Step 1 - Turn off all layers but 16, 17, and 18.
These are the copper layers that you will use to create a etching mask for your blank PCB.
Step 2 - Print!
- Either print out a single copy of the mask and skip to step 6 or...
- Create a digital image of the mask to use it over and over again.
- Export the image to a bitmap file using File->Export->Image
- change the settings to 1200 DPI and monochrome as shown
- Name the file. Press Ok (a bitmap .bmp file will bre created with the name you gave it)
Step 3 - Invert image
You need to change the negative image into a positive image. To do so, open in the digital image Microsoft Paint -- you'll see a negative of the image. Under Tools, select invert image and save the new positive image.
Step 4 - Cut & Paste Multiple copies!
Insert the image into Microsoft Office. Crop your image and arrange to fill the PCB.
Step 5 - Print a test page onto plain paper.
Step 6 - Print your mask onto Press-n-Peel
Image must print on the dull side of the blue sheet. If you are using the ATP printer then put the paper in the tray with the shiny side up.
Step 7 - Clean the PCB - Part I.
Use a scotch pad to "scrub" the PCB to remove oxidation. Don't overdo it!!
Step 8 - Clean the PCB - Part II.
Go outside to parking lot and use brake cleaner and paper towels to clean the PCB and remove all remaining grime, oily substances, etc. This is a critical step - when you are done, make sure not to touch the copper (hold using edges).
Step 9 - Align the Press-n-peel
Stack/Align as follows:
- Ironing board on bottom
- Clean PCB, copper side up
- Carefully aligned press-n-peel, put the mask (dull side down) on the copper
- Piece of plain white paper on top
Step 10 - Iron on the mask.
- Preheat iron with cotton setting
- Start by placing/holding iron onto stack for about 5 - 10 seconds. This will create a bond between the press-n-peel and the copper (prevent sliding)
Step 11 - Check to see if transfer complete!
- Remove the White Paper.
- You should see the mask evenly showing through the glossy side of the press-n-peel. If you don't see an even pattern, you probably didn't heat board consistently. Put white paper back on top, and focus some additional heat on the "light" areas.
- Re-check to make sure it is complete.
Step 12 - Transfer to cooling bath
Pick up the board by its edges and 'slide it into the water bath (orange bucket). Careful--the board is extremely hot!
Step 13 - Cool Down!
Let the board sit in the water a few seconds until it is cooled.
Step 15 - Peel & Inspect
- Remove board from bath
- Carefully peel off the transfer paper
- Pat dry the board with paper towel.
- Carefully inspect the board. Use a black sharpie to touch up any imperfections.
- Write your name on the copper as well (if you didn't think to do this in Eagle!!)
Step 16 - Etch!
- Turn in your board to be etched.
Example of etched pcb
Step 17 - Cut, Drill and Clean
- If you printed multiple board that need to be cut apart, use the band saw after you have received 5 minutes of safety training!!
- Now use the PCB drill to drill all holes
- Use 25 mil - 30 mil drill for most holes (resistors, caps, chip holders, etc.)
- Components with thicker leads will require large drill bits! Measuer using a caliper, then choose a drill bit size 10 mils larger.
- Be careful when handling the drill bits! They are very tiny and easy to break. You must go through 5 minute training before we let you use drills!
Step 18: Populate with Components and Solder!
