1. Printed Circuit BoardAnarchy DriveBy ITP - November 13, 2006 Nick Sears – http://jamesnsears.com Michael Ang – http://michaelang.com

2. What we’re going to do • Comparison of prototyping techniques • Designing a board • Schematic capture • Board layout

3. What we’re going to do (contd) • Making a board • Output file generation • Online fabricators • DIY • Resources and links • Surface-mount soldering demo

4. Breadboard vs Protoboard vs Printed Circuit Board

5. Breadboard • Fast! • Susceptible to vibration, dropping • Can document with good photo • Easy to debug

6. Breadboard • Being neat is worth it! (don’t do this)

7. Protoboard • Cheap! • Slower than breadboard • Hard to capture layout • Good reliability • Thought required while assembling

8. Circuit board • More startup cost/time • Good debugging • Easy to make more boards • Good reliability • Good for communicating design • Smallest!

9. Design Steps • Schematic capture • Board layout

10. Schematic capture • Add parts • Connect parts (create “nets”) • Create new devices (if necessary) • Electrical Rule Check (ERC)

11. Board Design • Create board from schematic • Place components • Route traces • Design Rule Check (DRC)

12. Common sizes • Check with board house for available drill sizes and trace widths • Some provide DRC file for Eagle • Holes • Vias - 20 mils (or smallest from board house) • Holes - ~50 mils • Traces • 10 mils (larger for power and where possible)

13. Board Layers • Top – top traces and SMT pads • Bottom – bottom traces and SMT pads • Pads – through-hole component legs • Vias – connect top and bottom signals • Dimension – outline of board • tPlace, (bPlace) – silkscreen • tStop, bStop – soldermask • (And a few more layers, e.g. for autorouter)

14. Generate Output Files • Generate Gerber files • Generate layer images

15. Sample Pricing • Most do boards up to a given size, or full panel • Can put multiple designs or copies on a single board/panel • Fabricator charges to score or cut • Group orders a good idea

16. Sample Pricing (contd) • http://batchpcb.com • $10 + $2.50/sq in (cheapest for small boards) • Wait while orders are batched • Shipping included (n weeks, where n=??) • http://goldphoenixpcb.biz • $120 for 14.5x10” panel • Shipping included (~1 week) • Depanelize??

17. Sample Pricing (contd) • http://custompcb.com • 2x 4x5.5” for $58 • $12 shipping • De-panelize for $.50/piece • Advanced Circuits (http://www.33each.com/) • $33 for 60 sq in (min 1 with student special) • Not sure about shipping

18. DIY Board Etching • ITP Board Etching Tutorial(thanks Todd!) • Use laser printer to print top and bottom layers • Transfer toner to copper clad board • Etch away excess copper using FeCl • Put in Hazmat when done!!!! • Drill holes

19. Next Steps • Design a board • Get it fabricated • Make a nice enclosure • Have your projects travel the world • Sleep soundly at night

20. Resources • Blog post will be updated: http://www.michaelang.com/a/102/printed-circuit-boards-driveby.html

21. Questions? Nick Sears – http://jamesnsears.com Michael Ang – http://michaelang.com (Stick around and watch Nick solder!)