Packaged semiconductor light emitting devices having multiple optical elements

• US 7,709,853 B2
• Filed: 02/12/2007
• Issued: 05/04/2010
• 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): Graybill; David E
• Application Number:
  US11/705,305
• Publication Number:
  US 20080194061A1
• Time in Patent Office: 1,177 Days
• Field of Search: None
• US Class Current: 257/99
• CPC Class Codes: B29C 33/0022 Multi-cavity moulds B29C33/301 takes precedence
• 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 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 2924/3011 Impedance
• CPC Class Codes: H01L 33/52 Encapsulations

Abstract

Methods of packaging semiconductor light emitting devices 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. 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. The first optical element and/or the second optical element are formed by compression molding the respective optical element.

Claims

1. A packaged semiconductor light emitting device, comprising:

a substrate;

a semiconductor light emitting device mounted on a front face of the substrate;

a first optical element on the front face of the substrate proximate the semiconductor light emitting device; and

a second optical element on the front face of the substrate over the semiconductor light emitting device and the first optical element, wherein the first optical element and/or the second optical element are molded on the front face of the substrate and wherein the first optical element and the second optical element extend over a portion of the front face of the substrate and do not extend over a second face of the substrate.

2. The device of claim 1, wherein the semiconductor light emitting device is mounted flush on the front face of the substrate without a reflector cavity and wherein the second optical element is molded to and extends from the front face of the substrate in a region surrounding the semiconductor light emitting device and extends over the semiconductor light emitting device.

3. The device of claim 1, wherein the compression molded optical elements comprise silicone lenses.

4. The device of claim 1, wherein the semiconductor light emitting device comprises a plurality of semiconductor light emitting devices and wherein the compression molded optical elements comprise a plurality of compression molded optical elements over corresponding ones of the semiconductor light emitting devices.

5. The device of claim 1, further comprising a contact on the front face of the substrate that is electrically coupled to the semiconductor light emitting device, wherein the first optical element and/or the second optical element extend over a first portion of the contact on the front face of the substrate and do not extend over a second portion of the contact.

6. The device of claim 5, wherein the semiconductor light emitting device comprises a plurality of semiconductor light emitting devices and the contact comprises a plurality of contacts on the front face electrically coupled to respective ones of the semiconductor light emitting devices and wherein the compression molded optical elements comprise a plurality of compression molded optical elements over corresponding ones of the semiconductor light emitting devices.

7. The device of claim 6, wherein the compression molded optical elements comprise silicone lenses.

8. The device of claim 5, further comprising a wire bond that electrically couples the semiconductor light emitting device to a contact portion of the substrate and wherein at least one of the compression molded optical elements directly contacts the wire bond.

9. The device of claim 1, 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.

10. The device of claim 1, wherein the first optical element and the second optical element are configured to provide a selected viewing angle to the packaged semiconductor light emitting device.

11. The device of claim 1, wherein the first optical element comprises a first material having an adhesion characteristic selected to facilitate adhesion of the first optical element to the substrate during compression molding and/or to limit stress applied to the light emitting device and/or a wire bond coupled thereto during thermal cycling of the packaged semiconductor light emitting device.

12. The device of claim 1, wherein the first optical element comprises a first material and the second optical element comprises a second material and wherein the first material and/or the second material include a phosphor and wherein the first material and/or the second material comprise silicone.

13. The device of claim 1, wherein the front face of the substrate is planar and the first optical element and the second optical element are both located entirely on the planar front face.

14. The device of claim 6, wherein the front face of the substrate is planar and the first optical element and the second optical element are both located entirely on the planar front face.

15. The device of claim 1, wherein the first optical element and/or the second optical element comprise compression molded optical elements.

16. A packaged semiconductor light emitting device, comprising:

a substrate;

a semiconductor light emitting device mounted on a front face of the substrate;

a contact on the front face of the substrate that is electrically coupled to the semiconductor light emitting device;

a first optical element on the front face of the substrate proximate the semiconductor light emitting device; and

a second optical element on the front face of the substrate over the semiconductor light emitting device and the first optical element, wherein the first optical element and/or the second optical element extend over a first portion of the contact on the front face of the substrate and do not extend over a second portion of the contact.

17. The device of claim 16, wherein the first optical element and/or the second optical element comprise compression molded optical elements.