Electronics Production
✔️ Characterize the design rules for your in-house PCB production process
✔️ Extra Credit: send a PCB out to a board house.
Individual Assignment
✔️ Make an in-circuit programmer that includes a microcontroller
✔️ Optionally customize it
✔️ Mill and stuff the board
✔️ Test it to verify that it works
1. The USB Bootloader
Left and Center: Failed PCB Boards; Right: Final Working PCB Board with Programmer.
2. Group Assignment: Characterize Milling Process
The working space.
Source PNG image used for characterizing the milling machine.
Finished part.
3. The Process
1. Mill the Board
I first put the double-sided tape on the back of the PCB board. Note that it also needs to be pasted in the middle, because during the cutting process you need to use tape to fix the part that has been cut.
Put the board on the mill machine and make sure the paste is firm and won't slip.
Install the drill. Note there are drill bits used for milling the surface and those used for cutting.
Manually adjust the height of the drill bit to make sure it is firmly touching the board surface.
Use Mods to generate G-Code path for milling and cutting, based on input PNG images.
Milling in progress. Wait for a while, it usually takes about 10 mins to mill this board.
Remove the powder away from the surface with vacuum cleaner. Be careful to hold down the cutted board with your hand to prevent it from being sucked away as well.
Here is a cleaned one.
Change the drill bit, and cut the outline with the input outline image.
After cutting, carefully lift the cut board with tweezers and take it out.
Mass Production
Since soldering is prone to failure, I made more boards as backup. First, I spliced the original cutting layout into a new one, and used Mods to generate cutting lines. This way I can create 8 PCB boards simultaneously in two steps.
2. Soldering
Soldering workspace
I soldered a total of three times before I succeeded. The wrong method was used the first time, and many solder joints that should not have been connected were connected together. Before the second soldering I went to a YouTube tutorial to make it clearer, but misplaced the controller. The third time I finally succeeded!
3. Load the Programmer
I asked Leo to help me load the programmer to the board. Yes, fortunately it worked!
