Injection pressure, shrink, the glass transition temperature of the polycarbonate, and the need to concentrate the shutoff areas around the area to be overmolded must be considered in the design of the part and tool. The overmolded polymer creates dynamic pressure on the base part and can be difficult to eject after overmolding if you don’t consider proper relief on the part and tool. The polycarbonate will insulate your second shot, so cooling will be inhibited and cycle times will increase. The processing temperature and shrink delta of the second polymer will determine how far the polymer can be pushed and will drive the design of the mechanical bond geometry.