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

• US 8,932,886 B2
• Filed: 05/20/2013
• Issued: 01/13/2015
• 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:
  US13/897,952
• Publication Number:
  US 20130323865A1
• Time in Patent Office: 603 Days
• Field of Search: 257/79, 257/99, 257/100, 257/706, 257/710, 257/E33.059, 257/E33.073, 438/27, 438/118
• US Class Current: 438/25
• 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 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;

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

coupling a lens to the body via an encapsulant material, the lens being provided over the opening of the body for defining an optical cavity, and comprising a first concave surface disposed above the molded body, and wherein a portion of the lens extends at least partially below an upper surface of the light emitting device; and

substantially filling the optical cavity with encapsulant while leaving an expansion space free of the encapsulant thereby allowing the encapsulant to expand and contract.

2. The method recited in claim 1 wherein the leadframe strip comprises thin metal.

3. The method recited in claim 1 wherein the leadframe strip is stamped from a metal sheet.

4. The method recited in claim 1 wherein the molded body comprises high temperature plastic.

5. The method recited in claim 1 further comprising coupling a heatsink to the leadframe strip.

6. The method recited in claim 1 further comprising encapsulating the light emitting device with an encapsulant.

7. The method recited in claim 1 wherein the lens is glass or plastic.

8. The method recited in claim 1 wherein the lens comprises a second concave surface coated with optical material comprising phosphors, dyes, diffusants, or fluorescent polymers.

9. The method recited in claim 1 further comprising:

removing a crossbar portion of the leadframe strip leaving the light emitting die package with external portions of the leads; and

bending the external portions of the leads.