Packaged semiconductor light emitting devices having multiple optical elements and methods of forming the same

• US 8,822,245 B2
• Filed: 06/01/2012
• Issued: 09/02/2014
• Est. Priority Date: 02/12/2007
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Medendorp, Nicholas W. Jr.
• Primary Examiner(s): FERNANDES, ERROL V
• Application Number:
  US13/486,223
• Publication Number:
  US 20120235180A1
• Time in Patent Office: 823 Days
• Field of Search: 257/89, 257/98, 257/99, 257/79, 257/82, 438/26, 438/29, 438/27
• US Class Current: 438/29
• CPC Class Codes: B29C 33/0022 Multi-cavity moulds B29C33/301 takes precedence
• CPC Class Codes: B29C 33/02 with incorporated heating or cooling means
• CPC Class Codes: B29C 43/021 characterised by the shape of the surface
• CPC Class Codes: B29C 43/18 incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles B29C43/206 takes precedence
• CPC Class Codes: B29L 2011/0016 Lenses
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 33/52 Encapsulations

Abstract

Methods of packaging a semiconductor light emitting device include providing a substrate having the semiconductor light emitting device on a front face thereof. A first optical element is formed from a first material on the front face proximate the semiconductor light emitting device but not covering the semiconductor light emitting device and a second optical element is formed from a second material, different from the first material, over the semiconductor light emitting device and the first optical element. Packaged semiconductor light emitting devices are also provided.

Claims

1. A method of packaging a semiconductor light emitting device, comprising:

providing a substrate having the semiconductor light emitting device on a front face thereof;

forming a first optical element from a first material on the front face proximate the semiconductor light emitting device using a process other than compression molding;

forming a second optical element from a second material, different from the first material, over the semiconductor light emitting device and the first optical element by compression molding the second optical element without leaving a gap between the first optical element and the second optical element, wherein the second optical element is formed to have a bi-axially symmetric shape centered over and surrounding the semiconductor light emitting device, wherein the bi-axially symmetric shape comprises a dome, and wherein the first optical element and the second optical element have different refractive indexes selected to provide a desired optical characteristic for the packaged semiconductor light emitting device;

removing the second material such that none of the second material remains outside of the dome; and

leaving an upper surface of the second optical element in contact with air in the packaged semiconductor light emitting device.

2. The method of claim 1, wherein the substrate includes a plurality of semiconductor light emitting devices on the front face thereof and wherein forming the first optical element and forming the second optical element comprise:

forming a plurality of first optical elements using a process other than compression molding over respective ones of the plurality of semiconductor light emitting devices; and

forming a plurality of second optical elements over respective ones of the plurality of semiconductor light emitting devices and first optical elements using compression molding, wherein respective ones of the plurality of second optical elements have different bi-axially symmetric shapes selected to provide a desired optical performance characteristic.

3. The method of claim 2, wherein forming a plurality of second optical elements comprises forming a plurality of second optical elements separated from each other.

4. The method of claim 2, wherein forming a plurality of second optical elements comprises forming a plurality of second optical elements such that the plurality of second optical elements are not connected to each other by the second material.

5. The method of claim 1, wherein forming the second optical element comprises forming the dome such that a bottom of the dome contacts the substrate.