Light emitting device and manufacturing method thereof

• US 9,997,676 B2
• Filed: 09/19/2016
• Issued: 06/12/2018
• Est. Priority Date: 05/14/2014
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Genesis Photonics Inc.
• Inventors: Hung, Cheng-Wei, Hung, Chin-Hua, Du, Long-Chi, Chang, Jui-Fu, Kuo, Po-Tsun, Lee, Hao-Chung, Lin, Yu-Feng
• Primary Examiner(s): AMER, MOUNIR S
• Application Number:
  US15/268,654
• Publication Number:
  US 20170005238A1
• Time in Patent Office: 631 Days
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 21/561 Batch processing
• CPC Class Codes: H01L 21/568 Temporary substrate used as encapsulation process aid H01L21/4832 and H01L21/566 take precedence
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68331 of passive members, e.g. die mounting substrate
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/18 High density interconnect [HDI] connectors; Manufacturing methods related thereto
• CPC Class Codes: H01L 2224/19 Manufacturing methods of high density interconnect preforms
• CPC Class Codes: H01L 2224/32105 the layer connector connecting bonding areas being not aligned with respect to each other
• CPC Class Codes: H01L 2224/32106 the layer connector connecting one bonding area to at least two respective bonding areas
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 2224/83 using a layer connector
• CPC Class Codes: H01L 2224/8392 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2224/9222 Sequential connecting processes
• CPC Class Codes: H01L 2224/96 the devices being encapsulated in a common layer, e.g. neo-wafer or pseudo-wafer, said common layer being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/19 Manufacturing methods of high density interconnect preforms
• CPC Class Codes: H01L 24/20 Structure, shape, material or disposition of high density interconnect preforms
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• CPC Class Codes: H01L 24/96 : the devices being encapsulated in a common layer, e.g. neo-wafer or pseudo-wafer, said common layer being separable into individual assemblies after connecting
• CPC Class Codes: H01L 24/97 : the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 25/0753 : the devices being arranged next to each other
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/18162 : of a chip with build-up interconnect
• CPC Class Codes: H01L 2933/0016 : relating to electrodes
• CPC Class Codes: H01L 2933/0025 : relating to coatings
• CPC Class Codes: H01L 2933/0041 : relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 : relating to encapsulations
• CPC Class Codes: H01L 33/38 : with a particular shape
• CPC Class Codes: H01L 33/46 : Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• 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 33/56 : Materials, e.g. epoxy or silicone resin

Abstract

A light emitting device includes a wavelength conversion layer, at least one light emitting unit and a reflective protecting element. The wavelength conversion layer has an upper surface and a lower surface opposite to each other. The light emitting unit has two electrode pads located on the same side of the light emitting unit. The light emitting unit is disposed on the upper surface of the wavelength conversion layer and exposes the two electrode pads. The reflective protecting element encapsulates at least a portion of the light emitting unit and a portion of the wavelength conversion layer, and exposes the two electrode pads of the light emitting unit.

Claims

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

providing a wavelength conversion layer;

disposing a plurality of light emitting units arranged at intervals on the wavelength conversion layer, and exposing two electrode pads of each light emitting unit;

forming a plurality of trenches on the wavelength conversion layer by removing a portion of the wavelength conversion layer, wherein the trenches are located between the light emitting units, and a depth of each trench is smaller than a thickness of the wavelength conversion layer;

forming a reflective protecting element on the wavelength conversion layer and between the light emitting units, and filling the reflective protecting element in the trenches, wherein the reflective protecting element exposes the electrode pads of the light emitting units; and

performing a cutting process by cutting the wavelength conversion layer and the reflective protecting element along the trenches to form a plurality of light emitting devices, wherein a lateral surface of each light emitting device exposes a portion of the wavelength conversion layer and a profile of each trench filled with a portion of the reflective protecting element.

2. The manufacturing method of the light emitting device as claimed in claim 1, wherein the depth of each trench is at least a half of the thickness of the wavelength conversion layer.

3. The manufacturing method of the light emitting device as claimed in claim 1 further comprising:

forming a light transmissible layer on the wavelength conversion layer after disposing the light emitting units arranged at intervals on the wavelength conversion layer.

4. The manufacturing method of the light emitting device as claimed in claim 1 further comprising:

forming a light transmissible layer on the wavelength conversion layer before disposing the light emitting units arranged at intervals on the wavelength conversion layer.

5. The manufacturing method of the light emitting device as claimed in claim 1, wherein the reflective protecting element further comprises a reflective surface in contact with the light emitting unit.

6. The manufacturing method of the light emitting device as claimed in claim 5, wherein the reflective surface of the reflective protecting element is a flat surface or a curved surface.

7. The manufacturing method of the light emitting device as claimed in claim 1, wherein the wavelength conversion layer further comprises a low concentration fluorescent layer and a high concentration fluorescent layer, the light emitting units are disposed on the high concentration fluorescent layer.