P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL TO BE COMPLETED BY APPLICANT Name of Applicant: Chao-Chin Yeh Address for Service: A.P.T. Patent and Trade Mark Attorneys PO Box 222, Mitcham, SA 5062 Invention Title: LED Cooling Structure The following statement is a full description of this invention, including the best method of performing it known to me/us:- LED COOLING STRUCTURE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to LED technology and more particularly, to a 5 LED cooling structure. 2. Description of the Related Art FIG. 1 illustrates the basic structure of a conventional LED lamp, which comprises a substrate 1 formed of, for example, a printed circuit board, a circuit layout 2 arranged on the substrate 1, and a light-emitting device 3 mounted at the substrate 1 10 and electrically connected to the circuit layout 2. This design of LED lamp encounters a heat dissipation problem. During operation of the light-emitting device 3 to give off light, waste heat will be produced. However, the printed circuit board 1 is made of a plastic material that is not a good heat transfer material. Waste heat generated by the light-emitting device 3 cannot be rapidly and effectively dissipated. 15 FIG. 2 illustrates the base structure of another prior art design of LED lamp, which comprises a substrate 1 made of aluminum alloy and generally known as the aluminum substrate, an insulative layer 4 covered on the substrate 1, a circuit layout 2 arranged on the insulative layer 4, and a light-emitting device 3 mounted at the insulative layer 4 and electrically connected to the circuit layout 2. This design uses a 20 high thermal conductivity aluminum substrate to substitute for a printed circuit board. Thus, an insulative layer 4 must be provided between the aluminum substrate 1 and the circuit layout 2 so that the circuit layout 2 can function normally. The insulative layer 4 is generally made of an electrically and thermally insulative material that isolates transmission of heat energy. In consequence, the aluminum substrate gives little help in 25 dissipating heat from the light-emitting device 3. 2 SUMMARY OF THE INVENTION The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a LED cooling structure, which rapidly and effectively transfers and dissipates heat. 5 To achieve this and other objects of the present invention, a LED cooling structure comprises a substrate, which comprises opposing top and bottom walls, a circuit layout and at least one thermally conductive plate arranged on the top wall, at least one through hole cut through the top and bottom walls, and a thermally conductive post mounted in each through hole and having its one end 10 connected with the at least one thermally conductive plate, and at least one light-emitting device mounted at the substrate and electrically connected to the circuit layout, each light-emitting device having a bottom side thereof disposed in contact with one thermally conductive plate for dissipation of heat. Further, the substrate can be an aluminum substrate, and the thermally 15 conductive post in each through hole can be formed integral with the aluminum substrate. Further, a metal plate can be arranged at the bottom wall of the substrate, and the thermally conductive post in each through hole can be formed integral with the metal plate. 20 Further multiple light-emitting devices can be mounted at the substrate and respectively connected to respective thermally conductive plates that are arranged around one respective through hole and one respective thermally conductive post. Other advantages and features of the present invention will be fully 25 understood by reference to the following specification in conjunction with the 3 accompanying drawings, in which like reference signs denote like components of structure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of a LED lamp according to the prior 5 art. FIG. 2 is a schematic sectional view of another design of LED lamp according to the prior art. FIG. 3 is a schematic sectional view of a LED cooling structure in accordance with a first embodiment of the present invention. 10 FIG. 4 is a top view of FIG. 3. FIG. 5 is a schematic sectional view of a LED cooling structure in accordance with a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 3 and 4, a LED cooling structure in accordance with a 15 first embodiment of the present invention is shown. The LED cooling structure comprises a substrate 10, at least one light-emitting device 20, and a metal plate 30. The substrate 10 can be a printed circuit board or aluminum substrate. In this embodiment, the substrate 10 is a printed circuit board, comprising a circuit layout 11 and at least one thermally conductive plate 14 arranged on the top wall thereof, at least 20 one through hole 12 cut through the opposing top and bottom walls thereof, and a thermally conductive post 13 mounted in each through hole 12. Further, the at least one thermally conductive plate 14 can be formed integral with the printed circuit board during the fabrication of the printed circuit board. Further, the thermally conductive post 13 in each through hole 12 can be a rivet, copper post or iron post, having its one 25 end connected to the at least one thermally conductive plate 14 by bonding, welding or 4 riveting. The at least one light-emitting device 20 is mounted at the substrate 10 and electrically connected to the circuit layout 11. Each light-emitting device 20 has its bottom side arranged on the at least one thermally conductive plate 14 so that waste 5 heat generated by the at least one light-emitting device 20 can be transferred toward the outside by the at least one thermally conductive plate 14. The metal plate 30 is made of copper, iron, or any other high conductivity metal material, and mounted at the bottom wall of the substrate 10 and connected with the thermally conductive post 13 in each through hole 12 by bonding, welding or 10 riveting. Further, the thermally conductive post 13 can be formed of a part of the metal plate 30 directly using a stamping technique. According to the aforesaid first embodiment of the present invention, each light-emitting device 20 has its bottom side kept in direct contact with the at least one thermally conductive plate 14. Thus, during operation of the at least one light-emitting 15 device 20 to give off light, waste heat generated by the at least one light-emitting device 20 can be effectively and rapidly transferred by the at least one thermally conductive plate 14 through the thermally conductive post 13 in each through hole 12 to the metal plate 30 for quick dissipation into the outside open air. Further, the location of the at least one through hole 12 is preferably adjacent to the at least one 20 light-emitting device 20, so that the thermally conductive post 13 can achieve the best results. Referring to FIG. 5, a LED cooling structure in accordance with a second embodiment of the present invention is shown. The LED cooling structure comprises a substrate 10, and at least one light-emitting device 20. 25 The substrate 10 can be a printed circuit board or aluminum substrate. In this 5 embodiment, the substrate 10 is an aluminum substrate, comprising an insulative layer 15 arranged on the top wall thereof, a circuit layout 11 and at least one thermally conductive plate 14 arranged on the insulative layer 15, at least one through hole 12 cut through the opposing top and bottom walls thereof, and a thermally conductive post 13 5 mounted in each through hole 12 and connected with the at least one thermally conductive plate 14. Further, each thermally conductive plate 14 can be a metal plate, for example, copper plate. Further, the thermally conductive post 13 in each through hole 12 can be a rivet, copper post or iron post, having its one end connected to the at least one thermally conductive plate 14 by bonding, welding or riveting. 10 The at least one light-emitting device 20 is mounted at the substrate 10 and electrically connected to the circuit layout 11. Each light-emitting device 20 has its bottom side arranged on the at least one thermally conductive plate 14 so that waste heat generated by the at least one light-emitting device 20 can be transferred toward the outside by the at least one thermally conductive plate 14. 15 According to the aforesaid second embodiment, the substrate is an aluminum substrate made of an aluminum alloy that has high thermal conductivity. During the operation of the at least one light-emitting device 20 to give off light, the insulative layer 15 isolates the waste heat generated by the at least one light-emitting device 20, enabling the waste heat to be effectively and rapidly transferred through the least one 20 thermally conductive plate 14 and the thermally conductive post 13 in each through hole 12 to the aluminum substrate 10 for quick dissipation. Further, the thermally conductive post 13 in each through hole 12 can be formed integral with the aluminum substrate 10. Further, in either of the aforesaid first or second embodiment of the present 25 invention, if multiple light-emitting devices are installed in the substrate, waste heat 6 can be effectively and rapidly transferred by the at least one thermally conductive plate to the thermally conductive post in each through hole of the substrate. Further, the number of the at least one through hole is determined subject to actual requirements. For example, two light-emitting devices or three light-emitting devices can shape one 5 through hole and one thermally conductive post, and these light-emitting devices are arranged around the through hole and the thermally conductive post. Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the 10 invention is not to be limited except as by the appended claims. 7