CNC Milling of PCBs

[TucsonSean]

Hi Everyone,

Since I mill my own PCBs I thought it would be good to start a new thread to answer any questions that may arise from my former posts here. Since I have been asked more than once which mill I use, I thought it would be a good idea to share all my information here so I can answer any quesitons that may arise.

Schematic capture and PCB design: Diptrace

G-code generation: Flatcam ver 8.55

G-code check/mod/correct: HSMWorks

3D modeling: Solidworks

I use HSMWorks since the postprocessor is set up in Solidworks to generate LinuxCNC compatible g-code for my milling operations. If it looks good in HSMWorks, I know it will work on my mill.

I use Solidworks to model my enclosures and HSMWorks to generate the toolpaths for any milling/drilling/engraving operations on enclosures that I need to make.

Mill: Taig Tools 5019CR ballscrew mill

I currently use a Taig 5019CR ballscrew mill with 4th axis driven by Clearpath servo motors and running LinuxCNC for control. I have the standard Taig ER16 spindle for most milling operations and I have an Ugra CNC 0.4kW ER11 24k spindle for running small tooling and making PCBs. I chose this spindle since I was given a 110V 1HP Allen Bradley VFD and it runs this spindle exceptionally well.

I have added a Digi3D probe from Topcom for workpiece location and this has really helped when I mill my enlosures. It ensures that I can get exactly centered on the parts. This has eliminated the offsets I initially got when milling the top jack holes in my enclosures.

Let me know if you have any further questions on my setup, procedure, or anything else CNC related. I have been CNC machining since 2010.

-Sean


Pics atached: My mill, Taig 5019CR from factory, latest PCB milled on my CNC, enclosure milled on my CNC

 

[Aentons]

Just curious if you have trouble not having a solder mask?

 

[NickKUK]

what bit do you use for pcb trace routing?

I assume a down spiral is used to prevent lifting?

 

[TucsonSean]

Aentons,

I have not had any issues with any of the boards that I have made in the last 15 years.

NickKUK,

I have used 4 flute, 1/32" endmills for trace isolation when I don't need fine pitch. For finer pitch, I use isolation routing bits from PreciseBits.com, they make 3 flute tapered stub endmills for isolation routing from 0.00145" tip diameter up to 0.025". These bits work great for isolation routing but they are not down-cut bits. I believe the flutes are too small for down spiral cutters in this size as they would clog with swarf very easily.

-Sean