Table of Contents
1. Grounding and Planes...................................................................................................... 7
1.1 Filters ............................................................................................................................ 7
1.2 Routing ......................................................................................................................... 8
1.3 Plane slots and boundaries .......................................................................................... 9
1.4 Decoupling capacitors ................................................................................................ 10
1.5 Power Distribution Network Impedance .................................................................... 11
2. High Speed Considerations ............................................................................................ 13
2.1 Identifying High Speed Signals ................................................................................... 13
2.2 Impedance .................................................................................................................. 14
2.2.1 Single Ended Characteristic Impedance ............................................................. 15
2.2.2 Differential Impedance ....................................................................................... 16
2.3 Terminations............................................................................................................... 18
2.3.1 Single Ended Terminations ................................................................................. 18
2.3.2 Differential Terminations ................................................................................... 20
2.4 Placement ................................................................................................................... 22
2.4.1 Partitioning ......................................................................................................... 22
2.4.2 Zoning ................................................................................................................. 22
2.4.3 Analog Buffers .................................................................................................... 23
2.5 Routing ....................................................................................................................... 24
2.5.1 Topology ............................................................................................................. 24
2.5.2 Bus Routing ......................................................................................................... 26
2.5.3 Corners ............................................................................................................... 28
2.5.4 Vias ..................................................................................................................... 28
2.5.5 Differential Routing ............................................................................................ 28
2.5.6 Proximity to Board Edge ..................................................................................... 30
2.6 Signal Timing ............................................................................................................... 31
2.6.1 Identifying time-critical signals ........................................................................... 31
2.6.2 Propagation time ................................................................................................ 32
2.6.3 Eye diagram analysis .......................................................................................... 32
2.7 Oscillators / Crystals ................................................................................................... 33
3. Crosstalk ......................................................................................................................... 35
3.1 Identifying Victims and Aggressors ........................................................................ 35
3.2 Layer Assignment ................................................................................................... 35
3.3 Orthogonality ......................................................................................................... 36
3.4 Parallelism .............................................................................................................. 36
3.5 Guarding ................................................................................................................. 37
3.6 Return paths ........................................................................................................... 38
3.7 Receiver Placement ................................................................................................ 39
4. EMC Considerations ....................................................................................................... 42
4.1 General Considerations .............................................................................................. 42
4.2 Components ............................................................................................................... 42
4.2.1 Component selection ......................................................................................... 43
4.2.2 High speed filters ................................................................................................ 43
4.2.3 Unused pins ........................................................................................................ 44
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Copyright © 2014 EMC FastPass
4.2.4 Heatsinks ............................................................................................................ 44
4.2.5 Shielded components ......................................................................................... 44
4.3 Power Supply .............................................................................................................. 45
4.3.1 Mains .................................................................................................................. 45
4.3.2 Voltage regulators .............................................................................................. 45
4.3.3 Switching mode power supplies ......................................................................... 46
4.4 Routing ....................................................................................................................... 47
4.4.1 Clock distribution ................................................................................................ 47
4.4.2 Guarding ............................................................................................................. 48
4.4.3 Stubs ................................................................................................................... 49
4.5 System design ............................................................................................................. 49
4.5.1 Chassis grounding ............................................................................................... 49
4.5.2 Cables ................................................................................................................. 50
4.5.3 Connectors ......................................................................................................... 51
4.6 ESD & Safety ............................................................................................................... 52
4.6.1 Connectors ......................................................................................................... 52
4.6.2 Sensitive pins .......................................................................................................... 54
4.6.3 High Voltage ........................................................................................................... 54
5. Design for Test ............................................................................................................... 55
5.1 Test Points .................................................................................................................. 55
5.2 Tooling Pins ................................................................................................................ 55
5.3 Push fingers ................................................................................................................ 56
5.4 Sealing ........................................................................................................................ 56
5.5 AOI .............................................................................................................................. 56
6. Design for Manufacture ................................................................................................. 57
6.1 Stackup ....................................................................................................................... 57
6.1.1 Symmetry ........................................................................................................... 57
6.1.2 Drill pairs ............................................................................................................. 57
6.1.3 Copper balance ................................................................................................... 58
6.2 Design Rules Check ..................................................................................................... 59
6.2.1 Clearance ............................................................................................................ 59
6.2.2 Width .................................................................................................................. 60
6.2.3 Annular Ring ....................................................................................................... 60
6.2.4 Slivers .................................................................................................................. 60
6.2.5 Acid Traps ........................................................................................................... 61
6.2.6 Silkscreen Over Pads ........................................................................................... 62
6.3 Mechanical ................................................................................................................. 62
6.3.1 Mechanical Drawings ......................................................................................... 62
6.3.2 Drill Drawings ..................................................................................................... 63
6.3.3 Slots .................................................................................................................... 63
6.3.4 Mounting holes .................................................................................................. 64
6.3.5 Panelization ........................................................................................................ 64
6.3.6 PCB manufacturing specifications ...................................................................... 65
6.4 Assembly Considerations ........................................................................................... 66
6.4.1 Assembly Flow .................................................................................................... 66
6.4.2 Stencils ................................................................................................................ 66
6.4.3 Panelized Assembly ............................................................................................ 67
6.4.4 Decals ................................................................................................................. 67
6.4.5 Fiducials .............................................................................................................. 68
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6.4.6 Thermal Relief .................................................................................................... 69
6.4.7 Assembly drawings and BOM ............................................................................. 69
6.4.8 PCB Assembly Specifications .............................................................................. 70
6.5 Manufacturing files .................................................................................................... 71
6.5.1 Gerber ................................................................................................................. 71
6.5.2 NC Drill ................................................................................................................ 71
6.5.3 Pick & Place ........................................................................................................ 71
6.5.4 Test Point Report ................................................................................................ 71
7. Thermal considerations ................................................................................................. 72
7.1 Power Dissipation ....................................................................................................... 72
7.2 Heatsinks .................................................................................................................... 72
7.3 Cooling Areas .............................................................................................................. 73
7.4 Current Carrying Capacity .......................................................................................... 73
8. Helpful Utilities .............................................................................................................. 75
8.1 IPC7351 Land Pattern Calculator ................................................................................ 75
8.2 PCB Fabrication Wall Chart ......................................................................................... 75
8.3 PCB Calculators ........................................................................................................... 75
8.4 Filter Selection Simulator ........................................................................................... 76
8.5 Circuit Simulation Tools ...........................................................
2022-01-18 09:32:55
2.48MB
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本书定位为PCB的EMC设计参考书,谨供各硬件工程师进行PCB设计时参考;众所周知PCB的设计要综合考虑功能实现、成本、生产工艺、EMC、美观等多种因素,片面的强调EM计,生搬硬套文中的只言片语都是不可取甚至错误的做法,一个杰出的CAD工程师其过人之处在于充分借鉴现有工作经验,在多种因素中进行折衷考虑,成功的完成原理图的物理实现。文中的有些观点、建议仅仅是现有工作经验的总结,由于EMC领域的诸多未知因素,加上编者的水平有限,错误、疏漏之处在所难免,还望大家不断批评、指正
2021-12-10 15:04:31
2.93MB
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EMC设计秘籍适合初学设计PCB
1.EMC设计工程师八大技能
2.EMC常用元件
3.EMC设计85问
4.EMC专用名词
2021-11-27 15:56:58
1.06MB
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EMC原理资料
pcb布线
PCB的EMC设计指南
华为PCB布线规范
无源滤波元器件电容的介绍和深入认识华为内部资料
硬件工程师手册
2021-11-27 14:46:39
5.06MB
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传导发射或抗扰度不合格的整改
1. 电源端口加滤波器，注意选择合适的滤波器和正确的安装方法。
(详见“电源滤波器”)
2. 改善开关电源的设计。
(详见“开关电源的骚扰抑制方法”)
3. 信号线上传导骚扰的抑制方法同“电场天线”，但应选择频率较低的抑制器件。
4. 注意被测线是否和其他强干扰线贴近？
2021-11-14 22:18:26
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