LED assembly preventing electrostatic accumulation thereon

1. An LED assembly comprising:

an LED module comprising a printed circuit board and a plurality of LEDs mounted thereon;

a grounded support; and

an electrically conductive fastener extending through the printed circuit board into the support to fix the LED module on the support;

wherein the printed circuit board comprises a metal substrate and an insulating layer formed on a top face thereof, a trough being defined in the insulating layer to expose the top face the substrate; and

wherein an end of the fastener is received in the trough and in direct contact with the top face of the substrate and electrical connection with a top face of the insulating layer whereby static electricity produced on the top face of the insulating layer is conductable via the fastener to the substrate which is grounded.

2. The LED assembly as claimed in claim 1 , wherein the printed circuit board has a through hole defined therethrough, the through hole receiving the fastener therein and being surrounded by the trough.

3. The LED assembly as claimed in claim 1 , wherein the trough is extended to a lower level spaced 0.2 mm from the top face of the substrate.

4. The LED assembly as claimed in claim 1 , wherein the fastener comprises a head, a pole extending downwardly from a bottom of the head, and a plurality of teeth extending downwardly to be in direct contact with the top face of the substrate.

5. The LED assembly as claimed in claim 4 , wherein the plurality of teeth surrounds an upper end of the pole.

6. The LED assembly as claimed in claim 4 , wherein the plurality of teeth is formed from the bottom of the head.

7. The LED assembly as claimed in claim 4 , wherein the fastener further comprises an annulus detachably sleeved on the pole, the plurality of teeth being formed from a bottom of the annulus.

8. The LED assembly as claimed in claim 4 , wherein the head of the fastener projects outside of the insulating layer.

9. The LED assembly as claimed in claim 4 , wherein each of the plurality of teeth is triangular.

10. The LED assembly as claimed in claim 1 , wherein the trough is formed by milling.

11. An LED assembly comprising:

an LED module comprising a printed circuit board and a plurality of LEDs mounted on the printed circuit board;

a grounded support; and

a fastener extending through the printed circuit board and into the support;

wherein the printed circuit board comprises a metal substrate and an insulating layer formed on the substrate; and

wherein the fastener has a plurality of teeth formed at an upper portion thereof, the plurality of teeth extending through the insulating layer and abutting against the substrate of the printed circuit board to thereby electrically connect a top face of the insulating layer and the substrate whereby static electricity produced on the top face of the insulating layer is conductable via the fastener to the substrate which is grounded.

12. The LED assembly as claimed in claim 11 , wherein the fastener is a screw, the plurality of teeth being extended from a head located at the upper portion of the screw.

13. The LED assembly as claimed in claim 11 , wherein the fastener comprises a screw and an annulus detachably sleeved on the screw, the plurality of teeth being formed from the annulus.

14. The LED assembly as claimed in claim 11 , wherein the plurality of teeth forms an annular groove in the substrate by scraping with the substrate.

15. The LED assembly as claimed in claim 14 , wherein a depth of the annular groove is 0.2 mm.

16. The LED assembly as claimed in claim 11 , wherein a top face of the fastener is located higher than the top face of the insulating layer of the printed circuit board.

17. The LED assembly as claimed in claim 11 , wherein each of the plurality of teeth has a sharp extremity extending toward the support.

18. The LED assembly as claimed in claim 1 , wherein the printed circuit board further comprises another insulating layer below the insulating layer and an electrically conductive layer between the insulating layer and the another insulating layer.

19. The LED assembly as claimed in claim 11 , wherein the printed circuit board further comprises another insulating layer below the insulating layer and an electrically conductive layer between the insulating layer and the another insulating layer.