热激发作为主动拆卸结构的激发方法,实现主动拆卸结构所述连接部位的连接关系失效,大幅度的提高了电子产品在生命周期终端的拆卸效率,降低了产品零部件的回收成本。电热激发属于局部加热激发,由于能量集中,加热时间短,激发所需的能耗低,激发对产品其它零部件的热损伤很小。文中给出了电热激发法的原理,提出了基于电热激发的主动拆卸驱动部件和主动拆卸卡扣的设计方法,通过有限元分析软件对主动拆卸卡扣温度场的模拟计算,提出了主动拆卸卡扣所需电热片或电热丝功率的选择方法。     

自热式印制板加热性能分析与评估

针对星载电子设备集成化、轻量化设计需求,基于机热一体化设计了一种自热式印制板,通过在多层印制板中埋置加热电阻实现其自加热功能.采用仿真分析,研究了印制板加热电阻布局、导热性能以及结构参数等对加热性能和力学特性的影响,完成自热式印制板样件研制和加热性能评估.研究结果表明,对印制板电路布局、结构参数进行优化设计,可以实现印制板温控区域良好的温度均匀性,满足航天产品温控要求.     

Thermal response simulation for tuning PID controllers in a 1016 mm guarded hot plate apparatus

A mathematical model has been developed and used to simulate the controlled thermal performance of a large guarded hot-plate apparatus. This highly specialized apparatus comprises three interdependent components whose temperatures are closely controlled in order to measure the thermal conductivity of insulation materials. The simulation model was used to investigate control strategies and derive controller gain parameters that are directly transferable to the actual instrument. The simulations take orders-of-magnitude less time to carry out when compared to traditional tuning methods based on operating the actual apparatus.The control system consists primarily of a PC-based PID control algorithm that regulates the output voltage of programmable power amplifiers. Feedback parameters in the form of controller gains are required for the three heating circuits. An objective is to determine an improved set of gains that meet temperature control criteria for testing insulation materials of interest.The analytical model is based on aggregated thermal capacity representations of the primary components and includes the same control algorithm as used in the actual hot-plate apparatus. The model, accounting for both thermal characteristics and temperature control, was validated by comparisons with test data.The tuning methodology used with the simulation model is described and results are presented. The resulting control algorithm and gain parameters have been used in the actual apparatus without modification during several years of testing materials over wide ranges of thermal conductivity, thickness, and insulation resistance values.     

Automatic PC disassembly for component recovery

In this article, a personal computer disassembly cell is presented. With this cell, a certain degree of automatism is afforded for the non-destructive disassembly process and for the recycling of these kinds of mass-produced electronic products. Each component of the product can be separated. The disassembly cell is composed of several sub-systems, each of which is dedicated to the planning and execution of one type of task. A computer vision system is employed for the recognition and localisation of the product and of each of its components. The disassembly system proposed here also has a modelling system for the products and each of its components, the information necessary for the planning of tasks, generating the disassembly sequence and planning of the disassembly movements. These systems co-operate with each other to achieve a semi-automatic disassembly of the product.     

Disassemblability Modeling Technology of Configurable Product Based on Disassembly Constraint Relation Weighted Design Structure Matrix（DSM）

The current research of configurable product disassemblability focuses on disassemblability evaluation and disassembly sequence planning. Little work has been done on quantitative analysis of configurable product disassemblability. The disassemblability modeling technology for configurable product based on disassembly constraint relation weighted design structure matrix （DSM） is proposed. Major factors affecting the disassemblability of configurable product are analyzed, and the disassembling degrees between components in configurable product are obtained by calculating disassembly entropies such as joint type, joint quantity, disassembly path, disassembly accessibility and material compatibility. The disassembly constraint relation weighted DSM of configurable product is constructed and configuration modules are formed by matrix decomposition and tearing operations. The disassembly constraint relation in configuration modules is strong coupling, and the disassembly constraint relation between modules is weak coupling, and the disassemblability configuration model is constructed based on configuration module. Finally, taking a hydraulic forging press as an example, the decomposed weak coupling components are used as configuration modules alone, components with a strong coupling are aggregated into configuration modules, and the disassembly sequence of components inside configuration modules is optimized by tearing operation. A disassemblability configuration model of the hydraulic forging press is constructed. By researching the disassemblability modeling technology of product configuration design based on disassembly constraint relation weighted DSM, the disassembly property in maintenance, recycling and reuse of configurable product are optimized.     

基于霍尔传感器的螺纹连接件智能拆卸

本文介绍了一种螺纹连接件的拆卸装置,重点介绍了螺纹分解状态的检测装置和控制原理。该系统未使用位移传感器和力矩传感器,而是把螺纹的轴向位移作为检测量,霍尔接近开关作为检测元件,由可编程控制器、霍尔接近开关和机械结构组成的检测控制系统实现了螺纹拆卸的智能控制。试验和实际使用表明该装置工作可靠。     

Disassembly method based on connection interface and mobility operator concepts

The impact of the disassembly process on the design of a product is a recognized fact, influencing recycling, maintenance, repair, and component/material re-using—essential aspects for a sustainable development. For simplifying and improving their work, as well as for designing proper and efficient disassembly plans, it is important for engineers to benefit from a disassembly method, for automatically generating dismounting sequences, incorporated in a software solution for providing rapid disassembly information that can be further used for real-time immersive simulations. The disassembly method proposed in this paper is based on two innovative elements: the connection interface concept and the mobility operator that integrates information on geometrical constraints, contact surface relative position and common area, neighboring components, and relative mobilities of the assembly components. All these data are corroborated with knowledge-based criteria and are used to generate a set of connection interfaces for a product to define mechanical joints, automating the identification of fasteners in the assembly and determining the components’ mobility within assembly. As a consequence, it is possible to calculate and realistically simulate components’ disassembly paths. In the proposed method, valid disassembly trajectories of a component relative to its surrounding ones are modeled based on the mobility operator, the swept volume approach is used to evaluate collisions between components, and finally, the disassembly sequences are determined through an improved layer peeling technique.     

复杂产品并行拆解建模及规划方法研究

为提高复杂产品并行拆解的效率,提出了一种针对复杂产品的并行拆解建模及规划方法。通过构建拆解约束图确定零件之间的连接关系,利用传递闭包算法进行聚类分析,将产品分解为若干个组件的集合。提取组件与组件之间的连接零件集合,利用人工蜂群算法对连接零件集合以及每个组件分别进行拆解规划,从而得到复杂产品的并行拆解模型及规划序列。以摩托车发动机的并行拆解为例,对该方法进行了验证,结果表明该方法能有效地实现复杂产品的并行拆解,提高复杂产品的拆解并行度和拆解效率。