Because Metal core Aluminum is conductor,could not fix DIP components.
Insulated holes technology is the solution to solve this problem.
Aluminum pcb with insulated hole Manufacturing step:
step 1:
Drilled the big holes through the aluminum,
Step 2:
filled the holes by epoxy resin.
Step 3:
Lamination process,copper + high thermal conductivity insulation layer
Then drill the small insulated holes.
