Backlight unit having light emitting diodes and method for manufacturing the same

• US 7,427,145 B2
• Filed: 05/30/2006
• Issued: 09/23/2008
• Est. Priority Date: 05/30/2005
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Inventors: Yee, Young Joo, Jang, Jun Ho
• Primary Examiner(s): Lee; Jong-Suk (James)
• Assistant Examiner(s): MAY, ROBERT J
• Application Number:
  US11/442,396
• Publication Number:
  US 20060268567A1
• Time in Patent Office: 847 Days
• Field of Search: 362/800, 362/612, 362/555, 362/561, 362235-236, 257 98-100, 257/594, 349/95
• US Class Current: 362/236
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• 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: Y10S 362/80 Light emitting diode

Abstract

A backlight unit including a substrate disposed thereon with conductive lines, a plurality of light emitting diodes each bonded to an upper surface of the substrate and spaced a predetermined distance apart from the substrate, and electrically connected to the conductive lines of the substrate; a transparent resin encompassing the plurality of light emitting diodes and formed on the upper surface of the substrate, and an optical transmission arrangement disposed on an upper surface of the transparent resin. Further, the arrangement includes a first layer for preventing light emitted from the light emitting diodes from being totally reflected by allowing an incident angle of the light to be less than a threshold angle, and a second layer for diffusing and emitting the light.

Claims

1. A backlight unit having light emitting diodes comprising:

a substrate disposed thereon with first conductive lines;

a plurality of light emitting diodes each bonded to an upper surface of the substrate and spaced a predetermined distance apart from the substrate, and electrically connected to the first conductive lines of the substrate;

a transparent resin encompassing the plurality of light emitting diodes and formed on the upper surface of the substrate; and

optical transmission means disposed on an upper surface of the transparent resin, the means including first means for preventing light emitted from the light emitting diodes from being totally reflected by allowing an incident angle of the light to be less than a threshold angle, and second means for diffusing and emitting the light,

wherein the substrate is further formed thereon with a plurality of first grooves, and each floor surface of the plurality of first grooves is bonded to the light emitting diode, and

wherein each interior of the plurality of grooves is bonded to a sub-mount substrate formed thereon with a second groove, a floor surface of the second groove formed with a conductive pattern, and formed thereon with a second conductive line electrically connected to the conductive pattern, and wherein each light emitting diode is flip-chip bonded to the conductive pattern existing on the floor surface of the second groove of the sub-mount substrate, and the second conductive line of the sub-mount substrate and the corresponding first conductive line of the substrate are wire-bonded.

2. The unit as defined in claim 1, wherein the substrate is a metal substrate, and wherein the metal substrate is further formed thereon with an insulation layer, and the corresponding first conductive line of the substrate is formed on an upper surface of the insulation layer.

3. The unit as defined in claim 1, wherein a margin of the substrate further comprises a ring-shaped guide part, and wherein the transparent resin is transformed in such a manner that a liquid transparent resin is coated on an inside of the guide part and the coated transparent resin is hardened to become a solid transparent resin.

4. The unit as defined in claim 3, wherein an inner wall of the ring-shaped guide part is inclined.

5. The unit as defined in claim 1, further comprising:

a guide substrate formed therein with a plurality of through holes each correspondingly positioned to the plurality of light emitting diodes, and bonded to an upper surface of the substrate,

wherein the optical transmission means is disposed on an upper surface of the guide substrate, and

wherein the first means of the optical transmission means is a micro lens array sheet including a plurality of lenses, and the second means is a light guide plate in direct contact with the plurality of lenses of the micro lens array sheet.

6. The unit as defined in claim 5, wherein an inner wall of each through hole at the guide substrate is inclined.

7. The unit as defined in claim 5, wherein the substrate is a metal substrate, and wherein the metal substrate is further formed thereon with an insulation layer, and a conductive line of the substrate is formed on an upper surface of the insulation layer.

8. The unit as defined in claim 5, wherein the through holes of the guide substrate further comprise a transparent resin layer wrapping and coated on the light emitting diode.

9. The unit as defined in claim 5, wherein the the light guide plate is in direct contact with an opposite side of the micro lens array sheet including the plurality of lenses.

10. The unit as defined in claim 5, wherein the optical transmission means is configured in such a manner that the micro lens array sheet is positioned on the guide substrate with the plurality of lenses facing the guide substrate, and the light guide plate is positioned on the micro lens array sheet.

11. The unit as defined in claim 5, wherein the optical transmission means is configured in such a manner that the light guide plate is positioned on the guide substrate, and the micro lens array sheet is positioned on the light guide plate with the plurality of lenses facing the light guide plate.