Fabricating Printed Circuit Boards

251 Pages·2002·1.616 MB·English

by  Varteresian J.

Fabricating Printed Circuit Boards
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Fabricating Printed Circuit Boards

Jon Varteresian
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Copyright © 2002, Elsevier Science (USA). All rights reserved.
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Dedication
For Katie and Emma, my brightest stars.
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Introduction .......................................................................... xi

Safety .................................................................................................. xiii

The Schematic Symbol ....................................................................... 1

1 Schematic Capture............................................................ 1

Symbol Properties............................................................................... 3

Schematic Generation......................................................................... 4

Generating a Netlist ............................................................................ 8

2 Basic Circuit Board Placement and Routing

Considerations ..................................................................... 11

Circuit Board Placement and Routing Basics ..................................... 11

Placement and Routing Guidelines..................................................... 21

General Placement Considerations .................................................... 24

General Routing Considerations ......................................................... 25

3 Placement and Routing Considerations for Various

Circuit Designs ..................................................................... 35

Placement and Routing Considerations for General-purpose............. 35

Analog Circuit Boards ......................................................................... 35

Placement and Routing Considerations for General-purpose............. 35

Digital Circuit Boards........................................................................... 35

Placement and Routing Considerations for High-performance ........... 37

Analog Circuit Boards ......................................................................... 37

Placement and Routing Considerations for High-speed Digital .......... 39

Circuit Boards...................................................................................... 39

Placement and Routing Considerations for RF Circuit Boards ........... 42

Special RF Routing Techniques: Microstrip ........................................ 47

Special RF Routing Techniques: Stripline........................................... 53

4 Real World Guidelines for Commercial Fabrication

Houses .................................................................................. 57

Design Guidelines ............................................................................... 57

Sample Fabrication House Guidelines................................................ 61

Nexlogic Technologies Design Guidelines .......................................... 62

Capital Electronics Design Guidelines ................................................ 63

Generation of Design Files.................................................................. 64

A Photoplotter Tutorial........................................................................ 65

Vector Photoplotters............................................................................ 66

Raster Photoplotters ........................................................................... 66

5 Making Printed Circuit Boards......................................... 69

Exposing and Developing the Resist Layer ........................................ 71

Etching the Printed Circuit Board ........................................................ 79

Tin-Plating the Printed Circuit Board ................................................... 81

Drilling and Shaping the Printed Circuit Board.................................... 83
6 Project Plans...................................................................... 89

Exposure Cone ................................................................................... 89

Building the Exposure Cone................................................................ 90

Building the Exposure Frame.............................................................. 94

Material List for the Exposure Frame.................................................. 96

7 Resource List..................................................................... 97

General Supplies................................................................................. 97

Commercial Printed Circuit Board Fabrication Houses ....................... 105

Design Services .................................................................................. 106

APPENDIX A Data Monitor Project ..................................... 107

How It Works ....................................................................................... 109

System Requirements ......................................................................... 110

Description of Data Monitor Hardware ................................................ 110

Personality Module.............................................................................. 116

Installation and Description of Data Monitor Software ........................ 120

Data Monitor Operation....................................................................... 121

Message Structure .............................................................................. 134

Firmware Flow Overview..................................................................... 158

Initialize Routine .................................................................................. 161

Data Monitor Schematics and PCB Foils ............................................ 173

Data Monitor Parts List........................................................................ 188

APPENDIX B Building the Data Monitor............................. 191

Skills Needed ...................................................................................... 191

Equipment Needed ............................................................................. 192

Building the Power Supply Section ..................................................... 193

Testing the Power Supply Section ...................................................... 194

Building the RS-232 Interface Section ................................................ 194

Building the Microprocessor Section ................................................... 195

Building the LED Status Section ......................................................... 197

Installing the Personality Module Connectors ..................................... 197

Preparing the Chassis ......................................................................... 198

Mounting the Circuit Board into the Chassis ....................................... 202

General I/O-Temperature Personality Module Assembly

Instructions.......................................................................................... 203

Building the Analog Input Section ....................................................... 203

Building the Digital Input Section ........................................................ 204

Building the Temperature Sensor Section .......................................... 205

Attaching the Host Connectors ........................................................... 206

Mounting the General I/O-Temperature Module into the .................... 207

Data Monitor........................................................................................ 207

Assembling the Input Breakout Connector.......................................... 208

Testing the Data Monitor ..................................................................... 208
APPENDIX C Data Monitor Temperature Sensor

Application Note ................................................................... 215

Setting Up the Data Monitor ................................................................ 217

Configuring the Data Monitor .............................................................. 218

Monitoring ........................................................................................... 219

Downloading ....................................................................................... 220

Analyzing............................................................................................. 221

Variations ............................................................................................ 222

Glossary ................................................................................ 225

Index ...................................................................................... 233
Introduction

How difficult is it to design and fabricate printed circuit boards?
When you look at a finished printed circuit board—with an often-complex
circuit pattern and a mixture of through-hole and surface mount components—
you may think creating your own boards would be a difficult, time-consuming
task that would require specialized tools and expertise. However, fabricating
your own printed circuit boards can be broken down into the following rela­
tively simple steps:
1. Generation of the schematic.
2. Placement and routing of the circuit board.
3. Generation of artwork.
4. Exposing and developing the resist layer.
5. Etching the printed circuit board.
6. Tin plating of the printed circuit board.
7. Drilling and shaping, including vias (or barrels).
Depending upon your particular situation, you may not need to complete all
of the steps listed above. The purpose of this book is to explain each of the steps
so you can create your own professional-quality printed circuit boards.
The method of producing printed circuit boards described in this book is
unique. It is a result of years of trial and error and lots of ruined circuit boards!
What makes this process unique is that you don’t need photographic equipment,
lots of strange and dangerous chemicals, or expensive traditional artworks. All
artworks used in this process are printed on plain white paper—no transparen­
cies or commercially produced photoplots are needed! You can generate these
artworks directly from your own laser printer, ink jet printer, or copier. This
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