Printed Circuit Board Design
Module Overview
This module has recently been developed and is intended to extend the knowledge base of the student into the more complex aspects and problems of printed circuit board design. Specific areas which will be considered are:
- Bypassing and decoupling issues
- Component packaging and manufacturing problems
- Signal integrity
- Correct termination strategies
- Electro-magnetic compatibility
- Thermal management
- Failure mechanisms and test
- Advanced design guides
- Current PCB design trends
Practical examples will be used throughout to develop understanding. The design tool used in this module will be the Cadence 610 HDL Suite.
Contents
- Unit 1: Review of PCB Design
- Unit 2: Bypassing and Decoupling
- Unit 3: Packaging and Manufacturing
- Unit 4: Signal Integrity Issues in PCBs
- Asssignment 1
- Unit 5: Terminations
- Unit 6: Electromagnetic Compatibility Issues in PCB Design
- Unit 7: Thermal Management & Analysis
- Unit 8: Inspection, Test and Failure Mechanisms
- Unit 9: Advanced Design Guides
- Unit 10: Current technological advances
- Walkthrough 1 Schematic Capture
- Walkthrough 2 Pre-Layout Simulation
- Walkthrough 3 Thermal Simulation and Analysis
- Walkthrough 4 Signal Integrity
- Assignment 2
The aim
At a conceptual level, a PCB presents as a piece of fibre-glass type material, generally coloured green, bearing a conductor pattern finished in copper, solder or nickel-gold. It will often be part of a ‘panel’ of several circuits which must be separated at a later stage in the process. Once all components have been mounted on the board and soldered to it, the individual circuit can be powered up and tested. In today’s challenging industrial environment, this simplified view is of diminishing value.
Printed circuit boards are a fundamental part of any new electronics system, and have an ever increasing influence on electrical performance, size, reliability, manufacturability and total cost of the final system
Huge increases in the component density of designs, vast increases in the number of pins per component, advances in PCB materials and packaging technology, together will increased clock frequencies, thermal issues and data rates of devices are all demanding an enormous amount of new skill development by industry technologists.
PCB designers must understand all stages and the effects that can result of both PCB manufacturing and PCB assembly. The need to have operationally correct and right first time designs is becoming increasingly essential due to the shorter life cycle of products.
A special problem is that of Signal Integrity (SI). For the adequate control of EMI, strict international standards and regulations have been developed worldwide. These standards require the suppression of electromagnetic emissions from circuits and systems, and their increased immunity to externally induced interference. The proper design of PCBs is a cost effective approach for the control of EMI in high-speed circuits.
What we are seeking to do in this module is to introduce good layout design practices and the need for a unified design process. It does not require the student to have a detailed knowledge of electronic circuit analysis. Such is the complexity of some of these issues that their effective design would be impossible without sophisticated CAD tools and the student is introduced to one of the market leading CAD packages to develop solutions.
How the module is structured
The two assignments are spread throughout the course and are essentially independent. You will be expected to reflect on the learning experience as well as carrying out specific tasks and critical evaluations. Typically the assignments will be similar to those below:
- Assignment 1, you will design a PCB that utilises on board mains voltage to information provided.
- Assignment 2 you will design a PCB that utilises analogue and high speed digital functional blocks to information provided.
Studying the module
The timetable below is based on a nominal 8 – 10 hour study week.
| Study Week | Unit | Walkthrough | Assignment | Unit / Assessment |
|---|---|---|---|---|
| 1 | 1 & 2 |
1 | PCB Design Review Bypassing and Decoupling |
|
| 2 | 3 | 1 | Packaging and Manufacturing | |
| 3 | 4 | 2 | Signal Integrity Issues | |
| 4 | 2 | 1 | Start Assignment 1 | |
| 4 | 1 | Complete Assignment 1 | ||
| 6 | 5 | 3 | Terminations | |
| 7 | 6 | 3 | Electromagnetic Compatibility Issues | |
| 8 | 7 | 4 | Thermal Management of PCBs | |
| 9 | 8 | 4 | 2 | Inspection, Test and Failure Mechanisms Start Assignment 2 |
| 10 | 9 & 10 |
2 | Advanced Design Guides Current Technological Advances |
|
| 11 - 12 | 2 | Complete Assignment 2 |
Resources
Software
The module will be based on the Cadence Design Systems 610 HDL suite of tools. This top –end industry standard package allows for all levels of complexity of design.
You will be introduced to the features of the software through a series of ‘walk thru’ exercises. The skills will build on those introduced on the ‘Concepts of PCB Design’ module. However, no actual prerequisite is required to study this module.
Web-based material
This module is intended to be self-standing as far as possible, but it makes references to a number of web-based resources.
Where we have linked to external materials, we would encourage you to look at most of those resources, rather than just skip past. Whilst their value varies, there is usually some insight to be gained, and often the sites chosen have visual material that is not directly available for us to incorporate in this module.
Books
During the course of preparing this module, we read a number of books, some of which are listed in the Module Descriptor under Indicative Reading..
Author/Tutor Profiles
| Alan Edgar |
|---|
Alan Edgar has worked at Napier University for many years, and is a Lecturer and Teaching Fellow in the School of Engineering. In that time, he has lectured and supervised project work in all areas of electrical and electronic engineering, both at undergraduate and postgraduate levels. Recently he had been responsible for the application of embedded systems and circuit implementation techniques. Over the years, Alan has been involved using a variety of CAD software packages for circuit design, simulation and PCB manufacture. He is an experienced author and provider of short specialist training courses, with the emphasis on all areas of the electronic manufacture and assembly business. |
| Murray MacCallum |
|---|
Murray MacCallum is a senior lecturer at Napier University in Edinburgh, where he has been a member of staff in the School of Engineering for nearly 20 years. During that time he has taught on a wide variety of courses, from general electronics to more specialist subjects like PCB manufacture and CAD. He has also supervised many projects at both undergraduate and postgraduate level. Murray has designed and delivered a range of short and longer-term training courses for industry, concentrating mostly on electronics manufacture. He is a qualified instructor with the US PCB authority, the IPC. He has also engaged in a number of consultancy projects, most notably the design and installation PCB prototyping laboratory in Sri Lanka. |
Updated 07.10.08 RA