TWI419362B - High luminous efficiency solid state light emitting element and its manufacturing method - Google Patents

Description

High luminous efficiency solid-state light-emitting element and method of manufacturing same

The present invention relates to a solid state light emitting device and a method of fabricating the same, and more particularly to a high luminous efficiency solid state light emitting device and a method of fabricating the same.

Light Emitting Diode (LED) is a kind of semiconductor component. Due to its small size, long life and low power consumption, LED has been widely used in 3C product indicators and display devices. As a display or a backlight, the luminous efficiency of a light-emitting diode has been a very important research topic.

In general, the luminous efficiency of a light-emitting diode element can be classified into internal quantum efficiency and external quantum efficiency. Internal quantum efficiency refers to the efficiency with which electrons and holes combine to emit photons in the luminescent layer. Therefore, it has a direct and close relationship with the organic or inorganic luminescent materials used in the epitaxial layer itself. The external quantum efficiency refers to the photon emitted from the component to the photo. The total efficiency of the extraction, which is the total product of the internal quantum efficiency and the photon extraction rate, and the photon extraction rate is the efficiency of the photon emitted from the inside of the LED component to the outside, which is deeply designed by the structure of the LED component itself. And the influence of physical characteristics, for example, effective to enhance the photon extraction rate to reflect the light generated by the epitaxial layer to the light emitting surface of the desired emission, so different reflective layers with high reflectivity are selected to enhance the light emitted from the emitting surface. s efficiency.

In order to improve the luminous efficiency of the LED component, in addition to considering the photon extraction rate, how to ensure the best luminous efficiency of the epitaxial layer in the electroluminescence process is another important consideration. example For example, a current dispersion layer that uniformly distributes the current to the light-emitting layer may be added between the subsequent unit and the epitaxial layer to ensure optimal bonding efficiency of electrons and holes in the epitaxial layer, or to emit light. The ohmic contact resistance between the polar body elements is minimized to increase the efficiency of current flow into the luminescent layer.

In addition, the heat dissipation problem is another important key to the development of light-emitting diodes. Since the photoelectric conversion efficiency of the current LED (LED) component is only about 10 to 30%, most of the electrical energy is wasted into waste heat during the photoelectric conversion process and accumulated in the LED component, especially in High-power and large-sized LED components generate more waste heat. Therefore, if the waste heat accumulated in the LED components cannot be discharged, the LED components will be degraded and the LEDs will be lowered. The lifetime of the body components, this new generation of artificial light sources can not make a greater breakthrough.

At present, the substrate commonly used for the red light emitting diode is a gallium arsenide (GaAs) substrate, and the substrate commonly used for the blue light emitting diode is a sapphire substrate, and the common disadvantage of both the gallium arsenide or the sapphire substrate is that Poor thermal conductivity (thermal conductivity of gallium arsenide 50w/m∘K, thermal conductivity of sapphire 40w/m∘K), so to solve the problem of heat dissipation, metal substrate has become an important development to solve the heat dissipation of light-emitting diodes. Directions, for example, a developed aluminum tantalum carbide composite substrate (thermal conductivity of 180 w/m ∘ K), a ruthenium substrate (thermal conductivity of 150 w/m ∘ K), and a copper substrate (thermal conductivity of 400 w/m ∘ K), The luminous efficiency of the element can be improved by its high heat dissipation.

Referring to FIG. 1 , a general LED component includes a substrate 11 , a plurality of epitaxial layers 121 , and a plurality of epitaxial layers 121 . The diode unit 12 of the top electrode 122 of the surface, and a subsequent unit 13 connecting the substrate 11 and the diode unit 12. The epitaxial layers 121 can emit light with a photoelectric effect when receiving electrical energy.

In addition to the heat dissipation of the substrate 11 , the material used to connect the substrate 11 and the subsequent unit 13 of the diode unit 12 is another effect on the heat dissipation of the light-emitting diode element. An important reason for the stability of polar components.

Among the constituent materials currently used for the soldering substrate 11 and the landing unit 13 of the diode unit 12, the most commonly used materials are tin (Sn)-based soft solder materials, and gold-tin ( AuSn) or gold-ruthenium (AuGe) alloy-based hard solders; tin has the advantage of being inexpensive but has the disadvantage of low strength and poor thermal stability, gold-tin (AuSn) or gold-ruthenium (AuGe) The advantages are high strength and good thermal stability, but the disadvantages are high price and poor thermal conductivity.

Referring to Table 1, Table 1 is an alloy material generally used for the landing unit 13. As shown in Table 1, gold-based alloys such as gold/20% tin (Au/20% Sn) and gold crucible (Au/Si) ), or Au/Ge, have good mechanical properties and thermal stability, but these alloy materials are very expensive because they all contain gold, and the operating temperatures of these alloy materials need to be higher. When the temperature is (280 to 363 ° C), it is easy to cause damage to the diode element and destroy the luminous efficiency of the light-emitting diode element.

It can be seen from the above description that, in addition to the heat dissipation performance of the substrate, the related bonding material is another performance that affects the stability of the LED component and the lifetime and operation of the subsequent LED component. Therefore, an illuminating element constituting material having low cost, high heat conduction performance, high strength, high temperature stability, and connection of a substrate and a diode unit under a relatively low temperature operating condition has been sought, and has been in the technical field. One of the important topics to be actively resolved.

Accordingly, it is an object of the present invention to provide a high luminous efficiency solid state light-emitting element that does not contain a solder material of gold and silver.

Another object of the present invention is a method of manufacturing a high luminous efficiency solid state light-emitting element that does not include a solder material of gold and silver.

Thus, a high luminous efficiency solid state light emitting device of the present invention comprises a substrate, a diode unit, and a subsequent unit.

The diode unit includes an epitaxial layer that extends mostly upwardly on the surface of the substrate and that emits light when externally supplied with electrical energy.

The bonding unit connects the substrate and the diode unit, and the constituent material of the bonding unit does not include any one of gold and silver.

Further, the method for producing a high luminous efficiency solid-state light-emitting element of the present invention comprises the following four steps.

First, a diode unit having a plurality of semiconductor epitaxial layers is formed on a growth substrate, and each of the epitaxial layers has an upper surface away from the growth substrate.

A metal layer is then formed on the surface of the substrate, and the substrate is disposed on the diode unit toward the upper surface of the epitaxial layers.

The substrate having the metal layer and the diode unit are heated to a predetermined temperature, and the metal layer is converted into a subsequent unit, and then the substrate is bonded to the diode unit.

The grown substrate is then removed to expose the surface of the epitaxial layers.

Finally, an electrode unit capable of supplying electric energy is formed on the surface of the majority of the exposed epitaxial layer to obtain the high luminous efficiency solid-state light-emitting element of the present invention.

The effect of the invention is that the diode unit is connected to the epitaxial layer by a bonding unit which does not comprise gold and silver, because the bonding unit has low cost, high thermal conductivity, high strength, and high temperature. Stability, therefore, can reduce the cost and improve the stability and reliability of the diode components in the subsequent process, thereby improving the yield and service life of the diode components.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Referring to Figures 2 and 3, the high luminous efficiency solid state light-emitting element of the present invention A first preferred embodiment is obtained by a method of fabricating a high luminous efficiency solid state light emitting device as shown in FIG.

The high luminous efficiency solid state light emitting device comprises a substrate 21, a diode unit 22, and a subsequent unit 23.

The substrate 21 is one selected from the group consisting of an aluminum lanthanum carbide (AlSiC) metal composite material, a tungsten copper alloy (CuW), and a molybdenum copper (CuMo) alloy.

The diode unit 22 includes a plurality of epitaxial layers 221 each made of a semiconductor material, and an electrode unit 222 disposed on a top surface of the plurality of epitaxial layers 221. Since this portion of the structure is well known in the industry, The composition and manufacturing method of the diode unit 22 are not the focus of the present invention, and therefore will not be further described.

The bonding unit 23 is connected to the substrate 21 and the diode unit 22, and the constituent material of the bonding unit 23 does not include any one of gold and silver. In the embodiment, the bonding unit 23 is gallium, and It is composed of an Al-Ga solid solution, a Cu-Ga solid solution, or a combination thereof.

Since the constituent material of the bonding unit 23 of the present invention does not contain the gold-containing solder of the conventional soldering diode unit and the substrate, the cost of the material can be effectively reduced, and the bonding unit 23 has high thermal conductivity and high strength, and The high temperature stability can improve the stability and reliability of the diode components in the subsequent process, thereby improving the yield and service life of the diode components.

The above-described high luminous efficiency solid-state light-emitting element can be more clearly understood after the following description of the manufacturing method of the high luminous efficiency solid-state light-emitting element of the present invention.

First, in step 101, a growth substrate made of sapphire is prepared, and a diode unit is formed on the growth substrate, and the diode unit has a plurality of epitaxial crystals formed by using a gallium nitride semiconductor as a material. a layer, and each of the epitaxial layers has an upper surface. Since this part of the structure is well known in the industry, and the composition and manufacturing method of the diode unit are not the focus of the present invention, they will not be described again.

Next, in step 103, a metal layer is formed on the surface of a substrate, the metal layer has a first metal film made of aluminum as a material and a second metal film made of copper as a material. And a third metal film made of gallium as a material, and then the metal layer is covered on the surface of the diode unit to obtain an intermediate composition.

Step 105 is further performed, the intermediate composition is heated to a temperature of not less than 254 ° C, and the metal layer is transformed into a bonding unit for soldering the substrate and the diode unit, and then the substrate and the diode are further Unit combination.

It is worth mentioning that the metal layer composed of gallium, copper, and aluminum metal, when the temperature rises to 254 ° C, the low temperature gallium (the melting point of gallium is about 30 ° C) will form a high temperature dielectric with copper. An intermetallic phase, CuGa _x ; and an aluminum-alloy solution formed with aluminum to be converted into the subsequent unit.

Referring to FIG. 4 and FIG. 5, FIG. 4 and FIG. 5 are respectively binary phase diagrams of copper-gallium and aluminum-gallium, and it can be seen from FIG. 4 that copper-gallium is not less than 254 ° C. The alloy is a solid phase except that the content of gallium is not more than 66% by weight of the copper-gallium alloy, and other ratios of copper-gallium alloy are liquid. Phase or solid-liquid phase coexist; in addition, as shown in Fig. 5, the aluminum-gallium alloy at a temperature of not less than 254 ° C is a solid phase other than the solid content of gallium content not greater than 20% by weight of the aluminum-gallium alloy. - Gallium alloys are all in the liquid phase or in the solid phase.

Therefore, in order to obtain a solid phase connecting unit that can be used to connect the substrate and the diode unit, preferably, the copper-gallium forming intermetallic phase, CuGa _x , gallium content is not more than copper. - 66% by weight of the gallium alloy (i.e., x is not greater than 2), and the content of gallium in the aluminum-gallium alloy is not more than 20% by weight of the aluminum-gallium alloy. In addition, the metal layer may be composed only of two metal layers of aluminum and gallium, and the obtained subsequent unit is composed of an Al-Ga solid solution, and the content of gallium in the aluminum-gallium alloy is not more than 20% by weight of the aluminum-gallium alloy. The bonding unit composed of gallium, aluminum-gallium and/or copper-gallium is not only lower in operating temperature than conventionally used gold-based solder, but also low in cost due to the absence of gold, and The bonding unit composed of gallium, aluminum-gallium solid solution and/or copper-gallium intermetallic alloy has high thermal conductivity, high strength, and high temperature stability, thereby improving the stability of the diode component in subsequent processes. And reliability, thereby improving the yield and service life of the diode components.

Referring to FIG. 6, further, it is worth mentioning that the step 105 can also use a bonding device 3 to convert the metal layer into a bonding unit for soldering the substrate and the diode unit, and the substrate and the diode. Unit combination.

The squeezing device 3 includes a pressure chamber 31, an air venting chamber 32, and a sealed accommodating space 33 defined by the pressure chamber 31 and the air venting chamber 32. The pressure chamber 31 has an air inlet 311 and an air outlet 312. The gas is taken in and out, and the suction chamber 32 has a heating unit 321 and a tubular suction member 322. When the step 105 is performed, the intermediate composition obtained in the step 103 can be placed in the suction chamber 32, and the heating layer 321 is heated to convert the metal layer into a subsequent unit that solders the substrate and the diode unit. The substrate is then combined with the diode unit. Alternatively, the intermediate composition may be placed in the accommodating space 33, and a foil such as aluminum foil, copper foil, polyamine, or graphite may be placed. The substrate is then adjusted to a pressure of about 15 to 200 psi by the pressure chamber 31, and while the temperature of the heating unit 321 is adjusted to a predetermined temperature and the air is drawn through the suction member 322, the substrate is applied through the foil. The non-isotropic pressure allows the substrate to achieve a more uniform adhesion to the epitaxial layers.

Further, it is worth mentioning that the stress caused by the difference in the expansion coefficient between the growth substrate and the epitaxial layer in the process of epitaxy generally causes the surface of the epitaxial layer to have an unevenness.

Referring to FIG. 7, the deformation of the gallium nitride-based semiconductor epitaxial layer formed on the sapphire substrate is as shown in FIG. 7. The sapphire substrate on which the epitaxial layer of the gallium nitride semiconductor is formed has an offset ratio of about 30 μm from the center to the edge. Therefore, the surface of the epitaxial layer is not flat. Generally, the rigid flat substrate is not easily adhered to the micro-deformed diode unit, and the poor adhesion is likely to cause subsequent sapphire substrate peeling process. The yield is reduced and the reliability of the diode components is affected. Therefore, in order to improve the adhesion between the substrate and the diode unit, the substrate is thin and flexible, and can be attached with the undulation of the epitaxial layers. Therefore, preferably, the thickness of the substrate For no more than 500 μm, more preferably, the thickness of the substrate is not more than 200 μm. A substrate having better adhesion to the diode unit is obtained.

Further, in step 107, the grown substrate is peeled off from the epitaxial layer by laser lift off or wet etching, and the surface of the epitaxial layer is exposed.

Finally, in step 109, an electrode unit capable of supplying electric energy is formed on the surface of the plurality of epitaxial layers, thereby obtaining a preferred embodiment of the high luminous efficiency solid-state light-emitting element as shown in FIG. 2.

In the process of stripping the grown substrate by electro-radiation in step 107, the selected laser wavelength passes through the sapphire growth substrate to reach an epitaxial layer composed of the semiconductor material, and the energy of the laser is epitaxial. After the layer is absorbed, high temperature is generated and the epitaxial layer is easily destroyed. Therefore, it is worth mentioning that the sapphire growth substrate used in step 101 can also form a metal layer as described in step 103 on the surface of the growth substrate. The melting point of the metal layer made of gallium is only about 30 ° C, so that only a small amount of energy is required to separate the grown substrate from the gallium metal layer as a release film, thereby avoiding the current laser The high temperature generated by the stripping process causes damage to the epitaxial layer.

In addition, in the process of epitaxial layer formation, since the thermal expansion coefficient of sapphire (about 6 ppm/∘K) is slightly larger than the epitaxial layer made of, for example, gallium nitride, it will be in the epitaxial layer. Compressive stress is generated. In order to avoid the destruction of the epitaxial layer caused by the rapid release of the internal stress when the growth substrate and the epitaxial layer are peeled off in step 107, the substrate selected in the step 103 is selected from the group consisting of The coefficient of thermal expansion is equal to or slightly larger than the coefficient of thermal expansion of the sapphire growth substrate to maintain the thermal expansion The internal stress of the crystal layer during the epitaxial formation process does not cause the destruction of the epitaxial layer caused by the rapid release of the internal stress due to the subsequent process.

Refer to Table 2, Table 2 for the thermal expansion coefficient and thermal conductivity of different materials. Therefore, in the embodiment, the substrate is made of a material selected from the group consisting of aluminum lanthanum carbide (AlSiC) metal composite material, tungsten copper alloy (CuW), and molybdenum copper (CuMo) alloy, and the thermal expansion coefficient is approximately equal to or slightly larger than the thermal expansion coefficient of sapphire. .

Referring to FIG. 8, it is more worth mentioning that the substrate 21 of the step 103 may have a base layer 211, and a reflective layer 212, a buffer layer 213, and a current dispersion formed by sequentially forming the surface of the base layer 211. Layer 214, which produces the high luminous efficiency solid state light emitting element as shown in FIG.

The reflective layer 212 is made of a highly reflective metal material and may be selected from any one of gold, aluminum, silver, copper, platinum, and palladium or a combination thereof.

The buffer layer 213 may be formed by stacking one or more dielectric constant materials having a refractive index no greater than the current dispersion layer 214, having a surface 215 and a plurality of through holes 216 extending downwardly from the surface 215.

The current dispersion layer 214 may be selected from the group consisting of indium tin oxide, nickel gold alloy, and cerium oxide, or a combination of these materials, having high conductivity and transparency. And a high refractive index, the current level is diffused and the light generated by the epitaxial layer 221 is transmitted, and the reflective layer 212 has a surface portion 217 deposited on the surface of the buffer layer 213, and most of the deposited The conductive portion 218 of the through holes 216.

The reflective layer 212 can be electrically connected to the current dispersion layer 214 via the conductive portions 218 .

When light is emitted from the epitaxial layer 221 to the surface portion 217 and the conductive portions 218, the light can be reflected and then substantially turned to the outside, and the shape, the aperture, and the distribution density of the through holes 216 can be adjusted. Preferably, the current dispersion layer 214 has a film thickness of 10 to 500 nm, the diameter of each of the through holes 216 is 2 to 20 μm, and the distance between any two of the holes 216 is 5 to 100 μm.

9 and FIG. 10, FIG. 9 is a schematic diagram of a high luminous efficiency solid-state light-emitting element having different perforations 216, and FIG. 10 is a partial enlarged view of FIG. 9 and showing light reflected by the surface portion 217 and the conductive portions 218. Schematic diagram of light distribution.

It can be seen from the above description that the diode unit is connected to the epitaxial layer by a bonding unit which does not contain gold and silver, because the bonding unit has low cost, high thermal conductivity, high strength, and high temperature stability. Therefore, the cost and the stability and reliability of the diode component in the subsequent process can be improved, thereby improving the yield and the service life of the diode component, so that the object of the present invention can be achieved.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention cannot be limited thereto, that is, the patent application according to the present invention The scope of the invention and the equivalent equivalents and modifications of the invention are still within the scope of the invention.

101‧‧‧Steps

103‧‧‧Steps

105‧‧‧Steps

107‧‧‧Steps

109‧‧‧Steps

21‧‧‧Substrate

211‧‧‧ grassroots

212‧‧‧reflective layer

213‧‧‧buffer layer

214‧‧‧current dispersion layer

215‧‧‧ surface

216‧‧‧Perforation

217‧‧‧ Surface

218‧‧‧Training Department

22‧‧‧diode unit

221‧‧‧Elevation layer

222‧‧‧electrode unit

23‧‧‧Next unit

3‧‧‧Next device

31‧‧‧ Pressure chamber

311‧‧‧Intake holes

312‧‧‧ Vents

32‧‧‧Exhaust chamber

321‧‧‧heating unit

322‧‧‧Exhaust parts

33‧‧‧ accommodating space

1 is a schematic view showing the structure of a conventional light-emitting diode element. FIG. 2 is a schematic view showing a first preferred embodiment of the high luminous efficiency solid-state light-emitting element of the present invention; FIG. 3 is a flow chart illustrating the present invention. FIG. 4 is a binary phase diagram illustrating a phase diagram of a copper-gallium two-component alloy; and FIG. 5 is a binary phase diagram illustrating an aluminum-gallium two-component alloy FIG. 6 is a schematic view showing the following device when the step 105 is performed; FIG. 7 is a curvature diagram illustrating the skew deformation curve of the sapphire substrate after epitaxial; FIG. 8 is a schematic view showing the reflective layer and the buffer Layer, and a high luminous efficiency solid-state light-emitting element of the current dispersion layer; FIG. 9 is a top plan view showing a schematic diagram of a perforation distribution of a buffer layer having different perforations of the high luminous efficiency solid-state light-emitting element of the present invention; and FIG. 10 is a schematic view illustrating The high luminous efficiency solid-state light-emitting element of the invention has a light distribution diagram of light reflected by the reflective layer.

21‧‧‧Substrate

22‧‧‧diode unit

221‧‧‧Elevation layer

222‧‧‧electrode unit

23‧‧‧Next unit

Claims (22)

A high luminous efficiency solid-state light-emitting element comprising: a substrate; a diode unit comprising an epitaxial layer extending mostly on a surface of the substrate and capable of emitting light when externally supplied with electric energy; and a subsequent unit connecting the substrate and the a diode unit, and the constituent material of the bonding unit does not include any one of gold and silver, the constituent material of the bonding unit includes gallium, and is selected from the group consisting of aluminum gallium solid solution, copper gallium alloy, or the like In combination, the gallium content in the aluminum gallium solid solution is not more than 20% by weight of the aluminum gallium solid solution. The high luminous efficiency solid-state light-emitting element according to claim 1, wherein the copper-gallium alloy is CuGax, x is not more than 2, and the content of gallium is not more than 70% by weight of the copper-gallium alloy compound. The high luminous efficiency solid-state light-emitting element according to claim 1, wherein the substrate is flexible and the thickness of the substrate is not more than 500 μm. The high luminous efficiency solid-state light-emitting element according to claim 1, wherein the substrate has a heat transfer coefficient of not less than 100 W/m ° C. The high luminous efficiency solid-state light-emitting device according to claim 1, wherein the substrate is a metal composite material selected from the group consisting of a coefficient of thermal expansion equivalent to a coefficient of thermal expansion of the epitaxial layer. The high luminous efficiency solid-state light-emitting element according to claim 5, wherein the substrate is composed of an aluminum alloy metal composite material having tantalum carbide. High luminous efficiency solid state light-emitting element according to item 5 of the patent application scope The substrate is made of a copper-tungsten alloy, a copper-molybdenum alloy, or a combination thereof. The high luminous efficiency solid-state light-emitting device of claim 1, wherein the substrate comprises a current dispersion layer, a buffer layer, and a reflective layer, the buffer layer having a plurality of perforations extending through the buffer layer, and The refractive index of the buffer layer is not greater than the current dispersion layer. The high luminous efficiency solid-state light-emitting element according to claim 8, wherein the current dispersion layer is selected from the group consisting of indium tin oxide, nickel gold alloy, cerium oxide, or a combination thereof. The high luminous efficiency solid-state light-emitting element according to claim 9, wherein the reflective layer is made of a material selected from the group consisting of gold, aluminum, silver, copper, platinum, palladium, or a combination thereof. A method for fabricating a high luminous efficiency solid-state light-emitting device, comprising: (a) forming a diode unit on a growth substrate, the diode unit including a plurality of semiconductor epitaxial layers, and each of the epitaxial layers has a distance Forming an upper surface of the substrate; (b) forming a metal layer on a surface of the substrate, and disposing the substrate on the diode unit toward the upper surface of the epitaxial layer, the metal layer including a first metal film made of aluminum as a material, a second metal film made of copper as a material and formed on the first metal film, and a material made of gallium and formed on the second metal a third metal film on the film; (c) heating the substrate and the diode unit to a predetermined temperature, converting the metal layer into a subsequent unit, and then the substrate and the diode are single (d) removing the grown substrate to expose the surface of the epitaxial layer; and (e) forming an electrode unit on the surface of the plurality of exposed epitaxial layers. The method for producing a high luminous efficiency solid-state light-emitting device according to claim 11, wherein the step (c) is carried out at a temperature not lower than 254 °C. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 11, further comprising a step (f) before the step (c), wherein the step (f) is to dispose a foil on the substrate surface. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 13, wherein the step (c) simultaneously applies a pressure to cause the substrate to be deformed along with the shape of the semiconductor epitaxial layer, and The surface of the epitaxial layer produces good adhesion. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 14, wherein the step (c) is: applying a negative pressure to the surface of the growth substrate opposite to the surface of the semiconductor epitaxial layer. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 15, wherein the step (c) is to generate a positive direction of the gas from the substrate toward the epitaxial layer via a foil disposed on the surface of the substrate. pressure. The method for producing a high luminous efficiency solid-state light-emitting device according to claim 13, wherein the foil is selected from the group consisting of aluminum, copper, polyamine, or graphite. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 11, wherein the step (d) is wet etching, mechanical polishing, Any one of the methods of laser stripping removes the grown substrate. The method for producing a high luminous efficiency solid-state light-emitting device according to claim 11, wherein the constituent material of the bonding unit does not include any one of gold and tin. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 19, wherein the constituent material of the bonding unit comprises gallium and is selected from the group consisting of an aluminum gallium solid solution, a copper gallium metal alloy compound, or the like. combination. The method for manufacturing a high luminous efficiency solid-state light-emitting element according to claim 20, wherein the copper-gallium metal alloy compound is selected from the group consisting of CuGax, x is not more than 2, and the content of gallium is not more than the weight of the copper-gallium metal alloy compound. 70%. The method for manufacturing a high luminous efficiency solid-state light-emitting device according to claim 21, wherein the content of gallium in the aluminum gallium solid solution is not more than 20% by weight of the aluminum gallium solid solution.