TWI632695B - Lighting elements - Google Patents

Abstract

The embodiment of the present invention includes a light emitting element, which includes a polygonal crystal grain, the polygonal crystal grain includes a plurality of light emitting diodes, each light emitting diode includes a plurality of epitaxial layers, and the epitaxial layers include a p-type layer, The n-type layer and multiple quantum wells are disposed between the p-type layer and the n-type layer. Each light emitting diode includes a p-type electrode and an n-type electrode, which are electrically coupled to the p-type layer and the n-type layer, respectively. A base is also included, and each light emitting diode is coupled to the base. The p-type electrode and the n-type electrode are located between the base and the epitaxial layer. The base contains a plurality of conductive components to lighten at least a part of the light-emitting diodes. The pole bodies are electrically coupled in series.

Description

Light emitting element

The embodiment of the present invention relates to a light-emitting element, and more particularly to a light-emitting element including a high-voltage light-emitting diode, which has improved heat dissipation efficiency, more efficient light extraction rate, and better electrical connection.

Light-emitting diodes (LEDs) are semiconductor optoelectronic components that emit light when a voltage is applied. Because light-emitting diodes have some advantageous characteristics, such as small component size, long life, efficient energy consumption, and Excellent durability and reliability make LEDs more and more popular. In recent years, light-emitting diodes have been developed in various applications, including indicators, light sensors, traffic lights, broadband data transmission, backlight units for liquid crystal displays, and other suitable lighting devices, such as light-emitting diodes. They are often used in lighting devices to replace traditional incandescent light bulbs, such as light emitting diodes used in typical lamps.

However, the current light-emitting diodes still have some disadvantages. For example, although traditional high-voltage light-emitting diodes can handle high voltages (such as hundreds of volts), these traditional high-voltage light-emitting diodes may still encounter some problems. For example, poor heat dissipation efficiency and frequent electrical failures. Compared with traditional high-voltage light-emitting diodes, traditional flip-chip LEDs may have better heat dissipation efficiency, but traditional flip-chip light-emitting diodes still cannot handle high voltages, and their light The extraction rate is poor. In addition, to some of the issues discussed above, other types The cutting process required for the light emitting diode may also be difficult.

Therefore, although the current light-emitting diodes have generally been able to meet the needs of their intended purposes, the current light-emitting diodes cannot fully meet the needs of every aspect, and have better heat dissipation efficiency and more efficient High-voltage light-emitting diodes with light extraction and more rugged electrical connections are still being sought.

An embodiment of the present invention relates to a light emitting element in one aspect. The light emitting element includes a substrate. A first light emitting diode is formed on the substrate and has a first platform structure. The first light emitting diode includes two electrodes located opposite to the substrate. One on the surface. This light-emitting element further includes a second light-emitting diode, which has a second platform structure and is formed on the substrate adjacent to the first light-emitting diode, wherein the first platform structure and the second platform structure have the same plan view shape. And different placement directions, or the first platform structure and the second platform structure have different top-view shapes, and the first platform structure and the second platform structure jointly form a first top-view geometry and a first top-view geometry It is different from the first platform structure, the second platform structure, or both of the first platform structure and the second platform structure in a plan view shape.

In some embodiments, the planar shapes of the first platform structure and the second platform structure are non-rectangular.

In some embodiments, the first platform structure and the second platform structure have different non-rectangular top shapes.

In some embodiments, the substrate has an outer contour similar to the first top-view geometry.

In some embodiments, the first platform structure has a first side, The second platform structure has a second side edge, and the first side edge is parallel to the second side edge.

In some embodiments, the first platform structure has a first side edge, the second platform structure has a second side edge, and the first side edge and the second side edge have a similar length.

In some embodiments, the substrate is a growth substrate.

In some embodiments, the substrate is a thinned substrate.

In some embodiments, the light-emitting element further includes a third light-emitting diode formed on the substrate, wherein a distance between the first light-emitting diode and the second light-emitting diode is smaller than that between the first light-emitting diode and the third Distance between light-emitting diodes.

In some embodiments, the light-emitting element further includes a third light-emitting diode, and the third light-emitting diode has a third platform structure, and the third platform structure and the first platform structure and the second platform structure jointly form a second plan view. The geometric shapes, the second top-view geometric shapes are different from the top-view shapes of the first platform structure, the second platform structure, the third platform structure, or the first, second, and third platform structures.

An embodiment of the present invention relates to a lighting device in one aspect. The lighting device includes a polygonal crystal grain including a plurality of light-emitting diodes, and each of the light-emitting diodes includes a plurality of epitaxial layers. A p-type layer, an n-type layer, and a multiple quantum well are disposed between the p-type layer and the n-type layer; and the p-type electrode and the n-type electrode are electrically coupled to the p-type layer and the n-type layer, respectively. The lighting device also includes a base, each light-emitting diode is coupled to the base, wherein the p-type electrode and the n-type electrode are located between the base and the epitaxial layer, and the base contains a plurality of conductive parts, and these conductive parts emit light At least a part of the light emitting diodes of the diodes are electrically coupled in series, and at least some of the light emitting diodes of the light emitting diodes are coupled in series. The body has a non-rectangular plan shape.

In some embodiments, at least some of the light-emitting diodes have a different top-view shape from the remaining light-emitting diodes of the light-emitting diodes.

In some embodiments, at least some of the light emitting diodes have a non-rectangular polygonal top view shape.

In some embodiments, at least some of the light-emitting diodes have curved edges in a top view.

In some embodiments, the first distance separating adjacent light emitting diodes of the first subset is greater than the second distance separating adjacent light emitting diodes of the second subset.

In some embodiments, the lighting device includes a plurality of polygonal grains.

In some embodiments, the base includes one of the following: a metal-based material, a silicon material on an insulator, a silicon base, a ceramic base, or a metal core printed circuit board base. In some embodiments, at least some of the above-mentioned conductive components include: a metal wire of an interconnect layer formed on a silicon substrate, or a metal wire formed on a printed circuit board substrate of a metal core.

In some embodiments, the light-emitting diodes include a number of light-emitting diodes of X, and the number of X-rays is selected such that when the number of X-light-emitting diodes is electrically coupled together in series, Greater than about 170 volts maximum operating voltage.

An embodiment of the present invention relates to a lighting device in one aspect. The lighting device includes: a crystal grain, which includes a plurality of light emitting diodes, and each of them emits light. The photodiode includes: a plurality of epitaxial layers, these epitaxial layers contain a p-doped III-V compound layer, an n-doped III-V compound layer, and a multiple quantum well disposed in the p-doped III-V Between the group compound layer and the n-doped group III-V compound layer; and the first electrode and the second electrode are electrically coupled to the p-doped group III-V compound layer and the n-doped group III-V, respectively. Compound layer. This lighting device also includes a base, which is bonded to the die, wherein the first electrode and the second electrode are located between the base and the epitaxial layer, and at least one of the following is true: some of these light-emitting diodes In the top view, there are different patterns from other light-emitting diodes; some of these light-emitting diodes have a non-rectangular polygonal pattern in the top view; and some of the light-emitting diodes in the top view Has one or more curved edges.

In some embodiments, the base contains a plurality of conductive components, and these conductive components electrically couple together at least a subset of the light emitting diodes in series.

In some embodiments, the lighting device includes a plurality of polygonal crystal grains, and the crystal grain is one of the polygonal crystal grains.

In some embodiments, the base includes one of the following: a metal-based material, a silicon material on an insulator, a silicon base, a ceramic base, or a metal core printed circuit board base. In some embodiments, at least some of the conductive components include metal wires formed in an interconnect layer on a silicon substrate, or metal wires formed on a printed circuit board substrate with a metal core.

In another aspect, the embodiment of the present invention relates to a method for manufacturing a high-voltage light-emitting diode device. The method includes: growing a plurality of epitaxial layers on a growth substrate in one or more epitaxial processes, wherein Crystal layer contains A p-doped III-V compound layer, an n-doped III-V compound layer, and a multiple quantum well are disposed between the p-doped III-V compound layer and the n-doped III-V compound layer. According to a lithographic pattern, a part of these epitaxial layers on the growth substrate is removed by etching to form a plurality of divided channels between the separated light emitting diodes. The above pattern includes non-rectangular A light-emitting diode; a p-type electrode and an n-type electrode are formed on each of the light-emitting diodes, wherein the p-type electrode is electrically coupled to the p-doped III-V compound layer, and the n-type electrode is electrically coupled Connected to the n-doped III-V compound layer; bonding these light emitting diodes to the base so that the p-type electrode and the n-type electrode are located between the base and the epitaxial layer after the bonding step; and then the growth substrate is thin Change or remove.

In some embodiments, the conversion of the epitaxial layer into a plurality of separate light emitting diodes is performed such that at least one of the following is true: at least some of the light emitting diodes have a Different patterns of the remaining light-emitting diodes of the diode; at least some of the light-emitting diodes have a non-rectangular polygonal pattern in a plan view; and at least some of the light-emitting diodes of the light-emitting diodes in a top view Has one or more curved edges in it.

In some embodiments, the growth substrate comprises a sapphire material, and the base comprises one of the following: a metal-based material, a silicon material on an insulator, a silicon base, a ceramic base, or a metal core printed circuit board base, the base A plurality of conductive members are included, and the bonding step is performed such that at least a subset of the light emitting diodes are electrically coupled in series through the conductive members.

In some embodiments, these separate light emitting diodes are polygonal Part of the shaped grain.

In some embodiments, the bonding step includes a wafer-level bonding process.

In some embodiments, the bonding step includes a die-level bonding process.

20‧‧‧High-voltage light-emitting diode grains

25‧‧‧light-emitting diode

30‧‧‧ sapphire substrate

35‧‧‧electrical conductor

40‧‧‧ wafer

45‧‧‧ Grain

50‧‧‧ growth substrate

60‧‧‧Epitaxial layer

60A, 60B, 60C‧‧‧Light-emitting diodes (platform structure)

70A, 70B, 70C‧‧‧Mirror layer

75A, 75B, 75C‧‧‧p-type electrode

80A, 80B, 80C‧‧‧n electrode

85A, 85B, 85C‧‧‧ passivation layer

90A, 90B, 90C‧‧‧p-type bonding metal

95A, 95B, 95C‧‧‧n type bonding metal

100‧‧‧ base

105‧‧‧ base substrate

110‧‧‧welded parts

115‧‧‧ base metal

120‧‧‧circuit

125‧‧‧Insulation material

150‧‧‧cooling path

155‧‧‧Light propagation path

160‧‧‧ conductive path

300‧‧‧Lighting equipment

320‧‧‧Lighting equipment base

350‧‧‧ diffuser

360‧‧‧ Space between light-emitting diode and diffuser

370‧‧‧Reflective structure

380‧‧‧Heat dissipation structure

390‧‧‧ Radiator Fin

400‧‧‧lighting module

410‧‧‧Base of lighting module

420‧‧‧ The main body of the lighting module

430‧‧‧lighting lamp

440‧‧‧ Beam of lighting module

500‧‧‧ Method for manufacturing high-voltage light-emitting diode device

Steps of the 510, 520, 530, 540, 550‧‧‧ method

In order to make the objects, features, and advantages of the embodiments of the present invention more comprehensible, the following detailed description is given in conjunction with the accompanying drawings. It is emphasized here that the various features in the drawings may not need to be in accordance with the semiconductor industry. Standard conventional drawing. In fact, the dimensions of various features can be arbitrarily expanded or reduced, so that the following discussion can be more clearly shown: Figure 1 is a schematic top view of a high-voltage light-emitting diode; Figure 2 is an embodiment according to the present invention Top view of a wafer containing a plurality of dies from various viewpoints; FIGS. 3-7 are schematic partial cross-sectional side views of a die containing a plurality of light emitting diodes according to various viewpoints of embodiments of the present invention; FIG. 8 In accordance with various viewpoints of the embodiments of the present invention, a schematic top view of an exemplary die including a plurality of light emitting diodes is shown. FIG. 9 is a schematic top view of an exemplary shape of a wafer including a plurality of die, including a plurality of light emitting diodes. A schematic top view of an exemplary shape of one of these crystal grains of the body, and a schematic top view of an exemplary shape of one of these light emitting diodes. Figure 10 is a schematic cross-sectional side view of a light emitting module including the crystal grains of Figures 3-7 according to various views of the embodiment of the present invention; Figure 11 is a view of various views according to the embodiment of the present invention, including Figure 10 of A schematic diagram of a lighting device of a light-emitting diode light-emitting module; and FIG. 12 is a flowchart of a method for manufacturing a high-voltage light-emitting diode light-emitting device according to various viewpoints of embodiments of the present invention.

The following content provides many different embodiments or examples to implement different components of various embodiments. The specific examples of the components and arrangements described below are used to simplify the description of the embodiment of the present invention. These specific examples are only for demonstration purposes. Is not intended to limit the embodiments of the present invention. For example, it is mentioned in the following description that forming a first component on or above a second component may include forming an embodiment where the first component and the second component are in direct contact, and may also include forming an additional component between the first component and the second component. The embodiment between the components makes the first component and the second component not in direct contact. In addition, "top", "bottom", "below", "above", and other similar terms are used for convenience of description, and are not intended to limit the scope of the embodiment to any particular direction. In addition, various components can also be arbitrarily drawn with different size specifications to achieve the purpose of simplicity and clarity. In addition, the embodiments of the present invention may repeatedly use reference numerals and / or symbols in various examples. This reuse is for simplicity and clarity, and is not intended to specify the relationship between the various embodiments and / or the states in question. .

Semiconductor elements can be used to make various optoelectronic elements, such as light emitting diodes (LEDs). When the element is turned on, the light emitting diodes can emit light, such as light of different colors in the visible light spectrum, and light with ultraviolet or infrared wavelengths. . Compared with traditional light sources (such as incandescent light bulbs), lighting devices using light emitting diodes as the light source can provide some advantages, such as smaller size, lower energy consumption, longer service life, and various available colors , And better These advantages are the same as the progress in the manufacturing technology of light-emitting diodes, which makes them cheaper and more durable. Therefore, in recent years, light-emitting diode-based lighting has been added. Growth and penetration of equipment.

However, the current light-emitting diodes still have some disadvantages. For example, referring to FIG. 1, which shows a top view of a high-voltage light-emitting diode (HVLED) die 20. The high-voltage light-emitting diode die 20 includes a plurality of Each light emitting diode 25 is disposed on a sapphire substrate 30. The high-voltage light-emitting diode grains 20 are configured to handle high voltages, such as voltages exceeding 12 volts, and these light-emitting diodes 25 are electrically coupled together in series (for example, through the electrical conductor 35). The high-voltage light-emitting diode grains 20 are realized. This method can disperse the high voltage and allow each light-emitting diode to withstand the dispersed voltage. However, the heat dissipation efficiency of the high-voltage light-emitting diode die 20 is poor, and the heat conduction path is transmitted from the light-emitting diode 25 down to the sapphire substrate 30. The sapphire substrate has poor thermal conductivity and is usually very thick, such as From 100 to 200 micrometers (μm), due to poor thermal conduction performance and relatively long thermal conduction paths, high-voltage light-emitting diode grains can easily be overheated. In addition, the electrical coupling by means of electrical conductors 35 is not very durable. These electrical conductors 35 may be easily disconnected, and the disconnection of a single electrical conductor may make the entire grain 20 defective. It occurs because all the light emitting diodes 25 are coupled in series.

Compared to the high voltage light emitting diode 20 discussed above, flip chip LEDs can have better heat dissipation characteristics. However, flip chip light emitting diodes may still have other disadvantages, one of which is Due to the current crowding problem, flip-chip light-emitting diodes easily lead to light extraction rate. Poor, another disadvantage of flip chip light emitting diodes is the difficulty in performing electrical connection.

According to the embodiments of the present invention, an improved high-voltage light-emitting diode lighting device is disclosed, which provides good heat dissipation efficiency, improved light extraction rate, and has a durable and easy-to-implement electrical coupling structure. According to some embodiments, the process for manufacturing a high-voltage light-emitting diode will be discussed below with reference to FIGS. 1-9, which have been simplified in the embodiments of the present invention.

Referring to FIG. 2, which shows a top view (or plan view) of wafer 40. In some embodiments, wafer 40 includes a sapphire material suitable for epitaxial growth of Group III-V compound materials thereon, Group III-V The compound contains an element from group III of the periodic table and another element from group V of the periodic table, for example, an element of group III may include boron, aluminum, gallium, indium, and titanium, and an element of group V may include Nitrogen, phosphorus, arsenic, antimony and bismuth.

The wafer 40 includes a plurality of dies 45 (or grain regions, because the III-V compound epitaxial layer has not grown on the wafer 40 during the manufacturing stage shown in FIG. 2). The purpose of the die 45 is to provide an example. The actual shape and size of the die 45 may vary. For example, although the shape of the die 45 is shown as a rectangle (in a top view), in various embodiments, the die 45 may actually be Shapes with other polygons, such as triangles or hexagons. According to various viewpoints of the embodiments of the present invention, a plurality of light-emitting diodes will be formed on each die 45. For simplicity, FIGS. 3-7 only show simplified cross-sectional side views of a single die 45 in various manufacturing stages. It can be understood that other dies 45 may also undergo the same manufacturing process.

Referring to FIG. 3, the die 45 includes a growth substrate 50. As discussed above, the growth substrate 50 may include a sapphire material. It is suitable for epitaxial growth of Group III-V compounds, such as gallium nitride, and the thickness of the substrate 50 may range from about 50 μm to about 1000 μm. In some embodiments, a low-temperature buffer film may be formed on the substrate 50, however, for simplicity, the low-temperature buffer film is not shown here.

In one or more epitaxial processes, a plurality of epitaxial layers 60 are grown on the growth substrate 50. Various layers of the epitaxial layer 60 will be discussed as follows.

The epitaxial layer 60 may include an undoped semiconductor layer formed on the substrate 50. The undoped semiconductor layer does not have a p-type dopant or an n-type dopant. In some embodiments, the undoped The semiconductor layer contains a compound containing an element from Group III of the periodic table and another element from Group V of the periodic table, such as an undoped gallium nitride (GaN) material. The undoped semiconductor layer can serve as a buffer layer (for example, to reduce stress) between the substrate 50 and other layers that will be subsequently formed on the undoped semiconductor layer. In order to effectively perform its function as a buffer layer, The doped semiconductor layer has fewer dislocation defects and good lattice structure quality. In some embodiments, the thickness of the undoped semiconductor layer ranges from about 1 μm to about 5 μm.

The epitaxial layer 60 includes a group III-V compound layer formed on an undoped semiconductor layer. The group III-V compound layer may be doped with an n-type dopant such as carbon (C) or silicon (Si). In this embodiment, the III-V compound layer includes gallium nitride (GaN), and thus may be referred to as an n-GaN layer. In some embodiments, the thickness of the n-GaN layer ranges from about 2 μm to about 6 μm.

The epitaxial layer 60 may include a pre-strained layer formed on the n-GaN layer. The pre-strained layer may be doped with an n-type dopant such as silicon. In various embodiments, the pre-strained layer may contain a plurality of pairs (eg, 20-40 pairs) of interleaved In _x Ga _1-x N sub-layers and GaN sub-layers, where x is greater than or equal to 0, but less than Or equal to 1. The pre-strained layer can be used to release tension and reduce the quantum-confined Stark effect (QCSE). The quantum-confined Stark effect describes the effect of an applied electric field on the light absorption spectrum of a quantum well layer. The layer system is formed on the pre-strained layer. In some embodiments, the total thickness of the pre-strained layer can range from about 30 nanometers (nm) to about 80 nm.

The epitaxial layer 60 includes multiple-quantum well (MQW) layers formed on a pre-strained layer. The multiple-quantum well layer includes a plurality of alternating (or staggered) active sub-layers and barriers. Barrier sub-layers. For example, the active sub-layer may include indium gallium nitride (In _x Ga _1-x N), and the barrier sub-layer may include gallium nitride (GaN). ). In some embodiments, the thickness of each barrier sublayer can range from about 2 nm to about 5 nm, and the thickness of each active sub layer can range from about 4 nm to about 17 nm.

The epitaxial layer 60 may optionally include an electron blocking layer formed on the multiple quantum well layer. The electron blocking layer helps to limit the recombination of the electron-hole carrier in the multiple quantum well layer 80. This can improve the quantum efficiency of the multiple quantum well layers and reduce radiation in undesired bandwidths. In some embodiments, the electron blocking layer may comprise undoped _{In x Al y Ga 1-xy} N , wherein x and y are greater than or equal to 0, but less than or equal to 1, and a p-type dopant may be doped For impurities such as magnesium, the thickness of the electron blocking layer can range from about 7 nm to about 25 nm.

The epitaxial layer 60 includes a III-V compound layer formed on the electron blocking layer. The III-V compound layer can be doped with a p-type dopant. In this embodiment, the III-V compound layer includes gallium nitride (GaN), and thus may be referred to as a p-GaN layer. In some embodiments, the thickness of the p-GaN layer ranges from about 150 nm to about 200 nm.

These epitaxial layers 60 constitute the core part of a light emitting diode. When a voltage (or charge) is applied to a doped layer of the light emitting diode (such as a p-GaN layer and an n-GaN layer), the multiple quantum well layer emits light. Out of the radiation, such as light, the color of the light emitted by the multiple quantum well layer corresponds to the wavelength of the radiation, this radiation can be visible, such as blue light, or invisible, such as ultraviolet light, the wavelength of the light (and the resulting Light color) can be adjusted by changing the composition and structure of the materials from which the multiple quantum well layers are made.

Referring to FIG. 4, the epitaxial layer 60 is patterned into a plurality of mesa structures 60A-60C by a lithography process, for example, by one or more etching processes. These mesa structures 60A-60C may also be referred to as light-emitting Diodes (LEDs) or light-emitting diode chips (LED chips) 60A-60C, the lithography process is performed so that p-GaN layer and n-GaN layer can be used in each light-emitting diode 60. In addition, although not shown in the cross-sectional view of FIG. 4, the top shape of the light-emitting diodes 60A-60C can be changed by adjusting the lithography process, for example, by changing the photomask on the photomask during the lithography process. pattern.

Referring to FIG. 5, additional elements are formed on the light-emitting diodes 60A-60C, and the light-emitting diodes 60A-60C are ready to be bonded to the submount in the bonding process discussed below. These additional elements include (but Not limited to: mirror layers 70A-70C (hereinafter collectively referred to as 70), p-type electrodes 75A-75C (hereinafter collectively referred to as 75), n-type electrodes 80A-80C (hereinafter collectively referred to as 80), passivation layer 85A -85C (hereinafter collectively referred to as 85), p-type bonding metal 90A-90C (hereinafter collectively referred to as 90) and n-type bonding metal 95A-95C (hereinafter collectively referred to as 95).

The mirror layer 70 contains a material that reflects radiation, such as a metal, such as aluminum or silver, thereby reflecting the light emitted from the light emitting diode 60 back to the light emitting diode 60.

The p-type electrode 75 and the n-type electrode 80 contain a conductive material (such as a metal) to provide electrical connection with the p-GaN and n-GaN layers of the light emitting diode 60, respectively, although the cross-sectional view of FIG. 5 is for each The light-emitting diode 60 only shows a single p-type electrode 75 and a single n-type electrode 80. It can be understood that in practice, more than one p-type electrode 75 or more than one p-type electrode 75 can be formed on each light-emitting diode 60. One or more n-type electrodes 80.

The passive layer 85 is used to protect the exposed surfaces of the light emitting diodes 60 and the p-type and n-type electrodes 75 and 80 from being affected by pollutants such as particles in the air and / or water vapor. In some embodiments, the passivation layer 85 contains a dielectric material.

The p-type bonding metal 90 and the n-type bonding metal 95 contain a metal material to assist the bonding between the p-type and n-type electrodes 75 and 80 and the base, as shown in FIG. 6, and a more detailed discussion thereof is as follows.

Referring to FIG. 6, the die 45 is turned upside down, and is bonded to the submount 100 in a bonding process. In more detail, in one method, the light-emitting diodes 60A-60C of the crystal grain 45 are bonded to the base 100 via the welding member 110, so that the p-type electrode 75 and the n-type electrode 80 are disposed on the base 100 and the light-emitting diode after bonding. Between polar bodies 60 (e.g. epitaxial layers). The base 100 includes a base substrate 105, a soldering member 110, a base metal 115, a circuit 120, and an insulating material 125. In some embodiments, the base substrate 105 may include Contains metal-based materials, such as copper or aluminum; in other embodiments, the base substrate 105 may also include silicon-on-insulator (SOI); in other embodiments, the base substrate 105 also It can be a silicon substrate, a ceramic substrate, or a metal core printed circuit board (MCPCB) substrate.

The insulating material 125 may be formed on the base substrate 105, and the circuit 120 and the base metal 115 may be formed in the insulating material to provide an electrical route for the light emitting diode. For example, the circuit 120 may be an interconnect structure The metal lines in one or more interconnect layers, wherein the interconnect structure is formed on the silicon substrate. In another example, the circuit 120 may be metal traces, such as copper wires, formed on a printed circuit board (PCB) substrate. In any example, the circuit 120 and the base metal 115 have been formed on the base 100 before the bonding process of the base 100 and the light emitting diode 60. After the bonding process, the p-GaN of the light emitting diode can be seen The n-GaN layer is electrically coupled to the circuit 120 via the electrodes 75/80, the bonding metal 90/95, the soldering member 110, and the base metal 115.

In some embodiments, such as the embodiment shown in FIG. 6, the light emitting diodes are electrically coupled together in series, that is, the p-GaN layer of one light emitting diode 60 is electrically coupled to The n-GaN layers of adjacent light emitting diodes 60 and vice versa. In this manner, a high voltage, for example, a voltage greater than about 50 to 100 volts (for example, 170 volts) can be applied to the entire light emitting diode 60 because the electrical coupling of the light emitting diode 60 is performed in series. Each light emitting diode 60 only needs to withstand a part of the high voltage, such as about 3 to 3.5 volts. Therefore, when a larger number of light emitting diodes are electrically coupled together in series, these light emitting diodes are Diodes can withstand higher voltages together. In this way, the die 45 (including a plurality of light-emitting diodes 60) can be used as a high-voltage light-emitting diode (HVLED). For example, the voltage can be as high as 170 volts. Therefore, It can be said that the die 45 has a maximum operating voltage greater than about 170 volts.

It can be seen that the electrical connection between the light-emitting diodes 60 disclosed herein is established without the use of bond wires and a conductive connection layer formed around each light-emitting diode. The sexual connection method is advantageous because the use of bonding wires and conductive connection layers will cause reliability problems. In some examples, the bonding wire or the conductive connection layer may be easily broken (especially under the condition of high current) or the problem of falling off occurs, and because the light emitting diodes are electrically coupled together in series, when bonding When a single wire or conductive connection layer fails, the entire high voltage light emitting diode (HVLED) will be defective. In contrast, the electrical coupling disclosed here is via the circuit 120 and the base metal 115 Finished, the circuit 120 and the base metal 115 are already formed in the base 100 before the bonding process. Therefore, the circuit 120 and the base metal 115 have better reliability in the case of resisting adverse conditions and high voltage / current. The pair of light emitting diodes 60 provides a more robust and durable electrical routing scheme.

In addition, the crystal grain 45 improves the light extraction rate because of its design. In more detail, each light-emitting diode has a relatively small platform structure. For example, compared to a conventional flip-chip light-emitting diode, this platform has a relatively small platform structure. The structure has a significantly smaller lateral size (width). When the flip-chip light-emitting diode is prone to current accumulation due to its large lateral epitaxial layer size, the platform structure of the light-emitting diode disclosed herein Smaller lateral dimensions significantly reduce current accumulation and replace What is more, the current path will make full use of the entire epitaxial layer region, and then the epitaxial layer (especially the multiple quantum well layer) will generate more light, thereby increasing the light extraction rate of the crystal grains 45. According to various viewpoints of the embodiments of the present invention, to some extent, the platform structure of the light emitting diode can be further sub-divided to further increase the light extraction rate of the crystal grains 45.

Although not specifically described, it can be understood that the bonding of the die 45 to the base 100 may be performed at a wafer level or a die level. In the wafer-level bonding process, the entire wafer (for example, as shown in FIG. 2) is used. The wafer 40 shown is bonded to the base 100. The wafer has a die 45 and other similar dies formed thereon. After bonding, wafer dicing and additional packaging processes can be performed. In the die-level bonding process, the wafer can be adhered to the tape, and then the wafer can be cut so that each die 45 is separated from its neighboring die, and each die is separately from its own on the base. Part bonding (this step can be performed simultaneously).

Referring to FIG. 7, the growth substrate 50 can be removed from the light emitting diode 60, for example, by using a laser lift-off process. In other embodiments, the growth substrate 50 can be thinned. In order to better explain some concepts of the embodiments of the present invention, FIG. 7 also shows a heat dissipation path 150, a light propagation path 155, and a conductive path 160 of the die 45.

As shown by the heat dissipation path 150, the heat generated by the light emitting diode 60 is dissipated downward to the base 100. Because the distance between the light-emitting diode 60 and the base is relatively short, and the base substrate 105 is relatively thin, although not shown here, a heat sink can be provided below the base substrate 105, so the light-emitting diode 60 generates The heat needs not to travel too far before reaching the base substrate 105. In addition, various materials along the heat dissipation path 150 have good thermal conductivity, thereby enabling heat dissipation Dispersion is more efficient.

As shown in the light propagation path 155, the light generated by the light emitting diode 60 will travel upward away from the base 100, and no matter how much light travels downward, these lights will be reflected back upward by the mirror layer 70 and the electrode 80. Because light encounters very few obstacles on its propagating propagation path, it can have a good light output, and as discussed above, the small lateral size of the light emitting diode 60 reduces the current gathering effect and further improves The light extraction rate of the light emitting diode 60 is shown.

As shown by the conductive path 160, current flows through the circuit 120, the base metal 115, the soldering member 110, the bonding metals 90 and 95, the electrodes 75 and 80, and the epitaxial layer 60 (such as a light emitting diode). In this manner, The light-emitting diodes are electrically coupled together in series without using bonding wires or conductive layers (used in traditional high-voltage light-emitting diodes), thereby making the electrical conduction of the crystal grains 45 more reliable and more reliable. strong and sturdy. It can be understood that, in some embodiments, not all the light-emitting diodes need to be electrically coupled in series, and instead, in some embodiments, only the light-emitting diodes in the selected subset are used. The pole bodies are electrically coupled in series.

FIG. 8 shows a simplified schematic top view of the die 45 according to some embodiments of the present invention. In the embodiment shown in FIG. 8, the die 45 includes 18 light emitting diodes (or light emitting diode wafers) 60. Each light emitting diode 60 can be similar to the light emitting diodes 60A-60C discussed above, and can be manufactured according to the same process. The light emitting diode 60 is bonded to the base 100. The base 100 includes the base substrate 105 shown in FIGS. 6-7. The light emitting diode 60 (or a subset thereof) uses a conductive member, such as the circuit 120 in the base 100, in series. Electrical coupling Thus, the circuit 120 may include, for example, metal lines in an interconnect layer or copper wires on a printed circuit board.

As shown in the top view of FIG. 8, each light emitting diode 60 has a triangular shape or pattern. The light emitting diodes 60 are arranged in pairs, and the light emitting diodes in each pair are arranged in pairs. Compared with other adjacent light-emitting diodes, its position is closer to its nearest adjacent light-emitting diode (that is, a member of the same pair). Each pair of adjacent light-emitting diodes 60 collectively form a similar rectangle. Or square top view pattern, however, the arrangement shown here is for demonstration purposes only. In other embodiments, the light emitting diodes can be arranged in any shape or geometry, and these shapes or geometry are suitable for the die 45 Top view pattern.

In order to better explain the above concepts, FIG. 9 shows different embodiments according to the present invention. In various top views of wafer level, die level and chip level, It is seen that in a wafer-level top view, the wafer contains a plurality of high-voltage light-emitting diode (HVLED) dies, each of which may be similar to the die 45 discussed above. In a grain-level top view, each high-voltage light-emitting diode die may include a plurality of light-emitting diodes (or light-emitting diode wafers). In a top view, each high-voltage light-emitting diode die may appear rectangular. Shapes, square shapes, diamond shapes, hexagonal shapes, or any other suitable polygonal shapes, these shapes may be suitable for cutting techniques currently known or later developed.

In a top view of a wafer level (ie, a light emitting diode level), each light emitting diode may have a rectangular shape, a square shape, a diamond shape, a triangular shape, a hexagonal shape, any other suitable Polygonal shapes, or even irregular shapes with one or more curved edges or edges. due to The light-emitting diodes are actually patterned through a lithographic process, and each light-emitting diode can be adjusted to any desired shape by adjusting the lithographic process (for example, by changing the pattern on the photomask). The light-emitting diodes of the embodiments of the present invention can provide various different shapes in plan view.

In addition to the variability of the top-view shape, each light-emitting diode grain may have a different top-view shape from the rest of the light-emitting diode grains. For example, in a single grain, one light-emitting diode may have a triangular shape. A top view shape, another light emitting diode may have a rectangular top view shape, another light emitting diode may have a hexagonal top view shape, and another light emitting diode may have an irregular top view shape. The irregular top-view shape has at least one non-straight edge / edge, and the light-emitting diodes can be configured to produce a top-view shape of any arrangement, which depends on design requirements and matters related to manufacturing. The flexibility and various versatility of the shape of the light emitting diode or the light emitting diode wafer can provide some benefits, such as increasing light extraction rate, better heat dissipation rate, and the like.

In order to complete the manufacturing of the high-voltage light-emitting diode (HVLED) die 45, additional processes such as cutting, packaging, and testing processes may be performed, but for the sake of simplicity, these processes are not described here.

The high-voltage light emitting diode (HVLED) die 45 can be implemented as a part of a lighting apparatus. For example, the HVLED die 45 can be used as a part of a lighting instrument 300 based on a light emitting diode. Partially implemented. A simplified cross-sectional view of the lighting device 300 is shown in FIG. 10. The embodiment of the lighting device 300 based on the light-emitting diode shown in FIG. 10 includes a plurality of light-emitting diodes of the HVLED die 45. 60, wherein the light emitting diodes (or a selected subset of the light emitting diodes) are electrically coupled together in series, although only three light emitting diodes 60 are drawn in the embodiment shown in FIG. 10 It can be understood that any other number of light emitting diodes can be implemented, thereby enabling the HVLED die to withstand high voltages, such as as high as 170 volts.

As discussed above, each light emitting diode 60 includes an n-doped III-V compound layer, a p-doped III-V compound layer, and a multiple quantum well (MQW) layer disposed between the n-doped and p-doped Between heterogeneous III-V compound layers. Because the structure of the light-emitting diode 60 is as discussed above, the light-emitting diode 60 of the high-voltage light-emitting diode grains disclosed herein can provide better heat dissipation rate, light extraction rate, and electricity than the traditional light-emitting diode. Reliability performance of sexual transmission.

In some embodiments, each light emitting diode 60 has a phosphor layer applied thereon, and the phosphor layer may include a phosphorescent material and / or a fluorescent material. The phosphor layer can be coated on the surface of the light-emitting diode 60 by being dispersed in a concentrated viscous fluid medium (such as a fluid colloid). The phosphor material becomes a light-emitting diode package in a viscous fluid state or a cured state. a part. In practical applications of the light emitting diode, the phosphor layer can be used to change the color of light emitted by the light emitting diode 60. For example, the phosphor layer can convert blue light emitted by the light emitting diode 60 into light of different wavelengths by changing The material composition of the phosphor layer can make the light emitting diode 60 emit a desired light color.

The light emitting diode 60 is fixed on the base 320. In some embodiments, the base 320 is similar to the base 100 discussed above. For example, the base 320 may include a metal core printed circuit board (MCPCB), and a metal core printed circuit board. Contains a metal base material, which can be made of aluminum (or an alloy of aluminum). The printed circuit board with a metal core also includes a thermally conductive but electrically insulating dielectric layer disposed on the metal base material. The printed circuit board with a metal core can also include A thin metal layer made of copper is disposed on the dielectric layer. In other embodiments, the base 320 may include other suitable thermally conductive structures, such as a silicon base or a ceramic base.

The lighting device 300 includes a diffuser cap 350, which can be used as a cover for the light emitting diode 60 underneath. In another way, the light emitting diode 60 is sealed by the diffuser cover 350 and the base 320. . In some embodiments, the diffuser cover 350 has a curved surface or profile. In some embodiments, the curved surface can adopt a semi-circular profile, so that each beam of light emitted by the light emitting diode 60 can be With a large incidence angle on the front side, for example, within a few degrees from 90 degrees, it reaches the surface of the diffusion cover 350. The curved shape of the diffusion cover 350 helps reduce the total internal reflection of the light emitted by the light emitting diode 60 (Total Internal Reflection; TIR).

The diffuser cover 350 may have a surface with a specific structure, for example, the surface of the specific structure may be rough or uneven, or may contain a plurality of small patterns, such as a polygon or a circle. The surface of the specific structure helps to diffuse the light emitting diode 60 The emitted light to make the light distribution more uniform. In some embodiments, the diffusion cover 350 may be coated with a diffusion layer containing diffusion particles.

In some embodiments, the space 360 between the light-emitting diode 60 and the diffusion cover 350 may be filled with air; in other embodiments, the space 360 may be made of optical-grade silicone (optical-grade silicone) -based adhesive material). This material is also called optical gel. In this embodiment, the phosphorescent particles can be mixed in an optical glue, Therefore, the light emitted from the light emitting diode 60 is further diffused.

Although it is shown in the embodiment described here that all the light-emitting diodes 60 are sealed in a single diffuser cover 350, it can be understood that in other embodiments, a plurality of diffuser covers may be used, such as each light-emitting diode The bodies 60 may each be sealed within one of the diffusers.

The lighting device 300 can also optionally include a reflective structure 370, which can be fixed on the base 320. In some embodiments, the reflective structure is shaped like a cup, so the reflective structure can also be called Reflection cup. Viewed from a top view, the reflective structure surrounds or surrounds the light emitting diode 60 and the diffuser 350 at a 360 degree angle. From a top view, the reflective structure 370 can have a circular outline, a hexagonal outline like a honeycomb, or another type. A suitable cellular profile to surround the diffusion shield 350. In some embodiments, the light emitting diode 60 and the diffusion cover 350 are located near the bottom of the reflective structure 370. In other words, the opening on the top or above of the reflective structure 370 is located above the light emitting diode 60 and the diffusion cover 350.

The reflective structure 370 can be used to reflect the light transmitted from the diffuser 350. In some embodiments, the internal surface of the reflective structure 370 is coated with a reflective film, such as aluminum, silver, or the foregoing alloy. It can be understood that In the embodiment, the sidewall surface of the reflective structure 370 may have a specific structure in a manner similar to that of the specific structure of the diffuser cover 350. Therefore, the reflective structure 370 may be used to further scatter the light emitted by the light emitting diode 60. This reduces the glare of light emitted by the lighting device 300 and makes the light emitted by it more suitable for the human eye. In some embodiments, the sidewall of the reflective structure 370 has a sloped or tapered profile, and the tapered profile of the reflective structure 370 is elevated. The light reflection efficiency of the reflective structure 370 is improved.

The lighting device 300 includes a heat dissipation structure 380, also referred to as a heat sink 380. The heat sink 380 is thermally coupled to the light emitting diode 60 (which generates heat during operation) via the base 320. In other words, the heat sink 380 is attached To the base 320, or the base 320 is located on the surface of the heat sink 380. The heat sink 380 is configured to promote heat dissipation to the surrounding air. The heat sink 380 contains a thermally conductive material, such as a metal material. The shape and geometry of the heat sink 380 are designed to provide a framework for common light bulbs, while dissipating or directing heat away from the light emitting diode 60. To improve heat transfer, the heat sink 380 may have a plurality of fins 390 protruding from the body of the heat sink 380, and the fins 390 may have a large surface area exposed to the surrounding air to promote heat transfer .

FIG. 11 shows a simplified schematic diagram of a lighting module 400 including some embodiments of the lighting device 300 discussed above. The lighting module 400 has a base 410, a main body 420 attached to the base 410, and a lamp 430. Attached to the main body 420. In some embodiments, the lamp 430 is a downward lamp (or a light-down lighting module). Referring to FIG. 10, the lamp 430 includes the lighting device 300 discussed above, and the lamp 430 is used to efficiently project the light beam 440. In addition, compared to traditional incandescent lamps, the lamp 430 can provide better durability and longer life. It can be understood that other lighting applications can use the light emission discussed above in the embodiments of the present invention. For example, the light-emitting diodes of the embodiments of the present invention can be used in some lighting applications, including but not limited to, headlights or taillights of vehicles, dashboard displays of vehicles, light sources of projectors, Electronic products such as LCD TVs or LCD monitors, tablets, mobile phones or light sources for laptops / laptops.

FIG. 12 is a flowchart illustrating a simplified method 500 for manufacturing a high-voltage light-emitting diode (HVLED) device according to various viewpoints of embodiments of the present invention. The high-voltage light-emitting diode device may include one or more crystal grains, each The die contains a plurality of light emitting diodes.

The method 500 includes a step 510 in which a plurality of epitaxial layers are grown on a growth substrate in one or more epitaxial processes. In some embodiments, the growth substrate comprises a sapphire material, and these epitaxial layers include a p-doped III-V compound layer, an n-doped III-V compound layer, and a multiple quantum well (MQW) set at the p-doped Between the heterogeneous III-V compound layer and the n-doped III-V compound layer.

The method 500 includes step 520. In this step, the epitaxial layers are transformed into a plurality of separate light-emitting diodes through a lithography process, and the separate light-emitting diodes are part of a polygonal crystal grain. In some embodiments, a conversion process is performed in step 520 so that at least one of the following descriptions is true: At least some of the light-emitting diodes have a light-emitting diode having a light-emitting diode in a top view compared to other light-emitting diodes. Different shapes of the body; at least some of the light-emitting diodes have a non-rectangular polygonal shape in a plan view; and at least some of the light-emitting diodes have one or more in a top view Curved edges.

The method 500 includes step 530. In this step, a p-type electrode and an n-type electrode are formed on each light-emitting diode, the p-type electrode is electrically coupled to the p-doped III-V compound layer, and n The type electrode is electrically coupled to the n-doped III-V compound layer.

The method 500 includes step 540. In this step, these two The polar body is bonded to the base so that the p-type electrode and the n-type electrode are positioned between the base and these epitaxial layers after bonding. In some embodiments, the base includes one of the following: a metal-based material, a silicon material on an insulator, a silicon base, a ceramic base, or a metal core printed circuit board (MCPCB) base. In some embodiments, the base contains a plurality of conductive components. In some embodiments, a bonding process is performed in step 540, so that at least a subset of the light-emitting diodes are electrically coupled in series by the conductive components. In some embodiments, the bonding process in step 540 includes a wafer-level bonding process. In some other embodiments, the bonding process in step 540 includes a die-level bonding process.

The method 500 includes a step 550 in which the growth substrate is thinned or removed after the bonding process in step 540.

Additional processes may be performed before, during, or after the steps 510-540 discussed herein to complete the fabrication of the photovoltaic element. For simplicity, these other processes are not discussed in detail here.

In the above description, the features of some embodiments have been briefly described, so that those with ordinary knowledge in this technical field can better understand the detailed description of the connection. Those skilled in the art can understand that the embodiments of the present invention can be used as a basis to design or modify other processes or structures, thereby achieving some of the objectives and / or advantages of the embodiments described herein.

Although the preferred embodiments of the present invention have been disclosed above, they are not intended to limit the present invention. Those skilled in the art can understand that without departing from the spirit and scope of the present invention, they can make some changes and Retouch. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application.

Claims (10)

A light emitting element includes: a substrate; a first light emitting diode is formed on the substrate and has a first platform structure; the first light emitting diode includes two electrodes on an upper surface opposite to the substrate; A passive state layer is formed on the first light-emitting diode and the two electrodes are exposed; two bonding metals are formed on the two electrodes and cover a part of the passive state layer, wherein the two bonding metals are on The surfaces are substantially on the same plane; and a second light-emitting diode has a second platform structure and is formed on the substrate adjacent to the first light-emitting diode, wherein the two bonding metals are not in contact with the first The two light emitting diodes are directly connected; wherein the first platform structure and the second platform structure have the same top shape and different placement directions, or different top shapes; wherein the first platform structure and The second platform structure collectively forms a first top-view geometric figure, which is different from the top-view shapes of the first platform structure, the second platform structure, or both. The light-emitting element according to item 1 of the scope of patent application, wherein the planar shapes of the first platform structure and the second platform structure are non-rectangular. The light-emitting element according to item 1 of the scope of patent application, wherein the first platform structure and the second platform structure have different non-rectangular plan shapes. The light-emitting element according to item 1 of the scope of patent application, wherein the substrate has an outer contour similar to the first top-view geometry. The light-emitting element according to item 1 of the scope of patent application, wherein the first platform structure has a first side edge, the second platform structure has a second side edge, the first side edge and the second side edge parallel. The light-emitting element according to item 1 of the scope of patent application, wherein the first platform structure has a first side edge, the second platform structure has a second side edge, the first side edge and the second side edge Have similar lengths. The light-emitting element according to item 1 of the scope of patent application, wherein the substrate is a growth substrate. The light-emitting element according to item 1 of the scope of patent application, wherein the substrate is a thinned substrate. The light-emitting element according to item 1 of the patent application scope further includes a third light-emitting diode formed on the substrate, wherein a distance between the first light-emitting diode and the second light-emitting diode is smaller than the The distance between the first light emitting diode and the third light emitting diode. The light-emitting element according to item 1 of the patent application scope further includes a third light-emitting diode, the third light-emitting diode has a third platform structure, the third platform structure and the first platform structure, and the The second platform structures collectively form a second top-view geometry that is different from the top-view shapes of the first platform structure, the second platform structure, the third platform structure, or three of them.