An insulated metal substrate (IMS) includes a metal substrate, an insulating layer, a plastic frame, and a plurality of conductive metal pads. The insulating layer is located on the metal substrate. The plastic frame is located on the insulating layer and has a plurality of aperture areas. The conductive metal pads are located on the insulating layer and are respectively located in the aperture areas, and the conductive metal pads have sidewalls are in contact with the plastic frame.