LIGHT SOURCE MODULE, FABRICATION METHOD THEREFOR, AND BACKLIGHT UNIT INCLUDING THE SAME

• US 20150085527A1
• Filed: 09/26/2014
• Published: 03/26/2015
• Est. Priority Date: 09/26/2013
• Status: Abandoned Application

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Nam, Ki Bum, Jung, Seoung Ho, Han, Yu Dae, Lee, Chung Hoon, Choi, Hyuck Jung
• Application Number:
  US14/498,086
• Publication Number:
  US 20150085527A1
• Time in Patent Office: Days
• US Class Current: 362/612
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• 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 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light source module, a fabrication method therefore, and a slim backlight unit including the same. The light source module includes a light emitting diode (LED) chip electrically connected to a substrate through a lower surface thereof, a wavelength conversion layer formed on the LED chip and enclosing at least the light exit face of the LED chip, and a reflector formed on a region of the LED chip excluding the light exit face.

Claims

1. A light source module comprising:

a light emitting diode (LED) chip electrically connected to a substrate through a lower surface thereof and comprising a laterally disposed light exit face through which light of the LED chip is emitted therethrough;

a wavelength conversion layer disposed on the LED chip and covering at least the light exit face; and

a reflector disposed on the LED chip and exposing the light exit face.

2. The light source module of claim 1, further comprising an underfill interposed between the substrate and the LED chip and comprising a reflective material.

3. The light source module of claim 2, wherein the reflective material comprises one material selected from the group consisting of TiO₂, SiO₂, ZrO₂, PbCO₃, PbO, Al₂O₃, ZnO, Sb₂O₃, and combinations thereof.

4. The light source module of claim 2, wherein the underfill comprises a fluorescent material.

5. The light source module of claim 1, wherein the LED chip is mounted on the substrate by flip-chip bonding or surface mount technology (SMT).

6. The light source module of claim 1, wherein the LED chip comprises:

a first semiconductor layer doped with a first conductivity-type impurity;

an active layer formed under the first semiconductor layer;

a second semiconductor layer doped with a second conductivity-type impurity and formed under the active layer;

a first electrode electrically connected to the first semiconductor layer;

a second electrode electrically connected to the second semiconductor layer;

a first electrode pad electrically connected to the first electrode; and

a second electrode pad electrically connected to the second electrode,

wherein the LED chip is electrically connected to the substrate through the first and second electrode pads.

7. A backlight unit comprising:

a light guide plate; and

a light source module disposed on at least one side of the light guide plate and configured to emit light,

wherein the light source module comprises;

a light emitting diode (LED) chip electrically connected to a substrate through a lower surface thereof and comprising a laterally disposed light exit face through which light of the LED chip is emitted;

a wavelength conversion layer disposed on the LED chip and covering at least the light exit face; and

a reflector disposed on the LED chip and exposing the light exit face.

8. The backlight unit of claim 7, wherein the light source module further comprises an underfill disposed between the substrate and the LED chip and comprising a reflective material.

9. The backlight unit of claim 8, wherein the underfill comprises a fluorescent material.

10. The backlight unit of claim 7, wherein the LED chip is mounted on the substrate by flip-chip bonding or surface mount technology (SMT).

11. A method of fabricating a light source module, comprising:

fabricating a light emitting diode (LED) chip including a lateral light exit face through which light of the LED chip is emitted;

forming a wavelength conversion layer on the LED chip to cover at least the light exit face of the LED chip; and

forming a reflector on the LED chip that exposes the light exit face.

12. The method of claim 11, wherein forming the reflector comprises:

forming the reflector on an upper surface and a side surface of the LED chip; and

exposing the wavelength conversion layer by removing the reflector from a region corresponding to the light exit face, if the reflector is formed on the light exit face.

13. The method of claim 12, wherein exposing the wavelength conversion layer comprises cutting the reflector to expose the light exit face.

14. The method of claim 11, further comprising forming an underfill comprising a reflective material, between the substrate and the LED chip, after forming the reflector.

15. The method of claim 14, wherein forming the underfill comprises:

forming a dam placed on the substrate to adjoin the light exit face of the LED chip;

injecting the underfill into a region between the substrate and the LED chip; and

removing the dam after forming the underfill.

16. The method of claim 11, further comprising electrically connecting the LED chip to a substrate,

wherein the LED chip is mounted on the substrate by flip-chip bonding or surface mount technology (SMT).

17. The method of claim 11, wherein fabricating the LED chip comprises:

forming a first semiconductor layer doped with a first conductivity-type impurity;

forming an active layer under the first semiconductor layer;

forming a second semiconductor layer doped with a second conductivity-type impurity under the active layer;

forming a first electrode electrically connected to the first semiconductor layer;

forming a second electrode electrically connected to the second semiconductor layer;

forming a first pad electrically connected to the first electrode; and

forming a second pad electrically connected to the second electrode.