Heat radiation device and illuminating device having said heat radiation device

1. A heat radiation device for a heat source, comprising a body and a coating layer, wherein the body has a first section and at least one second section projecting from the first section, the first section has a mounting surface for mounting and thermally contacting with the heat source and the coating layer is applied on a surface other than the mounting surface of the first section and a surface of the at least one second section, wherein the coating layer has higher thermal dissipation performance than the body, wherein at least one thermal via is opened in the first section and the at least one second section.

2. The heat radiation device according to claim 1 , wherein the coating layer is made of coating having a thermal conductivity greater than 5 W/m/K.

3. The heat radiation device according to claim 2 , wherein the coating is mixed with one component selected from a group consisting of nickel, silver, graphite, nano-carbon, TiO 2 , Al 2 O 3 , boron nitride, and spinel.

4. The heat radiation device according to claim 2 , wherein the coating layer has a thickness of 200 to 500 micron.

5. The heat radiation device according to claim 1 , wherein the body is made of low thermally conductive plastic with a thermal conductivity lower than 1 W/m/K.

6. The heat radiation device according to claim 5 , wherein the first section and the second section are moulded in one piece by injection moulding.

7. The heat radiation device according to claim 6 , wherein the low thermally conductive plastic is a polybutylene terephthalate, poly oxymethylene, polyamide, or acrylonitrile butadiene styrene material.

8. The heat radiation device according to claim 1 , wherein the at least one second section is at least one fin projecting from the first section.

9. The heat radiation device according to claim 1 , wherein the thermal vias in the first section extend traverse to extension direction of the first section and the thermal vias in the second section extend traverse to the extension direction of the second section.

10. The heat radiation device according to claim 9 , wherein the thermal via is filled by the same material as that of the coating layer.

11. An illuminating device, having a heat radiation device for a heat source, the heat radiation device comprising a body and a coating layer, wherein the body has a first section and at least one second section projecting from the first section, the first section has a mounting surface for mounting and thermally contacting with the heat source and the coating layer is applied on a surface other than the mounting surface of the first section and a surface of the at least one second section, wherein the coating layer has higher thermal dissipation performance than the body, wherein at least one thermal via is opened in the first section and the at least one second section.

12. The illuminating device according to claim 11 , wherein the heat source comprises a circuit board and an LED chip provided on the circuit board.

13. The illuminating device according to claim 12 , wherein the circuit board is configured as a non-electrically isolated metal core printed circuit board, or an electrically isolated ceramic printed circuit board.

14. The illuminating device according to claim 11 , wherein a circuit board and the body are moulded together.

15. The illuminating device according to claim 11 , wherein a circuit board is attached to the mounting surface of the first section of the body with a thermal interface material.