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

• US 20080233666A1
• Filed: 05/23/2008
• Published: 09/25/2008
• 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: Han, Seong Yeon, Lee, Seon Goo, Han, Kyung Taeg, Park, Jung Kyu
• Granted Patent: US 7,687,292 B2
• Time in Patent Office: Days
• US Class Current: 438/27
• 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

1-5. -5. (canceled)

6. 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 light emitting diode chip on the substrate;

forming an encapsulant on the light emitting diode chip and the substrate;

cutting the encapsulant; and

forming a reflective layer on the encapsulant.

7. The method according to claim 6, wherein the step of forming an encapsulant comprises Epoxy Molding Compound (EMC) transfer molding of transparent epoxy molding compound with phosphor mixed therein.

8. The method according to claim 6, wherein the step of cutting the encapsulant comprises dicing or etching only the encapsulant to obtain a desired form of encapsulant for the light emitting diode chip, and exposing a pattern electrode plated on the substrate.

9. The method according to claim 6, 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.

10. The method according to claim 6, 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.

11. The method according to claim 6, wherein the step of forming a reflective layer includes cutting the plated reflective layer and the substrate or the sputtered reflective layer and the substrate into individual light emitting diode packages.

12. The method according to claim 7, wherein the EMC transfer molding for forming an encapsulant comprises inserting the substrate and the light emitting diode chip 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.

13. The method according to claim 12, 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.

14. The method according to claim 13, 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.