Patent Application
20070081339
The present invention generally relates to a light emitting diode (LED) light source module, and more specifically to a high power, super bright LED light source module and its application lighting fixtures featured with high efficiency heat dissipation.
The historic use of light emitting diode (LED) sourced back to the 60's in the last millennium, when people used LEDs for indication of radio on/off states. In recent years, LEDs have been widely used in almost all aspects of daily lives, such as traffic lights, automobile rear lights, monitor screen displays, etc. Compared with the conventional incandescent bulbs, LED light source offers the advantages of low power consumption and being flicker free. Most amazingly, the life time of an LED light source can be as long as a couple of ten years. Instead of the fragile, high temperature, and short life filament, LEDs use durable semiconductors for electrical current transmission. To efficiently use LEDs for general light source, however, there is one major technical barrier needs to be resolved. Brighter LED light sources need higher power LEDs and also generate much more heat. Taking the LED arrays used for street lighting as an example, without an efficient heat dissipation facility, the resulting high heat will greatly reduce the life spend of the LED arrays and even affect the overall reliability of the whole equipment.
Referring to
The present invention provides a high efficiency heat dissipation LED light source module, wherein the thickness of the printed circuit board is less than 400 μm, preferably less than 200 μm. The design of the invention can be easily applied to lighting equipments with varieties of non-planer geometric designs of lighting fixture racks. With the bendable flexibility, the thin printed circuit board can easily accommodate and tightly affix to a non-planar lighting fixture rack. The whole lighting fixture rack can thus serve as a direct heat sink; this achieves the high efficiency heat resistant effect by dissipating the heat into the surrounding atmosphere through the large dissipation area on the lighting fixture rack. The fabrication of this thinner printed circuit board is a standard technology; there is no major modification to the existing manufacturing cost, equipments, and fabrication processes. In addition to the advantage of better fitting into various shapes of lighting fixture racks with the bendable flexibility, this thinner version of printed circuit board with its thickness less than 400 μm, preferably less than 200 μm, also enhances the heat dissipation effect through faster and thus improved heat conductivity.
To accomplish said both advantages, the present invention provides a high efficiency heat dissipation LED light source module, which comprises a printed circuit board with its thickness less than 400 μm; one LED array, which is composed of multiple high power, super bright emitter LEDs, and is installed on said printed circuit board. Each said emitter LED connects to the electrical conductivity layer of the printed circuit board with a transmission line.
With the present invention for a high efficiency heat dissipation LED light source module, a lighting equipment can be designed as follows: one lighting fixture rack; one printed circuit board, which is tightly attached to the inner layer of the lighting fixture rack, with its thickness less than 400 μm, with bendable flexibility; one LED array, as light source, installed on said printed circuit board, and connects to the electrical conductivity layer of the printed circuit board with a transmission line; one light cover which tightly affixes to the lighting fixture rack; wherein, the back side of the printed circuit board without the LED array, also affixes to the inner surface of the lighting fixture rack.
With the present invention, the thickness of said printed circuit board is less than 400 μm, preferably less than 200 μm. The design of the invention can be easily applied to lighting equipments with varieties of non-planer geometric designs of lighting fixture racks. With the bendable flexibility, the thin printed circuit board can easily accommodate and tightly affix to any non-planar lighting fixture rack. The whole lighting fixture rack can serve directly as a heat sink, thus achieves the highly efficient heat dissipation without the need for an extra planer metal heat dissipation base as was used in a conventional LED lighting design. Additionally, with the present invention, the thinner version of printed circuit board with thickness less than 400 μm, preferably less than 200 μm, also provides shorter route for heat conductivity, thus promotes the efficiency for heat dissipation onto the lighting fixture rack. In addition to the much improved heat dissipation efficiency, the lighting fixture designed with said highly efficient heat resistant LED light source module also advantages itself with not only lower cost but also with much compact fixture design.
The foregoing and other objects, features, aspects and advantages of the present invention will become better understood from a careful reading of a detailed description provided herein below with appropriate reference to the accompanying drawings.
Referring to
On the printed circuit board 6, there are metal patches b for setting each said emitter LED 70. The material of the metal patches b can be gold or copper, etc. Wherein, each metal patch b is for heat dissipation, and is different from the electrical metal circuitry 61 on the printed circuit board 6, which are for the electrical transmission. Metal patches b and metal circuitry 61 on the printed circuit board 6 are not connected to one another. The heats generated from each emitter LED 70 can be effectively dissipated by the thermal conductive layer a, plus the metal patch b onto the printed circuit board 6. With the present invention of said thin version of printed circuit board 6, the heat on said printed circuit board can be effectively conducted onto the other side of the printed circuit board, and thus enhances the overall heat dissipation effect. The overall heat dissipation effect for the whole unit can be further improved with more complementary thermal conductive parts, (such as on the lighting fixture rack, which will be described in the later section). The thinner version of said printed circuit board 6 also provides itself with the advantage of bendable flexibility for any non-planar geometric design of fixture rack with the LED lighting modules; this extends the horizon of the application varieties of the present invention.
The bendable flexibility of the thinner version of the printed circuit board 6 with the present invention advantages itself for easily affixing to the inner side of said lighting rack 8. This facilitates the lighting fixture rack 8 as a direct heat sink by expanding heat dissipation. Additionally, the thinner version of the printed circuit with the present invention, with thickness less than 400 μm, preferably less than 200 μm, enhances the thermal conductivity, and further promotes the overall heat dissipation effect of the whole unit of lighting fixture.
Although the present invention has been described with reference to the preferred embodiments, it will be understood that the invention is not limited to the details described thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
