There are many, many ways to get a PCB design onto a board for etching. Even with practice however, the quality of the result varies with the process and equipment used. With QFN parts becoming the norm, the days of etch-resist transfers and a permanent marker are all but gone. Luckily, new and improved methods of Gerber transfer have be devised in recent years thanks to hackers across the world.
One such hacker, [Henner] is working on a project called LDGraphy in an attempt to bring high-resolution etching to the masses. LDGraphy is a laser lithography device that makes use of a laser and a Beaglebone green to etch the layout onto the board. The best part is that the entire BOM is claimed to cost under a $100 which makes it affordable to people on a budget.
The system is designed around a 500 mW laser and a polygon mirror scanner meant for a laser printer. The board with photoresist is linearly actuated in the X-axis using a stepper motor and the laser beam which is bounced off the rotating hexagonal mirror is responsible for the Y-axis. The time critical code for the Programmable Realtime Unit (PRU) of the AM335X processor is written in assembly for the fast laser switching. The enclosure is, naturally, a laser cut acrylic case and is made at [Henner]’s local hackerspace.