LIGHT EMITTING DIODE PACKAGE AND METHOD OF MANUFACTURE

• US 20120223351A1
• Filed: 03/06/2012
• Published: 09/06/2012
• Est. Priority Date: 03/06/2011
• Status: Active Grant

• Current Assignee: LED Wafer Solutions LLC
• Original Assignee: Viagan Limited
• Inventors: Margalit, Mordehai
• Granted Patent: US 8,952,405 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0025 relating to coatings
• 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 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/0012 p-i-n devices
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/385 the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/647 : the elements conducting electric current to or from the semiconductor body

Abstract

A light emitting diode (LED) device and packaging for same is disclosed. In some aspects, the LED is manufactured using a vertical configuration including a plurality of layers. Certain layers act to promote mechanical, electrical, thermal, or optical characteristics of the device. The device avoids design problems, including manufacturing complexities, costs and heat dissipation problems found in conventional LED devices. Some embodiments include a plurality of optically permissive layers, including an optically permissive cover substrate or wafer stacked over a semiconductor LED and positioned using one or more alignment markers.

Claims

1. A light emitting device, comprising:

a semiconductor LED including doped and intrinsic regions thereof;

a first surface of said semiconductor LED being metallized with an electrically conducting metallization layer over at least a portion of said first surface;

an optically permissive layer proximal to a second surface of said semiconductor LED, said first and second surfaces of said semiconductor LED being on opposing faces thereof;

an optically definable material proximal to or within said optically permissive layer that affects an optical characteristic of emitted light passing therethrough; and

an optically permissive cover substrate covering at least a portion of the above components.

2. The light emitting device of claim 1, further comprising a lens covering at least a portion of said optically transmissive cover substrate.

3. The light emitting device of claim 1, further comprising at least one recess formed into said semiconductor LED to a depth allowing electrical connection between a first doped layer of said semiconductor LED and a first external driving electrode.

4. The light emitting device of claim 1, further comprising a passivation layer proximal to said first surface of said semiconductor LED, which is substantially electrically non-conductive yet provided with at least a pair of apertures for connection of conducting electrodes thereto.

5. The light emitting device of claim 4, said passivation layer further comprising a shaped edge configured to reflect light generated by said light emitting device outwardly therefrom.

6. The light emitting device of claim 1, further comprising an optically permissive adhesive layer coupling said optically permissive layer and said optically definable material.

7. The light emitting device of claim 1, further comprising a mechanical offsetting member providing a dimensional spacing between said optically permissive layer and said optically permissive cover.

8. The light emitting device of claim 1, further comprising at least one alignment mark indicative of a required position of said device with respect to said optically permissive cover in a manufacturing substrate that includes said optically permissive cover.

9. A method for making a light emitting device, the method comprising:

forming a plurality of doped layers in a light emitting device (LED) disposed on an optically permissive layer;

forming a recess in said LED so as to allow electrical contact with a first doped layer of said LED at a depth of said first doped layer in said LED;

metallizing at least a portion of a face of said LED so as to form a metallization layer provide electrical contact with said first doped layer and a second doped layer of said LED proximal to said face thereof; and

using an optically permissive adhesive to mechanically secure said optically permissive layer to an optically permissive cover substrate.

10. The method of claim 9, further comprising applying an electrically isolating passivation layer to said metallization layer, and further providing at least a pair of apertures in said passivation layer for electrical coupling of a corresponding pair of biasing electrodes with corresponding first and second doped layers of said LED.

11. The method of claim 9, further comprising placing one or more alignment marks on said LED so as to permit proper positioning of said LED with respect to said optically permissive cover substrate.