PCB Prototyping using a CNC UV Laser, LCD Mask and Isolation CNC Milling

I'm really amazed that still, in this day-and-age, we need to resort to messy and laborious etching methods when making PCB's and there still seems to be no easy way to merely print out a prototype PCB on a printer e.g. using conductive inks or merely a laser printer exposer. Perhaps the market is just too niche for the printer manufacturing giants to be interested in developing such a printer?

At a certain stages in our development process, we normally need to move from simple prototyping breadboards and start make various prototype PCB's.

I've already tried various prototype manufactures and PCB prototyping methods, such as using contact negative / positive films, PCB milling, direct PCB inkjet printing, direct PCB plotting (using permanent maker pens), use of various PCB group batch services and direct PCB UV laser exposure. The complexity of these various methods tend to increase dramatically when trying to make double sided PCB's!

I'm particular excited about direct laser plotting (UV light exposing) onto UV sensitive PCB. So I've create some webpages to record the exploration process.

For this PoC, I'm using a cheapo Chinese A5 CNC Laser Engraver and a Proxon MF70 CNC machine for drilling holes and board outline milling.

I've also reviewed various CNC Laser and Milling applications too. The Chinese CNC Laser Engraver comes with a simple two Axis Arduino based CNC controller board running GRBL. I'm actually quite impressed with the quality of the CNC Laser engraving machine and also with GRBL, so I've also converted our Proxon CNC from an older serial CNC controller board to a RAMPS + Arduino mega board that has 5 Stepper drivers. I've also loaded the RAMPS board with GRBL on RAMPS. The following webpages explain how I did this.

Just to be clear; I'm NOT actually laser cutting the copper on the PCB board (yes! that would be great), but am merely selectively exposing a PCB with UV sensitive etch resistant coating. These type of PCB's are just slightly more expensive than non-UV coated PCB material, but saves a bit of of time and hassle; compared to spray UV paint or ironing on UV sensitive films onto PCB*s, etc. but the other methods work in similar way too.

In this review I've also tested other methods of etch resist, such as black paint, SLA UV resins, masking films, etc ., with various degrees of success..., but the UV photo resist coating methods produced the best results for me so far.

So let's get started .....