第1章总则
1.1 概述 ................................................................................................................................1
1.2 我国电子制造业面临的困境 ..................................................................................2
1.2.1 困境之一:高端芯片的缺失 .............................................................................2
1.2.2 困境之二:DFM的严重缺失 ...........................................................................4
1.2.3 困境之三:不适应先进生产力发展的旧工艺管理体制 .................................6
1.2.4 困境之四:被严重低估了的工艺和制造价值 .................................................7
1.2.5 被扭曲了的电子装联标准 ................................................................................8
1.3 实现高可靠质量目标的因素 ..................................................................................9
1.4 中国制造需要“大国工艺” ..................................................................................10
1.4.1 精湛的工匠技艺源自先进的工艺技术 ...........................................................10
1.4.2 电子装联技术的重要性 ...................................................................................11
1.5 先进制造技术 ...........................................................................................................12
1.5.1 什么是先进制造技术 .......................................................................................12
1.5.2 电气互连先进制造技术 ...................................................................................12
1.5.3 新型元器件与高密度组装技术 .......................................................................12
1.5.4 微组装先进制造技术 .......................................................................................13
1.5.5 可制造性设计是实现先进制造技术的前提和技术支撑 ...............................13
1.6 可制造性设计理念的拓展.....................................................................................14
1.7 结束语 .........................................................................................................................15
第2章PCB/PCBA设计缺陷案例分析
2.1 焊盘尺寸设计缺陷 ..................................................................................................16
2.1.1 片式元器件焊盘设计缺陷 ...............................................................................17
2.1.2 片式元器件错误的“常见病、多发病” ........................................................20
2.1.3 焊盘两端不对称,走线不规范 .......................................................................21
2.1.4 焊盘宽度及相互间距离不均匀 .......................................................................23
2.1.5 IC焊盘宽度间距过大 ......................................................................................23
2.1.6 QFN焊盘设计缺陷 ..........................................................................................24
2.1.7 安装孔金属化,焊盘设计不合理 ...................................................................25
2.1.8 共用焊盘问题导致的缺陷 ...............................................................................26
2.1.9 热焊盘设计不合理 ...........................................................................................26
2.1.10 片式电容器焊盘长度设计不合理 .................................................................28
2.1.11 其他焊盘设计缺陷 .........................................................................................28
2.2 丝网和阻焊膜设计不良 .........................................................................................30
2.2.1 丝网设计不良 ...................................................................................................30
2.2.2 阻焊膜设计不良 ...............................................................................................33
2.3 元器件布局不合理 ..................................................................................................35
2.3.1 布局设计不良 ...................................................................................................35
2.3.2 应用波峰焊接工艺时,元器件布局没有采取克服“阴影效应”措施 .......37
2.3.3 元器件的排布不符合工艺要求 .......................................................................37
2.3.4 安放在PCB焊接面的QFP和SOIP没有设计成“菱形”和设计导流盘 ........37
2.3.5 双面组装PCBA焊接面元器件焊盘或本体边缘与插件零件边缘距离过小 ..............38
2.3.6 元器件布放不符合自动化生产要求 ...............................................................38
2.3.7 元器件布放位置距紧固件太近的设计缺陷 ...................................................39
2.3.8 波峰焊应用中的布局设计缺陷 .......................................................................40
2.3.9 再流焊应用中的布局设计缺陷 .......................................................................42
2.3.10 PCB布局混乱,严重影响焊接可靠性 ........................................................42
2.4 拼板设计不正确 .......................................................................................................44
2.5 PCB材料与尺寸不合适........................................................................................46
2.5.1 翘曲、扭曲 .......................................................................................................46
2.5.2 PCB材质选用不当,制作质量低劣 ..............................................................48
2.6 BGA的常见设计问题 ...........................................................................................49
2.7 _通孔插装中元器件引线直径与金属化孔孔径和焊盘的不匹配 ................51
2.8 “飞线”问题 ..............................................................................................................54
2.9 PCB缺少工艺边或工艺边设计不合理 ............................................................54
2.10 插装元器件安装设计不良 ...............................................................................59
2.11 导通孔设计不良 ..................................................................................................61
2.11.1 导通孔设计在焊盘上 .....................................................................................61
2.11.2 导通孔与焊盘或元器件距离过小 .................................................................63
2.11.3 导通孔在屏蔽罩位置 .....................................................................................67
2.11.4 导通孔尺寸过大 .............................................................................................67
2.11.5 导通孔在元器件底部 .....................................................................................68
2.12 电连接器接触偶与金属化孔间隙比 ...............................................................69
2.13 PCB缺少定位孔,定位孔位置不正确 .......................................................70
2.14 焊盘与导线的连接 ...............................................................................................71
2.15 PCB基准识别点缺失、设计不规范 ...........................................................72
2.16 元器件装配设计不良 ........................................................................................74
2.17 设计缺陷所造成的焊接缺陷 .............................................................................95
2.17.1 插装设计缺陷所造成的焊接缺陷 .................................................................95
2.17.2 贴装 .................................................................................................................97
2.18 大面积接地和大面积PCB应用设计缺陷 ...................................................99
2.19 工艺设计错误 ......................................................................................................100
2.20 镀金引线/焊端直接进行锡焊的缺陷案例分析 ......................................101
2.21 多种设计缺陷 ......................................................................................................101
2.22 _因设计缺陷、物流控制失控和焊接温度不符合规定要求引起的焊接故障 ................................................................................................................102
2.22.1 虚焊与冷焊 ...................................................................................................102
2.22.2 金属化孔透锡率不符合要求 .......................................................................104
2.23 设计缺陷对元器件返修返工的影响 .............................................................105
2.24 设计缺陷对检验检测的影响 ...........................................................................106
2.25 设计缺陷对清洗的影响 ....................................................................................106
2.26 印制电路板组件的反变形安装 ......................................................................106
2.27 潮湿敏感元器件(MSD)损坏 .....................................................................110
2.28 静电敏感元器件使用上的错误 .......................................................................111
2.29 返工返修(电装整修,二次焊接) ................................................................112
2.30 电子产品电路设计及制造缺陷实例 .............................................................113
第3章现代电子装联核心理念及发展趋势
3.1 现代电子装联核心理念 .......................................................................................117
3.1.1 电子装联技术与产品质量的关系 .................................................................117
3.1.2 应用DFX实施军品可靠性设计 ...................................................................117
3.1.3 基本概念 .........................................................................................................119
3.1.4 现代电子装联核心理念 .................................................................................122
3.2 电路设计现状 .........................................................................................................126
3.2.1 引言 .................................................................................................................126
3.2.2 概述 .................................................................................................................126
3.2.3 电路设计功能的逐渐弱化 .............................................................................127
3.3 电子装联技术的迅速发展...................................................................................129
3.3.1 电子装联工程的基本概念 .............................................................................129
3.3.2 电子装联元器件的高速发展 .........................................................................132
3.3.3 可制造性分析软件的应用 .............................................................................134
3.3.4 国内电子研制生产企业可制造性分析软件应用严重滞后原因分析 .........149
3.3.5 构建DFM平台 ..............................................................................................152
3.3.6 可制造性分析与可制造性设计 .....................................................................153
3.4 板级电路组装技术的发展趋势 .........................................................................154
3.4.1 元器件级 .........................................................................................................154
3.4.2 板级电路模块 .................................................................................................154
3.4.3 post-SMT .......................................................................................................155
3.4.4 堆叠装配技术 .................................................................................................157
3.4.5 高密度组装中的“微焊接”工艺设计 ........................................................159
3.4.6 电子产品高密度小型化设计 .........................................................................159
3.5 微波组件基本概念及应用技术标准现状 .......................................................161
3.5.1 微波组件基本概念 .........................................................................................161
3.5.2 微波电路应用标准现状 .................................................................................162
3.6 微组装技术基本概念及标准应用现状 ............................................................164
3.6.1 微组装技术的特征 .........................................................................................165
3.6.2 微组装技术的定义及关键点 .........................................................................165
3.6.3 微组装技术应用标准现状 .............................................................................166
3.6.4 微组装结构 .....................................................................................................168
3.6.5 微波组件微组装技术的应用 .........................................................................172
3.7 整机级先进制造技术 ............................................................................................175
3.7.1 3D线扎设计 ...................................................................................................175
3.7.2 立体建模的条件 .............................................................................................176
3.7.3 存在问题 .........................................................................................................176
3.7.4 3D布线的核心 ...............................................................................................177
3.7.5 整机/系统级“无线缆”连接技术 ..........................................................177
3.7.6 刚-挠基板连接技术 .....................................................................................178
3.7.7 背板连接技术 .................................................................................................179
3.7.8 机架安装 .........................................................................................................179
3.7.9 整机3D CAPP集成设计技术 .......................................................................180
3.7.10 电子产品虚拟装配技术 ...............................................................................182
第4章电路可制造性设计基础
4.1 概述 ............................................................................................................................184
4.1.1 电子产品电装生产质量问题的主要成因 .....................................................184
4.1.2 电路设计错误或缺乏可制造性给制造带来了什么 .....................................185
4.1.3 不使用DFM可能面临高成本与高风险的巨大挑战 ..................................186
4.1.4 可制造性设计的严重缺失是导致国内外电子产品质量差别的核心
要素之一 ........................................................................................................186
4.1.5 实施DFM提高核心竞争力 ..........................................................................187
4.1.6 在设计初期进行DFM ...................................................................................187
4.1.7 DFM是面向产品生命周期各环节设计的关键 ..........................................187
4.1.8 DFM不是单纯的一项技术,它是一种思想,一个先进的理念 ..............188
4.1.9 引入DFM来提高利润和产量 ......................................................................189
4.1.10 执行IPC、MIL或GJB、GB及行业标准的前提 ....................................189
4.1.11 缺乏DFM到处存在 ....................................................................................189
4.1.12 对设计缺陷的错误认识 ...............................................................................191
4.1.13 产品的质量和可靠性是设计出来的 ...........................................................192
4.2 电路可制造性设计是崭新的概念 .....................................................................192
4.2.1 电路可制造性设计是一个崭新的概念 .........................................................192
4.2.2 可制造性设计应用的广泛性 .........................................................................192
4.3 概述 ............................................................................................................................193
4.3.1 可制造性设计主要解决什么问题 .................................................................193
4.3.2 电路、结构和工艺三者之间的关系 .............................................................194
4.4 电路可制造性设计基本文件 ..............................................................................194
4.4.1 电子装联用基本电路设计文件 .....................................................................194
4.4.2 电子装联常用标准 .........................................................................................195
4.4.3 企业技术标准(典型工艺规范) ...................................................................204
4.4.4 电子装联常用产品工艺文件 .........................................................................205
4.5 可制造性设计(DFM)的基本理念 ..............................................................206
4.5.1 可制造性设计与设计工艺性或可生产性是一致的 .....................................206
4.5.2 DFM的诞生 ...................................................................................................207
4.5.3 DFM的定义 ...................................................................................................208
4.5.4 DFM基本工作目标 .......................................................................................208
4.5.5 DFM的职责 ..................................................................................................209
4.5.6 DFM的相关活动 ..........................................................................................210
4.5.7 DFM主要活动与原理 ...................................................................................210
4.5.8 DFM 团队与主要职责 ...................................................................................210
4.5.9 支持 DFM 工作的工具技能 ..........................................................................210
4.5.10 DFM系统的主要元素 .................................................................................211
4.5.11 DFM的涵盖面及定义 .................................................................................211
4.5.12 SMT领域的DFM ........................................................................................211
4.5.13 电路可制造性设计的基本理念及意义 .......................................................212
4.5.14 应用先进电子装联技术的电路可制造性设计 ...........................................213
4.6 关键在于理念的更新 ............................................................................................215
第5章PCB/PCBA可制造性设计(DFM)
5.1 概述 ............................................................................................................................216
5.2 PCBA设计缺陷的影响 ......................................................................................217
5.3 印制电路板组件DFM的核心理念 .................................................................218
5.4 可制造性设计的组织保证措施 .........................................................................219
5.5 可制造性设计实施方案 .......................................................................................219
5.6 电路设计文件可制造性审核(工艺性审核) ................................................220
5.6.1 电路设计文件工艺性审查的形式 .................................................................220
5.6.2 电路设计文件工艺性审查(以PCBA为例) ..............................................221
5.6.3 电装工艺设计原则与依据 .............................................................................227
5.6.4 工艺性审查存在的问题 .................................................................................228
5.7 印制电路组件可制造性设计(DFM)基本概念 .......................................228
5.7.1 印制电路板可制造性设计 .............................................................................228
5.7.2 印制电路板可制造性设计目的 .....................................................................228
5.7.3 印制电路板可制造性设计范围 .....................................................................229
5.7.4 印制电路板可制造性设计的重点 .................................................................229
5.7.5 印制电路板可制造性设计内容 .....................................................................229
5.7.6 可制造性设计程序解析 .................................................................................229
5.7.7 PCBA组装方式决定焊接工艺流程 .............................................................231
5.7.8 印制电路板电路设计 .....................................................................................239
5.8 确保PCBA可制造性设计实施的物料要素 .................................................243
5.8.1 总则 .................................................................................................................243
5.8.2 高可靠印制电路板的可接受条件 .................................................................244
5.8.3 高可靠电子装备电子元器件选用要求 .........................................................248
第6章PCB元器件布局设计及焊盘设计
6.1 表面组装技术元器件布局设计及片式元器件焊盘设计 .................................254
6.1.1 表面贴装元器件的焊接可靠性 .....................................................................254
6.1.2 SMT印制电路板电路设计一般要求 ..........................................................255
6.1.3 SMT工艺对元器件布局设计的要求 ..........................................................257
6.1.4 采用再流焊接焊工艺的元器件焊盘设计 .....................................................261
6.1.5 再流焊工艺导通孔设计 .................................................................................373
6.2 波峰焊工艺元器件布局设计及焊盘图形设计 ..............................................374
6.2.1 采用传统波峰焊工艺的元器件布局设计 ...................................................374
6.2.2 采用传统波峰焊工艺的元器件焊盘设计 .....................................................380
第7章通用设计技术
7.1 通用设计...................................................................................................................385
7.1.1 焊盘形状设计 .................................................................................................385
7.1.2 焊盘与印制电路板的距离 .............................................................................386
7.1.3 焊盘的开口 .....................................................................................................386
7.1.4 相邻焊盘设计 .................................................................................................386
7.1.5 大型元器件焊盘设计 .....................................................................................386
7.1.6 大导电面积设计 .............................................................................................386
7.1.7 采用传统波峰焊工艺时孔的设计规则 .........................................................386
7.1.8 焊盘设计 .........................................................................................................388
7.1.9 焊盘与孔的关系 .............................................................................................389
7.1.10 导通孔与焊盘的连接设计 ...........................................................................390
7.1.11 元器件孔距设计 ...........................................................................................395
7.1.12 环宽要求 .......................................................................................................395
7.1.13 导体层的隔热设计 .......................................................................................396
7.1.14 THT图形设计 ..............................................................................................397
7.1.15 焊盘和印制导线的连接 ...............................................................................398
7.1.16 双列直插式(DIP)集成电路焊盘设计 ....................................................401
7.1.17 元器件的安装间距 .......................................................................................403
7.1.18 布线设计 .......................................................................................................415
7.1.19 模板设计 .......................................................................................................428
7.2 设备对设计的要求 ................................................................................................441
7.2.1 印制电路板外形、尺寸设计 .........................................................................442
7.2.2 印制电路板定位孔的设计要求 .....................................................................444
7.2.3 印制电路板夹持边设计 .................................................................................446
7.2.4 光学定位基准标志(Mark)设计 ................................................................446
7.2.5 局部基准标志 .................................................................................................449
7.2.6 拼板设计 .........................................................................................................450
7.2.7 选择元器件封装及包装形式 .........................................................................454
7.3 阻焊、丝网的设计 ................................................................................................454
7.3.1 阻焊膜设计 .....................................................................................................454
7.3.2 丝网图形设计 .................................................................................................457
7.4 印制电路板组件导热和散热设计 .....................................................................458
7.4.1 概述 ................................................................................................................458
7.4.2 印制电路板导热和散热设计工艺性要求 .....................................................459
7.4.3 元器件导热和散热设计要求 .........................................................................459
7.4.4 元器件导热和散热设计的主要填充材料和使用 .........................................460
7.4.5 印制电路板散热设计的内容和要求 .............................................................464
7.5 印制电路板制图的基本要素 ..............................................................................470
7.5.1 印制电路板的表面镀涂 .................................................................................470
7.5.2 印制电路板的标记 .........................................................................................471
7.5.3 印制电路板图样的绘制 .................................................................................472
第8章通孔插装元器件焊接工艺选择
8.1 选择性波峰焊接是PCBA焊接工艺流程的必然选择 ..............................483
8.2 选择性波峰焊接对比手工焊接 .........................................................................484
8.3 选择性波峰焊接对比通孔回流焊接(PHR) ......................................487
8.3.1 通孔回流焊接工艺的优点 .............................................................................488
8.3.2 通孔回流焊接工艺的缺点 .............................................................................488
8.3.3 通孔回流焊接工艺的适用条件(例) ...........................................................491
8.3.4 结束语 .............................................................................................................492
8.4 选择性波峰焊接对比传统波峰焊接 ................................................................493
8.4.1 双面混装焊接工艺比较 .................................................................................493
8.4.2 避免了传统波峰焊接元器件布局的局限性 ...............................................496
8.4.3 使用带有治具的传统波峰焊接工艺 .............................................................500
8.4.4 选用选择性波峰焊的优越性 .........................................................................503
8.4.5 结束语 .............................................................................................................506
8.5 焊接质量要求 .........................................................................................................507
8.5.1 焊接润湿角 .....................................................................................................507
8.5.2 良好的焊点要素 .............................................................................................511
8.5.3 通孔插装元器件手工焊与选择性波峰焊质量比较 .....................................515
8.6 选择性波峰焊导流盘的设置 ..............................................................................518
8.6.1 传统双波峰焊原理 .........................................................................................518
8.6.2 传统的双波峰焊时DIP元器件的焊盘排列走向、桥连产生的原因及
导流盘的设置 ................................................................................................518
8.6.3 桥连现象及其产生的原因 .............................................................................520
8.7 高密度高可靠PCBA焊接工艺流程选择 .....................................................521
8.8 选择性波峰焊对PCB/PCBA设计的要求...................................................522
8.8.1 PCB设计一般要求 ........................................................................................522
8.8.2 选择性波峰焊PCB设计特殊要求 ...............................................................525
8.8.3 防止桥连工艺 .................................................................................................528
8.9 选择性波峰焊的局限性 .......................................................................................530
8.10 与波峰焊相关的禁限用工艺 .........................................................................531
第9章PCBA元器件可组装性设计(DFA)
9.1 通孔插装元器件穿孔安装...................................................................................532
9.1.1 一般要求 .........................................................................................................532
9.1.2 通孔插装元器件安装详细要求 .....................................................................535
9.2 表面安装...................................................................................................................563
9.2.1 有引线的表面安装 .........................................................................................563
9.2.2 无引线的表面安装 .........................................................................................564
9.2.3 GJB 3243、QJ 3086、QJ 3173A和QJ 165B规定的表面贴装元器件
安装要求 .........................................................................................................565
9.3 THC/THD在微波基板上的安装焊接设计 .................................................573
9.3.1 引线搭接 .........................................................................................................573
9.3.2 圆形引线搭接 .................................................................................................573
9.3.3 扁平引线搭接 .................................................................................................573
9.3.4 通孔插装元器件引线的搭接焊接要求 .........................................................574
9.4 非返工返修PCBA的跨接线(飞线、跳线) ..............................................574
9.4.1 跨接线的定义 .................................................................................................574
9.4.2 跨接线一般使用原则 .....................................................................................575
9.4.3 特殊情况下允许使用跨接线的原则 .............................................................575
9.5 PCBA返修和返工中跨接线的处理 ................................................................576
9.5.1 增设跨接线原则 .............................................................................................576
9.5.2 跨接线所选用的导线的选择 .........................................................................577
9.5.3 跨接线分类 .....................................................................................................577
9.5.4 跨接线的布线 .................................................................................................577
9.5.5 跨接线的连接 .................................................................................................579
9.5.6 THT跨接线焊接要求 ...................................................................................580
9.5.7 SMT跨接线焊接要求 ..................................................................................582
9.5.8 跨接线的黏接固定 .........................................................................................587
第10章高可靠PCBA禁限用工艺及分析
10.1 高可靠PCB/PCBA禁用设计与禁用安装工艺 ......................................589
10.1.1 概述 ...............................................................................................................589
10.1.2 什么是禁用工艺 ...........................................................................................589
10.1.3 什么是限用工艺 ...........................................................................................590
10.1.4 高可靠PCB/PCBA禁用设计与禁用安装工艺72条 ...............................590
10.1.5 高可靠电子设备禁用工艺与材料 ...............................................................592
10.1.6 高可靠电子设备限用工艺与设计 ...............................................................593
10.2 _军品PCBA轴向引线元器件通孔插装安装方式——不允许轴向引线元器件垂直安装 .........................................................596
10.2.1 问题提出 .......................................................................................................596
10.2.2 军品(3级或C级产品)PCBA轴向通孔插装元器件 ...........................597
10.2.3 分析 ...............................................................................................................598
10.3 军品(3级或C级产品)PCBA通孔插装元器件要求 ..........................599
10.3.1 轴向引脚水平安装 .......................................................................................599
10.3.2 径向引脚水平安装 .......................................................................................602
10.3.3 分析 ...............................................................................................................603
10.3.4 结束语 ...........................................................................................................604
10.4 3级电子产品PCBA片式元器件堆叠安装分析 .....................................604
10.4.1 概述 ...............................................................................................................604
10.4.2 问题提出 .......................................................................................................605
10.4.3 军标对军用PCBA“片式元器件堆叠安装”的规定 ...............................606
10.4.4 分析 ...............................................................................................................606
10.4.5 试验验证 .......................................................................................................610
10.4.6 结束语 ...........................................................................................................610
10.5 F型封装大功率管的安装焊接 .......................................................................610
10.6 QJ 3117A《导线在印制电路板上搭接焊接》质疑 .............................611
10.7 元器件镀金引线/焊端除金搪锡 ..................................................................614
10.7.1 问题提出 .......................................................................................................615
10.7.2 元器件引脚/焊端未除金搪锡导致的金脆化案例 ...................................615
10.7.3 金脆化分析 ...................................................................................................619
10.7.4 镀金引线/焊端的除金规定 .......................................................................621
10.7.5 无须纠结的镀金引线/焊端除金处理 .......................................................623
10.7.6 元器件引线/焊端“除金”工艺 ...............................................................624
10.7.7 射频电连接器焊杯除金工艺 .......................................................................627
10.7.8 低频(多芯)电连接器焊杯除金工艺 .......................................................627
10.7.9 先进除金搪锡设备及工艺介绍 ...................................................................632
10.7.10 镀金PCB焊接中产生的金脆化案例 .......................................................637
10.7.11 镀金引线除金的争议 .................................................................................639
10.7.12 结束语 .........................................................................................................642
10.8 军用PCBA通孔插装元器件“禁止双面焊” ............................................643
10.8.1 引言 ...............................................................................................................643
10.8.2 什么是禁限用工艺 .......................................................................................644
10.8.3 提出“禁止双面焊”的必要性 ...................................................................644
10.8.4 基于Pro/Mechanical对透锡量的验证 .......................................................649
10.8.5 “禁止双面焊”可以做到 .............................................................................655
10.8.6 影响通孔插装元器件金属化孔透锡率的主要因素 ...................................655
10.8.7 如何提高印制电路板金属化孔透锡率 .......................................................657
10.8.8 实践验证 ....................................................................................................664
10.8.9 结束语 ...........................................................................................................664
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