1. PCB Workshop Michael Hwang m-hwang@northwestern.edu 2/13/2008

2. 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

3. 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

4. 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).

5. 6-layer PCB cross section Insulator (e.g. Fiberglass laminate) Via Pad Track

6. 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

7. Avoid loops Good:Bad: Loop picks up noise from magnetic fields.

8. Bypass Capacitors V+ 0.01-0.1 uF

9. Traxmaker Abandoned Graphics bugs Stability bugs (save and backup often!) Some moves can’t be undo-ed – Duplicate, place component, etc.

11. Advanced Circuits Student Discount http://www.4pcb.com/index.php?load=conte nt&page_id=134 http://www.4pcb.com/index.php?load=conte nt&page_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.

12. Sources: Jones, David L. PCB Design Tutorial Rev.A. http://alternatezone.com/electronics/pcbdesi gn.htm