LED light source
An LED light source is described herein, which comprises: a hollow heat sink having a top wall, a bottom opening, and a sidewall, the top wall including an upper surface and a lower surface, the upper surface having a central area and a peripheral area, and the top wall having at least one first hole in the peripheral area; an interposer being overmolded on the peripheral area and the lower surface, and extending through the at least one first hole; an LED package comprising at least one LED chip and mounted in the central area; an LED driver located within the hollow heat sink and positioned on a side of the interposer facing the bottom opening.
1. An LED light source, comprising:
a hollow heat sink having a top wall, a bottom opening, and a sidewall between the top wall and the bottom opening, the top wall including an upper surface facing away from the bottom opening and a lower surface facing the bottom opening, the upper surface having a central area and a peripheral area surrounding the central area, and the top wall having at least one first hole in the peripheral area of the upper surface;
an interposer made of thermally conductive and electrically insulating material, the interposer being overmolded on the peripheral area of the upper surface and the lower surface of the top wall, and extending through the at least one first hole;
an LED package comprising at least one LED chip and mounted in the central area of the upper surface of the top wall; and
an LED driver located within the hollow heat sink and positioned on a side of the interposer facing the bottom opening to be electrically insulated from the hollow heat sink, and configured to provide driving current to the at least one LED chip, the interposer forming a thermal conduction path between the LED driver and the top wall of the heat sink.
2. The LED light source of claim 1 , further comprising a rear case located within the hollow heat sink and arranged to support the LED driver between the rear case and the interposer.
3. The LED light source of claim 1 , wherein the LED package further comprises:
a leadframe on which the at least one LED chip is arranged; and
a transparent encapsulation material with which the at least one LED chip and part of the leadframe are overmolded.
4. The LED light source of claim 3 , wherein the transparent encapsulation material comprises transparent epoxy or silicone.
5. The LED light source of claim 3 , wherein the leadframe comprises at least one second hole that is not overmolded with the transparent encapsulation material, through which connecting wires electrically connect the LED driver to the at least one LED chip.
6. The LED light source of claim 3 , wherein the leadframe is made of silver-plated copper.
7. The LED light source of claim 3 , wherein the transparent encapsulation material is shaped on a side of the leadframe where the at least one LED chip is located to shape the light output of the at least one LED chip.
8. The LED light source of claim 1 , wherein the central area of the upper surface of the top wall is raised above the peripheral area of the upper surface.
9. The LED light source of claim 1 , wherein the LED driver comprises a printed circuit board.
10. The LED light source of claim 1 , wherein the material of the interposer comprises resin, plastic, or nylon.
11. The LED light source of claim 1 , wherein a material of the heat sink comprises aluminum or copper.
12. The LED light source of claim 1 , wherein the hollow heat sink has a hollow cylindrical shape.
13. The LED light source of claim 12 , wherein the bottom opening has a diameter of 20-30 mm.
14. The LED light source of claim 1 , wherein the sidewall has a thickness of 1-1.5 mm.
15. The LED light source of claim 1 , wherein the top wall has at least one additional first hole therethrough in the peripheral area of the upper surface, and the interposer extends through the at least one additional first hole.
16. The LED light source of claim 1 , wherein (i) a portion of the interposer overmolded on the upper surface of the top wall extends laterally beyond a lateral extent of the LED package, or (ii) a portion of the interposer overmolded on the lower surface of the top wall extends laterally beyond the lateral extent of the LED package.
17. The LED light source of claim 16 , wherein a portion of the interposer overmolded on the lower surface of the top wall is in direct contact with the lower surface over an area that extends laterally beyond the lateral extent of the LED package.
18. The LED light source of claim 2 , wherein the LED driver is enclosed within a volume defined by the interposer, the rear case, and at least a portion of the sidewall, the rear case forming a thermal conduction path between the LED driver and the side wall of the heat sink.
19. The LED light source of claim 8 , wherein the central, raised area of the upper surface protrudes into a surrounding portion of the interposer.
20. A method for making an LED light source, the method comprising:
forming from thermally conductive and electrically insulating material an interposer, the interposer being overmolded on a corresponding peripheral area of an upper surface and a lower surface of a top wall of a hollow heat sink and extending through at least one first hole in the peripheral area of the upper surface of the top wall, the hollow heat sink further including a bottom opening and a sidewall between the top wall and the bottom opening, the upper surface of the top wall facing away from the bottom opening and the lower surface of the top wall facing the bottom opening, the upper surface having a central area with the peripheral area surrounding the central area;
mounting on the central area of the upper surface of the top wall an LED package comprising at least one LED chip; and
positioning on a side of the interposer facing the bottom opening an LED driver, the LED driver being (i) located within the hollow heat sink, the interposer forming a thermal conduction path between the LED driver and the top wall of the heat sink, (ii) electrically insulated from the hollow heat sink, and (iii) configured to provide driving current to the at least one LED chip.