目 录
第1 章 PCB设计介绍................................................................................................................1
1.1 PCB 设计的发展趋势..........................................................................................................1
1.1.1 PCB 的历史...............................................................................................................1
1.1.2 PCB 设计的发展趋势...............................................................................................1
1.2 PCB 设计流程简介..............................................................................................................4
1.3 高级PCB 设计工程师的必备知识....................................................................................5
1.4 基于Cadence 平台的PCB 设计........................................................................................5
第2 章 Allegro SPB 平台简介................................................................................................8
2.1 Cadence PCB 设计解决方案...............................................................................................8
2.1.1 PCB Editor技术........................................................................................................9
2.1.2 高速设计.................................................................................................................12
2.1.3 小型化.....................................................................................................................14
2.1.4 设计规划与布线.....................................................................................................14
2.1.5 生产制造选件.........................................................................................................15
2.1.6 模拟/射频设计........................................................................................................17
2.1.7 团队协作设计.........................................................................................................18
2.1.8 PCB Autorouter 技术..............................................................................................18
2.2 Allegro SPB 软件安装......................................................................................................18
第3 章 原理图和PCB交互设计..........................................................................................21
3.1 OrCAD Capture 平台简介.................................................................................................21
3.2 OrCAD Capture 平台原理图设计流程............................................................................25
3.2.1 OrCAD Capture 设计环境......................................................................................25
3.2.2 创建新项目.............................................................................................................28
3.2.3 放置器件并连接.....................................................................................................29
3.2.4 器件命名和设计规则检查.....................................................................................30
3.2.5 跨页连接.................................................................................................................33
3.2.6 网表和Bom ............................................................................................................34
3.3 OrCAD Capture 平台原理图设计规范............................................................................35
3.3.1 器件、引脚、网络命名规范.................................................................................35
3.3.2 确定封装.................................................................................................................36
X
Contents
3.3.3 关于改板时候的器件名问题.................................................................................36
3.3.4 原理图可读性与布局.............................................................................................37
3.4 正标与反标.........................................................................................................................38
3.5 设计交互..............................................................................................................................41
第4 章 PCB Editor 设计环境和设置..................................................................................44
4.1 Allegro SPB 工作界面.......................................................................................................44
4.1.1 工作界面与产品说明.............................................................................................44
4.1.2 选项面板.................................................................................................................47
4.2 Allegro SPB 参数设置.......................................................................................................49
4.3 Allegro SPB 环境设置.......................................................................................................53
第5 章 封装库的管理和设计方法........................................................................................63
5.1 PCB 封装库简介................................................................................................................63
5.2 PCB 封装命名规则............................................................................................................69
5.3 PCB 封装创建方法实例....................................................................................................70
5.3.1 创建焊盘库.............................................................................................................71
5.3.2 用Pad Designer 制作焊盘.....................................................................................72
5.3.3 手工创建PCB封装................................................................................................84
5.3.4 自动创建PCB封装................................................................................................89
5.3.5 封装实例以及高级技巧.........................................................................................93
5.4 PCB 封装库管理................................................................................................................98
第6 章 PCB设计前处理........................................................................................................100
6.1 PCB 设计前处理概述......................................................................................................100
6.2 网表调入............................................................................................................................100
6.2.1 封装库路径的指定...............................................................................................101
6.2.2 Allegro Design Authoring/Capture CIS 网表调入...............................................102
6.2.3 第三方网表...........................................................................................................104
6.3 建立板框............................................................................................................................106
6.3.1 手动绘制板框.......................................................................................................106
6.3.2 导入DXF 格式的板框.........................................................................................110
6.4 添加禁布区.......................................................................................................................112
6.5 MCAD-ECAD 协同设计................................................................................................115
6.5.1 第一次导入Baseline的机械结构图...................................................................115
XI
目 录
6.5.2 设计过程中的机械结构修改...............................................................................117
6.5.3 设计结束后建立新的基准（Re-Baseline）.......................................................122
第7 章 约束管理器...................................................................................................................123
7.1 约束管理器（Constraint Manager）介绍.....................................................................123
7.2 物理约束（Physical Constraint）与间距约束（Spacing Constraint）....................128
7.2.1 Physical 约束和Spacing 约束介绍......................................................................128
7.2.2 Net Group 和Net Class.........................................................................................128
7.2.3 建立Net Class.......................................................................................................129
7.2.4 为Class添加对象.................................................................................................130
7.2.5 设置Physical 约束的Default 规则......................................................................131
7.2.6 建立扩展Physical约束........................................................................................133
7.2.7 为Net Class添加Physical 约束..........................................................................134
7.2.8 设置Spacing约束的Default 规则......................................................................135
7.2.9 建立扩展Spacing 约束........................................................................................135
7.2.10 为Net Class添加Spacing约束.........................................................................136
7.2.11 建立Net Class-Class间距规则..........................................................................137
7.2.12 层间约束（Constraints By Layer）...................................................................137
7.2.13 Same Net Spacing 约束.......................................................................................138
7.2.14 区域约束.............................................................................................................138
7.2.15 Net 属性..............................................................................................................141
7.2.16 Component 属性和Pin 属性..............................................................................142
7.2.17 DRC 工作表........................................................................................................142
7.2.18 设计约束.............................................................................................................143
7.3 实例：设置物理约束和间距约束.................................................................................144
7.3.1 Physical 约束设置.................................................................................................145
7.3.2 Spacing 约束设置.................................................................................................147
7.4 电气约束（Electrical Constraint）................................................................................148
7.4.1 Electrical 约束介绍...............................................................................................148
7.4.2 Wiring 工作表.......................................................................................................149
7.4.3 Impedance 工作表.................................................................................................153
7.4.4 Min/Max Propagation Delays 工作表...................................................................154
7.4.5 Relative Propagation Delay 工作表......................................................................156
7.4.6 Total Etch Length 工作表.....................................................................................158
7.4.7 Differential Pair 工作表........................................................................................159
7.5 实例：建立差分线对......................................................................................................164
XII
Contents
第8 章 PCB布局......................................................................................................................168
8.1 PCB 布局要求...................................................................................................................168
8.2 PCB 布局思路...................................................................................................................171
8.2.1 接口器件，结构定位...........................................................................................171
8.2.2 主要芯片布局.......................................................................................................172
8.2.3 电源模块布局.......................................................................................................174
8.2.4 细化布局...............................................................................................................174
8.2.5 布线通道、电源通道评估...................................................................................175
8.2.6 EMC、SI、散热设计...........................................................................................178
8.3 布局常用指令...................................................................................................................180
8.3.1 摆放元件...............................................................................................................180
8.3.2 按照Room 放置器件...........................................................................................183
8.3.3 按照Capture CIS 原理图页面放置器件.............................................................186
8.3.4 布局准备...............................................................................................................188
8.3.5 手动布局...............................................................................................................191
8.4 其他布局功能...................................................................................................................195
8.4.1 导出元件库...........................................................................................................195
8.4.2 更新元件（Update Symbols）.............................................................................196
8.4.3 过孔阵列（Via Arrays）.....................................................................................197
8.4.4 模块布局和布局复用...........................................................................................198
第9 章 层叠设计与阻抗控制...............................................................................................202
9.1 层叠设计的基本原则......................................................................................................202
9.1.1 PCB 层的构成.......................................................................................................202
9.1.2 合理的PCB层数选择..........................................................................................203
9.1.3 PCB 层叠设置的常见问题...................................................................................204
9.1.4 层叠设置的基本原则...........................................................................................205
9.2 层叠设计的经典案例......................................................................................................205
9.2.1 四层板的层叠方案...............................................................................................205
9.2.2 六层板的层叠方案...............................................................................................206
9.2.3 八层板的层叠方案...............................................................................................207
9.2.4 十层板的层叠方案...............................................................................................208
9.2.5 十二层板的层叠方案...........................................................................................208
9.2.6 十四层以上单板的层叠方案...............................................................................210
XIII
目 录
9.3 阻抗控制............................................................................................................................210
9.3.1 阻抗计算需要的参数...........................................................................................210
9.3.2 利用Allegro软件进行阻抗计算.........................................................................213
第10 章 电源地处理................................................................................................................217
10.1 电源地处理的基本原则................................................................................................217
10.1.1 载流能力.............................................................................................................218
10.1.2 电源通道和滤波.................................................................................................220
10.1.3 直流压降.............................................................................................................220
10.1.4 参考平面.............................................................................................................221
10.1.5 其他要求.............................................................................................................221
10.2 电源地平面分割.............................................................................................................222
10.3 电源地正片铜皮处理....................................................................................................226
10.4 电源地处理的其他注意事项........................................................................................231
10.4.1 前期Fanout .........................................................................................................231
10.4.2 散热问题.............................................................................................................233
10.4.3 接地方式.............................................................................................................235
10.4.4 开关电源反馈线设计.........................................................................................237
第11 章 PCB布线的基本原则与操作.............................................................................241
11.1 布线概述及原则.............................................................................................................241
11.1.1 布线中的DFM要求..........................................................................................241
11.1.2 布线中的电气特性要求.....................................................................................244
11.1.3 布线中的散热考虑.............................................................................................246
11.1.4 布线其他总结.....................................................................................................246
11.2 布线规划............................................................................................................................246
11.2.1 约束设置.............................................................................................................246
11.2.2 Fanout ..................................................................................................................247
11.2.3 布线.....................................................................................................................251
11.3 手动布线..........................................................................................................................253
11.3.1 添加走线.............................................................................................................253
11.3.2 布线编辑命令.....................................................................................................260
11.3.3 时序等长控制.....................................................................................................265
11.4 各类信号布线注意事项及布线技巧...........................................................................268
XIV
Contents
第12 章 全局布线环境（GRE）.......................................................................................274
12.1 GRE 功能简介................................................................................................................274
12.1.1 新一代的PCB布局布线工具............................................................................275
12.1.2 自动布线的挑战.................................................................................................275
12.1.3 使用GRE 进行布局规划的优点.......................................................................276
12.2 GRE 高级布局布线规划...............................................................................................278
12.2.1 GRE 参数设置....................................................................................................279
12.2.2 处理Bundle.........................................................................................................281
12.2.3 规划Flow............................................................................................................284
12.2.4 规划验证.............................................................................................................287
12.3 高级布局布线规划流程................................................................................................290
12.4 高级布局布线规划实例................................................................................................292
12.5 自动互连技术Auto-I.XX..............................................................................................297
12.5.1 Flow 的快速创建及连接....................................................................................297
12.5.2 自动Breakout 的应用........................................................................................300
第13 章 PCB 测试...................................................................................................................306
13.1 测试方法介绍.................................................................................................................306
13.2 加测试点的要求.............................................................................................................308
13.3 加入测试点.....................................................................................................................308
13.4 测试点的生成步骤.........................................................................................................315
第14 章 后处理和光绘文件输出........................................................................................317
14.1 DFX概述........................................................................................................................317
14.1.1 可制造性要求（DFM）....................................................................................318
14.1.2 可装配性要求（DFA）.....................................................................................319
14.1.3 可测试性要求（DFT）......................................................................................319
14.2 丝印（Silkscreen）........................................................................................................319
14.2.1 丝印调整.............................................................................................................320
14.2.2 丝印设计常规要求.............................................................................................321
14.3 丝印重命名及反标注....................................................................................................322
14.3.1 器件编号重命名（Rename）............................................................................322
14.3.2 反标（Back Annotation）..................................................................................325
XV
目 录
14.4 工程标注.........................................................................................................................325
14.4.1 尺寸标注.............................................................................................................326
14.4.2 技术说明文档资料（Drill 层相关生产需求说明）.......................................332
14.5 输出光绘前的检查流程................................................................................................335
14.5.1 基于Check List 的检查......................................................................................335
14.5.2 Display Status 检查............................................................................................335
14.5.3 报表检查.............................................................................................................336
14.6 光绘输出.........................................................................................................................338
14.6.1 钻孔文件.............................................................................................................339
14.6.2 CAM 输出...........................................................................................................343
14.7 其他..................................................................................................................................349
14.7.1 valor 检查所需文件............................................................................................349
14.7.2 3D 视图...............................................................................................................349
14.7.3 打印PDF.............................................................................................................350
第15 章 PCB 设计的高级技巧...........................................................................................357
15.1 Skill 二次开发................................................................................................................357
15.2 团队协同设计.................................................................................................................361
15.3 设计数据导入导出.........................................................................................................366
15.4 无盘设计.........................................................................................................................371
15.5 背钻设计.........................................................................................................................373
15.6 DFA可装配性设计........................................................................................................378
15.7 走线跨分割检查（Segments over Voids）.................................................................381
15.8 Extracta ............................................................................................................................382
15.9 优化（Gloss）................................................................................................................384
15.10 Data Tips........................................................................................................................388
15.11 3D Viewer ......................................................................................................................389
15.12 任意角度走线...............................................................................................................391
15.13 超级蛇形线...................................................................................................................393
15.14 Ravel 语言.....................................................................................................................393
15.15 差分对的返回路径的过孔..........................................................................................395
15.16 Shape 编辑应用模式....................................................................................................396
15.17 Time Vision——High Speed Product Option ............................................................398
第16 章 高速PCB 设计.........................................................................................................400
16.1 高速PCB 设计理论.......................................................................................................400
XVI
Contents
16.1.1 高速PCB 设计定义............................................................................................400
16.1.2 高速PCB 相关的一些基本理论........................................................................402
16.1.3 高速PCB 设计基本原则....................................................................................409
16.2 信号完整性仿真.............................................................................................................410
16.2.1 普通信号完整性问题.........................................................................................410
16.2.2 时序问题（Timing）.........................................................................................412
16.2.3 GHz 以上串行信号问题.....................................................................................414
16.3 电源完整性仿真设计....................................................................................................416
16.3.1 直流电源问题.....................................................................................................416
16.3.2 交流电源问题.....................................................................................................417
16.4 板级EMC 设计..............................................................................................................420
16.4.1 板级EMC 设计的关注点..................................................................................420
16.4.2 Cadence 的EMC设计规则................................................................................423
第17 章 DDR3的PCB 设计实例.....................................................................................425
17.1 DDR3介绍......................................................................................................................425
17.1.1 Fly-By 设计.........................................................................................................428
17.1.2 动态ODT............................................................................................................430
17.1.3 其他更新.............................................................................................................430
17.2 DDR3 PCB 设计规则....................................................................................................431
17.2.1 时序规则.............................................................................................................431
17.2.2 电源设计要求及层叠、阻抗方案.....................................................................433
17.2.3 物理、间距规则.................................................................................................434
17.2.4 电气规则.............................................................................................................446
17.3 DDR3布局......................................................................................................................454
17.3.1 放置关键器件.....................................................................................................454
17.3.2 模块布局.............................................................................................................456
17.4 布线..................................................................................................................................459
17.4.1 电源处理.............................................................................................................459
17.4.2 Fanout ..................................................................................................................462
17.4.3 DDR3布线..........................................................................................................463
17.5 信号完整性和电源完整性仿真设计...........................................................................467
17.5.1 信号完整性仿真.................................................................................................467
17.5.1.1 定义仿真模板...................................................................................... 467
17.5.1.2 加载零件IBIS模型.............................................................................. 468
17.5.1.3 编辑互连线模型.................................................................................. 471
XVII
目 录
17.5.1.4 仿真设置.............................................................................................. 474
17.5.2 仿真结果展示.....................................................................................................475
17.5.2.1 时钟信号(800MHz) ............................................................................475
17.5.2.2 控制信号(800Mbps) ...........................................................................477
17.5.2.3 地址、命令信号(800Mbps) ...............................................................478
17.5.3 电源完整性仿真................................................................................................. 480
17.5.3.1 PowerDC仿真结果展示.......................................................................480
17.5.3.2 PowerSI仿真结果展示.........................................................................482
第18 章 小型化设计................................................................................................................485
18.1 小型化设计的工艺流程................................................................................................485
18.1.1 HDI 技术.............................................................................................................485
18.1.2 埋入零件.............................................................................................................491
18.2 实例：盲、埋孔设计....................................................................................................491
18.3 盲、埋孔设计的其他设置............................................................................................495
18.4 埋入零件设计的基本参数设置...................................................................................498
18.4.1 实例：埋入零件.................................................................................................501
18.4.2 埋入零件生产数据输出.....................................................................................505
第19 章 射频设计.....................................................................................................................509
19.1 RF PCB 设计背景..........................................................................................................509
19.2 RF PCB 设计的特点......................................................................................................511
19.3 RF PCB 设计流程..........................................................................................................511
19.4 Analog/RF 设计常用的命令.........................................................................................520
附录 帮助文件使用说明.........................................................................................................541
参考资料...........................................................................................................................................553