BATWING BEAM BASED LED AND BACKLIGHT MODULE USING THE SAME
A batwing beam is produced from an LED package having a primary LED lens by molding the LED lens directly over an LED on a package substrate. The LED lens includes a cavity over a center of the LED. The cavity surface reflects light from the LED through total internal reflection (TIR) or through a reflectivity gel coating. The cavity may be a cone or a pyramid.
1 . An optical emitter comprising:
a Light-Emitting Diode (LED) die;
a package substrate attached to one side of the LED die;
electrical connections connecting the LED die and terminals on the package substrate; and
a molded lens bonded to the package substrate directly contacting the LED die, said molded lens having an ellipsoidal cross section with a batwing cavity centered over the LED die.
2 . The optical emitter of claim 1 , wherein the molded lens includes a high reflectivity coating on the cavity surface.
3 . The optical emitter of claim 2 , wherein the high reflectivity coating reflects at least 90% of incident light.
4 . The optical emitter of claim 2 , wherein the high reflectivity coating includes a metal.
5 . The optical emitter of claim 1 , wherein the cavity is a cone.
6 . The optical emitter of claim 5 , wherein the cavity has an aperture that causes the cavity surface to totally internally reflect light generated from a center of the LED.
7 . The optical emitter of claim 1 , wherein the cavity is an elliptical cone.
8 . The optical emitter of claim 1 , wherein the cavity is a pyramid.
9 . The optical emitter of claim 1 , wherein the molded lens is a silicone, a resin, an epoxy, or a poly(methyl methacrylate) (PMMA).
10 . The optical emitter of claim 1 , wherein the optical emitter is about or smaller than 3.5 mm by 3.5 mm.
11 . The optical emitter of claim 1 , wherein the molded lens base is a polygon with rounded corners.
12 . A method of fabricating an optical emitter, comprising:
attaching a Light-Emitting Diode (LED) die to a package substrate;
electrically connecting the LED die and the package substrate; and,
molding a lens over the package substrate and the LED die, wherein the molded lens includes a batwing cavity over the LED die.
13 . The method of claim 12 , wherein the molding a lens over the package substrate and the LED die comprises:
placing a lens mold over the package substrate and the LED die;
inserting a lens glue into the lens mold; and
curing a molded lens.
14 . The method of claim 13 , wherein the inserting a lens glue includes evacuating a space inside the lens mold.
15 . The method of claim 13 , wherein the curing a molded lens comprises exposing the lens glue to ultraviolet light through the lens mold or heating the lens glue.
16 . The method of claim 12 , further comprising dispensing a high reflectivity gel into the batwing cavity that completely coats the conical cavity surface.
17 . The method of claim 16 , wherein the high reflectivity gel comprises a metal.
18 . The method of claim 16 , wherein the metal is silver.
19 . The method of claim 12 , wherein the molded lens is a half ellipsoid with a conical portion removed from middle of the curved surface away from the LED die.
20 . The method of claim 12 , further comprising
molding a reflector on the package substrate around the LED die; and
dispensing a phosphor material in a volume formed by the molded reflector,
wherein molding a lens occurs after dispensing the phosphor material.
21 . The method of claim 12 , further comprising:
forming a phosphor component over the LED die before the molding a lens.
22 . A display comprising:
a plurality of optical emitters, each optical emitter comprising:
a Light-Emitting Diode (LED) die;
a package substrate attached to one side of the LED die;
electrical connections connecting the LED die and the package substrate; and
a molded lens bonded to the package substrate directly contacting the LED die, said molded lens having an ellipsoidal cross section with a batwing cavity centered over the LED die.
23 . An optical emitter comprising:
a plurality of Light-Emitting Diode (LED) dies;
a package substrate attached to one side of the plurality of LED dies;
electrical connections connecting the plurality of LED dies and terminals on the package substrate; and
a molded lens bonded to the package substrate directly contacting the plurality of LED dies, said molded lens having an ellipsoidal cross section with a batwing cavity.