A novel COB structure with integrated multifunction

A novel COB (chip-on-board) structure with integrated multifunction is presented. The structure is prepared by laminating copper plate with FR4 board and then coating with a silver layer to offer high reflectivity and high conductivity. In comparison with MCPCB (aluminum) and ceramics (Al sub(2)O sub(3)) board, the substrate brings about 10% higher light extracting efficiency than aluminum board and 5% higher flux maintenance ratio than ceramics (Al sub(2)O sub(3)) board at 3000 h. With integrated multifunction, through an IC component driving high voltage serial LED chips, the COB can be directly connected to AC 110 V or 220 V power supply in lighting application.