EMC Expert System for Board Designs

1
EMC Expert System for Board Designs

• Marcel van Doorn (Marcel.van.Doorn_at_philips.com)
• Philips ElectroMagnetics Cooling Competence
  Center
• High Tech Campus Eindhoven
• 15 June 2005 Workshop EM-Tooling Amsterdam

2
Agenda

• The need for an EMC Expert System
• What is an EMC Expert System?
• Philips EMC Design Rules Set
• How to implement an EMC methodology?
• Conclusions Future Outlook

3

• Chapter 1
• The need for an EMC Expert System

4
Traditional Design Process the wrong way

5
Internal EMC Opinions
6
Solving the problem EMC methodology
7
Manual EMC Design Reviews

• Needs a lot of expertise
• Very time consuming
• Prone to human error
• Designs become more
• complex and dense
• EMC problems increase
• Radiation ?

8
Automated EMC Verification (Expert System)

• From manual design reviews towards automated EMC
  verification of board designs with an expert
  system.
• Knowledge base
• Controlled by design rules
• Fast
• Dominant problems are reported
• Advice is offered
• Useful for all engineers design, layout EMC
• Intelligent assumptions for missing or partial
  input data.

9
Value expectation early EMC Verification

• Impact of early detection of EMC problems
• no extra re-design / re-testing
• no extra hardware models
• lower Bill of Material cost at set level
• less panic at Design Release phase of the
  project
• Predictable development time prevention of a
  delayed market introduction
• Systematic and cost effective integration of EMC
  knowledge into the product creation process

10

• Chapter 2
• What is an EMC Expert System?

11
What is an Expert System?

• An expert system
• Gathers information
• Makes value judgements
• based on rules
• Report findings
• Offers advice
• New rules can be added to improve the systems
  knowledge base.

12
EMC Analysis Tools compared

13
Towards an EMC Expert System

• Develop and validate EMC Design Rules with
  modelling and simulations (field solvers)
• Understandable
• Scientific basis
• Implementable
• Effective
• Quantifiable (prioritise)

Automated Design Rules Check (DRC) Advice
Design/layout engineer
EMC engineer
14
An Expert System for Board Designs
Component Libraries EMC models
PCB Database
Routing
Expert System

• Problems
• report
• rules
• violations
• - advice

Schematic entry Critical Net / Component
Assignments
15

• Chapter 3
• Philips EMC Design Rules Set

16
EMC Design Rules for PCBs

• A. Layer Stack-up
• B. Component Placement
• C. Ground Layout
• D. Power Decoupling
• E. Signal layout

Focussing on EMC SI of high-speed boards
single-sided, double-sided and multi-layer
SI Signal Integrity
17
Overview EMC Design Rules

• Layer Stack-up
• 4, 6, 8, 10 layer board
• Component Placement
• Filter on I/O
• Component ground pins
• HS components from I/O
• Grouped components
• Shared vias
• Ground Layout
• Ground plane slots
• Ground fills
• Ground impedance
• Guard traces
• Ground return
• Ground grid

• Power Decoupling
• Decoupling capacitors
• Power pin filter
• High-Speed Signal Layout
• HS trace near edge
• Parallel trace
• Plane gap crossing
• Crosstalk on I/O
• Reflections
• Via usage
• Reference plane
• Transfer vias
• Stripline
• Differential pairs

18
EMC Design Rule Set controls

• Differential mode emission / immunity
• Common mode emission / immunity
• Crosstalk
• Reflections

SI
Proper layout of PCBs significantly reduces
system EMI
19

• Chapter 4
• How to implement an EMC methodology?
• Project approach within Philips

20
EMC Expert System ProjectOrganization
Development Process Support (Philips Board Design
Platform caretaker)- Integrator and deployer of
board process innovations to Philips Labs
Mentor Graphics Corporation - EMC
verification solution provider (Quiet Expert)
EMC Competence Center in Philips- EMC rule set
provider
21
EMC Expert System ProjectSummary
22
Quiet Expert Graphical User Interface

23
Example of an EMC rule
Power decoupling Do not put the decoupling
capacitor on an IC more than 5mm away from its
power pin.
Advice Reroute highlighted segment to reduce
length
Problem Pin to Decap Path length (12mm) more
than maximum (5mm).
24

• Chapter 5
• Conclusions Future Outlook

25
Conclusions

• An EMC rules-based expert system is a quick, cost
  effective, and understandable method to solve EMC
  problems
• Where? ? Why? ? How do I fix it?
• An expert system helps electrical engineers,
  board designers and EMC specialists to keep
  control over EMC design constraints during the
  design process.
• An expert system is an efficient methodology to
  spread EMC knowledge to the design community.

26
Future outlook

• Update enhancement of EMC rule set.
• Implement an EMC/SI design strategy
• a systematic workflow for the board design
  process with EMC SI tools
• From post-layout EMC/SI analysis/verification to
  automated synthesis of board designs taking all
  rules into account
• Auto-router with EMC/SI expertise.
• Develop EMC expert systems at cable, architecture
  and cabinet level.

27
(No Transcript)