Complete PCB Design Using OrCAD Capture and PCB Editor

Cover Page\r......Page 1
Copyright Page......Page 2
Introduction......Page 3
Acknowledgments \r......Page 7
Computer-Aided Design and the OrCAD Design Suite......Page 8
PCB Cores and Layer Stack-Up......Page 9
PCB Fabrication Process......Page 11
Photolithography and Chemical Etching......Page 12
Layer Registration......Page 14
Function of OrCAD PCB Editor in the PCB Design Process......Page 16
Artwork (Gerber) Files......Page 19
PCB Assembly Layers and Files......Page 20
Starting a New Project......Page 21
Placing Parts......Page 24
Wiring (Connecting) the Parts......Page 26
Creating the PCB Editor Netlist in Capture......Page 27
The PCB Editor Window......Page 28
Controlling the View......Page 29
Drawing the Board Outline......Page 30
Moving and Rotating Parts......Page 31
Using the Autorouter......Page 33
Manual Routing......Page 34
Performing a Design Rule Check......Page 36
Creating Artwork for Manufacturing......Page 37
Capture Projects Explained......Page 39
Capture Part Libraries Explained......Page 42
Terminology......Page 44
The Toolbar Groups......Page 45
View Group......Page 46
Shapes Group......Page 47
Display Group......Page 48
Route Group......Page 49
Visibility Pane......Page 50
Options Pane......Page 51
Command Window Pane......Page 52
Status Bar......Page 53
Constraint Manager......Page 54
Padstack Designer......Page 57
Manufacturing Artwork and Drill Files......Page 58
Understanding the Documentation Files......Page 60
Introduction to Industry Standards......Page 62
Electronic Industries Alliance (EIA)......Page 63
American National Standards Institute (ANSI)......Page 64
Performance Classes......Page 65
Fabrication Types and Assembly Subclasses......Page 66
Breakout and Annular Ring Control......Page 67
Standard Panel Sizes......Page 68
Standard Finished PCB Thickness......Page 69
Prepreg Thickness......Page 70
Copper Cladding/Foil Thickness......Page 71
Copper Trace and Etching Tolerances......Page 72
Standard Hole Dimensions......Page 73
References......Page 74
Other Items of Interest......Page 75
Assembly Processes......Page 76
Automated Assembly Processes (Pick and Place)......Page 77
Manual Soldering......Page 78
Wave Soldering......Page 79
Reflow Soldering......Page 81
Component Placement and Orientation Guide......Page 82
Component Spacing for Surface-Mounted Devices......Page 83
Footprint and Padstack Design for PCB Manufacturability......Page 87
Land Patterns for Surface-Mounted Devices......Page 89
SMD Padstack Design......Page 90
SMD Footprint Design......Page 94
Footprint Design for Through-Hole Devices......Page 95
Hole-to-Lead Ratio......Page 97
PTH Land Dimension (Annular Ring Width)......Page 98
Clearance between Plane Layers and PTHs......Page 99
References......Page 101
Background Noise......Page 102
Distortion......Page 103
Issues Related to PCB Layout......Page 104
Magnetic Fields and Inductive Coupling......Page 105
Loop Inductance......Page 108
Electric Fields and Capacitive Coupling......Page 110
Ground Planes and Ground Bounce......Page 111
Ground Bounce and Rail Collapse......Page 115
Split Power and Ground Planes......Page 117
Characteristic Limpedance......Page 119
Reflections......Page 124
Ringing......Page 129
Electrically Long Traces......Page 130
Transmission Line Terminations......Page 134
Parts Placement for Electrical Considerations......Page 137
PCB Layer Stack-Up......Page 138
Bypass Capacitors and Fan-Out......Page 142
Trace Width for Current-Carrying Capability......Page 143
Trace Width for Controlled Impedance......Page 144
Trace Spacing to Minimize Cross Talk (3w Rule)......Page 154
Traces with Acute and 90° Angles......Page 155
Using PSpice to Simulate Transmission Lines......Page 157
Simulating Digital Transmission Lines......Page 158
References......Page 161
Numbered References......Page 162
The Capture Part Libraries......Page 163
Heterogeneous Parts......Page 164
Pins......Page 165
Place Pin Array Tool......Page 166
Zoom to All......Page 167
Method 1. Constructing Parts Using the New Part Option (Design Menu)......Page 168
Design Example for a Passive, Homogeneous Part......Page 169
Design Example for an Active, Multipart, Homogeneous Component......Page 174
Assigning Power Pin Visibility......Page 176
Design Example for a Passive, Heterogeneous Part......Page 178
Method 2. Constructing Parts with Capture Using the Design Spreadsheet......Page 180
Method 3. Constructing Parts Using Generate Part from the Tools Menu......Page 183
Method 4. Generating Parts with the PSpice Model Editor......Page 184
Generating a Capture Part Library from a PSpice model library......Page 185
Making and/or Obtaining PSpice Libraries for Making New Capture Parts......Page 186
Downloading Libraries and/or Models from the Internet......Page 187
Making a PSpice Model from a Capture Project......Page 188
Adding PSpice Templates (Models) to Preexisting Capture Parts......Page 197
Constructing Capture Symbols......Page 198
Introduction to PCB editor’s symbols library......Page 201
Symbol Types......Page 202
Composition of a footprint......Page 203
Padstacks......Page 204
Graphical Objects......Page 205
Optional Footprint Objects......Page 206
Padstack Designer Parameters Tab......Page 207
Padstack Designer Layers Tab......Page 208
Footprint design examples......Page 209
Designing the through-hole padstack......Page 210
Designing a through-hole footprint symbol......Page 212
Example 2. Design of Surface-Mount Device from an Existing Symbol......Page 216
Modifying an existing symbol: determining design requirements......Page 217
Replacing a padstack definition......Page 218
Example 3. PGA Design Using the Symbol Wizard......Page 220
Flash symbols for thermal reliefs......Page 223
Mechanical symbols......Page 226
Mounting Holes......Page 227
Creating Mechanical Drawings......Page 229
Placing Mechanical Symbols on a Board Design......Page 230
Blind, buried, and microvias......Page 231
Using the IPC-7351 land pattern viewer......Page 233
References......Page 236
Introduction......Page 237
Overview of the design flow......Page 238
Example 1 Dual Power Supply, Analog Design......Page 240
Initial Design Concept and Preparation......Page 241
Setting Up the Project in Capture......Page 242
Placing parts......Page 243
Connect parts with wires (signal nets)......Page 245
Making power and ground connections......Page 246
Preparing the Design for PCB Editor......Page 249
Grouping related components (rooms)......Page 253
Cleanup cache......Page 254
Performing a schematic DRC in capture......Page 255
Problems during netlist creation......Page 256
Setting up the extents (work area boundary)......Page 257
Making a board outline......Page 259
Adding dimension measurements......Page 260
Adding mounting holes......Page 262
Placing parts......Page 264
Rotating parts......Page 268
Changing a part in capture......Page 270
Performing an engineering change order (ECO)......Page 271
Controlling layer visibility......Page 273
Controlling net visibility......Page 275
Cross-highlighting between capture and PCB editor......Page 276
Finding parts using the find filter pane......Page 278
Generating DRC reports......Page 280
DRC error markers......Page 281
Setting up the layout cross section......Page 282
Pouring a copper plane using the Setup → Outlines option......Page 286
Pouring a copper plane using the shape add tool......Page 288
Verifying Connectivity between Pins and Planes......Page 289
Adding thermal reliefs and clearances to padstacks......Page 291
Determining trace width......Page 293
Determining trace spacing requirements......Page 294
Routing fan-outs for power and ground......Page 296
Moving and deleting fan-outs......Page 298
To begin manually routing traces......Page 299
Running the autorouter......Page 300
Checking routing statistics......Page 302
Cleaning up a design by glossing......Page 304
Synchronizing the design with capture (back annotation)......Page 305
Mixed-Signal Circuit Design in Capture......Page 308
Power and ground connections to digital and analog parts......Page 310
Connecting separate analog and digital grounds to a split plane......Page 311
Using Buses for Digital Nets......Page 313
Defining the Layer Stack-Up for Split planes......Page 314
Defining the Layer Stack-up......Page 316
Setting up a split GND plane......Page 317
Setting up Separate Planes on a Single Plane Layer......Page 319
Setting Up Routing Constraints......Page 320
Moving a Routed Trace to a Different Layer......Page 323
Adding Ground Planes and Guard Traces to Routing Layers......Page 324
Routing Guard Traces and Rings......Page 325
Adding Ground Planes to Routing Layers......Page 326
Example 3 Multipage, Multipower, and Multiground Mixed A/D PCB design with PSpice......Page 330
Multiplane Layer Methodologies......Page 331
Capture Project Setup for PSpice Simulation and Board Design......Page 334
Adding Schematic Pages to the Design......Page 335
Using Off-Page Connectors With Wires......Page 336
Setting up Multiple-Ground Systems on the Schematic......Page 338
Setting up PSpice Sources......Page 340
Performing PSpice Simulations......Page 342
Designing the Board with PCB Editor......Page 344
Placing Parts on the Bottom (Back) of a Board......Page 345
Establishing net, plane, and constraint relationships......Page 346
Defining Blind Vias......Page 347
Basic Overview of Using Padstack Designer......Page 348
Assigning Vias to Nets......Page 352
Assigning Nets to Layers Using Custom, Physical Constraints......Page 353
Fan-outs using blind vias......Page 355
Alternate Methods of Connecting Separate Ground Planes......Page 358
Shorting the planes with copper etch......Page 359
Shorting the planes with a padstack......Page 360
High-speed digital design......Page 362
Layer Setup for Microstrip Transmission Lines......Page 364
Via design for heat spreaders......Page 366
Determining Critical Trace Length of Transmission Lines......Page 373
Routing controlled impedance traces......Page 374
Maximum neck length......Page 376
Routing curved traces......Page 377
Gate and Pin Swapping......Page 379
Using Swap Options......Page 381
Back Annotating the Swap Operations to Capture......Page 382
Using the Autoswap Option......Page 384
Autoswapping a Room......Page 385
Defining a Route Keep-out Area......Page 386
Positive planes......Page 387
Pros and Cons of Using Positive vs. Negative Planes......Page 393
Making a Custom PCB Editor Board Template......Page 395
Making a Custom PCB Editor Technology Template......Page 396
Using the board wizard......Page 397
References......Page 400
Schematic design in capture......Page 402
Routing the Board......Page 403
Mechanical symbols for fiducials......Page 405
Artwork control form......Page 408
Film Control......Page 409
Adding elements to the artwork control form......Page 413
Drill file format......Page 418
Generating Route Path Files......Page 420
Drawing the cut path......Page 421
Generating the Route File......Page 422
Verifying the Artwork......Page 423
Using CAD tools to 3-D model the PCB design......Page 424
Fabricating the Board......Page 426
Generating pick and place files......Page 428
References......Page 431
Appendices......Page 432
IPC Standards......Page 433
Military Standards......Page 434
Partial List of Packages and Footprints and Some of the Footprints Included in OrCAD Layout......Page 435
Rise and Fall Times for Various Logic Families......Page 448
Drill and Screw Dimensions......Page 450
Capacitors/Bypassing/Placement......Page 452
Layer Stack-Ups......Page 453
Solder......Page 454
Standards......Page 455
Assembly Types......Page 456
Hole-to-Land Ratio......Page 457
Rise and Fall Times of Logic Families......Page 458
Cross Talk......Page 459
Guard Rings and Traces......Page 460
Guard Shields......Page 461
EMI/EMC......Page 462
Reliability......Page 463
Trace Spacing (Voltage Withstanding)......Page 464
Characteristic Impedance (Microstrip, Stripline Topologies, Etc.)......Page 465
Propagation Delay Time......Page 466
Sharp Corners......Page 467
D......Page 468
L......Page 469
R......Page 470
V......Page 471
Z......Page 472