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

• US 20050269587A1
• Filed: 06/04/2004
• Published: 12/08/2005
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Negley, Gerald H., Loh, Ban P.
• Granted Patent: US 7,456,499 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• 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 including 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 including latches on the bottom side of said leadframe; and

a lens coupled to the molded body.

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 method of manufacturing a light emitting die package, the method comprising:

fabricating a leadframe strip, the leadframe strip including a plurality of leads, each lead and the leadframe strip having a top side and a bottom side, portions of a first lead defining a mounting pad;

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

the molded body including latches on the bottom side of the leadframe strip; and

mounting at least one light emitting device on the mounting pad.

6. The method recited in claim 5 wherein the leadframe strip comprises thin metal.

7. The method recited in claim 5 wherein the leadframe strip is stamped from a metal sheet.

8. The method recited in claim 5 wherein the molded body comprises high temperature plastic.

9. The method recited in claim 5 further comprising coupling a heatsink to the leadframe die by engaging the heatsink with the latches.

10. The method recited in claim 5 further comprising encapsulating the light emitting device with an encapsulant.

11. The method recited in claim 5 further comprising coupling a lens over the opening thereby defining an optical cavity.

12. The method recited in claim 11 wherein the lens is a composite optical lens including a reflector surface and a concave bottom surface placed over the mounting pad.

13. The method recited in claim 11 wherein the lens has a bottom surface coated with optical material adapted to operate on the light.

14. The method recited in claim 11 further comprising substantially filling the optical cavity with encapsulant while leaving an expansion space free of the encapsulant thereby allowing the encapsulant to expand and contract.

15. The method recited in claim 5 further comprising removing crossbar portion of the leadframe leaving the light emitting die package with external portions of the leads;

and bending the external portions of the leads.