WAVELENGTH CONVERTED LIGHT EMITTING DEVICE

• US 20160133803A1
• Filed: 01/18/2016
• Published: 05/12/2016
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Bierhuizen, Serge Joel Armand
• Granted Patent: US 10,868,224 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/6836 Wafer tapes, e.g. grinding or dicing support tapes adhesive tapes in general C09J7/20
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 2221/68336 involving stretching of the auxiliary support post dicing
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/52 Encapsulations

Abstract

Embodiments of the invention include a semiconductor structure comprising a light emitting layer. The semiconductor structure is attached to a support such that the semiconductor structure and the support are mechanically self-supporting. A wavelength converting material extends over the sides of the semiconductor structure and the support, wherein the wavelength converting material has a substantially uniform thickness over the top and sides of the semiconductor structure and the support.

Claims

1. A method comprising:

attaching a plurality of light emitting devices to a substrate, each light emitting device comprising a support attached to a semiconductor structure comprising a light emitting layer, wherein each light emitting device is mechanically self-supporting and neighboring devices are spaced apart on the substrate;

disposing a wavelength converting material over the plurality of light emitting devices, wherein the wavelength converting material extends over the sides of each semiconductor structure and support;

wherein disposing a wavelength converting material over the plurality of light emitting devices comprises pressing a pre-fabricated sheet of phosphor disposed in transparent binder material over the plurality of light emitting devices.

2. The method of claim 1 wherein each light emitting device has substantially vertical sidewalls.

3. The method of claim 1 further comprising:

attaching supports to a wafer of semiconductor structures to form a wafer of light emitting devices;

testing each light emitting device on the wafer of light emitting devices; and

dicing the wafer of light emitting devices.

4. The method of claim 3 wherein attaching a plurality of light emitting devices to a substrate comprises attaching only light emitting devices that meet a predetermined criterion.

5. The method of claim 4 wherein the predetermined criterion is peak emission wavelength range and disposing a wavelength converting material comprises disposing a wavelength converting material that is matched to the peak emission wavelength range.

6. The method of claim 1 wherein attaching a plurality of light emitting devices to a substrate comprises:

attaching a wafer of light emitting devices to handling tape;

dicing the wafer into a plurality of light emitting devices; and

stretching the handling tape to space the plurality of light emitting devices apart before disposing the wavelength converting material over the plurality of light emitting devices.

7. The method of claim 1 wherein disposing a wavelength converting material over the plurality of light emitting devices comprises molding wavelength converting material over each light emitting device.

8. The method of claim 1 wherein disposing a wavelength converting material over the plurality of light emitting devices comprises forming a wavelength converting material with a substantially uniform thickness over the top and sides of the semiconductor structure and the support.