Patent Application
20140340873
A light-emitting diode (LED) display is a flat panel display, which includes an LED backlight unit (BLU) as a light source. As the size of such display continues to enlarge, more LEDs are used in the LED display to meet this demand.
Despite the advancements made in the display industry with larger screen, better light color and longer life, improved heat dissipation of the LED lighting has utilitarian value with respect to LED performance. This is because approximately 30% of the LED energy is converted to light, while 70% of the LED energy is converted to heat, which can affect the performance and reliability of the LED display.
In one embodiment, there is a heat-transfer apparatus, comprising a composite. The composite 1 including a metal layer 4; a dielectric layer 3 located on the metal layer 4; and one or more electrically conductive layers 2 located on the dielectric layer 3 on an opposite side from the metal layer 4, as illustrated in
In an exemplary embodiment, the heat-transfer apparatus is a printed circuit board and functions as a heat dissipation device at the same time. The combination of the printed circuit board and the heat dissipation device reduces the thickness of the LED frame compared to a configuration where the heat dissipation functionality is achieved via a separate component from the printed circuit board.
In another embodiment, a back light apparatus is provided as illustrated in
In another embodiment, a method for heat dissipation in a backlight apparatus is provided, comprising the actions of:
Other features will become apparent in the following detailed description of some embodiments with reference to the accompanying drawings, in which:
As employed above and throughout the disclosure, the following terms, unless otherwise indicated, shall be understood to have the following meanings.
As used herein, the singular forms “a,” “an,” and “the” include the plural reference unless the context clearly indicates otherwise.
It is understood that the BLU described herein are composed of various sheets, layers, films or plates sandwiched together to form the BLU of at least some embodiments detailed herein and/or variations thereof, and such terms as sheets, layers, films, subsections or plates may be used interchangeably in conjunction with the description of at least some of the embodiments and/or variations thereof.
Referring to
The composite 1 is manufactured by, in an exemplary embodiment, combining the metal layer 4, dielectric layer 3 and electrically conducting layer 2 in a vacuum by heat (at a temperature higher than 350 degrees C.) and pressure (about 40 Kg/cm2) into a composite 1. The strata of layers below the surface of the composite 1 extends from the first leg A to the second leg B and is generally uniform from the first leg A to the second leg B. In one embodiment, the composite 1 is substantially free of adhesive. In another embodiment, the composite 1 is substantially free of thermoplastic and/or thermosetting materials.
The composite 1 has a first leg A and a second leg B, which are substantially planar and joined by a plastically deformed section C. The first leg A of the composite 1 has a first planar area that is at an angle (α) of between a value of about 70 degrees and a value that is less than about 180 degrees, or a value that is greater than about 180 degrees to a value that is less than about 360 degrees to the second planar area of the second leg B. In one embodiment, angle α is about 90 degrees and a cross-section of the composite 1 lying on a plane substantially normal to the first planar area and the second planar area is at least in about an “L” shape. In another embodiment, angle α is an angle corresponding to the legs being substantially perpendicular.
Still referring to
The plastically deformed section C is non-thermoplastically formed. In addition, the plastically deformed section C is substantially free of cracks, effectively free of cracks or completely devoid of cracks. In one exemplary embodiment, the presence (or, more appropriately, the absence) of cracks in the plastically deformed section C can be visually assessed by microscopy.
Referring more specifically to
In one embodiment, the composite 1 comprises a metal copper clad laminate (MCCL), which comprises an aluminum layer, a polyimide layer and a copper layer and the thickness is about 0.1 to about 1.5 mm.
The heat-transfer apparatus further comprising a heat dissipation device and non-limiting examples of the heat dissipation device include graphite sheet (e.g. Hik@xy@) and heat sink. In one embodiment, the heat dissipation device is in direct contact with the composite 1, as illustrated in
The electric conductive layer 2 can be disposed on the dielectric layer 3, and embedded within the masking layers 5, as illustrated in
In one embodiment, embodiments can be manufactured such that the electric conductive layers are added to the dielectric layer 3, using light (e.g. laser light).
In another embodiment, embodiments can be manufactured by coating or laminating an electric conductive layer (such as copper) on the dielectric layer 3 and the undesired portion of the electric conductive layer is removed by a substractive method, such as etching or pulsed laser, leaving only the desired electric conductive traces on the dielectric layer.
The metal layer 4 used in some exemplary embodiments can be constructed of any appropriate material with a thickness about 0.1 to 2 mm or any value or range of values therebetween in about 0.01 mm increments. Examples of such metal layer 4 include, by way of example only and not by way of limitation, the following: aluminum, copper, stainless steel, magnesium alloy, titanium alloy or mixtures thereof.
The dielectric layer 3 used in the composite of the heat-transfer apparatus of an exemplary embodiment includes, in some embodiments, by way of example only and not by way of limitation, any non-conductive substrate with a thickness about 10 to about 100 μm or any value or range of values therebetween in 0.1 μm increments. Non limiting examples of non-conductive substrate include, by way of example only and not by way of limitation, the following: epoxy resin, fiber-filled epoxy, thermal filler, polyimide, polymer, liquid crystal polymer, and a combination thereof. In one embodiment, the dielectric layer is polyimide.
The masking layer 5 may be composed of any suitable material. Examples of such suitable materials for the masking layer 5 include, but are not limited to, ink and dry film. The masking film 5 can be applied to the dielectric layer 3 and by various methods known in the field, such as by screen printing for ink or laminating process for dry film.
The composite 1 of at least some exemplary embodiments can be manufactured by press molding the metal layer 4, the dielectric layer 3 and the electrically conductive layer under heat.
The heat transfer apparatus of at least some embodiment can be formed by press molding the formed composite 1 at room temperature into a plastically deformed composite.
The amount of pressure for press molding can play an influential role in avoiding crack formation in the plastically deformed section C. In one embodiment, about 15 to about 25 tons is used to press mold a composite 1 with a thickness of about 0.6 mm.
The cross-section of the “L” shaped laminate 1 lying on a plane normal to a longitudinal axis of the laminate having the generally “L” shape includes a metal sub-section 4, a dielectric sub-section 3 and one or more electrically conductive sub-sections 2, each of the sections being generally “L” shaped, wherein the first leg A and the second leg B of the “L” shaped laminate 1 are connected together via a plastically deformed section C. In one embodiment, at least one of the legs of the “L” shaped laminate 1 has a zig-zag shape to accommodate the backlight unit (BLU) 9.
The backlight apparatus further comprises a heat dissipation device 14, which can touch or be in an alternate form of contact (e.g., indirect contact via another component interposed therebetween) with the composite 1.
Again referring to
The BLU comprises prism sheet and diffuser sheet 10, a light guide 11 and a reflective film 12. The light from the LED 7 is reflected to the light guide 11 via pathway 8.
In an exemplary embodiment, there is a method of heat dissipation in a backlight apparatus, comprising the actions of:
In one embodiment, the heat in the second leg B of the generally “L” shape laminate 1 is passed to the heat dissipation device 14, which enhances heat dissipation in the backlight apparatus.
While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
