week 04

Electronics Production

1.Preparation for milling cuting

Material list：

Follow the Tutorial, note and other students website in 2017, I bought those copper-clad laminates,0.4mm & 0.8mm End-mills and other Electronic components from Tamll.com
Remarkably we used Attiny 84 micro-controller (follow the Tutorials 2018) not Attiny 44. It’s almost same but Attiny 84 has more Program Memory /EEPROM /RAM Size.
About crystal, I can’t found the 1206 inch size (I believe there is no 1206 crystal in China）so I buy a minimum size 20MHz crystal.

Milling Machine & Cut PCB:

Our milling machine is Roland MDX-40A. I learn from the user's manual and software, knowing how to operate the machine.
One of my friend suggest me cutting the copper-board smaller make the surface more flatter. (but I think I cut it too small.)

2.Convert png to rml file

Fab-module

I was deeply interested in Fab modules science I first hear about it. It’s such a amazing tools to control all those fab-machine online. I choose the Fab ISP Parts Layout(20MHz crystal version) and PS our "Fablab Beijing Logo" on it.
I used the Web version Here is my parameters setting below:

Remember select the "PCB traces (1/64)"
Then click calculate & save button.

As above, we upload the outline.png file, select "PCB traces (1/32)"
then calculate & save the outline file.

3.Milling the PCB & soldering

Make a board:

Attach the copper-clad laminates on the base-plate and set the X0Y0 position.
Then set the Z0 position with a sensor,
import rml file then cut.

Finally, polish!!！you should polish pcb with one direction and flat.
Don't over scratch any copper circuit.
I finally made 2 version of this board the difference are between the logo.

Soldering:

I was sick badly in that time, waste 1 week in a hospital.
I really left the schedule behind
Actually I even start soldering in my sickroom and this is how I get this photo on right
photo in below is all the materials that I used.
Then board diagram that I followed.

Soldering Sequence:

Solder the Mini USB Header first .
Solder the micorcontroller second .
Solder the Crystal and capacitors .
Solder 1k resistor .
Solder two Diodes, attation please the diode has polarity.
Solder Jumpers .
Solder 6 pin programming header .