Being able to create PCB’s at home is a milestone in the DIYer’s arsenal. Whether you physically mill or chemically etch boards, it’s a tricky task to perfect. [Charlie & Victor] are working towards a solution to this complicated chore. They call their machine the DiyouPCB. DiyouPCB is an open source PCB etching project consisting of both hardware and software components.
The project is based on using a Blue Ray optical pickup. The pickup was used in its entirety, without any modification, to simplify the build process. In order to use the stock pickup, [Charlie & Victor] had to reverse engineer the communication protocol which also allowed them to take advantage of the auto-focus feature used while reading Blue Ray discs. The frame of the machine is reminiscent of a RepRap, which they used to do preliminary testing and laser tuning. The X and Y axes run on brass bushings and are belt driven by stepper motors which are controlled by an Arduino through a specially designed DiyouPCB Controller Shield.
To start the process a blank PCB board is cut to the final board size. Photoresist Dry-Film is applied to one side of the board before it is put face down on the machine. The PCB design is generated using Cadsoft Eagle PCB Design Software and exported as an HPGL file. The DiyouPCBRun software sends the HPGL information to the custom written Arduino firmware, which in turn controls the stepper motors and optical pickup using the DiyouPCB Controller Shield. The optical pickup’s laser removes the photoresist film from the non-trace areas of the board. The exposed copper is then etched away by means of an acid bath followed by stripping the remaining photoresist film to expose the copper traces. The result is a completed PCB board.
Admittedly, the PCB results are not perfect. The stepper motors are believed to be causing vibration which can be seen in some of the etchings. Axis stiffening and carriage damping reduced the vibration but did not eliminate it. To further combat the vibration issues, [Charlie & Victor] are debating upgrading to servo motors or sacrificing speed by replacing the belts with lead screws.
If you are wondering how you can get one of these machines, it’s easy. [Charlie & Victor] have made all of the necessary project files available on their website for you to download, including the 3D-printable .stl files, software, and controller shield.