Circuit Board Assembly and Backlight Module Comprising the Same

• US 20090103302A1
• Filed: 04/04/2008
• Published: 04/23/2009
• Est. Priority Date: 10/19/2007
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Lin, Yu-Kai, Chang, Ya-hsien
• Granted Patent: US 7,922,362 B2
• Time in Patent Office: Days
• US Class Current: 362/257
• CPC Class Codes: H05K 1/0206 by printed thermal vias
• CPC Class Codes: H05K 1/0207 using internal conductor planes parallel to the surface for thermal conduction, e.g. power planes
• CPC Class Codes: H05K 2201/0175 Inorganic, non-metallic layer, e.g. resist or dielectric for printed capacitor
• CPC Class Codes: H05K 2201/09309 Core having two or more power planes; Capacitive laminate of two power planes
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 3/0061 onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673

Abstract

A circuit board assembly and a backlight module comprising the circuit board assembly are provided. The circuit board assembly has a first surface and a second surface opposite to the first surface, and further comprises at least one laminate, a first conductive wiring structure and a coating. The first conductive wiring structure is formed on the first surface. The coating is formed on the coating area of the second surface, wherein the coating can conduct heat and provide electric insulation. Thus, the circuit board assembly is adapted to outwardly conduct heat from the laminate through the second surface and to promote the heat dissipation efficiency of the circuit board assembly.

Claims

1. A circuit board assembly having a first surface and a second surface opposite to the first surface, the circuit board assembly further comprising:

at least one laminate;

a first conductive wiring structure formed on the first surface; and

a coating at least formed on the second surface at a coating area thereof, wherein the coating is thermo-conductive and electro-insulating, and is adapted to outwardly dissipate heat from the at least one laminate through the second surface.

2. The circuit board assembly as claimed in claim 1, wherein the coating is made of a material selected from the group comprising:

boron nitride, silicon carbide, aluminum nitride, beryllium nitride and the combination thereof.

3. The circuit board assembly as claimed in claim 2, wherein the circuit board assembly is formed with a through hole and has a thermo-conductive structure formed in the through hole to conduct heat from the first surface to the second surface.

4. The circuit board assembly as claimed in claim 3, further including a pad disposed on the first surface to substantially cover the through hole at a periphery thereof.

5. The circuit board assembly as claimed in claim 4, wherein the thermo-conductive structure is made of a thermo-conductive material, formed in the through hole and connected with the pad, and the thermo-conductive material is a metallic material comprising copper.

6. The circuit board assembly as claimed in claim 1, further including a second conductive wiring structure formed on the coating area of the second surface to overlay the second conductive wiring structure.

7. The circuit board assembly as claimed in claim 1, wherein the coating is further applied onto the first conductive wiring structure.

8. The circuit board assembly as claimed in claim 1, further including an insulation coating, at least being applied onto the first conductive wiring structure.

9. The circuit board assembly as claimed in claim 1, wherein the circuit board assembly is a printed circuit board.

10. The circuit board assembly as claimed in claim 1, wherein the at least one laminate includes a plurality of laminates which are sequentially stacked, and the circuit board assembly further comprises at least one electrode layer disposed between the plurality of laminates.

11. The circuit board assembly as claimed in claim 10, wherein the at least one electric layer comprises a plurality of electrode layers disposed between the plurality of laminates, in which the coating is applied between the electrode layers.

12. A backlight module, including

a bezel;

a light source; and

a circuit board assembly disposed on the bezel, the circuit broad assembly having a first surface and a second surface opposite to the first surface, wherein the second surface faces the bezel and the first surface is provided for the light source, the circuit broad assembly further including;

at least one laminate;

a first conductive wiring structure formed on the first surface; and

a coating at least formed on the second surface at a coating area thereof, wherein the coating is thermo-conductive and electro-insulting and is adapted to conduct heat from the at least one laminate through the second surface to the bezel.

13. The backlight module as claimed in claim 12, wherein the coating is made of a material selected from the group comprising:

boron nitride, silicon carbide, aluminum nitride, beryllium nitride and the combination thereof

14. The backlight module as claimed in claim 13, wherein the circuit board assembly is formed with at least one through hole and has at least one thermo-conductive structure formed in the at least one through hole to conduct heat from the first surface to the second surface.

15. The backlight module as claimed in claim 14, wherein the at least one through hole includes a first through hole, the at least one thermo-conductive structure includes a first thermo-conductive structure, and the circuit board assembly further includes a pad disposed on the first surface to substantially cover the through hole at a periphery thereof.

16. The backlight module as claimed in claim 15, wherein the thermo-conductive structure is made of a thermo-conductive material, formed in the through hole and connected with the pad, and the thermo-conductive material is a metallic material comprising copper.

17. The backlight module as claimed in claim 15, wherein the light source includes a conductive wiring connected with the pad, in which heat is conducted from the light source to the bezel through the first thermo-conductive structure and the coating.

18. The backlight module as claimed in claim 15, wherein the at least one through hole further includes a second through hole and the at least one thermo-conductive structure further includes a second thermo-conductive structure formed in the second through hole, the light source connected with the second thermo-conductive structure through a heat slug, whereby, heat is conducted to the bezel through the heat slug, the second conductive structure and the coating.

19. The backlight module as claimed in claim 15, wherein the circuit broad assembly further includes a second conductive wiring structure formed on the coating area of the second surface, on which the coating overlays the second conductive wiring structure.

20. The backlight module as claimed in claim 12, wherein the coating further is applied onto the first conductive wiring structure.

21. The backlight module as claimed in claim 12, wherein the circuit broad assembly further includes an insulation coating at least being applied onto the first conductive wiring structure.

22. The backlight module as claimed in claim 12, wherein the circuit board assembly is a printed circuit board.

23. The backlight module as claimed in claim 12, wherein the at least one laminate includes a plurality of laminates which are sequentially stacked, and the circuit board assembly further comprises at least one electrode layer disposed between the plurality of laminates.

24. The backlight module as claimed in claim 23, wherein the at least one electrode layer comprises a plurality of electrode layers disposed between the plurality of laminates, in which the coating is applied between the electrode layers.