Light emitting diode structure

Abstract

The invention provides a light-emitting diode structure. The light-emitting diode structure comprises a substrate, a semiconductor light-emitting structure and an electrode structure. The semiconductor light-emitting structure is located on the substrate, and the semiconductor light-emitting structure comprises a light-emitting surface. The electrode structure is located on the light-emitting surface. The electrode structure comprises a main electrode part, at least one secondary electrode part and at least one transparent conductive part. A distance is kept between the main electrode part and each secondary electrode part, and each secondary electrode part is electrically connected with the main electrode part through any transparent conductive part to serve as a current conduction path.

Description

Technical Field

[0001] The present invention relates to a light emitting diode structure, and in particular to a light emitting diode structure capable of improving light emitting uniformity and light emitting efficiency. Background Art

[0002] In recent years, light-emitting diodes have been widely used in lighting, medical and 3C products. Light-emitting diode chips are mainly made of different semiconductor materials. When current flows through the connection surface of two semiconductor materials, an electroluminescent effect is generated to convert electrical energy into light energy, so that the light-emitting diode chip can not only emit high-brightness light, but also save energy and electricity.

[0003] In terms of structural design, a metal electrode is provided on the surface of the LED chip to be electrically connected to external components through welding wires. In order to improve the uniformity of the light emission of the LED chip, an extended electrode electrically connected to the metal electrode is additionally provided on the chip surface. The extended electrode transmits the current to the area with lower light emission efficiency, so that more current passes through the connection surface of the semiconductor material to enhance the light emission effect. However, since the extended electrode has a certain width, a part of the light emitting surface of the semiconductor material will be shielded by the opaque metal electrode and the extended electrode, thereby reducing the light emitting area of ​​the light emitting surface, which will lead to a decrease in the light emission efficiency or brightness attenuation of the LED chip.

[0004] Therefore, how to design a light emitting diode structure that can improve the above-mentioned problems is indeed a topic worth studying. Summary of the invention

[0005] The object of the present invention is to provide a light emitting diode structure which can improve light emitting uniformity and light emitting efficiency.

[0006] To achieve the above-mentioned purpose, the light-emitting diode structure of the present invention includes a substrate, a semiconductor light-emitting structure and an electrode structure. The semiconductor light-emitting structure is located on the substrate, and the semiconductor light-emitting structure includes a light-emitting surface. The electrode structure is located on the light-emitting surface. The electrode structure includes a main electrode portion, at least one transparent conductive portion and at least one secondary electrode portion. The main electrode portion and each secondary electrode portion are spaced apart, and each secondary electrode portion is electrically connected to the main electrode portion through any transparent conductive portion to serve as a current conduction path.

[0007] In one embodiment of the present invention, each transparent conductive portion and the semiconductor light emitting structure present high contact resistance or are electrically non-conductive.

[0008] In one embodiment of the present invention, each transparent conductive portion has a low contact resistance with the semiconductor light emitting structure.

[0009] In one embodiment of the present invention, each transparent conductive portion is made of zinc oxide, indium tin oxide, indium zinc oxide or indium gallium zinc oxide.

[0010] In one embodiment of the present invention, the main electrode portion, at least one transparent conductive portion and at least one sub-electrode portion are respectively in direct contact with the semiconductor light emitting structure, and a portion of each transparent conductive portion is disposed between the main electrode portion and the light emitting surface.

[0011] In one embodiment of the present invention, the main electrode portion, at least one transparent conductive portion and at least one sub-electrode portion are respectively in direct contact with the semiconductor light emitting structure, and a portion of each transparent conductive portion covers a partial outer surface of the main electrode portion.

[0012] In one embodiment of the present invention, at least one transparent conductive portion and at least one sub-electrode portion are respectively in direct contact with the semiconductor light emitting structure, and the main electrode portion is formed on at least one transparent conductive portion and is in indirect contact with the semiconductor light emitting structure.

[0013] In an embodiment of the present invention, when there are a plurality of at least one transparent conductive portion, ends of the transparent conductive portions electrically connected to the main electrode portion may be connected to each other.

[0014] In one embodiment of the present invention, the width of the transparent conductive portion is not less than 3 μm.

[0015] In one embodiment of the present invention, at least one transparent conductive portion covers the remaining portion of the light emitting surface except for the main electrode portion and the at least one sub-electrode portion.

[0016] In one embodiment of the present invention, the thickness of the transparent conductive portion is not less than

[0017] Accordingly, the light-emitting diode structure of the present invention can set at least one sub-electrode portion at any position on the light-emitting surface where current distribution needs to be controlled, and with the setting of at least one transparent conductive portion, the main electrode portion and each sub-electrode portion are electrically connected to transmit current. Accordingly, the light-emitting diode structure of the present invention has a more uniform current distribution on the light-emitting surface, and at least one transparent conductive portion does not block light, thereby improving the light-emitting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. 1 is a top view of a first embodiment of a light emitting diode structure of the present invention.

[0019] Figure 2 FIG. 4 is a cross-sectional view of a first embodiment of a light emitting diode structure of the present invention.

[0020] Figure 3 FIG. 4 is a top view of a second embodiment of a light emitting diode structure of the present invention.

[0021] Figure 4 FIG. 4 is a cross-sectional view of a second embodiment of a light emitting diode structure of the present invention.

[0022] Figure 5 FIG. 4 is a top view of a light emitting diode structure according to a third embodiment of the present invention.

[0023] Figure 6 FIG. 4 is a cross-sectional view of a light emitting diode structure according to a third embodiment of the present invention.

[0024] Figure 7 FIG. 4 is a cross-sectional view of a light emitting diode structure according to a fourth embodiment of the present invention.

[0025] Figure 8 FIG. 4 is a top view of a fifth embodiment of a light emitting diode structure of the present invention. DETAILED DESCRIPTION

[0026] Since the various aspects and embodiments are only illustrative and non-limiting, after reading this specification, those skilled in the art may also derive other aspects and embodiments without departing from the scope of the present invention. The features and advantages of these embodiments will become more apparent according to the following detailed description and the scope of the invention.

[0027] In this document, "a" or "an" is used to describe the elements and components described herein. This is only for convenience of description and to provide a general sense of the scope of the present invention. Therefore, unless it is obvious that it is otherwise intended, this description should be understood to include one or at least one, and the singular also includes the plural.

[0028] In this document, the terms "including", "having" or any other similar terms are intended to cover a non-exclusive inclusion. For example, an element or structure containing multiple (multiple) elements is not limited to only those elements listed herein, but may include other elements that are not explicitly listed but are generally inherent to the element or structure.

[0029] Please refer to the following Figure 1 and Figure 2 , Figure 1 and Figure 2 is a diagram related to the first embodiment of the light emitting diode structure of the present invention, wherein: Figure 2 For along Figure 1 The cross-sectional view of the line segment A-A'. Figure 1 and Figure 2As shown, the light emitting diode structure 1 of the present invention includes a substrate 10, a semiconductor light emitting structure 20 and an electrode structure 30. The substrate 10 is a basic structural component of the light emitting diode structure 1, and the substrate 10 can be a silicon (Si) substrate, an aluminum nitride (AlN) substrate, a copper tungsten (CuW) substrate or a molybdenum (Mo) substrate, but the present invention is not limited thereto. The substrate 10 includes a plurality of metal dots 11, and the plurality of metal dots 11 are arranged on a surface of one side of the substrate 10 (for example, a surface of the substrate 10 facing the semiconductor light emitting structure 20).

[0030] The semiconductor light emitting structure 20 is located on the substrate 10, and the semiconductor light emitting structure 20 is used to generate an electroluminescent effect to emit light. The semiconductor light emitting structure 20 includes a light emitting surface 24, and the light emitting surface 24 is the other side opposite to the side contacting the substrate 10. In one embodiment of the present invention, the semiconductor light emitting structure 20 may also include a first semiconductor layer 21 and a second semiconductor layer 22. The first semiconductor layer 21 is adjacent to the substrate 10. In the following embodiments, the first semiconductor layer 21 is illustrated by using gallium phosphide (GaP) as an example, but the present invention is not limited thereto. The first semiconductor layer 21 may also be made of gallium arsenide (GaAs), gallium nitride (GaN) or other semiconductor materials. The first semiconductor layer 21 may be formed into an N-type semiconductor or a P-type semiconductor by doping different metals.

[0031] The second semiconductor layer 22 is located on the first semiconductor layer 21. In the following embodiments, the second semiconductor layer 22 is illustrated by using aluminum gallium indium phosphide (AlGaInP) as an example, but the present invention is not limited thereto. The second semiconductor layer 22 can also be made of aluminum gallium arsenide (AlGaAs) or other semiconductor materials. The second semiconductor layer 22 can also be formed into an N-type semiconductor or a P-type semiconductor by doping different metals. Among them, when the first semiconductor layer 21 is an N-type semiconductor, the second semiconductor layer 22 is a P-type semiconductor; conversely, when the first semiconductor layer 21 is a P-type semiconductor, the second semiconductor layer 22 is an N-type semiconductor. A light-emitting layer 23 is formed between the first semiconductor layer 21 and the second semiconductor layer 22 (i.e., the interface between the first semiconductor layer 21 and the second semiconductor layer 22), and the light-emitting layer 23 here is a multiple quantum well (MQW) layer.

[0032] The electrode structure 30 is located on the light-emitting surface 24 of the semiconductor light-emitting structure 20, and the electrode structure 30 can be connected to a power supply. By supplying power to the electrode structure 30, a current is generated from the electrode structure 30 to the multiple metal points 11 of the substrate 10, so that the current flows through the light-emitting layer 23 to emit light. In the present invention, the electrode structure 30 at least includes a main electrode portion 31, at least one secondary electrode portion 32, and at least one transparent conductive portion 33. The main electrode portion 31 and the at least one secondary electrode portion 32 are made of metal or alloy, and a distance is maintained between the main electrode portion 31 and each secondary electrode portion 32. The main electrode portion 31 is used as a pad for welding a metal line electrically connected to a power supply or / and other electronic components. At least one secondary electrode portion 32 is used as an additional metal point for transmitting current. The number and position of at least one secondary electrode portion 32 can be changed according to different design requirements. For example, in each embodiment of the present invention, at least one sub-electrode portion 32 includes four sub-electrode portions 32, and each sub-electrode portion 32 is arranged in an area with lower luminous efficiency on the light-emitting surface 24 (for example, uniformly and dispersedly arranged around the main electrode portion 31), but the present invention is not limited thereto.

[0033] Each transparent conductive portion 33 is respectively connected to the main electrode portion 31 and any one of the sub-electrode portions 32, so that each sub-electrode portion 32 is electrically connected to the main electrode portion 31 through any one of the transparent conductive portions 33 as a current conduction path; that is, the current can be transmitted from the main electrode portion 31 to the corresponding sub-electrode portion 32 via the transparent conductive portion 33, so that the sub-electrode portion 32 becomes another current transmission source. In one embodiment of the present invention, each transparent conductive portion 33 is a transparent conductive film composed of zinc oxide (ZnO), indium tin oxide (ITO), indium zinc oxide (IZO) or indium gallium zinc oxide (IGZO). In terms of structural design, the thickness of the transparent conductive portion 33 is not less than If the transparent conductive portion 33 is substantially linear, the width of the transparent conductive portion 33 (ie, the radial distance perpendicular to the direction of the current mainly flowing through the transparent conductive portion 33 ) is not less than 3 μm, so as to provide a current transmission effect.

[0034] In the present invention, each transparent conductive portion 33 is in direct contact with the semiconductor light emitting structure 20, and according to different design requirements, each transparent conductive portion 33 and the semiconductor light emitting structure 20 may present different contact impedances or electrical conduction effects. For example, in one embodiment of the present invention, through the material selection and design of each transparent conductive portion 33, each transparent conductive portion 33 and the semiconductor light emitting structure 20 may present high contact impedance (for example, Schottky contact or ohmic contact with high contact impedance) or electrical non-conduction. Accordingly, the current will choose the characteristic of a path with lower impedance to be transmitted, so that the current will hardly be directly transmitted downward from the transparent conductive portion 33 to the semiconductor light emitting structure 20, but will be concentrated and laterally gathered to the corresponding sub-electrode portion 32, thereby achieving the effect of guiding the current to the area with lower luminous efficiency.

[0035] With respect to the first embodiment of the light emitting diode structure 1 of the present invention, after the semiconductor light emitting structure 20 is formed on the substrate 10 by an epitaxial growth process, at least one secondary electrode portion 32, at least one transparent conductive portion 33 and a main electrode portion 31 are sequentially formed on the light emitting surface 24 of the semiconductor light emitting structure 20 to form an overall electrode structure 30. In terms of structural design, the main electrode portion 31, at least one secondary electrode portion 32 and at least one transparent conductive portion 33 of the electrode structure 30 are respectively in direct contact with the semiconductor light emitting structure 20, and a portion of each transparent conductive portion 33 is disposed between the main electrode portion 31 and the light emitting surface 24 of the semiconductor light emitting structure 20. In addition, when there are multiple at least one transparent conductive portion 33, the ends of each transparent conductive portion 33 electrically connected to the main electrode portion 31 may be connected to each other, for example, to form a structure such as Figure 1 According to this, the main electrode portion 31 and the sub-electrode portion 32 can be electrically connected through the transparent conductive portion 33 .

[0036] When power is supplied to the main electrode portion 31, in addition to being able to be transmitted directly from the main electrode portion 31 through the semiconductor light-emitting structure 20 toward the metal point 11 of the substrate 10, the current can also be concentrated and laterally gathered from the main electrode portion 31 to each secondary electrode portion 32, and then directly transmitted from each secondary electrode portion 32 through the semiconductor light-emitting structure 20 toward the metal point 11 of the substrate 10. Accordingly, the light-emitting diode structure 1 of the present invention can achieve a uniform current distribution effect through the electrode structure 30, and the light emitted by the light-emitting layer 23 of the semiconductor light-emitting structure 20 can be directly emitted from the light-emitting surface 24 or penetrate each transparent conductive portion 33 before being emitted, thereby reducing the area range where the light may be shielded. For another example, by coordinating the position setting of the electrode structure 30 with the multiple metal points 11 of the substrate 10, the light-emitting diode structure 1 of the present invention can provide better light-emitting efficiency and light-emitting uniformity.

[0037] Please refer to Figure 3 and Figure 4 , Figure 3 and Figure 4 is a diagram related to the second embodiment of the light emitting diode structure of the present invention, wherein: Figure 4 For along Figure 3 The cross-sectional view of the line segment A-A'. Figure 3 and Figure 4 As shown, in the present embodiment, after the semiconductor light emitting structure 20 is formed on the substrate 10 through an epitaxial growth process, at least one secondary electrode portion 32a, a main electrode portion 31a and at least one transparent conductive portion 33a are sequentially formed on the light emitting surface 24 of the semiconductor light emitting structure 20 to form an overall electrode structure 30a. In terms of structural design, the main electrode portion 31a, at least one secondary electrode portion 32a and at least one transparent conductive portion 33a of the electrode structure 30a are respectively in direct contact with the semiconductor light emitting structure 20, and a portion of each transparent conductive portion 33a covers a partial outer surface of the main electrode portion 31a. In addition, when there are multiple at least one transparent conductive portion 33a, the ends of each transparent conductive portion 33a electrically connected to the main electrode portion 31a may be connected to each other, for example, to form a structure as shown in FIG. Figure 3 and Figure 4 The ring-like structure shown. Accordingly, the main electrode portion 31a and the sub-electrode portion 32a can be electrically connected through the transparent conductive portion 33a. Since the operating principle of the second embodiment of the light-emitting diode structure 1a of the present invention is the same as that of the first embodiment and can achieve similar effects, it will not be repeated here.

[0038] Please refer to Figure 5 and Figure 6 , Figure 5 and Figure 6 is a diagram related to the third embodiment of the light emitting diode structure of the present invention, wherein: Figure 6 For along Figure 5 The cross-sectional view of the line segment A-A'. Figure 5 and Figure 6 As shown, in the present embodiment, after the semiconductor light emitting structure 20 is formed on the substrate 10 through an epitaxial growth process, at least one secondary electrode portion 32b, at least one transparent conductive portion 33b and a main electrode portion 31b are sequentially formed on the light emitting surface 24 of the semiconductor light emitting structure 20 to form an overall electrode structure 30b. In terms of structural design, at least one secondary electrode portion 32b and at least one transparent conductive portion 33b of the electrode structure 30b are respectively in direct contact with the semiconductor light emitting structure 20, and the main electrode portion 31b is formed on at least one transparent conductive portion 33b and is indirectly in contact with the semiconductor light emitting structure 20. In addition, when there are multiple at least one transparent conductive portion 33b, the ends of each transparent conductive portion 33b electrically connected to the main electrode portion 31b may be connected to each other, for example, to form a structure as shown in FIG. Figure 5 and Figure 6 According to this, the main electrode portion 31b and the sub-electrode portion 32b are electrically connected through the transparent conductive portion 33b.

[0039] When the main electrode portion 31b is powered, the current can almost only be concentrated and laterally collected from the main electrode portion 31b to each sub-electrode portion 32b, and then directly transmitted from each sub-electrode portion 32b through the semiconductor light emitting structure 20 toward the metal point 11 of the substrate 10. In addition to the above-mentioned design, since the operating principle of the third embodiment of the light emitting diode structure 1b of the present invention is substantially the same as that of the first and second embodiments, and can achieve similar effects, it will not be repeated here.

[0040] Please refer to Figure 7 , Figure 7 FIG. 4 is a cross-sectional view of a fourth embodiment of the light emitting diode structure of the present invention. This embodiment is a variation of the first embodiment. Figure 7 As shown, in this embodiment, the light emitting diode structure 1c of the present invention can present low contact impedance (for example, ohmic contact with low contact impedance) between each transparent conductive portion 33c and the semiconductor light emitting structure 20 by selecting and designing the material of the transparent conductive portion 33c. Accordingly, although part of the current will be transmitted directly from the transparent conductive portion 33c through the semiconductor light emitting structure 20 toward the metal point 11 of the substrate 10, most of the current will still be collected laterally to the corresponding sub-electrode portion 32c, thereby achieving the effect of guiding the current to the area with lower light emitting efficiency.

[0041] Please refer to Figure 8 , Figure 8 FIG. 5 is a top view of a fifth embodiment of the light emitting diode structure of the present invention. This embodiment is a variation of the second embodiment described above. Figure 8 As shown, in this embodiment, the light-emitting diode structure 1d of the present invention covers the remaining part of the light-emitting surface 24 of the semiconductor light-emitting structure 20 except for the main electrode part 31d and at least one secondary electrode part 32d through a large-area transparent conductive part 33d, and a part of the transparent conductive part 33d covers the partial outer surface of the main electrode part 31d. That is to say, in this embodiment, by expanding the coverage area of ​​the transparent conductive part 33d, the overall electrode structure 30d (including the main electrode part 31d, four secondary electrode parts 32d and one large-area transparent conductive part 33d) will completely cover the light-emitting surface 24 of the semiconductor light-emitting structure 20. Accordingly, the main electrode part 31d and the secondary electrode part 32d can be electrically connected through the transparent conductive part 33d. In addition to the above-mentioned design, since the operating principle of the fifth embodiment of the light-emitting diode structure 1d of the present invention is substantially the same as that of the second embodiment, and can achieve similar effects, it will not be repeated here.

[0042] The above embodiments are essentially only auxiliary explanations, and are not intended to limit the embodiments of the application or the application or use of the embodiments. In addition, although at least one exemplary embodiment has been proposed in the aforementioned embodiments, it should be understood that the present invention can still have a large number of changes. It should also be understood that the embodiments described herein are not intended to limit the scope, use or configuration of the requested application in any way. On the contrary, the aforementioned embodiments will provide a simple guide to implement one or more of the embodiments described to those skilled in the art. Furthermore, various changes can be made to the functions and arrangements of the elements without departing from the scope defined by the scope of the invention, and the scope of the invention includes known equivalents and all foreseeable equivalents when the present invention is applied for.

[0043]

Explanation of symbols

[0044] 1. 1a, 1b, 1c, 1d…Light-emitting diode structure

[0045] 10...Substrate

[0046] 20…Semiconductor light-emitting structure

[0047] 21…First semiconductor layer

[0048] 22…Second semiconductor layer

[0049] 23…Luminous layer

[0050] 24…luminous surface

[0051] 30, 30a, 30b, 30c, 30d ... electrode structure

[0052] 31, 31a, 31b, 31c, 31d ... main electrode portion

[0053] 32, 32a, 32b, 32c, 32d ... secondary electrode portion

[0054] 33, 33a, 33b, 33c, 33d... transparent conductive part

Claims

1. A light emitting diode structure, comprising: substrate; a semiconductor light emitting structure, located on the substrate, the semiconductor light emitting structure comprising a light emitting surface; and An electrode structure is located on the light-emitting surface, and the electrode structure includes a main electrode portion, at least one secondary electrode portion and at least one transparent conductive portion. A spacing is maintained between the main electrode portion and each of the secondary electrode portions, and each of the secondary electrode portions is electrically connected to the main electrode portion through any one of the transparent conductive portions to serve as a current conduction path.

2. The light emitting diode structure according to claim 1, wherein: Each of the transparent conductive parts and the semiconductor light emitting structure presents high contact resistance or electrical non-conduction.

3. The light emitting diode structure according to claim 1, wherein: Each of the transparent conductive parts presents low contact resistance with the semiconductor light emitting structure.

4. The light emitting diode structure according to claim 1, wherein: Each of the transparent conductive parts is made of zinc oxide, indium tin oxide, indium zinc oxide or indium gallium zinc oxide.

5. The light emitting diode structure according to claim 1, wherein: The main electrode portion, the at least one transparent conductive portion, and the at least one sub-electrode portion are respectively in direct contact with the semiconductor light emitting structure, and a portion of each of the transparent conductive portions is disposed between the main electrode portion and the light emitting surface.

6. The light emitting diode structure according to claim 1, wherein: The main electrode portion, the at least one transparent conductive portion, and the at least one sub-electrode portion are respectively in direct contact with the semiconductor light emitting structure, and a portion of each of the transparent conductive portions covers a partial outer surface of the main electrode portion.

7. The light emitting diode structure according to claim 1, wherein: The at least one transparent conductive portion and the at least one sub-electrode portion are respectively in direct contact with the semiconductor light emitting structure, and the main electrode portion is formed on the at least one transparent conductive portion and is in indirect contact with the semiconductor light emitting structure.

8. The light emitting diode structure according to claim 1, wherein: When there are a plurality of the at least one transparent conductive portion, ends of the transparent conductive portions electrically connected to the main electrode portion may be connected to each other.

9. The light emitting diode structure according to claim 1, wherein: The width of the transparent conductive portion is not less than 3 μm.

10. The light emitting diode structure according to claim 1, wherein: The at least one transparent conductive portion covers the remaining portion of the light emitting surface except for the main electrode portion and the at least one sub-electrode portion.

11. The light emitting diode structure according to claim 1, wherein: The thickness of the transparent conductive part is not less than

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