Hi Guys, I have been PCB Isolation routing for quite some time now. I'm looking for some advice with regards to Aluminium backed PCB's. I have probably gone through about 20 150x100 boards generally without success. The problem is that somehow the copper becomes attached to the aluminium when routed.
I don't have this problem when I route small tracks or standard FR4 boards only long tracks on aluminium backed boards.

I originally used V bits but I have switched over to carbide engraving bits desinged for this purpose from preciseBIT. And have routed at 18,000 rpm and 26,000 rpm both at 550mm/minute. I have also run programs where I route the tracks 3 times over to ensure they are clear of any debris and I thoroughly clean them afterwards. I have inspeced the boards with a 200x viewing USB microscope and can see no interconneting bits.

Does anyone have any experience with this? Thanks