Deep molded reflector cup used as complete LED package
An LED package creates a narrow beam in a very compact package without use of a lens. A plastic is molded around a metal lead frame ( 12, 14 ) to form a molded cup ( 26 ), where the cup has parabolic walls extending from a bottom area of the cup to a top thereof. The lead frame forms a first set of electrodes exposed at the bottom area of the cup for electrically contacting a set of LED die electrodes ( 18, 20 ). The lead frame also forms a second set of electrodes outside of the cup for connection to a power supply. A reflective metal ( 28 ) is then deposited on the curved walls of the cup. An LED die ( 16 ) is mounted at the bottom area of the cup and electrically connected to the first set of electrodes. The cup is then partially filled with an encapsulant ( 64 ) containing a phosphor ( 66 ).
1. A light emitting device comprising:
a metal lead frame including a first lead and a second lead, such that the first lead and the second lead extend beyond lateral sides of the light emitting device;
a first bonding pad on the first lead;
a second bonding pad on the second lead;
a structure comprising plastic containing metal particles molded on the first lead and the second lead, the structure including walls extending from a first area of the structure proximate to the metal lead frame, the structure being at least 5 mm deep, and the structure comprising a top opening that is at least three times as large as a bottom area, the structure comprising a dichroic coating on the walls of the structure;
a light emitting diode (LED) die disposed on the first area of the structure, the LED die including a first electrode electrically coupled to the first bonding pad and a second electrode electrically coupled to the second bonding pad; and
an encapsulant partially filling the structure, the encapsulant forming a planar surface that meets with the walls of the structure and is situated below a top edge of the structure and forming sidewalls along the walls of the structure such that the sidewalls extend contiguously from the first area of the structure to the planar surface, the encapsulant having an index of refraction between an index of refraction of the LED die and air.
2. The light emitting device of claim 1 , wherein the structure is shaped as a compound parabolic concentrator.
3. The light emitting device of claim 1 , further comprising a metal film coating formed over the walls of the structure.
4. The light emitting device of claim 1 , further comprising a reflective material disposed on the walls of the structure.
5. The light emitting device of claim 1 , wherein the LED die is less than 2 mm wide and the first bonding pad and the second bonding pad are more than 2 mm wide.
6. The light emitting device of claim 1 , further comprising a layer of wavelength converting material formed over the LED die, the layer of wavelength converting material being disposed between the LED die and the encapsulant.
7. The light emitting device of claim 1 , wherein the structure is electrically conductive.
8. A method of forming a light emitting device comprising:
forming a metal lead frame including a first lead and a second lead, such that the first lead and the second lead extend beyond lateral sides of the light emitting device;
forming a first bonding pad on the first lead;
forming a second bonding pad on the second lead;
molding a first material, comprising plastic containing metal particles, over the first lead and the second lead to form a molded structure, the structure including walls extending from a first area of the structure proximate to the metal lead frame, the structure being at least 5 mm deep, and the structure having a top opening that is at least three times as large as a bottom area;
disposing a dichroic coating on the walls of the structure;
mounting a light emitting diode (LED) die on the first area of the structure;
electrically connecting a first electrode of the LED die to the first bonding pad and a second electrode to the second bonding pad; and
partially filling the structure with an encapsulant, the encapsulant forming a planar surface that meets with the walls of the structure and is situated below a top edge of the structure and forming sidewalls along the walls of the structure such that the sidewalls extend contiguously from the first area of the structure to the planar surface, such that the encapsulant has an index of refraction between an index of refraction of the LED die and air.
9. The method of claim 8 , further comprising depositing a reflective material on the walls of the structure.
10. The method of claim 8 , wherein the structure is shaped as a compound parabolic concentrator.
11. The method of claim 8 , wherein the LED die is less than 2 mm wide and the first bonding pad and the second bonding pad are more than 2 mm wide.
12. The method of claim 8 , further comprising depositing a layer of wavelength converting material over the LED die before the structure is filled with encapsulant.
13. The method of claim 8 , wherein the first material is electrically conductive.