Patent ID: 8421321

Claim:
An LED light bulb, comprising a light transparent shell, a power receiving base, a heat sink and a coupling holder located between the light transparent shell and the power receiving base, at least one light source baseboard located in the light transparent shell, and a power conversion board electrically connected to the light source baseboard and the power receiving base, the heat sink including a housing chamber to hold the power conversion board, wherein: the heat sink includes an annular coupling wall to form an area to couple with the light source baseboard, the light source baseboard including a contact surface on the circumference corresponding to the coupling wall to form compact coupling therewith to hold the light source baseboard securely on the heat sink, wherein the coupling holder includes an insulation wall surrounded to form a circuit holding compartment to hold the power conversion board, and a mask portion attached to a lower side of the heat sink to seal an opening at a lower end of the housing chamber, the LED light bulb further including an isolation member held in the housing chamber, the isolation member including an isolation wall interposed between the power conversion board and the heat sink, and a wiring outlet to allow wires of the power conversion board to pass through to connect the power conversion board with the light source baseboard, the insulation wall including an inner rim to form compact coupling with the isolation wall.