Patent Application
20070252133
The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
Referring to
In this embodiment, the material of the substrate 20 is mainly composed of the material with good thermal conductivity for providing proper heat dissipating efficiency. Preferably, the material of the substrate 20 is copper, copper alloy, or a thermal conductive material.
The first metal layer 23 of the light emitting apparatus 2 is disposed on the substrate 20. The material of the first metal layer 23 includes aluminum, magnesium, titanium or their alloys. Considering of the material characteristics of the first metal layer 23, the first insulating layer 21 may be directly formed by oxidizing, nitridizing or carbidizing the surface of the first metal layer 23. The material of the first insulating layer 21 accordingly may be aluminum oxide, magnesium oxide, titanium oxide, aluminum nitride, magnesium nitride, titanium nitride, aluminum carbide, magnesium carbide or titanium carbide. Also, the first metal layer 23 has a structure 201 for increasing the light emitting efficiency.
The light emitting device 22 is disposed at a predetermined position of the first metal layer 23 and on the substrate 20. In this embodiment, the light emitting device 22 includes a first electrode, a second electrode and a light emitting layer (not shown). More specifically, the light emitting device 22 may be a light emitting diode (LED), a laser diode (LD) or an organic light emitter diode (OLED).
The light emitting apparatus 2 of this embodiment may further include a second metal layer 23′ disposed on the first insulating layer 21. The second metal layer 23′ is directly electrically connected to the light emitting device 22, preferably, by wire bonding. The material of the second metal layer 23′ may be silver, gold, copper, aluminum or alloys thereof.
In order to dispose the second metal layer 23′ on the first insulating layer 21, the connecting layer 26 may further be formed between the second metal layer 23′ and the first insulating layer 21. The connecting layer 26 is adhesive, or has a property of enabling the second metal layer 23′ to be formed thereon. For example, the initial layer required may be made of chromium, titanium, nickel or alloys thereof when the second metal layer 23′ is formed by way of plating.
In this embodiment, the protective layer 29 is disposed on the light emitting device 22 to cover and protect the light emitting device 22. Meanwhile, the surface shape of the protective layer 29 are curved so that the protective layer 29 functions as a lens for diverging or converging the light outputted from the light emitting device 22 to meet various display requirements.
In this embodiment, the structure 201, for increasing the light emitting efficiency on the surface of the first metal layer 23, is a recess of spherical shape, elliptical shape or parabolic shape. Preferably, the light emitting device 22 is disposed at a focus of the recess. Thus, when the lateral light outputted from the light emitting device 22 strikes the structure 201, the curved structure 201 can reflect and converge the lateral light generated by the light emitting device 22 and then output the converged lateral light. Thus, the light emitting efficiency may be directly enhanced. In addition, the light emitting apparatus 2 may further include a reflective layer 28 disposed on the structure 201, as shown in
In addition, the invention provides the second embodiment, shown in
A third metal layer 23″ may be additionally disposed on the second insulating layer 21′ and electrically connected to the light emitting device 22 via a wire 24. In order to enable the third metal layer 23″ to be disposed on the second insulating layer 21′, a connecting layer 26 may also be formed between the third metal layer 23″ and the second insulating layer 21′. The connecting layer 26 is adhesive or has a property of enabling the third metal layer 23″ to be formed thereon. For example, the initial layer required may be made of chromium, titanium, nickel or alloys thereof when the third metal layer 23″ is formed by way of plating.
In this embodiment, the light emitting device 22 is electrically connected to the third metal layer 23″ via the wires 24 so that the light emitting device 22 may be directly disposed at the predetermined position of the first metal layer 23 so that it become unnecessary to dispose the insulating layer at the predetermined position. Of course, this is only an example and is not for limitations of the present invention.
The invention also provides another light emitting apparatus 2 according to the third embodiment, as shown in
As shown in
In summary, the first metal layer of the light emitting apparatus is formed with the structure for increasing the light emitting efficiency, and the light emitting device is disposed at the predetermined position of the first metal layer in the light emitting apparatus according to the present invention. Regarding to the material characteristics of the first metal layer, an insulating layer can be directly formed after performing a ceramization procedure, and the light emitting device can be disposed on the insulating layer. Also, the light emitting efficiency is enhanced because the structure on the first metal layer can reflect and concentrate the light outputted from the light emitting device. Meanwhile, superior heat dissipating effect and thus longer lifetime of the light emitting apparatus may be achieved by using the substrate which has advantages of good thermal conductivity, large area, and may be composed of metal or alloys to guide and dissipate the heat generated by the light emitting device during operation. Compared with the prior art, it is unnecessary to dispose and attach a heat sink in this invention. So, it is possible to reduce the manufacturing cost, reduce the manufacturing time, simplify the manufacturing steps, avoid the problems of high thermal resistance and ageing caused by the heat sink, and thus enhance the heat dissipating efficiency and the product reliability.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 095115255 | Apr 2006 | TW | national |
