# US 7,607,790 B2 · Backlighting apparatus and manufacturing process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,790 B2 - Document ID: US7607790B2 - Status: Granted - Kind: B2 - Application number: 11/640,587 - Filed: 2006-12-18 - Published: 2008-06-19 - Granted: 2009-10-27 - Earliest claimed: 2006-12-18 - Assignees: Hong Kong Applied Science and Technology Research Institute Company Limited - Inventors: Shou Lung Chen; Kwan Wah Ng; Ying Liu - Web page: https://patentgrep.com/patent/US7607790B2 ## CPC - H05K 1/0204: {using means for thermal conduction connection in the thickness direction of the substrate (H05K1/0207 takes precedence)} - G02F 1/133603: {with LEDs} - G02F 1/133605: {including specially adapted reflectors} - G02F 1/133611: {including means for improving the brightness uniformity} - H05K 1/056: {the metal substrate being covered by an organic insulating layer} - H05K 1/181: associated with surface mounted components - H05K 3/0061: {onto a metallic substrate, e.g. a heat sink (heat sinks for electric apparatus H05K7/20)} - H05K 2201/09054: Raised area or protrusion of metal substrate - H05K 2201/10106: Light emitting diode [LED] - H05K 2203/1572: Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides - Y10S 362/80: Light emitting diode - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Apparatuses for backlighting and manufacturing processes thereof are disclosed. There is provided a backlight module. The backlight module comprises a double-sided circuit board with thermal conducting material as one of the core layers; a plurality of light source components mounted on the first surface of the circuit board; and, a plurality of electronic components mounted on the second surface of the circuit board. The thermal conducting core layer discharges heat generated by the light source components. The circuit board has at least one window on the surface layer at the second surface to expose the thermal conducting core layer for thermal dissipation. As such, the component heights on the illuminating side of the circuit board are unified, and the reflector can be made as a smooth planar sheet to provide a more uniform backlight illumination compared to a single-side circuit board design. Further, such an arrangement reduces the complexity in manufacturing the reflector and hence the cost thereof. ## Claims ### Claim 1 A display backlight module comprising: an LCD display backlight having at least one contiguous double-sided circuit board with a thermal conducting material as one of the core layers thereof, said thermal conducting core layer discharging heat generated by light source components; a plurality of light source components mounted on one side of said circuit board; and a plurality of electronic components mounted on the opposite side of said circuit board; wherein said circuit board has at least one ventilation window formed in a surface layer on the electronic component side of the circuit board exposing said thermal conducting core layer for thermal dissipation and a thermal dissipating planar structure to cover the electronic component side of said circuit board, said planar structure having a protruding portion in contact with said thermal conducting core layer of said circuit board through said ventilation window. ### Claim 2 (depends on 1) A backlight module according to claim 1, further comprising a thin thermal interface material that mediates between said thermal conducting core layer of said display backlight circuit board and said protruding portion of said planar structure. ### Claim 3 (depends on 2) A backlight module according to claim 2, wherein said thermal interface material is selected from the group of materials consisting of thermal grease, thermally conductive gap fillers, phase change thermal interface material and thermal conductive adhesive/tape. ### Claim 4 (depends on 1) A backlight module according to claim 1, wherein said planar structure has at least one ventilation window to expose said circuit components on said display backlight circuit board for dissipating heat generated by said circuit components. ### Claim 5 (depends on 1) A backlight module according to claim 1, wherein said planar structure is part of a light box that accommodates said backlight module. ### Claim 6 (depends on 1) A backlight module according to claim 1, wherein said material composing said thermal conducting material is selected from the group of materials consisting of aluminum, aluminum alloy, ceramic and copper. ### Claim 7 (depends on 1) A backlight module according to claim 1, wherein said thermal dissipating planar structure is made of materials selected from the group of materials consisting of aluminum, aluminum alloy, steel and copper. ### Claim 8 (depends on 1) A backlight module according to claim 1, wherein said light source components are light emitting diodes. ### Claim 9 (depends on 1) A backlight module according to claim 1, further comprising an optical cover plate that is disposed over said light source components for diffusing light emitted therefrom. ### Claim 10 (depends on 1) A backlight system, comprising a plurality of backlight modules according to claim 1 that are arranged laterally and a plurality of electrical connectors, said backlight modules being interconnected by said electrical connectors. ### Claim 11 A process for manufacturing a display backlight module, comprising the steps of: fabricating conductive pathways on a contiguous double-sided circuit board wherein the circuit board is adapted to be used in an LCD display backlight and has a thermal conducting material as one of the core layers thereof; fabricating at least one ventilation window on a surface layer on one side of said circuit board exposing said one of the thermal conducting core layers for thermal dissipation; assembling light source components on the opposite side of said circuit board; and assembling other electronic components on the windowed side of said circuit board. ### Claim 12 (depends on 11) The process for manufacturing a backlight module according to claim 11, further comprising the step of attaching a thermal dissipating planar structure to cover the electronic component side of said display backlight circuit board, said planar structure having a protruding portion in contact with said thermal conducting core layer of said circuit board through said ventilation window. ### Claim 13 (depends on 12) The process for manufacturing a backlight module according to claim 12, further comprising the step of mediating a thin thermal interface material between said thermal conducting core layer of said display backlight circuit board and said protruding portion of said planar structure. ### Claim 14 (depends on 13) The process for manufacturing a backlight module according to claim 13, wherein said thermal interface material is selected from the group of materials consisting of thermal grease, thermally conductive gap fillers, phase change thermal interface material and thermal conductive adhesive/tape. ### Claim 15 (depends on 12) The process for manufacturing a backlight module according to claim 12, wherein said planar structure has at least one ventilation window to expose said circuit components on said display backlight circuit board for dissipating heat generated by said circuit components. ### Claim 16 (depends on 12) The process for manufacturing a backlight module according to claim 12, wherein said planar structure is part of a light box that accommodates said backlight module. ### Claim 17 (depends on 12) The process for manufacturing a backlight module according to claim 12, wherein said thermal dissipating planar structure is made of materials selected from the group of materials consisting of aluminum, aluminum alloy, steel and copper. ### Claim 18 (depends on 11) The process for manufacturing a backlight system, comprising the steps of arranging laterally a plurality of backlight modules manufactured from process according to claim 11, said backlight modules being interconnected by electrical connectors. ### Claim 19 (depends on 11) The process for manufacturing a backlight module according to claim 11, wherein said material composing said thermal conducting core layer is selected from the group of materials consisting of aluminum, aluminum alloy, ceramic and copper. ### Claim 20 (depends on 11) The process for manufacturing a backlight module according to claim 11, wherein said light source components are light emitting diodes. ### Claim 21 (depends on 11) The process for manufacturing a backlight module according to claim 11, further comprising the step of disposing an optical cover plate over said light source components for diffusing light emitted therefrom.