Direct-type backlight unit having surface light source

1. A direct-type backlight unit comprising:

a board having upper and lower surfaces defining a thickness therebetween; and

a plurality of unit light sources mounted on the board,

wherein each of the unit light sources comprises:

a wiring pattern formed on the board; and

a light emitting device disposed on the wiring pattern to electrically connect thereto;

a non-conductive side wall surrounding, without interruption, the light emitting device at a predetermined interval therefrom, the non-conductive side wall having a height lower than that of the light emitting device;

an encapsulant formed in a dome shape inside the side wall, the encapsulant comprising a transparent resin or a phosphor-mixed transparent resin; and

an opaque layer or a light diffusing layer formed on an upper end portion of the encapsulant, bounded by an area corresponding to the light emitting device, located in a vertical upward direction of the light emitting device and blocks light generated from the light emitting device from traveling in an upward direction to prevent a bright light spot from forming,

wherein the non-conductive side wall has a ring shaped structure with a through hole formed inside thereof and blocks a resin dispensed inside the non-conductive side wall from spreading out to form the dome shaped encapsulant.

2. A direct-type backlight unit comprising:

a board having upper and lower surfaces defining a thickness therebetween; and

a plurality of unit light sources mounted on the board,

wherein each of the unit light sources comprises;

a wiring pattern formed on the board; and

a light emitting device disposed on the wiring pattern to electrically connect thereto;

a non-conductive side wall surrounding, without interruption, the light emitting device on the hoard at a predetermined interval therefrom, the non-conductive side wall having a height lower than that of the light emitting device;

an encapsulant formed in a dome shape inside the side wall, the encapsulant comprising a transparent resin or a phosphor-mixed transparent resin; and

an opaque layer formed on an upper end portion of the encapsulant located in a vertical upward direction of the light emitting device and blocks light generated from the light emitting device from travelling in an upward direction to prevent a bright light spot from forming,

wherein the non-conductive side wall comprises a plurality of coating layers having an identical width, and

wherein the non-conductive side wall has a ring shaped structure with a through hole formed inside thereof and blocks a resin dispensed inside the non-conductive side wall from spreading out to form the dome shaped encapsulant.

3. The direct-type backlight unit according to claim 2 , wherein the opaque layer is bounded by an area corresponding to the light emitting device.

4. A direct-type backlight unit comprising:

a board having upper and lower surfaces defining a thickness therebetween; and

a plurality of unit light sources mounted on the board,

wherein each of the unit light sources comprises:

a wiring pattern formed on the board; and

a light emitting device disposed on the wiring pattern to electrically connect thereto;

a non-conductive side wall surrounding, without interruption, the light emitting device at a predetermined interval therefrom, the non-conductive side wall being constructed of a plurality of coating layers and having a height lower than that of the light emitting device; and

an encapsulant formed in a dome shape inside the side wall,

wherein the side wall has an outer wall surface inclined toward an inner wall surface in such a way that the side wall has a width decreasing toward an apex.

5. The direct-type backlight unit according to claim 4 , wherein the encapsulant comprises a transparent resin or a phosphor-mixed transparent resin.

6. The direct type backlight unit according to any one of claims 1 , 2 and 4 , wherein the wiring pattern in each of the unit light sources comprises:

upper terminals formed on the upper surface of the board where the light emitting device is disposed to be electrically connected to the light emitting device;

lower terminals formed on the lower surface of the board; and

internal connectors extending through the board to connect the upper and lower terminals together.

7. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein the light emitting device is electrically connected to the wiring pattern by wire bonding.

8. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein the light emitting device is electrically connected to the wiring pattern by flip chip bonding.

9. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein the side wall has a width that is 1.5% to 3% of a diameter of the encapsulant.

10. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein the side wall has a height that is 1% to 1.5% of a diameter of the encapsulant.

11. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein the encapsulant has a height that is 25% to 35% of a diameter thereof.

12. The direct-type backlight unit according to claim 11 , wherein the encapsulant has a height that is ⅓ of a diameter thereof.

13. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein each of the unit light sources comprises at least two of the light emitting devices mounted inside the side wall.

14. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein some of the encapsulants in the light sources comprise a transparent resin and the other encapsulants comprise a phosphor-mixed transparent resin,

wherein the encapsulants comprising the transparent resin and the encapsulants comprising the phosphor-mixed transparent resin are mixed together.

15. The direct-type backlight unit according to any one of claims 1 , 2 and 4 , wherein the inside surface of the non-conductive side wall encircles and is in direct contact with an outside surface of the lower portion of the dome-shaped encapsulant.