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1. INTRODUCTIONToday's changing environment challenges businesses to transition and ramp up personnel into new roles. The Cadence® Design Foundations Front-to-Back Board Design offering provides the fundamental knowledge required for the engineer with no previous experience in the printed circuit board (PCB) area to start designing in a short space of time.
This course series combines tools, methodology, best practices and design to provide a cost-effective and low-risk program enabling teams to bridge knowledge gaps associated with significant technology and team transitions. It replaces the typical training techniques that usually include:
- Learning on-the-fly, or learning from mistakes
- Ad-hoc training from manuals, web help, and so on
- Reduced productivity of experienced staff mentoring others
The goal of this course series is to supply the learner with the information needed to be self sufficient in the front-to-back design of a PCB. This will be accomplished by using a series of lectures describing certain milestones, followed by detailed lectures on tool usage to meet those milestones, and concluding with labs to reinforce the lectures.
The Front-to-Back Board Design course series starts with an introduction to circuit board design, followed by an introduction to schematic capture. The Allegro® Design Entry HDL tool will be used to show how schematics are typically captured. After schematic entry, board layout will be introduced. The Allegro PCB Editor tool will be used to show the typical board placement and routing techniques that can be employed. The Allegro PCB Router will also be introduced and used as an example of how to automatically route the design.
Post-processing the board for manufacturing will be discussed next. Appropriate output files will be shown and generated. A brief introduction to the Cadence SKILL programming language will follow, showing examples of how this language can be used to customize the environment. Finally, a final project will be given to the students, where they will use all of the information and skills learned throughout the offering to complete a design from schematic entry through output to manufacturing
Along with the final project, group activities, in-class quizzes, assessments and assignments will be used to ensure that critical topics are understood. Books and suggested readings will also be used to reinforce the material being presented.
2. AUDIENCE
- New engineer out of college with little to no PCB exposure
- New engineer to company who has not used Cadence tools
- Person transitioning to new position, and new to PCB design, including:
- IC designer
- Mechanical drafter
- Test engineer
- Any person wishing to broaden their skills or wanting to cross train into PCB design
3. PCB FRONT-TO-BACK CURRICULUM ABSTRACTThe following diagram illustrates the member courses that make up this design foundations curriculum and indicate the order in which the courses should be completed.
4. PCB FRONT-TO-BACK CURRICULUM OBJECTIVES
- Understand the main concepts behind PCBs
- Articulate the steps followed when creating a design from idea to implementation
- Recognize key phrases and terminology used in board fabrication
- Be able to effectively communicate the design requirements with the board fabrication house
- Create schematic parts
- Set up for library development
- Create symbol, package, part table, and simulation views
- Learn more part building, asymmetrical and split parts, and advanced skills
- Create both flat and hierarchical schematics
- Set up a new project
- Create a flat, multi-sheet design
- Check the design
- Use part tables
- Package a design
- Create and customize a Bill of Materials (BOM)
- Build a hierarchical design
- Create physical parts
- Create padstacks
- Mechanical holes, surface-mount pads, through-hole pads
- Create physical footprints
- Surface-mount parts, through-hole parts
- Create the constraints for the design
- Define specific net scheduling of high-speed nets; match the propagation delay of nets and connections; define minimum and maximum propagation delays for nets and connections
- Identify high-speed constraint violations
- Create spacing and physical constraints as well as area constraints and class-to-class rules
- Place and route the design manually
- Use interactive and quick placement, and special placement techniques
- Swap gates and pins
- Use interactive routing
- Route the design using the AutoRouter
- Understand some of the underlying program data and processes involved when routing an Allegro PCB Editor design using Allegro PCB Router
- Create do files to control the autorouting process or modify design rules
- Perform batch mode routing to test various strategies
- Analyze router log files to predict success or failure as early as possible
- Autoroute only specific nets and/or parts
- Restrict routing to specific areas of the board, and learn how to keep signals away from other areas
- Understand the fanout router and fanout a design
- Examine strategies for routing difficult designs
- Clean up autorouted connections, diagonalize corners, and reduce via counts to improve manufacturability
- Synchronize the board layout and schematic
- Backannotate logical changes made during board design
- Post-process the design for manufacturing
- Use the post-processing routines for such items as silk screening and testing
- Create required files for manufacturing, such as drill files and artwork
- Customize the environment using SKILL
- Overview of the Allegro PCB Editor SKILL environment
- Control program flow
- Work with lists
- Access the PCB Editor database
- Interact with the user through the PCB Editor user interface
- Build menus and forms with PCB Editor SKILL
- Register new PCB Editor commands
5. PCB FRONT-TO-BACK CURRICULUM AGENDAThis design foundations curriculum offering is composed of four courses. The courses, course product numbers and the agenda for each course are listed below.
5.1 SCHEMATIC ENTRY
Course Name: Design Foundations: Schematic Entry, v1.0
Course Duration: 3 days
Course Number: ES_82190_1.0
Day 1
- Define a printed circuit board (PCB)
- Determine where in the package hierarchy the PCB resides
- Review other types of packages
- Review the materials that typically comprise a board
- Review the steps required to create a PCB using a CAD system (this will start from schematic library creation and proceed to schematic layout)
- Create a test library
- Use the Part Developer to build and test Allegro Design Entry HDL library parts
Days 2 and 3
- Go through project setup
- Create a schematic and check for errors
- Cross reference signal names from one sheet to another
- Assign reference designators manually and automatically
- Create a block symbol to support hierarchical design
- Build a hierarchical structure
- Cross reference and plot the hierarchical design
- Create BOM and netlist reports
- Create an alternate ‘stuff list’ for assembly variations
5.2 INTRODUCTION TO PRINTED CIRCUIT BOARDS AND CONSTRAINT MANAGEMENT
Course Name: Design Foundations: Introduction to Printed Circuit Boards and Constraint Management v1.0
Course Duration: 4 days
Course Number: ES_82191_1.0
Days 1 and 2
- Review the steps required to manufacture a double-sided PCB
- Review the steps required to manufacture a multi-layer PCB
- Review the steps required to create a PCB using a CAD system (this will include physical part creation and proceed through board layout)
- Introduction to the use of a typical CAD board layout tool
Days 3 and 4
- Create padstacks for a number of typical pins, such as through-hole and surface-mount pads
- Create typical through-hole and surface-mount packages
- Create board mechanical symbols
- Calculate characteristic impedance for stripline and microstrip transmission lines
- Calculate propagation delay for transmission lines
- Create a lattice diagram to estimate the integrity of a signal down a transmission line
- Constrain net lengths to reduce reflections and improve signal integrity
- Implement differential pair rules
- Control impedance
- Match net lengths to reduce the effects of signal skewing
5.3 PCB PLACE AND ROUTE
Course Name: Design Foundations: PCB Place and Route, v1.0
Course Duration: 4 days
Course Number: ES_82192_1.0
Days 1 and 2
- Use floorplanning to organize the placement of components with the same ROOM property
- Assign reference designators to pre-placed parts
- Interactively place components
- Interactively route connections
- Manually update existing connections
Days 3 and 4
- Route a design using a basic do file
- Learn to route a design in batch mode
- Learn about the “adaptive behavior” of the Allegro PCB Router
- Identify the two phases of autorouting in the Allegro PCB Router
- Determine and analyze route results for success and failure
- Learn the techniques to fan out a design
- Learn strategies to improve route results on a difficult design
5.4 PCB POST PROCESSING
Course Name: Design Foundations: PCB Post Processing, v1.0
Course Duration: 4 days
Course Number: ES_82193_1.0
Days 1 and 2
- Articulate the concepts of backannotation between the PCB and the schematic
- Identify and create most of the standard outputs required for the PCB manufacturing process, which include
- Artwork files
- Fabrication drawing
- Drilling information
- Assembly drawing
- Pick and place file
- Test file
- Bill of Materials
Days 3 and 4
- Write custom commands using the SKILL programming language
- Perform a Final Project to reinforce all the learned topics
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