Patent Application
20130141910
1. Field of the Invention
The present invention relates to a method for assembling LEDs to a ceramic heat conductive piece and a structure produced by the method, which is capable improving heat dissipation while reducing light decline.
2. Description of the Prior Art
LED (Light Emitting Diode) has been widely used. However, LED related products are not often seen in the market because the temperature of a lighting LED is very high, and if heat dissipation is not good, the light of the LED will decline, or even the LED will be damaged.
Hence, many LED related products are designed to have an exposed heat dissipation structure. For example, the lamp holder is designed as a heat dissipation structure which is non-metal and formed with a plurality of thermal holes. The exposed heat dissipation structure not only looks ugly, but also is likely to burn the user. Therefore, some heat dissipation structures of the LED are designed to be located inside the lamp holder, wherein the lampshade is made of porous material, LED is disposed in the lampshade, and outside the lampshade is covered a metal cover. There is a large distance between the LED and the inner surface of the lampshade. The heat produced by the LED is transmitted to the lampshade by thermal radiation and finally radiated into ambient air via the metal cover. However, the thermal radiation has a very low heat dissipation efficiency and is unable to take away the heat generated by the LED in a short period of time, consequently causing heat accumulation and light decline. Another type of heat dissipation device is provide with heat dissipation plates which are connected one another, and only the middle portions of the respective heat dissipation plates are in contact with one another, so that the heat dissipation passage is too narrow, and as a result, the heat dissipation efficiency is low.
There is a patent in Taiwan, which is another invention of the author of the present invention, disclosed another heat dissipation structure, wherein the LED lamp is disposed on a ceramic base which is used as a heat dissipation structure.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.
The primary object of the present invention is to provide a method for assembling LEDs to a ceramic heat conductive piece and a structure produced by the method, which is capable improving heat dissipation while reducing light decline.
To achieve the above object, a method for assembling LEDs to a ceramic heat conductive piece in accordance with the present invention comprises: the following steps:
A structure produced by the method comprises the silver layer formed along a predetermined route on the surface of the cold end of the ceramic heat conductive piece, the LEDs are located between the paired conductive binders, and each of the LEDs includes a LED wafer disposed on a substrate, so that the heat generated by the LEDs can be transmitted quickly to the ceramic heat conductive piece via the conductive binders and the silver layer.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention.
Referring to
The method 50 for assembling the LEDs 14 to the ceramic heat conductive piece 30 comprises the following steps, with reference to
Step 51 of forming the ceramic heat conductive piece: Magnesium oxide, aluminum oxide or aluminum nitride, silicon dioxide, zinc oxide, niobium oxide or bismuth oxide or zirconium oxide, these ceramic materials, are mixed in certain proportion and then subjected to hot pressing a temperature of 350-1400° C. and pressure of 150-250 tons for 1-15 seconds to form the ceramic heat conductive piece 30, and the proportions are such that 10-15% Magnesium oxide, 65-70% aluminum oxide or aluminum nitride, 10-15% silicon dioxide, 5-10% zinc oxide, 5-10% niobium oxide or bismuth oxide or zirconium oxide.
Step 52 of forming silver layer: the surface of the cold end 301 of the ceramic heat conductive piece 30 is subjected to sliver printing process 520, drying process 521 and silver reduction process 522 to form a silver layer 31 of certain thickness along a predetermined route. The sliver printing 520 is performed along the predetermined route on the surface of the cold end 301 to form the silver layer 31 with a thickness of 0.1-0.5 mm, or can be performed by manual coating. The sliver layer 31 is composed of 40-60% sliver powder, and 40-60% silica binder. After the silver printing process 520, the drying process 521 is performed at a temperature of 120-200 ° C. for 8-22 minutes, and meanwhile the silver reduction process 522 is performed at a temperature of 700-800 ° C. for 1-3 hours to deoxidize the silver layer 31.
Step 53 of wiring: choosing (530) conductive binders 32, and the conductive binders 32 in accordance with the present invention is Tin paste composed of 50-60% Tin and 40-50% additive. Then the conductive binders 32 are applied to the silver layer 31 by coating process 531.
Step 54 of attaching and welding: attaching the LEDs 14 between the paired conductive binders 32 by welding, so that the LEDs 14 and the conductive binders 32 form an electric circuit loop with a voltage below 36 volts and a current of 250 mA.
Step 55 of getting a finished product: after the LEDs 14 are welded, the ceramic heat conductive piece 30 can be connected to drive circuit after being provided with power wires and a ground wire, so that a final product of ceramic heat conductive piece 30 is finished.
The final product made by the aforementioned method is shown in
The conductive binder 32 and the silver layer 31 are made of highly electric and thermal conductive material. Furthermore, the sliver layer 31 can be easily filtered into the clearance of the ceramic heat conductive piece 30 since it is composed of small and fine particles, enabling the silver layer 31 and the ceramic heat conductive piece 30 to be better jointed, the heat can be effectively transmitted to the ceramic heat conducive piece 30, and the voltage of the conductive binders 32 and the silver layer 31 can make the ceramic heat conducive piece 30 get more thermal electromotive force.
The heat dissipation member 40, as shown in
To improve heat dissipation, at the bottom of the housing 11 is further provided a plurality of holes 110 for dissipating the heat from the heat dissipation member 40.
The conductive binders 32 on the cold end 301 of the ceramic heat conductive piece 30 are connected in series and in parallel manner, as shown in
While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
