Presentation on theme: "Produce Your Own PCB Board Jack Ou Engineering Science Sonoma State University."— Presentation transcript:
Produce Your Own PCB Board Jack Ou Engineering Science Sonoma State University
Four-Bit Adder-Subtractor (4 bit ripple adder)
A Four-Bit Adder/Subtractor on Breadboard Problem: too many wires!
Tips Double click to terminate a wire
Add Junction to the Schematic Add junction to the schematic.
Add Power and Gnd of Each IC Chip to the schematic 1. Right click on a part (74LS08N in this example) 2. Click on Invoke
Invoke a Part Select PWRN, Press OK.
Power and Ground Added
Move Use the Move button to alter any component’s location Click on + to move a part
Display Net Name 1. Enter a net name 2. Display the netname
ERC error Use ERC to check connectivity of the wire.
Rewire to Clear ERC Error
To Start a New Board File
Board Editor If you keep both windows open, changes made on the schematic window will be reflected in the layout window.
Turn on the Grid
Rearrange the Comopnents (Right-Click to rotate a component) (The smaller the board, the more economical)
Click on Route to Start Wiring Up the Circuit (Left click to select air wire to route) Double click To remove wire
Routing Menu (Two Metal Layers) (Width of a wire) You should select the width of the wire to be 0.04 inches (40 mils) or greater. Add angel to the wiring
Reduce the Active Area Hieight is 2.5 inches
Load the Design Rules
Minimum Width of 40 miles
Change Clearance Distance
Outer Via Dimensions
Alternative: Load the default autorouter file
Auto Router Click this option to start autoroute
Result of Auto Route 2 metal layers used Not area efficient
Use only the top metal layer for layout
Header Termination Terminate the traces going to the header at the bottom metal layer Reason: this is where the IC will be soldered. Header terminates at the top metal layer—not a good practice
How to Change Metal Layer Step 1: Click on ripup, double click a wire to delete.
How to Change Metal Layer Step 2: Move the wires to create sapce
How to Change Metal Layer Step 3: Route wire. Start routing at the top metal level. Step 4: Click once to place the wire in an empty area. Step 5: Switch to the bottom layer Step 6: Make contact with the pad at the bottom layer
Change the Shape of Via to Round
A Sample Eagle Layout Clean up the metal layer
Jumpers You will need to use physical wires as jumpers in places where you can’t route across existing copper trace.
Add Vias – Drill 0.03149 (Assumptions: 1. drill bit is approximately 31 mils in diameter 2. wire size is 29 mils) – Diameter 0.056 (56 mils)
Provide Connection Via Jumper (Right click to bend the wire by 45 degrees)
A Sample Layout
Display only the necessary Metal Layers
Print Only Necessary Metal Layers (Show Bottom trace, pads, and via)
Display top layer problem
Print Top Layer
Print the Bottom Layer
Print the Layout to a Transparency
Run the transparency through the laser printer twice to produce better transfer Practice with regular paper before you use transparency. Look at your layout on paper and see if it will work at all.
Cut the Transparency
PCB Development With contribution from Kevin Zack
Cut the PCB Board Please clean up after you are done!
Smooth out the rough edge with Dremel
Clean the PCB with a scotch pad or fine sandpaper
When the board is shiny, use acetone to remove any oil or grease on the board
General Procedure Transfer Image 1.Run the transparency through the laser printer twice to produce better transfer. 2.Tape the printed transparency on to the a cleaned PCB board. 3.Heat a hobby iron. With light pressure, iron the transparency onto the copper. 4.After the board has cooled, peel off the transparency. 5.Use Sharpie to complete image transfer
Details Instruction for Double Sided PCB Line up the bottom layer with the top layer (with the ink side facing the PCB)
Details Instruction for Double Sided PCB Make sure it can go on the PCB
Details Instruction for Double Sided PCB Slide in the PCB (Kevin Zack)
Details Instruction for Double Sided PCB Tape the transparency to PCB
Tape the printed transparency on to the a cleaned PCB board (Single Sided PCB)
Heat a hobby iron. With light pressure, iron the transparency onto the copper Use highest Setting-- 3
You can also try the laminator
After the board has cooled, peel off the transparency.
Failed Image Transfer
Use Sharpie to Repair PCB Board
Precaution Etching Solution may leave stain on skin and utensils. The use of rubber gloves is recommended. Avoid prolonged or repeated breathing of vapor or contact with skin.
Develop PCB 1.Ferric Chloride is used to remove the copper not protected by the toner. 2.Place the printed board into a container with a lid and pour about ¼” of the acid solution over the board. 3.Secure the lid and using a swirling motion, agitate the solution for 15 minutes to 30 minutes until the unwanted copper is removed. 4.After the excess copper is removed, pour water over the board to halt the etching process. 5. Dispose the left over chemical properly. (Include the chemical rinsed off with water)
Place the printed board into a container with a lid and pour about ¼” of the acid solution over the board
Agitate the solution
You can also try the orbital shaker
Dispose Chemical Properly
Post Processing Clean off the toner protecting the traces with a scotch pad or sandpaper. Clean off any residue with acetone. Drill the board with a drill press. (Use 31 mil drill bit)