The first method uses a 3 axis milling machine to mill a circuit board, then the electrical components are soldered on individually. I started with this method, and it worked out pretty well, but my ISP became damaged. the 6 pin header broke off and took some of the copper with it.
The second method involved already manufactured boards. We placed the boards under a stencil and applied solder paste to them. then all we needed to do was add the components and put them in an oven. This was the result:
