Cadence印刷電路板設計：Allegro PCB Editor設計指南（第2版）

Cadence SPB平臺中國區技術經理，負責Cadence公司封裝、PCB、信號完整性工具的技術支持，擁有19年的EDAI具使用經驗。

目 錄
第1 章 PCB設計介紹................................................................................................................1
1.1 PCB 設計的發展趨勢..........................................................................................................1
1.1.1 PCB 的歷史...............................................................................................................1
1.1.2 PCB 設計的發展趨勢...............................................................................................1
1.2 PCB 設計流程簡介..............................................................................................................4
1.3 高級PCB 設計工程師的必備知識....................................................................................5
1.4 基於Cadence 平臺的PCB 設計........................................................................................5
第2 章 Allegro SPB 平臺簡介................................................................................................8
2.1 Cadence PCB 設計解決方案...............................................................................................8
2.1.1 PCB Editor技術........................................................................................................9
2.1.2 高速設計.................................................................................................................12
2.1.3 小型化.....................................................................................................................14
2.1.4 設計規劃與布線.....................................................................................................14
2.1.5 生產制造選件.........................................................................................................15
2.1.6 模擬/射頻設計........................................................................................................17
2.1.7 團隊協作設計.........................................................................................................18
2.1.8 PCB Autorouter 技術..............................................................................................18
2.2 Allegro SPB 軟件安裝......................................................................................................18
第3 章 原理圖和PCB交互設計..........................................................................................21
3.1 OrCAD Capture 平臺簡介.................................................................................................21
3.2 OrCAD Capture 平臺原理圖設計流程............................................................................25
3.2.1 OrCAD Capture 設計環境......................................................................................25
3.2.2 創建新項目.............................................................................................................28
3.2.3 放置器件並連接.....................................................................................................29
3.2.4 器件命名和設計規則檢查.....................................................................................30
3.2.5 跨頁連接.................................................................................................................33
3.2.6 網表和Bom ............................................................................................................34
3.3 OrCAD Capture 平臺原理圖設計規範............................................................................35
3.3.1 器件、引腳、網絡命名規範.................................................................................35
3.3.2 確定封裝.................................................................................................................36
X
Contents
3.3.3 關於改板時候的器件名問題.................................................................................36
3.3.4 原理圖可讀性與布局.............................................................................................37
3.4 正標與反標.........................................................................................................................38
3.5 設計交互..............................................................................................................................41
第4 章 PCB Editor 設計環境和設置..................................................................................44
4.1 Allegro SPB 工作界面.......................................................................................................44
4.1.1 工作界面與產品說明.............................................................................................44
4.1.2 選項面板.................................................................................................................47
4.2 Allegro SPB 參數設置.......................................................................................................49
4.3 Allegro SPB 環境設置.......................................................................................................53
第5 章 封裝庫的管理和設計方法........................................................................................63
5.1 PCB 封裝庫簡介................................................................................................................63
5.2 PCB 封裝命名規則............................................................................................................69
5.3 PCB 封裝創建方法實例....................................................................................................70
5.3.1 創建焊盤庫.............................................................................................................71
5.3.2 用Pad Designer 制作焊盤.....................................................................................72
5.3.3 手工創建PCB封裝................................................................................................84
5.3.4 自動創建PCB封裝................................................................................................89
5.3.5 封裝實例以及高級技巧.........................................................................................93
5.4 PCB 封裝庫管理................................................................................................................98
第6 章 PCB設計前處理........................................................................................................100
6.1 PCB 設計前處理概述......................................................................................................100
6.2 網表調入............................................................................................................................100
6.2.1 封裝庫路徑的指定...............................................................................................101
6.2.2 Allegro Design Authoring/Capture CIS 網表調入...............................................102
6.2.3 第三方網表...........................................................................................................104
6.3 建立板框............................................................................................................................106
6.3.1 手動繪制板框.......................................................................................................106
6.3.2 導入DXF 格式的板框.........................................................................................110
6.4 添加禁布區.......................................................................................................................112
6.5 MCAD-ECAD 協同設計................................................................................................115
6.5.1 第一次導入Baseline的機械結構圖...................................................................115
XI
目 錄
6.5.2 設計過程中的機械結構修改...............................................................................117
6.5.3 設計結束後建立新的基準（Re-Baseline）.......................................................122
第7 章 約束管理器...................................................................................................................123
7.1 約束管理器（Constraint Manager）介紹.....................................................................123
7.2 物理約束（Physical Constraint）與間距約束（Spacing Constraint）....................128
7.2.1 Physical 約束和Spacing 約束介紹......................................................................128
7.2.2 Net Group 和Net Class.........................................................................................128
7.2.3 建立Net Class.......................................................................................................129
7.2.4 為Class添加對象.................................................................................................130
7.2.5 設置Physical 約束的Default 規則......................................................................131
7.2.6 建立擴展Physical約束........................................................................................133
7.2.7 為Net Class添加Physical 約束..........................................................................134
7.2.8 設置Spacing約束的Default 規則......................................................................135
7.2.9 建立擴展Spacing 約束........................................................................................135
7.2.10 為Net Class添加Spacing約束.........................................................................136
7.2.11 建立Net Class-Class間距規則..........................................................................137
7.2.12 層間約束（Constraints By Layer）...................................................................137
7.2.13 Same Net Spacing 約束.......................................................................................138
7.2.14 區域約束.............................................................................................................138
7.2.15 Net 屬性..............................................................................................................141
7.2.16 Component 屬性和Pin 屬性..............................................................................142
7.2.17 DRC 工作表........................................................................................................142
7.2.18 設計約束.............................................................................................................143
7.3 實例：設置物理約束和間距約束.................................................................................144
7.3.1 Physical 約束設置.................................................................................................145
7.3.2 Spacing 約束設置.................................................................................................147
7.4 電氣約束（Electrical Constraint）................................................................................148
7.4.1 Electrical 約束介紹...............................................................................................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 實例：建立差分線對......................................................................................................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，結構定位...........................................................................................171
8.2.2 主要芯片布局.......................................................................................................172
8.2.3 電源模塊布局.......................................................................................................174
8.2.4 細化布局...............................................................................................................174
8.2.5 布線通道、電源通道評估...................................................................................175
8.2.6 EMC、SI、散熱設計...........................................................................................178
8.3 布局常用指令...................................................................................................................180
8.3.1 擺放元件...............................................................................................................180
8.3.2 按照Room 放置器件...........................................................................................183
8.3.3 按照Capture CIS 原理圖頁面放置器件.............................................................186
8.3.4 布局準備...............................................................................................................188
8.3.5 手動布局...............................................................................................................191
8.4 其他布局功能...................................................................................................................195
8.4.1 導出元件庫...........................................................................................................195
8.4.2 更新元件（Update Symbols）.............................................................................196
8.4.3 過孔陣列（Via Arrays）.....................................................................................197
8.4.4 模塊布局和布局復用...........................................................................................198
第9 章 層疊設計與阻抗控制...............................................................................................202
9.1 層疊設計的基本原則......................................................................................................202
9.1.1 PCB 層的構成.......................................................................................................202
9.1.2 合理的PCB層數選擇..........................................................................................203
9.1.3 PCB 層疊設置的常見問題...................................................................................204
9.1.4 層疊設置的基本原則...........................................................................................205
9.2 層疊設計的經典案例......................................................................................................205
9.2.1 四層板的層疊方案...............................................................................................205
9.2.2 六層板的層疊方案...............................................................................................206
9.2.3 八層板的層疊方案...............................................................................................207
9.2.4 十層板的層疊方案...............................................................................................208
9.2.5 十二層板的層疊方案...........................................................................................208
9.2.6 十四層以上單板的層疊方案...............................................................................210
XIII
目 錄
9.3 阻抗控制............................................................................................................................210
9.3.1 阻抗計算需要的參數...........................................................................................210
9.3.2 利用Allegro軟件進行阻抗計算.........................................................................213
第10 章 電源地處理................................................................................................................217
10.1 電源地處理的基本原則................................................................................................217
10.1.1 載流能力.............................................................................................................218
10.1.2 電源通道和濾波.................................................................................................220
10.1.3 直流壓降.............................................................................................................220
10.1.4 參考平面.............................................................................................................221
10.1.5 其他要求.............................................................................................................221
10.2 電源地平面分割.............................................................................................................222
10.3 電源地正片銅皮處理....................................................................................................226
10.4 電源地處理的其他註意事項........................................................................................231
10.4.1 前期Fanout .........................................................................................................231
10.4.2 散熱問題.............................................................................................................233
10.4.3 接地方式.............................................................................................................235
10.4.4 開關電源反饋線設計.........................................................................................237
第11 章 PCB布線的基本原則與操作.............................................................................241
11.1 布線概述及原則.............................................................................................................241
11.1.1 布線中的DFM要求..........................................................................................241
11.1.2 布線中的電氣特性要求.....................................................................................244
11.1.3 布線中的散熱考慮.............................................................................................246
11.1.4 布線其他總結.....................................................................................................246
11.2 布線規劃............................................................................................................................246
11.2.1 約束設置.............................................................................................................246
11.2.2 Fanout ..................................................................................................................247
11.2.3 布線.....................................................................................................................251
11.3 手動布線..........................................................................................................................253
11.3.1 添加走線.............................................................................................................253
11.3.2 布線編輯命令.....................................................................................................260
11.3.3 時序等長控制.....................................................................................................265
11.4 各類信號布線註意事項及布線技巧...........................................................................268
XIV
Contents
第12 章 全局布線環境（GRE）.......................................................................................274
12.1 GRE 功能簡介................................................................................................................274
12.1.1 新一代的PCB布局布線工具............................................................................275
12.1.2 自動布線的挑戰.................................................................................................275
12.1.3 使用GRE 進行布局規劃的優點.......................................................................276
12.2 GRE 高級布局布線規劃...............................................................................................278
12.2.1 GRE 參數設置....................................................................................................279
12.2.2 處理Bundle.........................................................................................................281
12.2.3 規劃Flow............................................................................................................284
12.2.4 規劃驗證.............................................................................................................287
12.3 高級布局布線規劃流程................................................................................................290
12.4 高級布局布線規劃實例................................................................................................292
12.5 自動互連技術Auto-I.XX..............................................................................................297
12.5.1 Flow 的快速創建及連接....................................................................................297
12.5.2 自動Breakout 的應用........................................................................................300
第13 章 PCB 測試...................................................................................................................306
13.1 測試方法介紹.................................................................................................................306
13.2 加測試點的要求.............................................................................................................308
13.3 加入測試點.....................................................................................................................308
13.4 測試點的生成步驟.........................................................................................................315
第14 章 後處理和光繪文件輸出........................................................................................317
14.1 DFX概述........................................................................................................................317
14.1.1 可制造性要求（DFM）....................................................................................318
14.1.2 可裝配性要求（DFA）.....................................................................................319
14.1.3 可測試性要求（DFT）......................................................................................319
14.2 絲印（Silkscreen）........................................................................................................319
14.2.1 絲印調整.............................................................................................................320
14.2.2 絲印設計常規要求.............................................................................................321
14.3 絲印重命名及反標註....................................................................................................322
14.3.1 器件編號重命名（Rename）............................................................................322
14.3.2 反標（Back Annotation）..................................................................................325
XV
目 錄
14.4 工程標註.........................................................................................................................325
14.4.1 尺寸標註.............................................................................................................326
14.4.2 技術說明文檔資料（Drill 層相關生產需求說明）.......................................332
14.5 輸出光繪前的檢查流程................................................................................................335
14.5.1 基於Check List 的檢查......................................................................................335
14.5.2 Display Status 檢查............................................................................................335
14.5.3 報表檢查.............................................................................................................336
14.6 光繪輸出.........................................................................................................................338
14.6.1 鉆孔文件.............................................................................................................339
14.6.2 CAM 輸出...........................................................................................................343
14.7 其他..................................................................................................................................349
14.7.1 valor 檢查所需文件............................................................................................349
14.7.2 3D 視圖...............................................................................................................349
14.7.3 打印PDF.............................................................................................................350
第15 章 PCB 設計的高級技巧...........................................................................................357
15.1 Skill 二次開發................................................................................................................357
15.2 團隊協同設計.................................................................................................................361
15.3 設計數據導入導出.........................................................................................................366
15.4 無盤設計.........................................................................................................................371
15.5 背鉆設計.........................................................................................................................373
15.6 DFA可裝配性設計........................................................................................................378
15.7 走線跨分割檢查（Segments over Voids）.................................................................381
15.8 Extracta ............................................................................................................................382
15.9 優化（Gloss）................................................................................................................384
15.10 Data Tips........................................................................................................................388
15.11 3D Viewer ......................................................................................................................389
15.12 任意角度走線...............................................................................................................391
15.13 超級蛇形線...................................................................................................................393
15.14 Ravel 語言.....................................................................................................................393
15.15 差分對的返回路徑的過孔..........................................................................................395
15.16 Shape 編輯應用模式....................................................................................................396
15.17 Time Vision——High Speed Product Option ............................................................398
第16 章 高速PCB 設計.........................................................................................................400
16.1 高速PCB 設計理論.......................................................................................................400
XVI
Contents
16.1.1 高速PCB 設計定義............................................................................................400
16.1.2 高速PCB 相關的一些基本理論........................................................................402
16.1.3 高速PCB 設計基本原則....................................................................................409
16.2 信號完整性仿真.............................................................................................................410
16.2.1 普通信號完整性問題.........................................................................................410
16.2.2 時序問題（Timing）.........................................................................................412
16.2.3 GHz 以上串行信號問題.....................................................................................414
16.3 電源完整性仿真設計....................................................................................................416
16.3.1 直流電源問題.....................................................................................................416
16.3.2 交流電源問題.....................................................................................................417
16.4 板級EMC 設計..............................................................................................................420
16.4.1 板級EMC 設計的關註點..................................................................................420
16.4.2 Cadence 的EMC設計規則................................................................................423
第17 章 DDR3的PCB 設計實例.....................................................................................425
17.1 DDR3介紹......................................................................................................................425
17.1.1 Fly-By 設計.........................................................................................................428
17.1.2 動態ODT............................................................................................................430
17.1.3 其他更新.............................................................................................................430
17.2 DDR3 PCB 設計規則....................................................................................................431
17.2.1 時序規則.............................................................................................................431
17.2.2 電源設計要求及層疊、阻抗方案.....................................................................433
17.2.3 物理、間距規則.................................................................................................434
17.2.4 電氣規則.............................................................................................................446
17.3 DDR3布局......................................................................................................................454
17.3.1 放置關鍵器件.....................................................................................................454
17.3.2 模塊布局.............................................................................................................456
17.4 布線..................................................................................................................................459
17.4.1 電源處理.............................................................................................................459
17.4.2 Fanout ..................................................................................................................462
17.4.3 DDR3布線..........................................................................................................463
17.5 信號完整性和電源完整性仿真設計...........................................................................467
17.5.1 信號完整性仿真.................................................................................................467
17.5.1.1 定義仿真模板...................................................................................... 467
17.5.1.2 加載零件IBIS模型.............................................................................. 468
17.5.1.3 編輯互連線模型.................................................................................. 471
XVII
目 錄
17.5.1.4 仿真設置.............................................................................................. 474
17.5.2 仿真結果展示.....................................................................................................475
17.5.2.1 時鐘信號(800MHz) ............................................................................475
17.5.2.2 控制信號(800Mbps) ...........................................................................477
17.5.2.3 地址、命令信號(800Mbps) ...............................................................478
17.5.3 電源完整性仿真................................................................................................. 480
17.5.3.1 PowerDC仿真結果展示.......................................................................480
17.5.3.2 PowerSI仿真結果展示.........................................................................482
第18 章 小型化設計................................................................................................................485
18.1 小型化設計的工藝流程................................................................................................485
18.1.1 HDI 技術.............................................................................................................485
18.1.2 埋入零件.............................................................................................................491
18.2 實例：盲、埋孔設計....................................................................................................491
18.3 盲、埋孔設計的其他設置............................................................................................495
18.4 埋入零件設計的基本參數設置...................................................................................498
18.4.1 實例：埋入零件.................................................................................................501
18.4.2 埋入零件生產數據輸出.....................................................................................505
第19 章 射頻設計.....................................................................................................................509
19.1 RF PCB 設計背景..........................................................................................................509
19.2 RF PCB 設計的特點......................................................................................................511
19.3 RF PCB 設計流程..........................................................................................................511
19.4 Analog/RF 設計常用的命令.........................................................................................520
附錄 幫助文件使用說明.........................................................................................................541
參考資料...........................................................................................................................................553