Building the $100 night light, Part IV

Continuing with the "Building the $100 night light" series, Part IV focuses on the building a PCB in Eagle...

Before starting the process of designing the board, I selected a fabrication house that I would use for manufacturing.  This is done up front because every manufacturer has different tolerances and costs.  After some research I selected Sunstone Circuits, a manufacturer in Oregon.  Sunstone publishes a set of Design for Manufacturing (DFM) rules and CAM files which can be downloaded here, and installed in Eagle to help validate your design as you work and generate the final GERBER files.

While in Eagle with the schematic open, I switched to the board view, which creates a new board, inserts all of the schematic components, and connects the components with air wires.  For this simple project, I used a 2 layer board (top and bottom).

The first step was to resize the board to dimensions that would fit within the Hammond ABS enclosure, followed by moving the components onto the board.  I used the Eagle Autorouter tool to create the initial set of traces, and then tweaked a few of the runs by hand.  As the final step, I created a ground plane on the top and bottom layer of the board.  The final board layout is shown below.

The last step was generating the files needed by Sunstone Circuits.  Sunstone had an excellent writeup on the process, in a PDF file titled "EAGLE v5.0+ Board Convert to Gener Made Easy".  The process outlined in the document was followed, and worked without issue.  The major steps were:

- Change Eagle font usage, by chosing Options |  User, and selecting "ALWAYS VECTOR FONT"
- Run DRILLCFG.ULP to generate the DRL file
- Run the CAM processor, EXCELLON.CAM job, to generate the NC drill file
- Run PROCESS JOB, 2LPlus-Sunstone.cam, to generate the GERBER files
- Zip up the files created in the above steps (the zip file contents are listed below):

This file was uploaded/ordered to the Sunstone website, and within a few weeks I received the manufactured board (photo below).  The total cost for the board was about $30.  In hindsight, I would have ran a number of the traces differently to make soldering easier.