Light emitting diode package with metal reflective layer and method of manufacturing the same

• US 7,687,292 B2
• Filed: 05/23/2008
• Issued: 03/30/2010
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Park, Jung Kyu, Han, Seong Yeon, Lee, Seon Goo, Han, Kyung Taeg
• Primary Examiner(s): Bryant; Kiesha R
• Assistant Examiner(s): Yang; Minchul
• Application Number:
  US12/153,719
• Publication Number:
  US 20080233666A1
• Time in Patent Office: 676 Days
• Field of Search: 438/26, 438/29, 438/33, 257/E21.499, 257/E21.502, 257/E21.503
• US Class Current: 438/33
• 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 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• 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 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 2924/12041 LED
• CPC Class Codes: H01L 2924/15787 Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

The invention relates to an LED package having a metal reflective layer for focusing and emitting light through a side of the package, and a manufacturing method of the same. The LED package includes a substrate with an electrode formed thereon, a light emitting diode chip disposed on the substrate, and an encapsulant covering the LED chip and the substrate to protect the LED chip. The LED package also includes a metal reflective layer surrounding side surfaces of the encapsulant to form a light transmitting surface on a top surface of the encapsulant. The invention minimizes light loss, improves luminance, can be mass-produced as a PCB type, and adopts EMC transfer molding to minimize irregular color distribution, thereby improving optical quality.

Claims

1. A method of manufacturing a light emitting diode package for emitting light from a light emitting diode chip in one direction, comprising steps of:

providing a substrate with an electrode formed thereon;

disposing a plurality of light emitting diode chips on the substrate;

forming an encapsulant on the substrate to encapsulate the light emitting diode chips;

removing portions of the encapsulant to divide the encapsulant into each unit light emitting diode package;

forming a reflective layer in the same shape as the removed portions of the encapsulant by filling the removed portions of the encapsulant with a reflective material; and

cutting the reflective layer and the substrate into the each unit light emitting diode package.

2. The method according to claim 1, wherein the step of forming an encapsulant comprises Epoxy Molding Compound (EMC) transfer molding of transparent epoxy molding compound with phosphor mixed therein.

3. The method according to claim 1, wherein the step of forming a reflective layer comprises depositing or plating metal selected from a group consisting of Al, Au, Ag, Ni, W, Ti and Pt.

4. The method according to claim 1, wherein the step of forming a reflective layer comprises forming a sputtered layer made of highly reflective metal around an outer surface of the encapsulant via vacuum sputtering, and removing a portion of the sputtered layer via polishing, thereby forming a light transmitting surface.

5. The method according to claim 2, wherein the EMC transfer molding for forming an encapsulant comprises inserting the substrate and the plurality of light emitting diode chips in a mold maintained at a temperature ranging from 150°

C. to 190°

C., inserting a solid mixture of transparent epoxy molding compound and phosphor maintained at a temperature ranging from 80°

C. to 90°

C. into the mold, thereby changing a phase of the mixture of transparent EMC and phosphor from solid to liquid to form an encapsulant.

6. The method according to claim 5, further comprising a step of compressing the solid mixture of transparent epoxy molding compound and phosphor into the mold at 500 psi to 1000 psi.

7. The method according to claim 6, wherein the mixture is cured into the encapsulant without precipitation of the phosphor in the transparent epoxy molding compound in order to minimize irregular color distribution.