TWI517442B - Light emitting diode (led) device and manufacturing method thereof - Google Patents

Description

Light-emitting diode device and manufacturing method thereof

The present invention relates to a light emitting diode device and a method of fabricating the same, and more particularly to a high voltage light emitting diode device and a method of fabricating the same.

The light-emitting diode has advantages such as long life, small volume, high shock resistance, low heat generation, and low power consumption, and thus has been widely used as an indicator or a light source in households and various devices. In recent years, due to the increasing luminous efficiency of light-emitting diodes, light-emitting diodes have gradually replaced fluorescent lamps and incandescent light bulbs in certain fields, such as scanner light sources requiring high-speed response, backlights for liquid crystal displays, or front light source vehicles. Dashboard lighting, traffic lights, and general lighting. The principle of the light-emitting diode is to convert electric energy into light, that is, to apply current to the light-emitting diode, and to release the light through the combination of electrons and holes, thereby achieving the effect of light emission.

The technical means of achieving a high-voltage light-emitting diode light source by means of packaging is to produce a single light-emitting diode wafer, and then to fix a plurality of light-emitting diode wafers on a package substrate, and to complete the electricity by using a wire bonding method. Sexual connection. In detail, high The manufacturing process of a voltage-emitting diode package generally involves mounting a plurality of light-emitting diode chips on a carrier, such as a printed circuit board carrier, substrate or sub-mount. Then, a plurality of wires are formed between the contacts of the light-emitting diode chip and the contacts of the carrier to electrically connect the light-emitting diode chip to the carrier. The light-emitting diode chip mainly emits light by applying a voltage difference to the wire to cause the light-emitting active layer of the light-emitting diode chip to emit light, and the light-emitting active layer also generates heat energy.

In this way, the high-voltage light-emitting diode package generates more heat energy than the light-emitting diode package in which only one light-emitting diode chip is generally disposed, and the heat dissipation is through the growth substrate with poor thermal conductivity (for example, Sapphire substrate) to conduct thermal energy to the outside. Therefore, if the heat generated by the light-emitting active layer of the light-emitting diode chip is not efficiently discharged, especially when driven by a high current, the light-emitting diode chip is often easily damaged by overheating.

The invention provides a light emitting diode device, which can improve the heat dissipation efficiency of the device, thereby improving the power of each light emitting diode.

The light emitting diode device of the present invention comprises a substrate, a first light emitting diode, a second light emitting diode, an insulating layer, a wire layer, a reflective layer, a first pad and a second pad. The first light emitting diode is disposed on a surface of the substrate and includes a first electrode and a first light emitting region. The second light emitting diode is disposed on the surface and has a gap between the first light emitting diode and the first light emitting diode. The second light emitting diode includes a second electrode and a second light emitting region. The wire layer is disposed in the gap and electrically connected to the first and second light emitting diodes body. The reflective layer is continuously disposed on the first light emitting diode and the second light emitting diode, and is located between the first light emitting region and the first pad and between the second light emitting region and the second pad. The first pad and the second pad are respectively disposed on the first electrode and the second electrode and electrically connected to the first electrode and the second electrode.

The manufacturing method of the light-emitting diode device of the present invention comprises the following steps. First, a light emitting diode structure is provided, comprising a substrate, a first light emitting diode, a second light emitting diode, and a wire layer, wherein the first light emitting diode is disposed on a surface of the substrate And including a first electrode and a first light emitting region. The second light emitting diode is disposed on the surface and has a gap between the first light emitting diode and the first light emitting diode. The second light emitting diode includes a second electrode and a second light emitting region. The wire layer connects the first light emitting diode and the second light emitting diode. Next, a first insulating layer is formed to cover the light emitting diode wafer structure. Next, a reflective layer is formed to cover the first insulating layer and is located on the first light emitting region and the second light emitting region. Next, a second insulating layer is formed to cover the reflective layer. Then, a first pad and a second pad are respectively disposed on the first electrode and the second electrode.

In an embodiment of the invention, the first light emitting diode includes a first semiconductor layer, a first light emitting layer and a second semiconductor layer stacked in sequence from the surface. The first luminescent layer defines a first illuminating region. The first electrode is disposed on the second semiconductor layer. The second light emitting diode includes a third semiconductor layer, a second light emitting layer and a fourth semiconductor layer stacked in sequence from the surface. The second luminescent layer defines a second illuminating region. The second electrode is disposed on the third semiconductor layer.

In an embodiment of the invention, the wire layer is connected to the first semiconductor a layer and a fourth semiconductor layer.

In an embodiment of the invention, the insulating layer contacts the first semiconductor layer, the second semiconductor layer, the third semiconductor layer, and the fourth semiconductor layer, and covers the surface of the reflective layer.

In an embodiment of the invention, the first semiconductor layer and the third semiconductor layer are N-type semiconductor layers. The second semiconductor layer and the fourth semiconductor layer are P-type semiconductor layers.

In an embodiment of the invention, the first semiconductor layer and the third semiconductor layer are N-type semiconductor layers. The second semiconductor layer and the fourth semiconductor layer are P-type semiconductor layers.

In an embodiment of the invention, the first luminescent layer and the second luminescent layer comprise a multiple quantum well (MQW).

In an embodiment of the invention, the light emitting diode device further includes a reflective layer disposed in the gap, and the insulating layer covers the surface of the reflective layer.

In an embodiment of the invention, after the step of forming the second insulating layer, the method further includes the steps of exposing the top surfaces of the first electrode and the second electrode, the steps comprising: first, after forming the first insulating layer, A portion of the first insulating layer is removed to expose the top surfaces of the first electrode and the second electrode. Then, after the reflective layer is formed, a portion of the reflective layer is removed to expose the top surfaces of the first electrode and the second electrode. Next, after the second insulating layer is formed, a portion of the second insulating layer is removed to expose the top surfaces of the first electrode and the second electrode.

Based on the above, the light emitting diode device of the present invention is in a table away from the substrate A pad is disposed on the surface, and the electrical conductivity of the electrode is extended to the pad, so that the LED device can be connected to the carrier by flip chip bonding. In this way, the thermal energy generated by the light-emitting diode device can conduct heat energy to the carrier through the heat-conducting pad, without dissipating heat through the substrate with poor thermal conductivity, thereby improving the heat dissipation of the light-emitting diode device. effectiveness. Furthermore, since the heat dissipation efficiency of the light-emitting diode device is improved, the driving current that the light-emitting diode can carry can also be increased, thereby reducing the number of light-emitting diodes in the light-emitting diode device, thereby reducing the production cost. . In addition, the reflective layer is disposed between the light-emitting layer of the light-emitting diode device and the pad to reflect the light emitted by the light-emitting layer, thereby improving the light-emitting efficiency of the light-emitting diode device.

The above described features and advantages of the invention will be apparent from the following description.

100‧‧‧Lighting diode device

110‧‧‧Substrate

112‧‧‧ surface

120‧‧‧First light-emitting diode

122‧‧‧First semiconductor layer

124‧‧‧First luminescent layer

126‧‧‧Second semiconductor layer

128‧‧‧First electrode

130‧‧‧Second light-emitting diode

132‧‧‧ third semiconductor layer

134‧‧‧second luminescent layer

136‧‧‧fourth semiconductor layer

138‧‧‧second electrode

140‧‧‧Insulation

140a‧‧‧first insulation

140b‧‧‧Second insulation

150‧‧‧ wire layer

160‧‧‧first mat

170‧‧‧second mat

190‧‧‧reflective layer

200‧‧‧carrier

G‧‧‧ gap

1A-1H are schematic cross-sectional views showing a manufacturing process of a light emitting diode device according to an embodiment of the invention.

2 is a cross-sectional view of a light emitting diode device in accordance with an embodiment of the present invention.

1A-1H are schematic cross-sectional views showing a manufacturing process of a light emitting diode device according to an embodiment of the invention. The system of the light-emitting diode device of this embodiment The method includes the following steps: First, a light emitting diode structure as shown in FIG. 1A is provided, which includes a substrate 110, a first light emitting diode 120, a second light emitting diode 130, and a wire layer. 150. In this embodiment, the substrate 110 may be a growth substrate for semiconductor growth, such as a sapphire substrate. The first light emitting diode 120 is disposed on one surface 112 of the substrate 110 and includes a first electrode 128 and a first light emitting layer 124, wherein the first light emitting layer 124 defines a first light emitting region. In detail, the first light emitting diode 120 includes a first semiconductor layer 122, a first light emitting layer 124, and a second semiconductor layer 126 stacked from the surface 112 in a direction away from the surface 112, and the first light emitting layer. 124 defines the first illuminating region described above. The first LED 128 further includes a first electrode 128 and a third electrode (not shown). The first electrode 128 is disposed on the second semiconductor layer 126, and the third electrode is disposed on the first semiconductor layer 122. on.

In the above, the second LED 230 is disposed on the surface 112 and has a gap G between the first LEDs 120. The second light emitting diode 130 includes a second electrode 138 and a second light emitting layer 134, wherein the second light emitting layer 134 defines a second light emitting region. In detail, the second LED 230 includes a third semiconductor layer 132, a second luminescent layer 134, and a fourth semiconductor layer 136, which are sequentially stacked from the surface 112 in a direction away from the surface 112, and second. The luminescent layer 134 defines the second illuminating region described above. The second LED 130 further includes a fourth electrode (not shown). The second electrode 138 is disposed on the third semiconductor layer 132, and the fourth electrode is disposed on the fourth semiconductor layer 136. Specifically, the first semiconductor layer 122 and the third semiconductor layer 132 of the embodiment are N-type semiconductor layers, and the second half The conductor layer 126 and the fourth semiconductor layer 136 are P-type semiconductor layers. In addition, the first luminescent layer 124 and the second luminescent layer 134 are, for example, multiple quantum wells (MQW).

In the above, the present invention provides a wire layer 150 on the surface of the substrate 110 and is located in the gap G. As shown in FIG. 1A, the first LED body 120 and the second LED body 130 are electrically connected. More specifically, the wire layer 150 is a third electrode electrically connected to the first light emitting diode 120 and a fourth electrode of the second light emitting diode 130. The material of the wire layer 150 includes, but is not limited to, nickel (Ni), gold (Au), rhenium (Rh), silver (Ag), titanium (Ti), aluminum (Al), tantalum (Ta), vanadium (V), and the like. Conductive material or a combination thereof Next, as shown in FIG. 1B, a first insulating layer 140a is formed, which covers the light emitting diode wafer structure as shown in FIG. 1A, that is, the first insulating layer 140a covers the first light emitting diode. 120, the second light emitting diode 130 and the surface of the wire layer 150. In this embodiment, the first insulating layer 140a contacts the first semiconductor layer 122, the second semiconductor layer 126, the third semiconductor layer 132, and the fourth semiconductor layer 136, and the material thereof is an oxide, including but not limited to cerium oxide. An insulating material such as (SiO ₂ ) or titanium dioxide (TiO ₂ ). Next, as shown in FIG. 1C, a portion of the first insulating layer 140a positioned on the top surface of the first electrode 128 and the second electrode 138 is removed to expose the top surfaces of the first electrode 128 and the second electrode 138. In the present embodiment, the method of removing a portion of the first insulating layer 140a is, for example, etching. It is to be noted that since the first insulating layer 140a of the present invention is formed between the wiring layer 150 and the subsequently formed reflective layer, and contacts the first semiconductor layer 122, the second semiconductor layer 126, the third semiconductor layer 132, and the The fourth semiconductor layer 136, therefore, in addition to the electrical isolation characteristics of the first insulating layer 140a of the present invention, the metal atoms of the reflective layer can be prevented from diffusing into the semiconductor layer, thereby affecting the luminous efficiency of the light-emitting diode wafer.

Referring to FIG. 1D and FIG. 1E simultaneously, a reflective layer 190 is formed to cover the first insulating layer 140a such that the first insulating layer 140a is located between the wire layer 150 and the reflective layer 190. In this embodiment, the reflective layer 190 is a material having high reflectivity, including but not limited to a material having high reflectivity such as silver (Ag), and the reflective layer 190 is continuously formed in the first light-emitting region and the second light-emitting region. The region and the wire layer 150 are located between the first luminescent layer 124 and the first pad 160 and between the second luminescent layer 134 and the second pad 170 to simultaneously reflect the first luminescent layer 124 and the second luminescent layer 134 emitted light. The reflective layer 190 is formed on the top surface of the first insulating layer 140a, the first electrode 128, and the second electrode 138, as shown in FIG. 1D, for example, as shown in FIG. 1D, and is removed by, for example, an etching process. The first electrode 128 and a portion of the top surface of the second electrode 138 are reflective layer 190 to expose the top surfaces of the first electrode 128 and the second electrode 138 as shown in FIG. 1E. It should be noted that, since the reflective layer 190 of the present invention is disposed on the first light emitting diode 120 and the second light emitting diode 130, the reflective layer 190 of the present invention can simultaneously reflect the first light emitting layer 124 and The light of the second light-emitting layer 134, as a result, improves the overall luminous efficiency of the light-emitting diode wafer of the present invention.

Referring to FIG. 1F and FIG. 1G simultaneously, a second insulating layer 140b is formed to cover the reflective layer 190. Therefore, the first insulating layer 140a and the second insulating layer 140b cover the reflective layer 190. In the present embodiment, the material of the second insulating layer 140b includes, but is not limited to, an insulating material such as cerium oxide (SiO ₂ ) or titanium oxide (TiO ₂ ), and covers the reflective layer 190 and the first electrode 128 as shown in FIG. 1F. And a top surface of the second electrode 138. Next, as shown in FIG. 1E, a portion of the second insulating layer 140b positioned on the top surface of the first electrode 128 and the second electrode 138 is removed by, for example, an etching process to expose the first electrode 128 as shown in FIG. 1G. The top surface of the second electrode 138. Next, a first pad 160 and a second pad 170 are disposed on the first electrode 128 and the second electrode 138 and electrically connected to the first electrode 128 and the second electrode 138. In this embodiment, the materials of the first pads 160 and the second pads 170 include, but are not limited to, solder materials such as gold-tin. Thus, the process of the light-emitting diode device 100 of the present embodiment is substantially completed.

2 is a cross-sectional view of a light emitting diode device in accordance with an embodiment of the present invention. Referring to FIG. 2 , the LED device 100 according to the above manufacturing method includes a substrate 110 , a first LED 120 , a second LED 130 , and an insulating layer 140 . (140a, 140b), a wire layer 150, a first pad 160, and a second pad 170. The first light emitting diode 120 is disposed on a surface 112 of the substrate 110. The first light emitting diode 120 includes a first electrode 128, a third electrode (not shown), and a first light emitting region. The second light emitting diode 130 is also disposed on the surface 112 and has a gap with the first light emitting diode 120. The second LED 130 includes a second electrode 138, a fourth electrode (not shown), and a second light emitting region. In detail, the first LEDs 120 may be sequentially stacked in a direction away from the surface 112 from the surface 112 as described above including a first semiconductor layer 122, a first luminescent layer 124, and a second semiconductor layer 126. The first luminescent layer 124 defines a first illuminating region, and the first electrode 128 is disposed at a second On the semiconductor layer 126, a third electrode is disposed on the first semiconductor layer 122. The second light emitting diode 130 may also be sequentially stacked from the surface 112 away from the surface 112 as described above, wherein the second light emitting layer 134 is defined by a second semiconductor layer 132, a second light emitting layer 134, and a fourth semiconductor layer 136. The second light emitting region is disposed, and the second electrode 138 is disposed on the third semiconductor layer 132, and the fourth electrode is disposed on the fourth semiconductor layer 136.

The wire layer 150 is disposed in the gap G and electrically connected to the first light emitting diode 120 and the second light emitting diode 130. More specifically, the wire layer 150 is electrically connected to the first light emitting diode 120. The third electrode and the fourth electrode of the second LED 130. The insulating layer 140 is between the wire layer 150 and the reflective layer 190 to electrically isolate the wire layer 150 from the reflective layer 190. In this embodiment, the reflective layer 190 is disposed on the first and second light emitting diodes 120 and 120, and between the first light emitting layer 124 and the first light emitting layer 160 and the second light emitting layer. 134 is between the second pad 170. The insulating layer 140 is disposed between the wire layer 150 and the first pad 160 and the second pad 170, and contacts the first semiconductor layer 122, the second semiconductor layer 126, the third semiconductor layer 132, and the fourth semiconductor layer 136. The surface of the reflective layer 190 is coated to prevent the reflective layer 190 from diffusing to the first semiconductor layer 122, the second semiconductor layer 126, the third semiconductor layer 132, and the fourth semiconductor layer 136.

In this way, the LED device 100 can be electrically connected to the carrier 200 through the first pad 160 and the second pad 170. That is to say, the LED device 100 of the present embodiment can be electrically connected to the carrier 200 by means of flip chip bonding. Therefore, the light-emitting diode device 100 can be replaced by a heat-transfer efficiency A pad 160 and a second pad 170 conduct heat generated by the pad 160 to the carrier without dissipating heat through the substrate 110 having poor thermal conductivity, thereby improving the heat dissipation efficiency of the LED device 100. The reflective layer 190 can simultaneously reflect the light emitted by the first light-emitting layer 124 and the second light-emitting layer 134 to increase the light-emitting efficiency of the light-emitting diode device 100.

In an embodiment, the number of layers of the first insulating layer may be a single layer or a plurality of layers, and the material may be one or more. The number of layers of the second insulating layer may be a single layer or a plurality of layers, and the material may be one or more. The first insulating layer and the second insulating layer may have the same or different number of layers and materials. In an embodiment, the number of layers of the reflective layer may be a single layer or multiple layers, and the material may be one or more. The reflective layer does not have to be formed integrally on the electrode region, or may be partially formed on the electrode region. The reflective layer can be a metal or an insulating material. In one embodiment, the substrate is not limited to sapphire, and may be an insulating substrate, a plastic substrate, a glass substrate, a Gallium Nitride (GaN) substrate, a Silicon Carbide (SiC) substrate, or a crucible (Silicon, Si). a substrate or a metal substrate. An Indium Tin Oxide (ITO) transparent electrode pattern can also be formed on the electrode. In an embodiment, the pads can be completed through a planarization process. In an embodiment, a superlattice structure may be further included between the active layer and the semiconductor layer. In one embodiment, the light emitting diode device is disposed on the carrier in a flip chip bonding manner.

In summary, the light-emitting diode device of the present invention is provided with a pad on a surface away from the substrate, and extends the electrical conductivity of the electrode to the pad, so that the light-emitting diode device can be connected to the flip-chip bonding manner. On the carrier. So, the light-emitting diode device The generated heat energy can conduct heat energy to the carrier through the heat-conducting pad, and does not need to transmit heat through the substrate with poor heat conduction efficiency, thereby improving the heat dissipation efficiency of the light-emitting diode device. Furthermore, since the heat dissipation efficiency of the light-emitting diode device is improved, the driving current that the light-emitting diode can carry can also be increased, thereby reducing the number of light-emitting diodes in the light-emitting diode device, thereby reducing the production cost. . In addition, the reflective layer is disposed between the light-emitting layer of the light-emitting diode device and the pad to reflect the light emitted by the light-emitting layer, thereby improving the light-emitting efficiency of the light-emitting diode device.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Lighting diode device

110‧‧‧Substrate

112‧‧‧ surface

120‧‧‧First light-emitting diode

122‧‧‧First semiconductor layer

124‧‧‧First luminescent layer

126‧‧‧Second semiconductor layer

128‧‧‧First electrode

130‧‧‧Second light-emitting diode

132‧‧‧ third semiconductor layer

134‧‧‧second luminescent layer

136‧‧‧fourth semiconductor layer

138‧‧‧second electrode

140‧‧‧Insulation

140a‧‧‧first insulation

140b‧‧‧Second insulation

150‧‧‧ wire layer

160‧‧‧first mat

170‧‧‧second mat

190‧‧‧reflective layer

200‧‧‧carrier

Claims (8)

A light-emitting diode device comprising: a substrate having a surface; a first light-emitting diode disposed on the surface, the first light-emitting diode comprising a first electrode and a first light-emitting region; a second light emitting diode disposed on the surface and having a gap with the first light emitting diode, the second light emitting diode comprising a second electrode and a second light emitting region; a wire layer, The first light-emitting diode and the second light-emitting diode are electrically connected to the first light-emitting diode and the second light-emitting diode, respectively disposed on the first electrode and the second electrode And electrically connected to the first electrode and the second electrode; and a reflective layer continuously disposed on the first light emitting diode and the second light emitting diode, and located in the first light emitting region and the Between the first pads and between the second light emitting region and the second pads. The illuminating diode device of claim 1, wherein the first illuminating diode comprises a first semiconductor layer, a first luminescent layer and a second semiconductor layer sequentially stacked from the surface. The first illuminating layer defines the first illuminating region, the first electrode is disposed on the second semiconductor layer, and the second illuminating diode comprises a third semiconductor layer, a second luminescent layer and a fourth semiconductor layer The second light emitting layer defines the second light emitting region, and the second electrode is disposed on the third semiconductor layer. The illuminating diode device of claim 2, wherein the wire layer is electrically connected to one of the third electrode of the first illuminating diode and the fourth electrode of the second illuminating diode. The illuminating diode device of claim 2, wherein the A semiconductor layer and the third semiconductor layer are N-type semiconductor layers, and the second semiconductor layer and the fourth semiconductor layer are P-type semiconductor layers. The illuminating diode device of claim 1, further comprising an insulating layer disposed between the wire layer and the first pad and the second pad. The illuminating diode device of claim 5, wherein the insulating layer comprises a first insulating layer and a second insulating layer, the first insulating layer contacting the first semiconductor layer and the second semiconductor layer The third semiconductor layer and the fourth semiconductor layer, and the first insulating layer and the second insulating layer cover the reflective layer. A method for fabricating a light-emitting diode device includes: providing a light-emitting diode structure including a substrate, a first light-emitting diode, a second light-emitting diode, and a wire layer, wherein the first The light emitting diode is disposed on a surface of the substrate, and includes a first electrode and a first light emitting region, wherein the second light emitting diode is disposed on the surface and has a relationship between the first light emitting diode and the first light emitting diode a second light-emitting diode includes a second electrode and a second light-emitting region. The wire layer connects the first light-emitting diode and the second light-emitting diode; forming a first insulating layer covering the a light emitting diode structure; forming a reflective layer covering the first insulating layer and located on the first light emitting region and the second light emitting region; forming a second insulating layer covering the reflective layer; and respectively providing a The first pad and the second pad are on the first electrode and the second electrode. The method for fabricating a light-emitting diode device according to claim 7, further comprising the step of exposing the top surfaces of the first electrode and the second electrode after the step of forming the second insulating layer, wherein the step of forming the second insulating layer The method includes: after forming the first insulating layer, removing a portion of the first insulating layer to expose a top surface of the first electrode and the second electrode; After forming the reflective layer, removing a portion of the reflective layer to expose the top surface of the first electrode and the second electrode; and after forming the second insulating layer, removing a portion of the second insulating layer a layer to expose the first electrode and a top surface of the second electrode.