Power light emitting die package with reflecting lens and the method of making the same

• US 8,446,004 B2
• Filed: 06/26/2008
• Issued: 05/21/2013
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Loh, Ban P., Negley, Gerald H.
• Primary Examiner(s): Ingham, John C
• Application Number:
  US12/215,319
• Publication Number:
  US 20080283861A1
• Time in Patent Office: 1,790 Days
• Field of Search: 257/99, 257/710, 257/E33.073, 257/666, 257/675, 257/E31.117, 359/726
• US Class Current: 257/706
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/642 characterized by the shape
• CPC Class Codes: H01L 33/644 in intimate contact or integrated with parts of the device other than the semiconductor body

Abstract

A light emitting die package and a method of manufacturing the die package are disclosed. The die package includes a leadframe, at least one light emitting device (LED), a molded body, and a lens. The leadframe includes a plurality of leads and has a top side and a bottom side. A portion of the leadframe defines a mounting pad. The LED device is mounted on the mounting pad. The molded body is integrated with portions of the leadframe and defines an opening on the top side of the leadframe, the opening surrounding the mounting pad. The molded body further includes latches on the bottom side of the leadframe. The lens is coupled to the molded body. A composite lens is used as both reflector and imaging tool to collect and direct light emitted by LED(s) for desired spectral and luminous performance.

Claims

1. A light emitting die package comprising:

a leadframe comprising a plurality of leads, said leadframe having a top side and a bottom side, and a portion of said leadframe defining a mounting pad;

at least one light emitting device mounted on the mounting pad;

a molded body integrated with portions of said leadframe, said molded body defining an opening on the top side of said leadframe, the opening surrounding the mounting pad;

said molded body comprising latches suitable for coupling a heatsink on the bottom side of said leadframe; and

a lens coupled to the molded body, wherein a lower portion of the lens extends downward along angled sides of the opening toward said leadframe so that a portion of said lens is even with or below a top surface of said light emitting device;

wherein said lens terminates above said leadframe to form a gap between the top side of said leadframe and said lens.

2. The light emitting die package recited in claim 1 wherein said molded body comprises molded plastic.

3. The light emitting die package recited in claim 1 further comprising a heatsink coupled, via a dielectric adhesive film, to said leadframe, said heatsink latched to said leadframe by the latches.

4. The light emitting die package recited in claim 1 wherein said lens is a composite optical lens.

5. A light emitting die package comprising:

a leadframe comprising a plurality of leads, a portion of said leadframe defining a mounting pad;

at least one light emitting device mounted on the mounting pad;

a molded body comprising an upper portion positioned above a top side of said leadframe, said molded body defining an opening surrounding the mounting pad;

a lens coupled to the molded body, at least a portion of said lens occupying a substantial amount of the opening defined in the molded body, and wherein a lower portion of the lens extends downward along angled sides of the opening toward said leadframe so that a portion of the lens is even with or below a top surface of said light emitting device;

wherein said lens terminates above said leadframe to form a gap between the top side of said leadframe and said lens.

6. The light emitting die package recited in claim 5, wherein said molded body comprises molded plastic.

7. The light emitting die package recited in claim 5, wherein said lens is a composite optical lens.

8. The light emitting die package recited in claim 5, wherein said lens has a concave bottom surface placed over said light emitting device, an outer surface of said lens surrounding said concave bottom surface being coated with reflective material.

9. The light emitting die package recited in claim 5, wherein said lens comprising a ledge, said lens being fixed to the molded body at its ledge, thereby providing the gap between said lens and the top side of said leadframe.

10. The light emitting die package recited in claim 5, wherein said lens has a semispherical upper portion and a frustoconical lower portion, the semispherical upper portion tapering at a ledge for fitting onto the upper portion of the molded body, the frustoconical lower portion fitting into and being attached to the angled sides of the opening and having a concave bottom surface thereby surrounding said light emitting device.

11. The light emitting die package recited in claim 5, wherein said lens has an upper portion disposed over the lower portion, the lower portion fitting into the opening and surrounding said light emitting device on the mounting pad, wherein the lower portion has a concave bottom surface in combination with the top side of said leadframe forming an enclosed optical cavity, the enclosed optical cavity being partially filled with the encapsulant.

12. A light emitting die package comprising:

a leadframe comprising a plurality of leads, said leadframe having a top side and a bottom side, and a portion of said leadframe defining a mounting pad;

at least one light emitting device mounted on the mounting pad;

a molded body integrated with portions of said leadframe, said molded body defining an opening on the top side of said leadframe, the opening surrounding the mounting pad, and said molded body comprising latches suitable for coupling a heatsink on the bottom side of said leadframe; and

a lens comprising an upper portion terminating at a ledge and a lower portion, said lens coupled to the molded body at the ledge, the lower portion of said lens occupying a substantial amount of the opening defined in the molded body.

13. The light emitting die package recited in claim 12, wherein the lower portion of said lens extends downward toward said leadframe so that a portion of the lower portion of said lens is substantially even with said light emitting device;

and

wherein the lower portion of said lens terminates above said leadframe to form a gap between the top side of said leadframe and the lower portion of said lens.

14. A light emitting die package comprising:

a leadframe comprising a plurality of leads, the leadframe having a top side and a bottom side, and a portion of the leadframe defining a mounting pad;

at least one light emitting device mounted on the mounting pad;

a molded body integrated with portions of the leadframe, the molded body defining an opening on the top side of the leadframe, the opening surrounding the mounting pad;

said molded body comprising latches suitable for coupling a heatsink on the bottom side of said leadframe; and

a lens coupled to the molded body and extending downward toward said leadframe;

wherein said lens terminates above said leadframe to form a gap between the top side of said leadframe and said lens, wherein the gap is free of encapsulant.

15. The light emitting die package of claim 14, where the gap comprises an expansion space free of encapsulant.

16. The light emitting die package of claim 14, wherein said molded body comprises molded plastic.

17. The light emitting die package of claim 14, further comprising a heatsink coupled, via a dielectric adhesive film, to said leadframe, said heatsink latched to said leadframe by the latches.

18. The light emitting die package of claim 14, wherein said lens is a composite optical lens.