Patent Application
20070252159
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 composed of the material with good thermal conductivity for providing proper heat dissipating efficiency. Preferably, the material of the substrate 20 is made of copper, aluminum, magnesium, titanium and alloys thereof. Alternatively, the substrate can be composed of ceramic material or thermal conductive material. Furthermore, the substrate 20 can be a rigid substrate or a flexible substrate, and the substrate can have a plate, curve or saw shape.
The insulating layer 21 is disposed on the substrate 20 and has a patterned area 211 to expose at least a portion of the substrate 20. To form the patterned area 211, the insulating layer 21 is processed by a photolithography process or a screen printing process. The material of the insulating layer 21 can be made of aluminum oxide, magnesium oxide, titanium oxide, aluminum nitride, magnesium nitride, titanium nitride, aluminum carbide, magnesium carbide, titanium carbide, and compositions thereof. The insulating layer can be deposited by oxidizing, nitridizing or carbidizing the surface of the substrate 20. Alternatively, the insulating layer 21 can be formed on the substrate 20 by way of evaporating, sputtering, electroplating or CVD (Chemical Vapor Deposition). In more detailed, if the material of the substrate 20 is aluminum, magnesium, titanium or alloys thereof, the insulating layer 21 can be formed by oxidizing, nitridizing or carbidizing the surface of the substrate 20. If the substrate 20 is not made of aluminum, magnesium, titanium or alloys thereof, the insulating layer 21, which is composed of aluminum oxide, magnesium oxide or titanium oxide, can be formed on the substrate 20 by evaporating, sputtering, electroplating or CVD (Chemical Vapor Deposition).
The light emitting device 22 is disposed on the substrate 20 and is located within the patterned area 211. 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 can be an LED (Light Emitting Diode), an LD (Laser Diode) or an OLED (Organic Light Emitter Diode).
The light emitting apparatus 2 of this embodiment further includes a metal layer 23 disposed on the insulating layer 21. The metal layer 23 is directly electrically connected to the first and second electrodes of the light emitting device 22 through at least one wire 24. The metal layer 23 can be used as a bonding pad electrically connecting to external circuits. The material of the metal layer 23 can be made of silver, gold, copper, aluminum and alloys thereof.
In order to dispose the metal layer 23 on the insulating layer 21, a connecting layer 26 can be formed between the metal layer 23 and the insulating layer 21. The connecting layer 26 has an adhesive property, or enables the metal layer 23 to be formed thereon. For example, the connecting layer 26 can be the initial layer for forming the metal layer 23 by way of plating. In this case, the connecting layer 26 is made of chromium, titanium, nickel and alloys thereof. In addition, the connecting layer 26 can be made of electrical conductive adhesive comprising copper, silver and tin.
As shown in
As shown in
Referring to
Alternatively, in a light emitting apparatus 2D according to the invention shown in
In addition, the light emitting apparatus 2 further includes a reflective layer 28 disposed on the structure 201 for enhancing the reflection and convergence of the lateral light of the light emitting device 22. As shown in
Referring to
In summary, in the light emitting apparatus according to the invention, the light emitting device is disposed on the large size substrate, which can be made of the material with good thermal conductivity, such as metal or alloys. Thus, the substrate can conduct and dissipate the heat generated by the light emitting device. By the superior heat dissipating effect, the light emitting apparatus can have longer lifetime. Compared with the prior art, the large-sized substrate has better heat dissipating effect without attached with a heat sink. Therefore, it is possible to reduce the manufacturing cost, reduce the manufacturing time, simplify the manufacturing steps, avoid the problems of 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 |
|---|---|---|---|
| 095115251 | Apr 2006 | TW | national |
