The goal of this project is to develop the electronics and scan head for a PCB machine which can expose a PCB with a track width smaller than 100 micrometers, i.e. 4 mil. The PCB machine also has a spindle to CNC a PCB board and create through holes. The transparent polygon scanner, which can get a high accuracy and telecentric projection, has been developed. The electronics and software to cut boards with a spindle and expose it with a laser has been developed.
The current goal is to bring the quality of the scanhead to a higher level so it can be sold as minimum viable product.
The current version of the Hexastorm has the following specifications:
- wavelength: 405 nm
- rotation frequency: up to 21000 RPM, current 2400 RPM
- line speed: up to 34 meters per min @ 21000 RPM
- spot size FWHM: circular, 25 micrometers diameter
- cross scanner error: 40 micrometers (error orthogonal to scanline)
- stabilization accuracy scanning direction : 2.2 micrometers (disabling/enabling scanhead)
- jitter: 35 microns (error parallel to scanline)
- laser driver frequency: 2.6 MHz
- maximum scan line length: 24 mm
- typical scan line length: 8 mm
- optical power: 500 mW
- facets: prism has 4 facets
- Beaglebone green
- Firestarter cape (laser driver, 3x TMC2130 stepper drivers, PWM spindle and fan control)
An image can be uploaded to the scanner and exposed on a substrate.
An exposure result on cyanotype paper is shown below.
Resolution looks to be around 100 microns. Stitching still needs to be fixed, results in white lanes.
The idea is that throughholes are made with a spindle. There is a project on hackaday where a PCB is cut with an EDM.
At the moment, the goal is develop the scanhead so it can be sold with electronics as MVP.
An exposure goes as follows (for the result see above).