TWI479695B - A light emitting diode chip and a light emitting element - Google Patents

Description

Light-emitting diode chip and light-emitting element

The invention is a light-emitting element, in particular a light-emitting element having multi-directional light-emitting characteristics.

Light Emitting Diode (LED) is a solid-state light-emitting component made of a semiconductor material with small size, low power consumption and high reliability. It uses a combination of III-V chemical elements such as gallium phosphide or gallium arsenide to apply a voltage to the compound semiconductor to cause the holes and electrons to meet under different electrode voltages, and the electrons will fall. To the lower energy level, while releasing in the photon mode, the electric energy is converted into light energy to achieve the luminous effect.

The driving force behind this kind of lighting technology is that the non-renewable resources such as coal, natural gas and petroleum are gradually lacking, especially the international oil price is not stable. Therefore, while developing new energy, it is also necessary to develop energy conservation. Products to slow down the consumption of surplus fossil fuels. Under the pressure of these natural conditions, the world is actively investing in the key moments of energy-saving product development. The light-emitting diodes, which are referred to as green light sources, meet this energy-saving trend, and the technology is becoming more mature and progressive, and its application fields. It is also more extensive. At present, the light-emitting diode has been widely applied to the 3C product indicator and display device; and with the improvement of the production yield of the light-emitting diode, the unit manufacturing cost has also been greatly reduced, prompting the use of the light-emitting two in various fields. The polar body is a lighting material.

As mentioned above, since the development of high-intensity light-emitting diodes has become a national factory The research and development focus of the business, so how to further reduce the cost of the light-emitting diode, is the focus of Shaoguan light-emitting diodes can be further popularized in life. However, the light-emitting diode itself is a directional light source, and is not a divergent light source as in the conventional light bulb, and thus it is difficult to effectively apply the light pattern required for general indoor and outdoor lighting fixtures.

In terms of the structure of the light-emitting diode, after the light-emitting diode wafer is prepared, a packaging process will be performed. The function of the package is to provide the necessary support for the power input, light energy output or heat dissipation of the LED chip. For example, semiconductor components are exposed to the atmosphere for a long time, and are aged by chemicals in water vapor or other environments, causing degradation of characteristics. In the so-called packaging process, the current technology can be roughly divided into three processes: die bonding, wire bonding, and encapsulation.

In the past technology, most of the early die-bonding procedures used silver paste to bond the light-emitting diode wafer to the substrate, but the heat dissipation and bonding strength of the silver paste could not cope with the demand of the high-power light-emitting diode. Later, the metal-based solder material was used as the bond of the light-emitting diode wafer, but the subsequent cleaning problem caused by the flux was caused. As for the wire bonding, the two ends of the gold wire or the aluminum wire are respectively joined to the wafer and the lead frame or the substrate by thermocompression bonding, ultrasonic wave wedge bonding or ultrasonic-assisted thermocompression bonding.

However, although the procedures of solid crystal and wire bonding have been developed quite mature in this field, they are still a huge cost in the process of light-emitting diodes, and each process itself has a yield problem; therefore, if To improve and simplify this point, the popularity of LEDs will have better prospects.

The main object of the present invention is to provide a luminescence with multi-directional light-emitting characteristics. The component is such that the epitaxial layer of the LED chip is covered by the two transparent electrodes simultaneously, so that the light emitted by the epitaxial layer can penetrate the transparent electrodes and travel in multiple directions in the space without being hindered. The illumination angle of the light-emitting element is enlarged.

A secondary object of the present invention is to provide a light-emitting element having multi-directional light-emitting characteristics, wherein an electrode of a light-emitting diode wafer is directly connected to a metal electrode on a substrate so that it can be directly supplied by an external power source, and the present invention It is quite simple in the process, eliminating the steps of solid crystal and wire bonding, which not only improves the yield, but also reduces the cost and has practical economic benefits.

In order to achieve the above object, the present invention discloses a light-emitting element having a large illuminating angle characteristic, which structurally comprises: a substrate; a metal electrode region disposed on the substrate, comprising a first metal separated An electrode and a second metal electrode; and a light-emitting diode chip having an epitaxial layer, wherein the upper and lower portions of the epitaxial layer respectively have a first electrode and a second electrode, and the light-emitting diode chip transmits the light-emitting diode The first electrode and the second electrode are electrically coupled to the first metal electrode and the second metal electrode respectively to supply power to the epitaxial layer, and are disposed on the substrate in a side direction of the epitaxial layer. The light emitting diode chip is placed on the substrate. Through such a combination of structures, the multi-directional light output and high preparation yield performance desired by the present invention can be achieved.

1‧‧‧Substrate

11‧‧‧Insulated heat sink

2‧‧‧Metal electrode area

21‧‧‧First metal electrode

22‧‧‧Second metal electrode

3‧‧‧Lighting diode chip

31‧‧‧First electrode

32‧‧‧second electrode

33‧‧‧ epitaxial layer

331‧‧‧First semiconductor layer

332‧‧‧Second semiconductor layer

333‧‧‧Lighting layer

334‧‧‧Transparent conductive materials

4‧‧‧Drilling carbon film

5‧‧‧ energy conversion layer

6‧‧‧Electrical and thermal conductive adhesive

7‧‧‧Sapphire substrate

81‧‧‧Side side of the first electrode

82‧‧‧ Side of the second electrode

83‧‧‧ Surface of the first metal electrode

84‧‧‧ Surface of the second metal electrode

91‧‧‧ upper

92‧‧‧ lower

93‧‧‧ side

1 is a schematic structural view of a preferred embodiment of the present invention; FIG. 2 is a schematic view showing the structure of a light emitting diode according to a preferred embodiment of the present invention; and a third to third D diagram : is a schematic structural view of a light-emitting diode wafer according to a preferred embodiment of the present invention; 4A to 4D are schematic views showing the structure of a light emitting diode according to another preferred embodiment of the present invention; and FIG. 5 is a light emitting diode according to still another preferred embodiment of the present invention. Schematic diagram of a wafer structure; and a sixth diagram: a schematic diagram of a package structure according to a preferred embodiment of the present invention.

The features of the present invention and the achievable effects are illustrated by the preferred embodiment and the detailed description. As a result, since the conventional LED chip must be packaged through a die bonding and wire bonding process, there are yields and materials. Therefore, the present invention also designs a light-emitting element having multi-directional light-emitting characteristics for the procedures, and eliminates the programs to reduce the cost.

First, referring to the first figure, the main structure of the present invention comprises a substrate 1; a metal electrode region 2; a light emitting diode chip 3; a first electrode 31; a second electrode 32; and an epitaxial layer 33. .

In the embodiment of the figure, the metal electrode region 2 is disposed on the substrate 1 and can be divided into the first metal electrode 21 and the second metal electrode 22 to avoid a short circuit; the LED body 3 is An electrode 31 and a second electrode 32 are respectively disposed on the upper portion 91 and the lower portion 92 of the epitaxial layer 33, and the sides of the first electrode 31 and the side of the second electrode 32 are respectively associated with the first metal electrode 21 and The second metal electrode 22 is in direct contact with the light-emitting diode 3 and the substrate 1.

The substrate 1 is a heat-conductive substrate, and may be made of a ceramic substrate, a tantalum carbide substrate, an anodized aluminum substrate, or an aluminum nitride substrate, and has a function of carrying and heat conduction, and is not limited to a conductor. The substrate 1 and the metal electrode region 2 can be further packaged It comprises an insulating heat dissipation layer 11 whose function is to prevent leakage or short circuit of the metal electrode region 2.

In addition to the above structure, reference may be made to the second figure, which is a schematic diagram of the structure of the LED substrate 3. The epitaxial layer 33 includes a first semiconductor layer 331, a second semiconductor layer 332 and a light-emitting layer 333. The light emitting layer 333 is disposed between the first semiconductor layer 331 and the second semiconductor layer 332. This is a common composition in a general light-emitting diode epitaxial structure. The materials of a first semiconductor layer 331 and a second semiconductor layer 332 are respectively N-type and P-type gallium nitride, and the light-emitting layer 333 located between the two is a light-emitting region in which electrons and holes are mainly combined, and may be generally A doped luminescent layer or a multiple quantum well (MQW) luminescent layer or the like is where light energy is generated.

The first electrode 31 and the second electrode 32 may be composed of a transparent conductive layer (TCL). The transparent conductive layer may be made of a metal mesh film, indium tin oxide (ITO) or zinc oxide (ZnO). Because of its good light transmission effect, when the light generated by the light-emitting layer 333 is directed toward the first electrode 31 and the second electrode 32, it is not attenuated by a large amount of reflection or absorption, and the light can be emitted with maximum efficiency. In addition, the side 81 of the first electrode and the side 82 of the second electrode are respectively in direct contact with the surface 83 of the first metal electrode and the surface 84 of the second metal electrode in the embodiment disclosed in the first figure. position.

In the procedure for fabricating the LED chip 3, please refer to the sequence disclosed in the third to third D drawings. As shown in FIG. 3A, the first semiconductor layer 331, the light-emitting layer 333, and the second semiconductor layer 332 are sequentially formed on the sapphire substrate 7 to be epitaxially formed on the sapphire substrate 7. The structure of the epitaxial layer 33. Next, as shown in FIG. B, the first electrode 31 is provided on the upper portion 91 of the epitaxial layer 33 by bonding, plating, coating or doping. As described above, the material of the first electrode 31 is composed of a transparent conductive layer, so that the light energy generated by the light-emitting layer 333 is directly or completely penetrated.

After forming the first electrode 31 on the epitaxial layer 33, please refer to the third C diagram, followed by laser lift off (LLO), grinding or etching technology to make the sapphire substrate 7 and the epitaxial layer. 33 separation. Finally, referring to the third D figure, after the sapphire substrate 7 is removed, and finally, the second electrode 32 is formed in the lower portion 92 of the epitaxial layer 33 in the same manner as the first electrode is formed, and the LED body 3 is completed. Structure.

In the structure of the light-emitting diode wafer 3, the area of the first electrode 31 and the second electrode 32 is larger than the epitaxial layer 33 located therebetween, and based on the epitaxial layer 33 is located at the first electrode 31 and In the middle of the two electrodes 32, when the light-emitting diode wafer 3 is disposed on the metal electrode region 2 in the direction of the side 91 of the epitaxial layer, only the first electrode 31 and the second electrode 32 are in contact with the metal electrode region 2. This can replace the wire bonding and the need for the conductive gold wire in the conventional packaging process, and can directly introduce the current supplied from the external power source to the LED chip 3.

In addition, in order to improve the heat dissipation effect of the light-emitting diode wafer 3, the first electrode 31 and the second electrode 32 may be bonded, plated, coated or doped to form a layer. Diamond Like Carbon (DLC), because the diamond-like carbon film is transparent and has high thermal conductivity, can quickly derive the thermal energy of the LED chip 3. Please refer to the fourth A to the fourth D, which is a structure preparation procedure when the diamond-like carbon film 4 is formed on the first electrode 31 and the second electrode 32, and the program disclosed in the third to third D drawings Basically the same, except that the diamond-like carbon film 4 is added at this time, and the heat dissipation structure is formed on the surfaces of the first electrode 31 and the second electrode 32.

In order to allow the light-emitting diode chip 3 to be fixed on the metal electrode region 2, Referring to the first figure, the joint between the two parts can be assisted by the bonding of the conductive and thermal conductive adhesive 6. The conductive conductive adhesive 6 has the functions of conducting and conducting heat, so that the metal electrode region 2 can be combined with the first electrode. 31 and the second electrode 32 are electrically connected, and the heat energy generated by the LED chip 3 can also be conducted.

Referring to the fifth figure, between the epitaxial layer 33 and the first electrode 31 and the second electrode 32, a transparent conductive material 334 is further disposed, so that the light emitting diode chip 3 and the light emitting element reduce the driving current requirement or reduce the darkness. A better effect is achieved by the current isoelectricity requirement or the improvement of the light extraction efficiency.

In the general process of light-emitting diodes, in addition to solid crystal and wire bonding, there are still procedures for filling the glue to protect the wire or adjust the color of the light. The light-emitting element with multi-directional light-emitting characteristics of the present invention does not need to be filled with glue to protect the wire, but can still be encapsulated by a colloid having a phosphor powder to achieve different light-emitting colors. Referring to the sixth figure, the LED chip 3 can be covered by the energy conversion layer 5 containing the energy conversion material, and the color of the light is changed. This energy conversion material is the aforementioned phosphor powder.

According to the structural design of the light-emitting element having the multi-directional light-emitting characteristics of the present invention, the process of the light-emitting diode can be greatly simplified, and the light-emitting effect of the light-emitting diode can be maintained at a high level, and can simultaneously be applied to the light-emitting diode wafer. Front, back, left, right, and top light. The present invention is a design with high economic value under the production cost of yield, material, processing, etc., which can be directly excluded from the solid crystal and the wire.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and the variations, modifications, and modifications of the shapes, structures, features, and spirits described in the claims of the present invention. All should be included in the scope of the patent application of the present invention.

1‧‧‧Substrate

11‧‧‧Insulated heat sink

2‧‧‧Metal electrode area

21‧‧‧First metal electrode

22‧‧‧Second metal electrode

31‧‧‧First electrode

32‧‧‧second electrode

33‧‧‧ epitaxial layer

4‧‧‧Drilling carbon film

6‧‧‧Electrical and thermal conductive adhesive

83‧‧‧ Surface of the first metal electrode

84‧‧‧ Surface of the second metal electrode

Claims (10)

A light emitting diode chip comprising: an epitaxial layer comprising a first semiconductor layer, a second semiconductor layer and a light emitting layer, wherein the light emitting layer is disposed on the first semiconductor layer and the second semiconductor layer And a first electrode and a second electrode are respectively coupled to the upper portion and the lower portion of the epitaxial layer; wherein at least one side of the first electrode and at least one side of the second electrode are both The side of the epitaxial layer. The light-emitting diode chip of claim 1, wherein the first electrode and the second electrode are transparent conductive layers. The light-emitting diode chip according to claim 2, wherein the material of the first electrode and the second electrode is selected from the group consisting of a metal mesh film, indium tin oxide (ITO) or zinc oxide (ZnO). ). The illuminating diode chip according to any one of the preceding claims, wherein the first electrode and the second electrode completely cover an upper portion and a lower portion of the epitaxial layer, respectively. The illuminating diode chip according to any one of claims 1 to 2, wherein the area of the one electrode and the second electrode is larger than an area of the epitaxial layer covered. The light-emitting diode wafer according to any one of claims 1, 2, and 4, further comprising a type of drilled carbon film covering the first electrode surface. A light-emitting element comprising: a substrate; a metal electrode region disposed on the substrate, comprising a first metal electrode and a And a light-emitting diode wafer according to any one of claims 1 to 2, wherein the light-emitting diode chip has a side direction of one of the epitaxial layers The first electrode and the second electrode are electrically coupled to the first metal electrode and the second metal electrode, respectively. A light-emitting element comprising: a substrate; a metal electrode region disposed on the substrate, comprising a first metal electrode and a second metal electrode; and any one of claim 5 The light emitting diode chip; wherein the light emitting diode chip is disposed on the substrate in a side direction of one of the epitaxial layers, so that the first electrode and the second electrode respectively and the first metal The electrode is electrically coupled to the second metal electrode. The light-emitting element of claim 7, wherein the side of the first electrode is in direct contact with the first metal electrode. The light-emitting element of claim 8, wherein the side of the first electrode is in direct contact with the first metal electrode.