PCB's with UV sensitive etch resist coating are slightly more expensive then non-UV coated PCB material but in our option saves quite some some time having to ironing on UV sensitive films, or using etch resist pens, etc.Įven low powered UV lasers (e.g. We're NOT actually laser cutting the copper on the PCB board (yes! that would be great), but merely selectively exposing a the UV sensitive etch resistant coating on the PCB. We're particular excited about using UV lasers to exposing UV sensitized PCB's.
However, in the meantime we had bought a replacement laser head from Bangood, but bought the replacement kit for $80 for GearBest too to develop a double sided PCB exposure solution. In total, the replacement process tool about 6 months to resolve. We were somewhat reluctant as we still hadn't completed our PoC so had no idea if this would actually work. GearBest spent many weeks trying to get a replacement from the manufacturer but eventually offered to send another complete Laser kit for an additional $80. We bought the kit from GearBest, but experienced quite a lot of support issues when trying to replace a faulty Laser. We were very impressed with the presentation of the kit with all parts nicely packed and prepared. It's important to get the Ultraviolet Laser diode as this is what most UV PCB material is sensitive to. It came with a 2500mW near Ultravilot Laser (405nm) and an Arduino based controller with a version of the GRBL firmware installed. This is the laser engraver we used for the PoC, which we purchased from GearBest. Wear eye protection or you could be blinded!! )Įleks maker Laser Engraver (approx $200 from Gearbest or Banggood): (Note: a laser is very dangerous if the beam (or scattered beam) comes in contact with your eyes or skin. Laser Exposure of UV sensitive PCB material do NOT rinse the chemicals into your drains!). UV exposed areas will be 'curred' and remain on the PCB for up to 5 minutes when left in the solution but this depends on dilution and temperature and how often the solution has been used before.įor the chemical enchant of the copper layers we used Natriumhydroxid, at a temperature of 25 deg.C.Īs with all chemicals, please be careful and use eye, hand, body protection and dispose of the material environmentally safely according to the directives of your local bylaws (i.e. which takes typically 45 seconds at 20 deg.C. The development process used is Natriumhydroxid (1g NaOH mixed with 1l Water).
Diptrace pcb for cnc code#
In the same way with a laser a test strip should be made to see the optimum speed (GCode F value)) and intensity (G Code S value) of the laser.
This depends greatly on the light box being used and so they recommend making test strips within 20 second intervals to confirm this. The specification states that the UV material becomes cured (etch resistance) after exposure from a 2kW UV light at a distance of 1m for 90 seconds with an optimum exposure of 120 seconds (exposure of 1,5 mJ/cm’ is required). This is OK for creating areas of isolation around the tracks but ideally to save 'lasering' time we will also testing UV 'negative' PCB material where the exposed areas becomes the etch resit and the un-exposed areas then etched away.Īs a summary, the UV etch resistant coating has a peak spectral sensitivity of 400nm wavelength which matches well with the Blue UV laser at 405nm. what is exposed to UV light is etched away. This PCB material is positive UV sensitive material i.e. A specification of the material is (in German) -> here. The UV PCB (positive) material used for this PoC is from Bungard which can be obtained from most suppliers such as Conrad, Reichelt, eBay, etc.
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