LED package with multiple element light source and encapsulant having curved and/or planar surfaces
LED packages are disclosed that are compact and efficiently emit light, and can comprise encapsulants with planar surfaces that refract and/or reflect light within the package encapsulant. The LED package are also directed to features or arrangements that allow for improved or tailored emission characteristic for LED packages according to the present invention. Some of these features or arrangements include, but are not limited to, higher ratio of light source size to submount size, the used of particular materials (e.g. different silicones) for the LED package layers, improved arrangement of a reflective layer, improved composition and arrangement of the phosphor layer, tailoring the shape of the encapsulant, and/or improving the bonds between the layers. There are only some of the improvements disclosed herein, with some of these resulting in LED packages the emit light with a higher luminous intensity over conventional LED packages.
1. A light emitting diode (LED) package comprising:
a submount with two or more LED chips mounted on said submount with a space between adjacent ones of said two or more LED chips;
a phosphor layer covering at least two adjacent ones of said two or more LED chips and comprising a bridge spanning the space between said at least two adjacent ones of said two or more LED chips, wherein said phosphor layer extends on a surface of the submount that is adjacent said two or more LED chips;
a filler in said space between said at least two adjacent ones of said two or more LED chips and below said bridge;
a reflective layer on the phosphor layer and adjacent said two or more LED chips such that said phosphor layer is between said reflective layer and said submount; and
an encapsulant over said two or more LED chips and said submount.
2. The LED package of claim 1 , wherein a top surface of said filler is aligned with or higher than top surfaces of said at least two adjacent ones of said two or more LED chips.
3. The LED package of claim 1 , wherein said encapsulant comprises a curved surface.
4. The LED package of claim 3 , wherein said encapsulant comprises a plurality of planar side surfaces connected to one another by said curved surface.
5. The LED package of claim 4 , wherein said submount comprises a plurality of outermost edges, and at least one of said plurality of planar side surfaces is in alignment with a respective one of said plurality of outermost edges.
6. The LED package of claim 1 , wherein said bridge is in the direct emission path of light from said at least two adjacent ones of said two or more LED chips.
7. The LED package of claim 6 , wherein said phosphor layer is dispensed on said at least two adjacent ones of said two or more LED chips and over said space, said phosphor layer having a viscosity in the range of 1-75 PaS when dispensed.
8. The LED package of claim 1 , wherein said phosphor layer comprises a phosphor in a binder, wherein the phosphor to binder ratio is 3 to 1 or greater.
9. The LED package of claim 1 , wherein said filler comprises a reflective material.
10. The LED package of claim 1 , wherein said filler comprises reflective particles mixed in silicone or epoxy.
11. The LED package of claim 10 , wherein said reflective particles comprise TiO 2 or ZrO 2 .
12. A light emitting diode (LED) package comprising:
a submount with two or more LED chips on said submount, at least two adjacent ones of said two or more LED chips having top surfaces at substantially the same height;
a phosphor matrix layer covering the top surfaces of said at least two adjacent ones of said two or more LED chips and covering a surface of said submount adjacent said at least two adjacent ones of said two or more LED chips, wherein said phosphor matrix layer comprises a bridge between said at least two adjacent ones of said two or more LED chips;
a reflective layer on the phosphor matrix layer and adjacent said two or more LED chips such that said phosphor matrix layer is between said reflective layer and said submount; and
a filler in a space between said at least two adjacent ones of said two or more LED chips and below said bridge.
13. The LED package of claim 12 , further comprising an encapsulant over said two or more LED chips.
14. The LED package of claim 13 , wherein said encapsulant comprises a curved surface and a plurality of planar side surfaces.
15. The LED package of claim 12 , wherein a top surface of said filler is aligned with or higher than the top surfaces of said at least two adjacent ones of said two or more LED chips.
16. The LED package of claim 12 , wherein said filler comprises a reflective material.
17. The LED package of claim 12 , wherein said filler comprises reflective particles mixed in silicone or epoxy.
18. The LED package of claim 17 , wherein said reflective particles comprise TiO 2 or ZrO 2 .
19. A light emitting diode (LED) package comprising:
a submount;
two or more LED chips on said submount and adjacent to one another with a space between adjacent ones of said two or more LED chips;
a phosphor binder layer covering at least two adjacent ones of said two or more LED chips and comprising a bridge spanning the space between said at least two adjacent ones of said two or more LED chips to form an air gap below said bridge and between said at least two adjacent ones of the two or more LED chips, wherein said phosphor binder layer extends on a surface of the submount that is adjacent said two or more LED chips;
a reflective layer on the phosphor binder layer and adjacent said two or more LED chips such that said phosphor binder layer is between said reflective layer and said submount; and
an encapsulant over said two or more LED chips comprising a curved surface.