TW200406936A - Electrode structure for a light-emitting device - Google Patents

Abstract

An electrode structure for a light-emitting device includes a first electrode and a second electrode. The first electrode has a plurality of first fingers paralleling with each other, a first connective element, and at least a first contact element. Each first finger has a first end and a second end. A plurality of first ends connect to the first connective element. The first contact element interposes between any first end and the first connective element. The second electrode has a plurality of second fingers paralleling with each other, a second connective element, and at least a second contact element. Each second finger has a third end and a fourth end, and any second finger is between and parallels to any two first fingers. A plurality of third ends connect to the second connective element. The second contact element interposes between any third end and the second connective element. The second electrode defines a plurality of hexagonal units among a plurality of second ends. Each hexagonal unit shares its four sides to its adjacent hexagonal units, and the four sides include two of the second fingers and the second connective element. Each second end extends to the center of each hexagonal unit.

Description

200406936 V. Description of the invention (1) 1. [Technical field to which the invention belongs] The present invention relates to an electrode structure of a light-emitting element, and more particularly to an electrode structure of a light-emitting element formed with a hexagonal structure. 2. [Previous Technology] Because gallium nitride (GaN) has a wide band gap (Eg = 3.4 eV at room temperature) and its emission range is near the blue light wavelength, gallium nitride is very suitable as a short-wavelength light-emitting element. Therefore, it has become one of the most popular materials in the development of photovoltaic elements in recent years. After continuous research and development, the current technology can stably grow gallium nitride on a sapphire substrate 'and if a proper arrangement of stupid crystals and electrodes is used', a short-wavelength light-emitting device can be manufactured . As shown in the first figure, a schematic plan view of an electrode of a conventional light-emitting element is shown. When a voltage is applied to the first electrode 110, current flows into the light-emitting element through the contact pads connected to the first electrode, and energy is generated by recombination of minority carriers caused by passing through the internal P / N junction in a forward direction. After the light is emitted, the current will converge to the second electrode 1 2 0 through different paths (for example, current paths 11 2, 11 4 and 1 16 etc.), and flow out through the contact pad connected to the second electrode 1 2 0. This light-emitting element. However, the paths from which the current flows from the first electrode 110 to the second electrode 120 are not all equidistant current paths, which also causes the phenomenon of non-uniform current distribution and causes the uneven brightness of the light-emitting element. . For example: the current density of the edge current paths 1 1 2 and 11 6 is longer than the center current path due to the longer path distance.

Page 6 200406936 V. Description of the invention (2) The current density of the diameter 1 1 4 is low, so the light-emitting element at the edge portion is not as bright as the light-emitting element at the center portion. In addition, uneven current density distribution is also one of the main reasons for the poor reliability of light emitting devices. In order to improve the luminous brightness of light-emitting elements, gallium nitride (GaN) light-emitting elements have gradually shifted to the development of high-power and large-area elements. As shown in the second figure, it is the outline of another finger-type electrode common in high-power semiconductor elements. Top view of structure. The first electrode 150 is perpendicularly connected to the extending electrodes 150-1 and 150-2 which are parallel to each other to form a so-called finger electrode structure. The second electrode 16 0 is also connected to the extending electrodes 16 0-1, 16 0-2 and 16 0-3 which are parallel to each other to form another finger electrode structure. Due to the interdigitated and parallel electrode structure formed by the two-finger electrode structure, the distance between each extension electrode and the adjacent extension electrode is equal. Therefore, the distance from the extension electrode to the adjacent extension electrode is equal. Current path, thereby averaging the current density and luminous intensity of each part in the light-emitting element. However, the impedance of the finger-shaped structure on the extension electrode will increase as the distance from the electrode increases, for example: the impedance from point B to the first electrode 150 is greater than the impedance from point A to the first electrode 150 . This means that the intensity of the current flowing to point B will be smaller than the intensity of the current flowing to point A. Therefore, the current density near the extension electrode B will also be lower than the current density near the point A, which will cause the light intensity near the point B. That is, the intensity of light emission is relatively weaker than that near the point A. In view of the shortcomings of the electrode structure of the light-emitting element described above and the limitations in actual production, it is always necessary to continuously develop new and improved structures to overcome the first

200406936 V. Description of the invention (3) Various defects in the previous art. So, how to equidistant the current path between the two electrodes-. Diameter, how to average the distance impedance between the electrode and the extension electrode, and how to use a standard process to meet the different needs of high-power light-emitting elements, are issues that will inevitably be encountered in this technical field, and are also problems to be solved by the invention. 3. [Summary of the Invention] In view of the above background of the invention, the electrode structure of the light-emitting element in the conventional art has problems such as uneven current distribution and different distance impedances. The present invention utilizes the geometric characteristics of a hexagon to cover the entire plane, and provides an electrode structure of a light-emitting element formed by using a hexagon as a framework, thereby improving various shortcomings in the conventional art. An object of the present invention is to make the current paths between the first electrode and the second electrode equidistant by using an electrode structure formed by using a hexagon as a framework. Another object of the present invention is to average the distance impedance between an electrode and an extended electrode by using a concept of an electrode structure formed by using a hexagon as a framework, and the distance between each adjacent vertex is the same. According to the above-mentioned object, the present invention provides an electrode structure of a light-emitting element, including: a first electrode, the first electrode includes a plurality of first finger portions parallel to each other, a first connection portion and at least one First pick

200406936 V. Description of the invention (4) Each of the first finger-shaped portions has a first end and a second end, wherein the first ends are connected to the first connection portion, and the first contact portion is interposed. Between any first end and the first connection portion; and a second electrode, the second electrode includes a plurality of second finger portions parallel to each other, a second connection portion and at least one second contact portion, each A second finger portion has a third end and a fourth end, and any one of the second finger portions is located between any two adjacent first finger portions, and the third ends are connected to the second connection. Part, the second contact part is inserted between any third end and the second connection part. Wherein the above-mentioned second electrode defines a plurality of hexagonal units between the above-mentioned plurality of second ends, each hexagonal unit is in close proximity to the other hexagonal units with four coedges, and every two second finger portions And the second connecting part constitute four common sides of each hexagonal unit, and each second end extends from the other two sides of each hexagonal unit to the geometric center of each hexagonal unit. Embodiments Some embodiments of the present invention will be described in detail as follows. However, in addition to the detailed description, the present invention can be widely implemented in other embodiments, and the scope of the present invention is not limited, which is subject to the scope of subsequent patents. 'Moreover, in order to provide a clearer description and easier understanding of the present invention, the parts in the diagram are not drawn according to their relative dimensions, and the proportions of certain dimensions to other relevant dimensions have been exaggerated; irrelevant details are not completely Draw for simplicity.

Page 9 200406936 V. Description of the invention (5) The present invention provides an electrode structure of a light-emitting element, including: a first electrode, the first electrode includes a plurality of first finger portions parallel to each other, a first connection portion And at least one first contact portion, each first finger portion has a first end and a second end, wherein the first ends are connected to the first connection portion, and the first contact portion is interposed at any one Between the first end and the first connection portion; and a second electrode, the second electrode includes a plurality of second finger portions parallel to each other, a second connection portion and at least one second contact portion, each second The finger portion has a third end and a fourth end, and any second finger portion is located between any two adjacent first finger portions, and the third end is connected to the second connecting portion. The two contact portions are inserted between any third end and the second connection portion. The second electrode of the above-mentioned · defines a plurality of hexagonal units between the plurality of second ends described above, each hexagonal unit is adjacent to the other hexagonal units with four coedges, and every two second fingers The part and the second connecting part constitute four common sides of each hexagonal unit, and each second end extends from the other two sides of each hexagonal unit to the geometric center of each hexagonal unit. As shown in FIG. 3A, it is a schematic diagram of an electrode structure according to a preferred embodiment of the present invention. The first electrode includes a plurality of first finger portions 3 1 0 parallel to each other, a first connection portion connected to the bottom end of the first finger portions 3 1 0, points 3 2 0, and at least one first contact portion 3 3 0. The first contact portion 3 3 0 can be inserted between the bottom end of any of the first finger portions 3 1 0 and the first connection portion 3 2 0. In this embodiment, two rectangular first contact portions 3 3 0

Page 10, 200,406,936 V. Description of the invention (6) Insert the first finger-shaped part 3 1 0 at the bottom of the space separately, and /, the part of the contact pad, which must be emphasized here: '化成 ^ ^ A contact portion is not limited to only a few geometric shapes replaced in the κ embodiment. It can also be a second -4t parallel to each other, a second portion 340 connecting the bottom end of these second finger portions 34o, and at least one second contact portion 36o. Which of this? : Divided into 3 5 ^ with 3 4 0 apex in parallel to any two adjacent-button f heart shape. P knife, and the second contact portion 3 6 0 can be inserted between any U: portion 3 1 0 and Γ. In this embodiment, the two circular ones; =; stand on the bottom of the ㈣-shaped portions on both sides ☆ 3 4 0 and are connected to the first: 4 minutes 3 5 0, α forming the part of the metal contact pad, the same The reason is that the first contact portion is not limited to the circular geometry, and the beans are replaced with other geometric shapes. /, And the above-mentioned first electrode means a plurality of hexagonal cells 370, 380 between the tops of these first finger-shaped portions 31, as shown in the third β diagram. Each hexagonal unit 37o, 380 has four common sides (for example: two adjacent and same-direction second finger portions 340 and a first connecting portion 350 connecting the two second finger portions 34o) It is next to other hexagonal elements 370 and 38 0, and f two adjacent second finger portions 34 0 in the same direction may also form the second contact portion 36 0 of each hexagonal element 37 0, 38 Four coedges. In this embodiment, the four common edges of each hexagonal cell 3 7 〇 include 0 to 丨 second contacts.

200406936 V. Description of the invention (7) The contact portion 3 6 0; and the four total contact portions 3 6 0 of each hexagonal unit 38 0. It is expected that each of the first finger-shaped portions 3 corresponds to the two first phases and the other two sides of the hexagonal unit 3 7 0, 3 8 0 extend to: each corresponding hexagonal unit 3 7 0, 3 8 0 Geometric center. In other words, "The above-mentioned finger parts, connecting parts, and descriptive parts" are all arranged in a continuous hexagon. Please refer to Part B of Part Three. Take the hexagonal units 3 7 0 and 3 8 0 and connect the vertices of the% subparameters as the bottom ends of the second finger parts 3 4 0, and set the numbers. The common sides of three adjacent hexagonal units 3 7 0 and any two neighboring hexagonal units ^ any two common sides form a plurality of second finger portions 34 0, which are formed only when a total of 'two = ft 3 7 0 The second finger portion 3 4 0 of the side has a direction opposite to that of the second finger portion 3 4 0 formed on the common side of the hexagonal unit 3 8 0. A second connecting portion 3 50 is then formed by the common sides of the hexagonal cells 37 and 38 connected to the bottom end of the second finger portion 3 40. The first finger portion 3 1 0 is located at the opposite vertex of the hexagonal unit 3 70 where the bottom end of the second finger portion 3 40 is located. The first contact portion 3 3 0 and the second contact portion 3 60 may be formed at the vertices of the hexagonal unit 37 °. In addition, the first finger portion 3 丨 〇 may be formed at the diagonal apex of a hexagonal unit 3 8 〇 of the same size formed between adjacent hexagonal singles το 3 7 0. The first finger portion 3 1 0 on the shape unit 37 is opposite. Then, on the complete plane formed by the plurality of hexagonal cells 3 7 0 and 38 0, there is an AND between the two adjacent second finger portions 3 4 0 in the same direction.

Page 12 200406936 V. Description of the invention (8) The parallel first finger-shaped portions 3 1 0; in other words, every two adjacent first finger-shaped portions 3 1 0 will also be parallel to each other第二 指 状 部 340。 The second finger portion 340. Since the sides of each side of the hexagonal units 370 and 38 0 are equal and the distance between the first finger portion 3 1 0 and the second finger portion 3 4 0 is approximately equal, the appropriate layout (1 ayout) will The first contact portion 33 ° and the second contact portion 360 are inserted at the vertices of the hexagonal cells 37 and 38, so that the current paths between the two electrodes are approximately equidistant, and the average distance between the electrodes and the extended electrodes can be evened. Distance impedance. The so-called appropriate layout mentioned above is based on considerations such as current dispersion and $ line transmission. For example: general wiring (bonding) = less current than the high-power light-emitting element actually used in the current-limiting specifications: : Therefore, the current is dispersed to avoid smoke by increasing the contact portion and the wire. # 亓 杜 π π ι + Μ Γ-Excessive contact portions will be blocked and cause the luminous efficiency of the light-emitting element ^ soil; the above two factors The appropriate consideration depends on the contact. Two, and the number of contact portions and the number of each other 'may also be less than the above-mentioned preferred embodiment of the trowel of the second contact portion (for example, a light-emitting diode (a light-emitting diode) The concept of equal geometric layout and equal distance between points, instead, creates the problem of different impedances; using the concept of equal distance, the two electrodes are equidistant. The present invention emphasizes light emitting elements

Emitting Diode; LED)) two electrical structures, using the current path I between the center point of the hexagon and the distance between the vertices due to the distance between any adjacent top electrode and the extended electrode of the hexagon. In addition, using six

Page 13 200406936 V. Description of the invention (9) The symmetrical geometric patterns of the polygons make the most effective area utilization of the entire wafer plane, thereby improving the area utilization problem of the light-emitting element due to the asymmetric electrode structure. In other words, the hexagonal electrode structure can meet the requirements of the above conditions under the consideration of the average current density and luminous intensity in a small unit of the light-emitting element and the utilization of a large-sized wafer area, which is also the spirit of the present invention. The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of patent application of the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following The scope of patent application.

Page 14 200406936 Brief description of the drawings V. [Simplified description of the drawings] The first diagram is a schematic view of a schematic structure of a conventional light-emitting element electrode; the second diagram is a schematic structure of a finger-shaped electrode of another conventional light-emitting element Top view; A third view is a top view of an electrode structure of a preferred light-emitting element of the present invention; and a third B view is a third A view plus a hypothetical hexagonal plan view. Representative symbols of main parts: 1 1 0, 1 50 0 first electrode. 1 1 2, 1 1 4, 1 1 6 current path 1 2 0, 1 6 0 second electrode 150-1, 150-2 first electrode Extension electrode 160-1, 160-2, 160-3 Second electrode extension electrode 310 First finger portion 3 2 0 First connection portion 3 3 0 First contact portion 34 0 Second finger portion 3 5 0 Second Connection section 3 6 0 Second contact section 370, 380 Hexagonal unit

Page 15 200406936 Schematic illustration A, B points A, B

BB Page 16

Claims (1)

200406936 6. Scope of patent application 1. An electrode structure of a light-emitting element, comprising: a first electrode; the first electrode includes a plurality of first finger portions parallel to each other, a first connection portion and at least one first contact portion Each of the first finger portions has a first end and a second end, wherein the plurality of first ends are connected to the first connecting portion, and the first contact portion is interposed in any of the first Between one end and the first connection portion; and a second electrode, the second electrode including a plurality of second finger portions, a second connection portion and at least one second contact portion, each of which The two-finger portions have a third end and a fourth end, and any one of the second finger portions is located between any two adjacent first finger portions, and the plurality of third ends are connected to the first Two connecting portions, the second contact portion is inserted between any of the third end and the second connecting portion, and wherein the second electrode defines a plurality of hexagonal units between the plurality of second ends Every one of the hexagons Four common edges are in close proximity to the other hexagonal units, each of the four common edges includes every two of the second finger portion and the second connecting portion, and each of the second ends is formed by each of the six sides The other two sides of the shape element extend to the geometric center of each of the hexagonal elements. 2. The electrode structure of the light-emitting element according to item 1 of the scope of the patent application, wherein the first parallel finger portions and the second parallel finger portions are interspersed with each other in parallel. 3. The electrode structure of the light-emitting element according to item 1 of the scope of patent application, wherein when the above-mentioned first contact portion is plural, it includes insertion at intervals. Page 17 200406936 6. Scope of patent application The electrode structure between any one of the first end and the first connection part. 4. The electrode structure of the light-emitting element according to item 1 of the scope of patent application, wherein when the second contact portion is plural, it includes a spaced interval between any of the third end and the second connection portion. Electrode structure. 5. The electrode structure of the light-emitting element according to item 1 of the scope of patent application, wherein the four common edges further include an odd number of second contact portions. 6. The electrode structure of the light-emitting element according to item 1 of the scope of patent application, wherein the four common sides further include an even number of second contact portions. 7. An electrode structure of a light-emitting diode, comprising: a first electrode, the first electrode comprising a plurality of first finger portions parallel to each other, a first connection portion and at least one first contact portion, The first finger portion has a first end and a second end, wherein the plurality of first ends are connected to the first connection portion, and the first contact portion is inserted (inter ρ 〇se) to any of the first Between the end and the first connection portion; and a second electrode, the second electrode includes a plurality of second finger portions, a second connection portion and at least one second contact portion, each of which The finger portion has a third end and a fourth end, and any one of the second finger portions is located between any two adjacent first finger portions, and the plurality of third ends are connected to the second portion. Connection part, the second contact part is inserted and inserted Page 18, 200406936 6. The scope of patent application is between any one of the third end and the second connection part, and wherein the second electrode defines a plurality of hexagonal units between the plurality of second ends, each The hexagonal unit is adjacent to the other hexagonal units by four common sides, each of the four common sides includes every two of the second finger portion and the second connecting portion, and each of the second ends is formed by The other two sides of each hexagonal element extend to the geometric center of each hexagonal element. 8. The electrode structure of the light emitting diode according to item 7 in the scope of the patent application, wherein the first parallel finger portions and the second parallel finger portions are interspersed with each other in parallel. 9. The electrode structure of a light-emitting diode according to item 7 in the scope of the patent application, wherein when the above-mentioned first contact portion is plural, it includes inserting at intervals between any of the first end and the first connection portion, respectively. Between the electrode structure. 10. The electrode structure of the light-emitting diode according to item 7 in the scope of the patent application, wherein when the above-mentioned second contact portion is plural, it includes spaced apart. Inserted at any of the third end and the second Electrode structure between connected parts. 1 1. The electrode structure of the light-emitting diode according to item 7 of the scope of the patent application, wherein the four common edges described above further include an odd number of second contact portions. 12. The electrode structure of a light-emitting diode according to item 7 of the scope of the patent application, wherein the four common edges further include an even number of second contact portions.