PCB Workshop

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PCB Workshop

• Michael Hwang
• m-hwang_at_northwestern.edu
• 2/13/2008

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Terminology

• PCB Printed Circuit Board
• mil 1/1000 inch
• thou same as mil
• pitch Spacing between components (e.g. pins on
  an IC package)
• Reflow/wave soldering industrial methods for
  mass-production soldering

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Terminology

• track/trace Copper wires on the board
  connecting components.
• pad Exposed copper on which you can solder
  things. Thru-hole pads often act like vias.
• via A hole in the board that is plated on the
  inside. Used to connect tracks on different
  layers of a board.
• silkscreen Print legend on PCB
• soldermask insulating coating that protects
  covered parts from solder. Mandatory for
  fine-pitch wave/reflow soldering

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Terminology

• Thru-hole components components with leads that
  go through the circuit board and get soldered on
  the other side.
• Surface-mount (SMD/SMT) components Components
  that are meant to be soldered on the same surface
  on which it is mounted (these are usually smaller
  and harder to solder).

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6-layer PCB cross section
Track
Pad
Insulator (e.g. Fiberglass laminate)
Via
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Tips

• Use snap grid to keep components at regular
  intervals
• Keep tracks neat
• Use large tracks when possible, no smaller than
  10 mils.
• Keep at least 10 mils between tracks
• Put prototyping area in empty space
• Add test points

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Avoid loops
Good
Bad
Loop picks up noise from magnetic fields.
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Bypass Capacitors
V
0.01-0.1 uF
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Traxmaker

• Abandoned
• Graphics bugs
• Stability bugs (save and backup often!)
• Some moves cant be undo-ed
• Duplicate, place component, etc.

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Advanced Circuits Student Discount

• http//www.4pcb.com/index.php?loadcontentpage_id
  134
• No minimum order for 33 each offer, enter
  Student in comments section when ordering.
• Single-part orders only, so connect all parts,
  then saw after they arrive.

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Sources

• Jones, David L. PCB Design Tutorial Rev.A.
  http//alternatezone.com/electronics/pcbdesign.htm