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12-CRS-0106 REVISED 8 FEB 2013 Printed Circuit Board Design IEEE Concordia Electronics Workshop Presented by Marc-Alexandre Chan Concordia University, room EV 2.184 19 November 2014 Photo by Christian Taube, CC-BY-SA 2.5.

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12-CRS-0106 REVISED 8 FEB 2013 1. Why PCBs? 2. Background Board, components & software 3. Design Process Component selection, positioning, routing, power & ground, fabrication Design your own! Positioning Routing Power & Ground Fabrication considerations Make your own PCB! Why PCBs? Technology Comparison Current Usage Absence in Coursework Technical Background Board Materials Layer Structure Component Technologies Design Software Design Process Component Selection Positioning Routing Techniques Ground/Power Planes Fabrication Restrictions Advanced Design External Connections High-Frequency Circuits Internal Layers Workshop Overview

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12-CRS-0106 REVISED 8 FEB 2013 Workshop Overview 1. Why PCBs? 2. Background Board, components & software 3. Design Process Component selection, positioning, routing, power & ground, fabrication Design your own! 4. Some advanced considerations External connectors, multi-layer boards, high frequency

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12-CRS-0106 REVISED 8 FEB 2013 PCB Basics

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12-CRS-0106 REVISED 8 FEB 2013 Why PCBs? Limited alternatives Breadboard, perfboard, chassis mount Custom designed for each circuit High flexibility Compact (high density) Protective solder mask 20+ layers possible Robots! (or cheap overseas labour) Photo by Christian Taube, CC-BY-SA 2.5.

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12-CRS-0106 REVISED 8 FEB 2013 Technical Background

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12-CRS-0106 REVISED 8 FEB 2013 Board MaterialsLayer Structure Most common: FR4 Epoxy and fibreglass Heat resistant, cheap High-frequency boards Controlled impedance Usable at 1 GHz or more Well-known: Rogers Corp. Copper layers Allows traces to cross More heat dissipation More compact board Surface Layers Solder mask Silkscreen printing Board Technologies

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12-CRS-0106 REVISED 8 FEB 2013 Board Technologies Components, solder mask, and silkscreen layers on a PCB. Photo by Christian Taube, CC-BY-SA 2.5.

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12-CRS-0106 REVISED 8 FEB 2013 Packages: Through-Hole Photo credits: Abdullah Al Mamun, CC-BY-SA 2.5 Generic / Wikimedia Commons; Nunikasi, CC-BY-SA 3.0 Unported / Wikimedia Commons; Adafruit Industries, CC-BY-NC-SA, Flickr; Yves-Laurent Allaert, CC-BY-SA 3.0 Unported / Wikimedia Commons; Kimmo Palosaari, public domain / Wikimedia Commons; Common types of through-hole capacitors (aluminium 4, ceramic 4) Axial lead resistorDiodes in DO-41 package Inline packages: SIP and DIP (above); Plastic (PDIP, above), ceramic (CDIP) TO (transistor outline): TO-220 (left), TO-92 (right), metal can, etc.

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12-CRS-0106 REVISED 8 FEB 2013 SMD capacitors Resistors are similar Sizes in photo: 1206, 1206, 0603, 0603 1210, 1206, 0805, 0805 1812, 1812, 1206, 1210 Packages: Surface Mount (1) Photo credits: Shaddack, public domain / Wikimedia Commons.

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12-CRS-0106 REVISED 8 FEB 2013 Packages: Surface Mount (2) Photo credits: All images on this slide from Wikimedia Commons. Leapfrog, public domain; Swift.Hg, CC-BY-SA3.0 Unported; SPHL, CC-BY-SA 3.0 Unported; NobbiP, CC-BY-SA 3.0 Unported; NobbiP, CC-BY-SA 3.0 Unported. SOT-23-3 (3-pin small-outline transistor 23) QFP40 (40-pin quad flat pack) 0.65mm pitch SO-8 (SOIC family) (with PDIP for comparison) Left to right: SOIC-14, SSOP16, QFN-28 BGA-16 (left, top and bottom of package), with SOT23-6

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12-CRS-0106 REVISED 8 FEB 2013 HobbyistProfessional Eagle (Win) DipTrace (Win/Mac/Lin) KiCad (Win/Mac/Lin) gEDA (Linux) Mfgs software Cadence OrCAD/Allegro Altium Designer Agilent ADS Pulsonix Design Software

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12-CRS-0106 REVISED 8 FEB 2013 Design Process

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12-CRS-0106 REVISED 8 FEB 2013 Courses vs. real world Class: 100nF capacitor Real world: What?! Material; polarised? Maximum voltage Physical size/package Heat capacity Error tolerance Cost!! Digi-Key: 10HV23B104KN 100nF, 1kV, 10%, $70 ea. Component Selection Photo by Megger Ltd. CC-BY 3.0. Photo by John Fader. CC-BY-SA 3.0.

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12-CRS-0106 REVISED 8 FEB 2013 Balance of objectives Room for traces Compactness (cost) Heat dissipation Design simplicity Assembly (soldering) IC pin layouts Common sense atypical Dictated by IC structure Deal with it Component Placement Photo by Nicholas Wang (modified). CC-BY-SA 2.0.

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12-CRS-0106 REVISED 8 FEB 2013 Component Pinout Example Yes, you are reading the diagram correctly. The pinout uses order A-D-B-C and A-B-C-D-E-G-F. From the CD4543BE datasheet (Texas Instruments). Used for illustrative purposes.

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12-CRS-0106 REVISED 8 FEB 2013 Like wires on a PCB Point A to point B Angled lines Cant cross each other Usually CNC milled Avoid right angles Avoid T junctions Classic PCB look Routing Techniques: Traces Photo by Creativity103 (flickr). CC-BY 2.0.

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12-CRS-0106 REVISED 8 FEB 2013 Connect layers All: Straight through Some: Buried/blind vias Difficult and expensive Allows trace tunnels Pass under another trace Tips for vias Through hole pads = vias! Allow for extra space High current: more vias Routing Techniques: Vias Photo by Karl-Ludwig G. Poggemann. CC-BY 2.0.

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12-CRS-0106 REVISED 8 FEB 2013 Large area of copper High thermal capacity Large current capacity Obstacle for traces Obvious light colour Copper pour tips Might need thermals Can have vias in them Island/deadzone removal Software priority order Routing Techniques: Copper Pour Photo by t0msk (flickr). CC-BY-NC-SA 2.0.

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12-CRS-0106 REVISED 8 FEB 2013 Ground/power planes Pours cover whole layer Common in 4+ layer PCB Lowest priority Many and/or larger vias Can use several pours Battery/supply voltage Regulated voltage Logic level voltage Multiple grounds Routing components Take advantage of mask! Traces between pins Traces under SMD pads Fabrication constraints DRC limits Trace-trace clearance Board edge clearance Trace-pad clearance Real-world drill sizes Practical Strategies

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12-CRS-0106 REVISED 8 FEB 2013 Board-to-DeviceBoard-to-Board Pin Headers Sockets Dedicated Connectors JST/Servo Computer Cables Barrel Connectors Chassis Mounting Slotting Routing / Fabrication Gold Fingers Tab Routing Stacking Arduino Shields External Connections

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12-CRS-0106 REVISED 8 FEB 2013 Connector Examples Photo credits (clockwise from top left): oomlout (flickr), CC-BY-SA 3.0; Appaloosa, CC-BY-SA 3.0 / Wikimedia Commons; M7, public domain / Wikimedia Commons; Mike1024, public domain / Wikimedia Commons

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12-CRS-0106 REVISED 8 FEB 2013 High-FrequencyMultilayer Design Board RF Behavior Transmission line effects Digital circuit switching Intentional antennas Unintentional antennas Controlled Impedance Simulation / fabrication Problems Alleviated Ground loops Traces to ground have impedance in real world! Crosstalk Internal Planes Free capacitor Buried/blind vias High-Frequency Considerations

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12-CRS-0106 REVISED 8 FEB 2013 Design Walkthrough Activity Design a PCB from start to finish! Link to PCB software: http://ieee.concordia.ca/go/pcb Photo by Windell Oskay. CC-BY 2.0.

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12-CRS-0106 REVISED 8 FEB 2013 Alarm/Buzzer Module Schematic: Alarm/buzzer module

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12-CRS-0106 REVISED 8 FEB 2013 Alarm/Buzzer Module How it works: When TRIG is LO (0V):nothing happens (low power) When TRIG is HI (5V):buzzer sounds (higher power) TRIG short circuit to ground same as LOW TRIG open circuit same as HI (pull-up resistor) Ideas for the module Plug a switch in between TRIG and GND Use reed switch on a door frame and a magnet on door! Make a microcontroller module to control the alarm Arm/disarm, intruder detection, alarm patterns, etc.

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12-CRS-0106 REVISED 8 FEB 2013 Basic schematic capture Choose components Connect with wires Custom components LM555CN Custom symbol (pins) Standard DIP8 pattern Speaker custom symbol and pattern Convert to PCB Create board outline Target size: 5cm 8cm Pre-place components Verify packages and sizes Routing the board Ground and power planes Traces for programming Check drill sizes Prepare for manufacturing To Do List

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12-CRS-0106 REVISED 8 FEB 2013 Board Layout Sample PCB layout: top layer (left) and bottom layer (right)

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12-CRS-0106 REVISED 8 FEB 2013 Ready for Manufacturing Sample PCB Gerber file (bottom layer traces)

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12-CRS-0106 REVISED 8 FEB 2013 Ready for Manufacturing How can you manufacture your design? Do it yourself with traditional methods Photosensitive two-sided copper boards Regular copper board + a laser printer + glossy paper In all cases: ferric chloride to eat away unwanted copper Get a fab house to do it Many companies can do prototypes/small orders for cheap APCircuit (Alberta, http://www.apcircuits.com)http://www.apcircuits.com Advanced Circuits (US, http://www.4pcb.com)http://www.4pcb.com ITEAD (China, http://iteadstudio.com)http://iteadstudio.com SeeedStudio (China, http://www.seeedstudio.com)http://www.seeedstudio.com OSHPark (US, https://oshpark.com)https://oshpark.com

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12-CRS-0106 REVISED 8 FEB 2013 Want to learn more? More details and good practices for PCBs? http://alternatezone.com/electronics/files/ PCBDesignTutorialRevA.pdfhttp://alternatezone.com/electronics/files/ PCBDesignTutorialRevA.pdf Want to start getting into advanced PCB design? High power and high current design Copper thickness (weight: standard is 1 oz) Maximum current through a trace Isolation slots, circuit isolation High frequency design (100MHz to many GHz) Transmission line effects, microstrip design (ELEC351/353/453) Cross-talk, resonant circuit layout, etc.

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12-CRS-0106 REVISED 8 FEB 2013 Thank you for participating in this workshop! Questions? info@ieee.concordia.ca http://ieee.concordia.ca This work is licensed under the Creative Commons BY-NC-SA 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA. Copyright 2013-2014 the Institute of Electrical and Electronics Engineers, Inc. Contributors: Marc-Alexandre Chan, Ryan Desgroseilliers.