Light source module and backlight unit having the same

Patent metadata

Field	Value
Publication number	US-11056622-B2
Application number	US-201916256712-A
Country	US
Kind code	B2
Filing date	Jan 24, 2019
Priority date	May 9, 2013
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

A backlight unit including a light guide plate, a first light source and a second light source adjacent to the light guide plate, each of the light sources including a light emitting diode chip including a substrate and a semiconductor stack disposed on the substrate, a wavelength conversion layer covering the light emitting diode chip, and a plurality of reflectors disposed on at least two opposing side surfaces of the light emitting diode chip, in which at least a portion of the wavelength conversion layer of the first light source facing the second light source is exposed by the reflectors.

First claim

What is claimed is:

1. A backlight unit comprising:
a light guide plate; and
a first light source and a second light source adjacent to the light guide plate, each of the light sources comprising:
a light emitting diode chip comprising a growth substrate and a semiconductor stack disposed on the growth substrate;
a wavelength conversion layer directly disposed on the light emitting diode chip and extending to cover a side surface of the semiconductor stack of the light emitting diode chip;
a plurality of reflectors disposed on at least two opposing side surfaces of the light emitting diode chip; and
electrode pads disposed on a lower surface of the light emitting diode chip, the electrode pads not overlapping the reflectors,

wherein at least a portion of the wavelength conversion layer of the first light source facing the second light source is exposed by the reflectors, and
wherein an upper surface of at least one of the reflectors is flush with an upper surface of the wavelength conversion layer.

2. The backlight unit of claim 1 , wherein the first and second light sources face each other through a surface on which the reflectors are not disposed, respectively.

3. The backlight unit of claim 1 , wherein the reflectors comprise a first reflector and a second reflector, the first and second reflectors disposed on a substantially same plane as top and bottom surfaces of the light guide plate, respectively.

4. The backlight unit of claim 1 , wherein the first and second light sources are disposed along a longitudinal direction of the growth substrate with a first interval therebetween.

5. The backlight unit of claim 4 , wherein:
the wavelength conversion layer has a first surface facing a light entering surface of the light guide plate, and second side surfaces opposing each other; and
the first surface and the second side surfaces are exposed by the reflectors.

6. The backlight unit of claim 1 , wherein:
the wavelength conversion layer includes a first region disposed on an upper surface of the light emitting diode chip, and a second region disposed on side surfaces of the light emitting diode chip; and
the first region and the second region have the same thickness.

7. The backlight unit of claim 1 , wherein:
the wavelength conversion layer includes a first region disposed on an upper surface of the light emitting diode chip, and a second region disposed on side surfaces of the light emitting diode chip; and
the first region has a greater thickness than the second region.

8. The backlight unit of claim 1 , wherein one end of the reflector faces the light guide plate and the other end thereof faces the growth substrate.

9. The backlight unit of claim 1 , wherein a surface of the wavelength conversion layer interfacing the reflector has a convex-concave pattern.

10. The backlight unit of claim 1 , wherein the reflector comprises at least one of a resin coated with a reflective layer and a resin including a reflective material.

11. The backlight unit of claim 1 , wherein:
each of the semiconductor stacks comprises:
a growth substrate;
a first conductive type semiconductor layer formed on the growth substrate;
a mesa formed on the first conductive type semiconductor layer and including an active layer and a second conductive type semiconductor layer;
an electrode formed on the mesa;
a current spreading layer on the mesa and the first conductive type semiconductor layer; and
a lower insulation layer formed between the mesa and the current spreading layer and insulating the current spreading layer form the mesa;
an upper insulation layer formed on the current spreading layer; and
a first pad and a second pad formed on the upper insulation layer;

the first pad is electrically connect to the current spreading layer; and
the second pad is electrically connect to the electrode.

12. A backlight unit comprising:
a light guide plate having a substantially flat shape; and
at least one light source disposed adjacent to the light guide plate, the light source comprising:
a light emitting diode chip comprising a plurality of semiconductor stacks;
a wavelength conversion layer directly disposed on the light emitting diode chip and extending to cover a side surface of each of the semiconductor stacks, respectively;
a reflective unit disposed on at least one side surfaces of the wavelength conversion layer, and having an upper surface flush with an upper surface of the wavelength conversion layer; and
electrode pads disposed on a lower surface of the light emitting diode chip, the electrode pads not overlapping the reflective unit,
wherein each of the semiconductor stacks comprises:
a growth substrate;
a first conductive type semiconductor layer formed on the growth substrate;
a mesa formed on the first conductive type semiconductor layer and including an active layer and a second conductive type semiconductor layer;
an electrode formed on the mesa;
a current spreading layer on the mesa and the first conductive type semiconductor layer; and
a lower insulation layer formed between the mesa and the current spreading layer and insulting the current spreading layer form the mesa;
an upper insulation layer formed on the current spreading layer; and
a first pad and a second pad formed on the upper insulation layer;

wherein the first pad is electrically connect to the current spreading layer, and
wherein the second pad is electrically connect to the electrode.

13. The backlight unit of claim 11 , wherein the reflective unit comprises:
a first reflector disposed on a first surface of the light source, the first surface being disposed on a substantially the same plane as an upper surface of the light guide plate; and
a second reflector disposed on a second surface of the light source, the second surface being disposed on a substantially the same plane as a bottom surface of the light guide plate.

14. The backlight unit of claim 12 , further comprising a printed circuit board (PCB),
wherein:
the light source is provided in plural on the PCB; and
the reflective unit of each light source covers each side surface of the wavelength conversion layer that contacts the PCB and is substantially parallel to a longitudinal direction of the PCB.

15. The backlight unit of claim 12 , wherein the first and second reflectors are not disposed on a surface of the light source that faces an adjacent light source.

16. The backlight unit of claim 11 , wherein a surface of the wavelength conversion layer interfacing the reflective unit has a convex-concave pattern.

17. The backlight unit of claim 14 , wherein the reflective unit comprises at least one of a resin coated with a reflective layer and a resin including a reflective material.

18. The backlight unit of claim 11 , wherein a lower surface of the reflective unit is flush with a lower surface of the wavelength conversion layer.

Assignees

• Seoul Semiconductor Co Ltd

Inventors

• Song Young Jun
• Kim Da Hye
• Jung Seoung Ho

Classifications

• H10H20/856

  Reflecting means · CPC title

• H10H20/8514 Primary

  characterised by their shape, e.g. plate or foil · CPC title

• G02B6/0073 Primary

  Light emitting diode [LED] · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title

• H01L33/505 Primary

  Electricity · mapped topic