Patent Application
20110065218
1. Field
The present disclosure relates to a light emitting diode (LED) array module, and more particularly, to a pre-thermal greased LED array.
2. Description of Related Art
LEDs have been developed for many years and have been widely used in various light applications. As LEDs are light weight, consume less energy, and have a good electrical power to light conversion efficacy, they have been used to replace conventional light sources, such as incandescent lamps and fluorescent light sources. LEDs may be utilized in an array module. Heat is conducted from the LED array to a heat sink. The interface between the LED array and the heat sink may have gaps or voids. As such, a thermal interface material, such as thermal grease, may be used to fill the gaps and voids to aid in conducting heat from the LED array to the heat sink. Whether the thermal grease is applied by hand or by machine, the thermal grease may be misapplied, thus causing variation in thermal grease thickness and/or exposed areas where the thermal grease was not applied. Misapplication of the thermal grease to the LED array may shorten the lifespan of the LED array. As such, there is a need for a method for improving and an apparatus with improved thermal grease application.
In one aspect of the disclosure, an apparatus includes a backing material carrying a thermally conductive non-solid substance, and a solid state component set into the thermally conductive non-solid substance. The backing material is arranged with the solid state component so that the backing material may be removed from the apparatus leaving at least a portion of the thermally conductive non-solid substance on the solid state component for mounting to a heat sink.
In one aspect of the disclosure, an apparatus includes a backing material, a solid state component, and a thermally conductive non-solid substance between the backing material and the solid state component. The backing material is arranged with the solid state component so that the backing material may be removed from the apparatus leaving at least a portion of the thermally conductive non-solid substance on the solid state component for mounting to a heat sink.
In one aspect of the disclosure, an apparatus includes a solid state component and a backing material carrying a thermally conductive non-solid substance. The backing material is attached to the solid state component such that the thermally conductive non-solid substance is between the backing material and the solid state component. The backing material is arranged with the solid state component so that the backing material may be removed from the apparatus leaving at least a portion of the thermally conductive non-solid substance on the solid state component for mounting to a heat sink.
In one aspect of the disclosure, a method of producing a module from an apparatus having a backing material, a solid state component, and a thermally conductive non-solid substance between the backing material and the solid state component is provided. The method includes removing the backing material from the apparatus leaving at least a portion of the thermally conductive non-solid substance on the solid state component, and mounting the solid state component to a heat sink with the thermally conductive non-solid substance being between the solid state component and the heat sink.
In one aspect of the disclosure, a method of producing a plurality of apparatus includes applying a thermally conductive non-solid substance to a backing material, setting a solid state component into the thermally conductive non-solid substance in each of a plurality of backing material sections, and splitting the backing material into the sections to separate each of the backing sections.
In one aspect of the disclosure, an apparatus includes a frame, a solid state component secured to the frame, and a phase change thermal interface material coupled to the solid state component. The phase change thermal interface material is configured to be liquefied to fill voids adjacent the solid state component.
Various aspects of the present invention will be described herein with reference to drawings that are schematic illustrations of idealized configurations of the present invention. As such, variations from the shapes of the illustrations as a result, for example, manufacturing techniques and/or tolerances, are to be expected. Thus, the various aspects of the present invention presented throughout this disclosure should not be construed as limited to the particular shapes of elements (e.g., regions, layers, sections, substrates, etc.) illustrated and described herein but are to include deviations in shapes that result, for example, from manufacturing. By way of example, an element illustrated or described as a rectangle may have rounded or curved features and/or a gradient concentration at its edges rather than a discrete change from one element to another. Thus, the elements illustrated in the drawings are schematic in nature and their shapes are not intended to illustrate the precise shape of an element and are not intended to limit the scope of the present invention.
It will be understood that when an element such as a region, layer, section, substrate, or the like, is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. It will be further understood that when an element is referred to as being “formed” on another element, it can be grown, deposited, etched, attached, connected, coupled, or otherwise prepared or fabricated on the other element or an intervening element. In addition, when a first element is “coupled” to a second element, the first element may be directly connected to the second element or the first element may be indirectly connected to the second element with intervening elements between the first and second elements.
Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the drawings. It will be understood that relative terms are intended to encompass different orientations of an apparatus in addition to the orientation depicted in the drawings. By way of example, if an apparatus in the drawings is turned over, elements described as being on the “lower” side of other elements would then be oriented on the “upper” side of the other elements. The term “lower” can therefore encompass both an orientation of “lower” and “upper,” depending of the particular orientation of the apparatus. Similarly, if an apparatus in the drawing is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The terms “below” or “beneath” can therefore encompass both an orientation of above and below.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and this disclosure.
As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The term “and/or” includes any and all combinations of one or more of the associated listed items.
Various aspects of an LED array module may be illustrated with reference to one or more exemplary configurations. As used herein, the term “exemplary” means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other configurations of an LED array module disclosed herein.
Furthermore, various descriptive terms used herein, such as “on” and “transparent,” should be given the broadest meaning possible within the context of the present disclosure. For example, when a layer is said to be “on” another layer, it should be understood that that one layer may be deposited, etched, attached, or otherwise prepared or fabricated directly or indirectly above or below that other layer. In addition, something that is described as being “transparent” should be understood as having a property allowing no significant obstruction or absorption of electromagnetic radiation in the particular wavelength (or wavelengths) of interest, unless a particular transmittance is provided.
An example of a solid state light emitting cell is an LED. The LED is well known in the art, and therefore, will only briefly be discussed to provide a complete description of the invention.
Referring to
The electrodes 106 and 108 may be formed on the surface of the epitaxial-layer structure 104. The p-type semiconductor region 118 is exposed at the top surface, and therefore, the p-type electrode 106 may be readily formed thereon. However, the n-type semiconductor region 114 is buried beneath the p-type semiconductor region 118 and the active region 116. Accordingly, to form the n-type electrode 108 on the n-type semiconductor region 114, a portion of the active region 116 and the p-type semiconductor region 118 is removed to expose the n-type semiconductor region 114 therebeneath. After this portion of the epitaxial-layer structure 104 is removed, the n-type electrode 108 may be formed.
As discussed above, one or more light emitting cells may be used to construct a light emitting element. A light emitting element may be constructed in a 2-dimensional planar fashion. One example of a light emitting element will now be presented with reference to
The light emitting element may be configured to produce white light. White light may enable the light emitting element to act as a direct replacement for conventional light sources used today in incandescent, halogen and fluorescent lamps. There are at least two common ways of producing white light. One way is to use individual LEDs that emit wavelengths (such as red, green, blue, amber, or other colors) and then mix all the colors to produce white light. The other way is to use a phosphor material or materials to convert monochromatic light emitted from a blue or ultra-violet (UV) LED to broad-spectrum white light. The present invention, however, may be practiced with other LED and phosphor combinations to produce different color lights.
An example of a white light emitting element will now be presented with reference to
In an alternative configuration of a white light emitting element, each LED may have its own phosphor layer. As those skilled in the art will readily appreciate, various configurations of LEDs and other light emitting cells may be used to create a white light emitting element. Moreover, as noted earlier, the present invention is not limited to solid state lighting devices that produce white light, but may be extended to solid state lighting devices that produce other colors of light.
The frame 504 has torsion pins 504′ for attaching to the corresponding holes 506′ in the LED array 506. The torsion pins 504′ extend slightly below the legs 505 of the frame 504. Such a configuration of the legs 505 and torsion pins 504′ allow for a constant pressure to be applied against the LED array 506 when the frame 504 is attached to a heat sink. In one configuration, the thermal grease sheet 406 is a phase change thermal interface material. Phase change thermal interface pads melt and liquefy when heated. The liquefied thermal interface material fills micro voids, thus providing better contact between the heat sink and the metalized bottom surface of the LED array 506. The pressure applied by the frame 504 on the LED array 506 takes up any voids left by the displaced liquefied thermal interface material. As such, after the phase change thermal interface pads are melted, the metalized bottom surface of the LED array 506 maintains a good thermal metal-to-metal contact with the heat sink through the liquefied thermal interface material.
The thermal grease sheet 406 may be plastic, wax paper, or another suitable material for covering a layer of thermal grease on the bottom surface of the LED array 408, 506. When the LED array 408 is attached to the heat sink 402 or when the module 500 is mounted to a heat sink, the thermal grease sheet 406 is removed, revealing the layer of grease. The layer of grease conducts heat from the LED array 408, 506 to the heat sink.
As discussed supra, the LED array modules 400, 500 include an LED array. However, the modules 400, 500 may alternatively include a solid state component, the solid state component being a device built entirely from solid materials in which the electrons are entirely confined within the solid material. The solid state component may be a light source. The light source may be constructed from an array of light emitting semiconductor cells. One example of a light emitting semiconductor cell is an LED.
The various aspects of this disclosure are provided to enable one of ordinary skill in the art to practice the present invention. Modifications to various aspects of an LED array module presented throughout this disclosure will be readily apparent to those skilled in the art, and the concepts disclosed herein may be extended to other applications. Thus, the claims are not intended to be limited to the various aspects of an LED array module presented throughout this disclosure, but are to be accorded the full scope consistent with the language of the claims. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”
Pursuant to 35 U.S.C. §119(e), this application claims the benefit of U.S. Provisional Application Ser. No. 61/242,221 filed on Sep. 14, 2009, the contents of which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61242221 | Sep 2009 | US |
