Light emitting diode

Abstract

The present invention provides a light emitting diode comprising a transparent substrate, a first surface of the transparent substrate comprising a first region and a second region covered by a semiconductor light emitting sequence; the semiconductor light-emitting sequence comprises a first conductive type semiconductor layer, a light-emitting layer and a second conductive type semiconductor layer, and one surface of the first conductive type semiconductor layer is provided with a light-emitting layer and second conductive type semiconductor layer covering area and a first electrode electric connection area; the insulating medium layer covers the semiconductor light-emitting sequence and is provided with a first opening and a second opening; the periphery of the semiconductor light-emitting sequence sequentially comprises a first edge, a second edge, a third edge and a fourth edge along a surrounding direction; the second area of the first surface of the transparent substrate has four widths W1, W2, W3 and W4 around the first edge, the second edge, the third edge and the fourth edge of the semiconductor light-emitting sequence respectively; the first electrode electric connection area is located on part of the first edge and part of the second edge, and W1 is larger than W3.

Description

Technical Field

[0001] The present invention relates to a small light-emitting diode. Background Art

[0002] With the decline in the cost of LED light-emitting diodes and the progress of technology, coupled with the recent sluggish growth of the LED lighting industry, LED light-emitting diode and packaging giants at home and abroad have begun to search for new market growth points. As a new technology with broad market prospects, small-sized LEDs have received particular attention in the past two years. Among them, LEDs without a transparent substrate support with a size below 100 microns are currently difficult to be commercialized on a large scale in a short time due to uncertain technical routes and high costs. Small-sized LEDs with a transparent substrate support, as an extension of small-pitch LED products and a prelude to LEDs without a substrate with a size below 100 microns, have begun to be shipped in LCD backlights and RGB display products. For example, small-sized LEDs with a transparent substrate such as sapphire support for P0.9 that have been mass-produced and shipped use the same light-emitting diodes, equipment, and processes as small-pitch LED displays, thus effectively ensuring the high cost performance and mass production feasibility of the products.

[0003] The structure of one kind of small-sized LED with a transparent substrate support is as Figure 1 shown, which is the structure of a small-sized flip-chip LED, including a transparent substrate 100, a semiconductor light-emitting sequence (102, 103, 104) carried on the first surface of the transparent substrate 100, and a certain-width edge of the substrate exposed around the semiconductor light-emitting sequence. The certain-width edge of the first surface of the substrate is used for laser scribing and cutting. Figure 2 A planar schematic diagram is shown, and the edge has widths: W1, W2, W3, W4. Usually, W1 = W2 = W3 = W4. The exposed edge of the transparent substrate 100 and the surface of the semiconductor light-emitting sequence will be covered with an insulating dielectric layer. However, limited by the current scribing process and the required cutting lane width for the splitting process, it is at least 10 microns. As the size of the LED light-emitting diode shrinks, the area ratio of the exposed edge region of the transparent substrate around the light-emitting semiconductor sequence will be relatively large, and the area ratio of the light absorption area (the insulating layer absorbs light) or the light reflection region area (in the case where the insulating dielectric layer is a reflective layer) formed by the exposed edge of the substrate will also be relatively large, resulting in serious brightness loss of the light emitted from the sidewalls of the semiconductor light-emitting sequence reaching the first surface of the substrate. Summary of the Invention

[0004] Based on the object of the present invention, the first light-emitting diode with a small light-emitting area and improved light-emitting brightness is provided, which includes: a transparent substrate, a semiconductor light-emitting sequence, an insulating dielectric layer, a first electrode, and a second electrode; The transparent substrate has a first surface, and the first surface includes an inner first region and an outer second region; A semiconductor light-emitting sequence, including a first-conductivity-type semiconductor layer, a light-emitting layer, and a second-conductivity-type semiconductor layer stacked on the first surface of a transparent substrate, covering a first region of the first surface of the transparent substrate; One surface of the first-conductivity-type semiconductor layer includes: a region covered by the light-emitting layer and the second-conductivity-type semiconductor layer, and a first electrode electrical connection region; An insulating dielectric layer, at least covering the semiconductor light-emitting sequence, and having a first opening and a second opening; A first electrode and a second electrode, respectively electrically connecting the first-conductivity-type semiconductor layer and the second-conductivity-type semiconductor layer through the first opening and the second opening; Viewed from above the second-conductivity-type semiconductor layer, the periphery of the semiconductor light-emitting sequence sequentially includes a first edge, a second edge, a third edge, and a fourth edge along a surrounding direction; The second region of the first surface of the transparent substrate has four widths respectively around the first edge, the second edge, the third edge, and the fourth edge of the semiconductor light-emitting sequence, defined as W1, W2, W3, and W4; It is characterized in that: the first electrode electrical connection region of the first-conductivity-type semiconductor layer is located at a part of the first edge and at least a part of the second edge, and W1 is greater than W3.

[0005] Preferably, W1 + W3 is 10 to 50 microns, and W2 + W4 is 10 to 50 microns.

[0006] Preferably, the side length of the first edge of the semiconductor light-emitting sequence is greater than or equal to the side length of the second edge.

[0007] Preferably, the W1 is 10 to 30 microns.

[0008] Preferably, the W3 is between 0 to 5 or 5 to 20 microns.

[0009] Preferably, the ratio of W1:W3 is (2 to 40):1.

[0010] Preferably, the first electrode electrical connection region of the first-conductivity-type semiconductor layer is located at a part of the first edge and a part of the second edge, not located at the third edge and the fourth edge, W1 is greater than W3 and W2 is greater than or equal to W4.

[0011] More preferably, the W2 is 10 to 30 microns.

[0012] More preferably, the W4 is between 0 to 5 or 5 to 20 microns.

[0013] More preferably, the ratio of W2:W4 is (2 to 40):1.

[0014] The present invention also provides a second light-emitting diode with a small light-emitting area and improved luminous brightness, which includes: a transparent substrate, a semiconductor light-emitting sequence, an insulating dielectric layer, a first electrode, and a second electrode; The transparent substrate has a first surface, and the first surface includes an inner first region and an outer second region; The semiconductor light-emitting sequence includes a first-conductive-type semiconductor layer, a light-emitting layer, and a second-conductive-type semiconductor layer stacked from the first surface of the transparent substrate, covering the first region of the first surface of the transparent substrate; One surface of the first-conductive-type semiconductor layer includes a region covered by the light-emitting layer and the second-conductive-type semiconductor layer and a region electrically connected to the first electrode; The insulating dielectric layer covers at least the semiconductor light-emitting sequence and has a first opening and a second opening; The first electrode and the second electrode are respectively electrically connected to the first-conductive-type semiconductor layer and the second-conductive-type semiconductor layer through the first opening and the second opening; Viewed from above the second-conductive-type semiconductor layer, the periphery of the semiconductor light-emitting sequence sequentially includes a first edge, a second edge, a third edge, and a fourth edge along a surrounding direction; The second region of the first surface of the transparent substrate has four widths, defined as W1, W2, W3, and W4, respectively, around the first edge, the second edge, the third edge, and the fourth edge of the semiconductor light-emitting sequence; It is characterized in that: the first-electrode electrical connection region of the first-conductive-type semiconductor layer is located at the first edge, all the second edges, and a part of the third edge, and W2 is greater than W4.

[0015] Preferably, W1 is greater than or equal to W3, and W2 is greater than W4.

[0016] Preferably, the side length of the first edge of the semiconductor light-emitting sequence is greater than or equal to the side length of the second edge.

[0017] Preferably, the W2 is 10 to 30 micrometers.

[0018] Preferably, the W4 is between 0 to 5 or 5 to 20 micrometers.

[0019] Preferably, the W1 is 10 to 30 micrometers.

[0020] Preferably, the ratio of W2:W4 is (2 to 40):1.

[0021] More preferably, the first or second light-emitting diode has at least one of the following characteristics: The ratio of the area of the first region of the first surface of the transparent substrate to the area of the first surface of the transparent substrate is 40% to 90%.

[0022] The side length of the edge of the first surface of the transparent substrate is between 200 and 300 microns, or between 100 and 200 microns, or between 40 and 100 microns.

[0023] The transparent substrate includes a second surface, opposite to the first surface, and the second surface is the main light-emitting surface.

[0024] The insulating dielectric layer includes a multi-layer insulating dielectric layer or a single-layer insulating dielectric layer. The multi-layer insulating dielectric layer is preferably a DBR layer, or the thickness of the single-layer insulating dielectric layer is more than 2 microns.

[0025] The thickness of the insulating dielectric layer covering the top surface of the semiconductor light-emitting sequence is different from the thickness of the insulating dielectric layer covering the side wall of the semiconductor light-emitting sequence.

[0026] The thickness of the insulating dielectric layer covering the side wall of the semiconductor light-emitting sequence is 40% to 90% of the thickness of the insulating dielectric layer covering the top surface of the semiconductor light-emitting sequence.

[0027] The surface of the second conductive type semiconductor layer further includes a transparent electrode layer.

[0028] The semiconductor light-emitting sequence is directly grown on the first surface of the transparent substrate, or is bonded to the first surface of the transparent substrate through a transparent bonding layer.

[0029] The insulating dielectric layer covers the second region of at least a part of the first surface of the transparent substrate.

[0030] The present invention also provides a light-emitting diode package, including a mounting substrate and at least one light-emitting diode mounted on the mounting substrate, wherein at least one or more or all of the light-emitting diodes are the first or second light-emitting diodes as described above.

[0031] The present invention also provides a light-emitting diode module as follows, including a mounting substrate and multiple rows and columns of light-emitting diodes mounted on the mounting substrate, wherein at least one or more or all of the light-emitting diodes are the first or second light-emitting diodes as described above.

[0032] The present invention also provides a light-emitting diode module as follows, including a mounting substrate and multiple light-emitting diodes mounted on the mounting substrate, wherein the multiple light-emitting diodes are arranged in multiple rows and columns, and each light-emitting diode includes: a transparent substrate, a semiconductor light-emitting sequence, an insulating dielectric layer, a first electrode, and a second electrode; A transparent substrate having a first surface, and the first surface includes an inner first region and an outer second region; A semiconductor light-emitting sequence, including a first-conductivity-type semiconductor layer, a light-emitting layer, and a second-conductivity-type semiconductor layer stacked on the first surface of a transparent substrate, covering a first region of the first surface of the transparent substrate; One surface of the first-conductivity-type semiconductor layer includes a region covered by the light-emitting layer and the second-conductivity-type semiconductor layer, and a first electrode electrically connected region; An insulating dielectric layer, at least covering the semiconductor light-emitting sequence, and having a first opening and a second opening; A first electrode and a second electrode, respectively electrically connecting the first-conductivity-type semiconductor layer and the second-conductivity-type semiconductor layer through the first opening and the second opening; The second region of the first surface of the transparent substrate has four widths, defined as W1, W2, W3, and W4, respectively, around the first edge, second edge, third edge, and fourth edge of the semiconductor light-emitting sequence; It is characterized in that: The light-emitting diodes in a column on the side closest to the mounting substrate have the third edge of the semiconductor light-emitting sequence parallel to and closest to the side closest to the mounting substrate compared with other edges, and W1 is greater than W3.

[0033] Preferably, the light-emitting diodes in a row on the other side closest to the mounting substrate have the fourth edge of the semiconductor light-emitting sequence parallel to and closest to the other side closest to the mounting substrate compared with other edges, and W2 is greater than W4.

[0034] Preferably, W1 + W3 is 10 to 50 microns, and W2 + W4 is 10 to 50 microns.

[0035] Preferably, W1 is 10 to 30 microns, and W3 is between 0 to 5 or 5 to 20 microns.

[0036] Preferably, the ratio of W1:W3 is (2 to 40):1.

[0037] Preferably, W2 is 10 to 30 microns, and W4 is between 0 to 5 or 5 to 20 microns.

[0038] Preferably, the ratio of W2:W4 is (2 to 40):1.

[0039] Preferably, the side length of the first edge of the semiconductor light-emitting sequence is greater than or equal to the side length of the second edge.

[0040] Preferably, the multiple columns of light-emitting diodes at least include a column of red light-emitting diodes, a column of green light-emitting diodes, and a column of blue light-emitting diodes.

[0041] Preferably, the multiple rows and multiple columns of light-emitting diodes are all blue light-emitting diodes.

[0042] Preferably, the mounting substrate includes two horizontal side edges and two longitudinal side edges. The light-emitting diodes are arranged in multiple rows along the horizontal side edges of the mounting substrate and in multiple columns along the longitudinal side edges of the mounting substrate. The light-emitting diodes in the first column and the last column are respectively arranged such that the third edge of the semiconductor light-emitting sequence is closest to and parallel to the two horizontal side edges of the mounting substrate, and the light-emitting diodes in the first row and the last row are respectively arranged such that the fourth edge of the semiconductor light-emitting sequence is closest to and parallel to the two longitudinal side edges of the mounting substrate.

[0043] The present invention also provides an RGB display device, which is characterized in that it includes the aforementioned light-emitting diode modules spliced together.

[0044] The present invention also provides a backlight display screen, which is characterized in that it includes the aforementioned light-emitting diode modules spliced together to form a backlight source.

[0045] The beneficial effects of the present invention will be described in detail through embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Attached Figure 1 is a cross-sectional schematic view of the light-emitting diode mentioned in the background art; Attached Figure 2 is a plan schematic view of the light-emitting diode mentioned in the background art; Attached Figures 3 - 4 is a structural schematic view of the light-emitting diode mentioned in Embodiment 1, Figure 3 is a plan schematic view, Figure 4 is a cross-sectional schematic view obtained along the dotted line position on the plan schematic view of Figure 3 .

[0047] Attached Figure 5 is a curve graph showing the relationship between the proportion of the horizontal cross-sectional area of the light-emitting semiconductor sequence of the light-emitting diode covering the first surface of the transparent substrate and the horizontal cross-sectional area of the first surface of the transparent substrate of the light-emitting diode.

[0048] Attached Figures 6 - 16 is a structural schematic view of the manufacturing process flow of the light-emitting diode mentioned in Embodiment 2. Among them, Figure 7 is Figure 8 a longitudinal cross-sectional view of the shown plan view along the dotted line position; Figure 9 is Figure 10 a longitudinal cross-sectional view of the shown plan view along the dotted line position; among them Figure 13 is a plan schematic view, Figure 12 is Figure 13 a cross-sectional schematic view obtained along the dotted line in Figure 15 is Figure 14Schematic cross-sectional structure diagram of any two semiconductor light-emitting sequences supported on an unseparated transparent substrate. Figure 16 For Figure 14 Schematic cross-sectional view of a semiconductor light-emitting sequence in a circle supported on a separated individual transparent substrate.

[0049] Appendix Figure 17 Is a schematic diagram of the encapsulation structure.

[0050] Appendix Figure 18 Is a schematic plan view of the light-emitting diode mentioned in the second embodiment.

[0051] Appendix Figure 19 Is the backlight display screen mentioned in the third embodiment.

[0052] Appendix Figures 20 - 22 Is a schematic plan view of the encapsulation module for the backlight display screen mentioned in the third embodiment spliced on the backlight board.

[0053] Appendix Figures 23 - 24 Is a schematic plan view and cross-sectional view of the light-emitting diode mentioned in the third embodiment. Detailed implementation manners

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0055] In the following embodiments of the present invention, words related to directions, such as "upper", "lower", "left", "right", "horizontal", "vertical", etc., are only for better understanding of the present invention by those skilled in the art and should not be construed as limiting the present invention. Embodiment

[0056] The present invention provides a light-emitting diode 10 with a small light-emitting area and improved light-emitting brightness as follows. As Figure 3 shown in the schematic cross-sectional view, it includes the following stacked layers: a transparent substrate 100, a semiconductor light-emitting sequence, an insulating dielectric layer 106, a first electrode 107, and a second electrode 108.

[0057] The following is a detailed description of each stacked layer structure.

[0058] Among them, as Figure 3As shown, the transparent substrate 100 can be an insulating substrate or a conductive substrate. The transparent substrate 100 can be a growth substrate for growing a semiconductor light-emitting sequence, such as a sapphire substrate, or a semiconductor light-emitting sequence can be bonded to the transparent substrate 100 through a transparent bonding layer. The transparent substrate 100 includes a first surface, a second surface, and sidewalls, wherein the first surface and the second surface are opposite to each other, and the transparent substrate 100 includes a plurality of protrusions formed at least in at least a part of the area of the first surface. For example, the transparent substrate 100 can be a patterned sapphire substrate.

[0059] The light-emitting diode can be a small light-emitting diode having a small horizontal area. The size of the light-emitting diode can be reflected by the size of the first surface of the transparent substrate. For example, the side length dimension of the first surface of the transparent substrate 100 is preferably less than or equal to 300 microns, and preferably, it is between 100 and 300 microns, or between 100 and 200 microns, or a smaller size of less than 100 microns, and preferably between 40 and 100 microns. The horizontal area (horizontal cross-sectional area) of the first surface of the transparent substrate is 90,000 square microns or less, or a smaller one such as more than 10,000 square microns and less than 50,000 microns, or less than 10,000 square microns and more than 2,000 square microns (for example, 40 microns * 60 microns). The thickness of the transparent substrate 100 is between 40 and 150 microns, thicker cases are 80 to 150 microns, and thinner cases are 40 to 80 microns. The thickness of the semiconductor light-emitting sequence is between 1 and 10 microns. The light-emitting diode of this embodiment has the above-mentioned horizontal area and thickness, so the light-emitting diode can be easily applied to various electronic devices that require small and / or thin light-emitting devices.

[0060] A partial area of the first surface of the transparent substrate 100 is covered by the semiconductor light-emitting sequence. Therefore, the first surface of the transparent substrate 100 is divided into a first area covered by the semiconductor light-emitting sequence inside and a second area around the semiconductor light-emitting sequence. Since a cutting channel with a certain width is reserved for the substrate separation process such as laser scribing and cleavage during the manufacturing process of the light-emitting diode, the cutting channel forms the second area of the first surface of the transparent substrate 100 around the light-emitting semiconductor sequence after the separation process. The width of the cutting channel is at least 10 microns and at most 50 microns.

[0061] The second surface of the transparent substrate 100 is the light-emitting surface of the light-emitting diode and is the main light-emitting area.

[0062] The second region of the first surface of the transparent substrate 100 is not covered by the semiconductor light-emitting sequence. That is, during the manufacturing process of the semiconductor light-emitting element, the semiconductor light-emitting sequence is separated on the substrate surface before the substrate is separated, exposing the second region of the first surface of the transparent substrate 100, which can reduce the stress generated by the semiconductor light-emitting sequence on the substrate, thereby promoting the reduction of bending during the manufacturing process of the light-emitting diode, preventing damage to the semiconductor light-emitting sequence, and improving the manufacturing yield.

[0063] As Figure 5 shown, when looking down from the second-conductive-type semiconductor layer, the first region covered by the semiconductor light-emitting sequence is smaller than the horizontal area of the first surface of the transparent substrate 100. Preferably, the proportion of the horizontal cross-sectional area of the first region of the first surface of the transparent substrate 100 in the horizontal cross-sectional area of the first surface of the transparent substrate is 40% - 90%. As the size becomes smaller, the area ratio of the semiconductor light-emitting sequence also becomes smaller accordingly. For example, when the horizontal area of the light-emitting diode, that is, the area of the first surface of the substrate, is 28,000 square micrometers, the coverage area ratio of the semiconductor light-emitting sequence is about 86%, and the area ratio of the second region of the first surface of the substrate around the semiconductor light-emitting sequence is 14%.

[0064] The semiconductor light-emitting sequence includes a first-conductive-type semiconductor layer 102, a light-emitting layer 103, and a second-conductive-type semiconductor layer 104. Specifically, the semiconductor light-emitting sequence may include III-V nitride semiconductors, such as nitride semiconductors such as (Al, Ga, In)N, or phosphide semiconductors including (Al, Ga, In)P, or arsenide semiconductors including (Al, Ga, In)As. The first-conductive-type semiconductor layer 102 may include n-type impurities (e.g., Si, Ge, Sn), and the second-conductive-type semiconductor layer 104 may include p-type impurities (e.g., Mg, Sr, Ba). And, the above impurity types can also be reversed. The light-emitting layer 103 may include a multi-quantum well structure (MQW), and the element composition ratio of the semiconductor can be adjusted to emit a desired wavelength. In this embodiment, the second-conductive-type semiconductor layer 104 may be a p-type semiconductor layer.

[0065] As Figure 4 shown, the first surface of the first-conductive-type semiconductor layer 102 is divided into a region covered by the mesa 201 and a first electrode electrical connection region. The mesa 201 includes a combination of the light-emitting layer 103 and the second-conductive-type semiconductor layer 104 on the light-emitting layer 103.

[0066] The surface of the first electrode electrical connection region is not covered by the mesa and is used for the first electrode 106 to be electrically connected to the first conductive type semiconductor layer 102. The area of the electrical connection region formed by the actual first electrode 107 on the surface of the first conductive type semiconductor layer 102 can be less than or equal to the area of the region of the surface of the first conductive type semiconductor layer 102 exposed in the process for positioning this electrical connection region.

[0067] For the electrical connection between the second electrode 108 and the second conductive type semiconductor layer 104, a contact electrode 105 is located on the second conductive type semiconductor layer 104. The contact electrode 105 can be in ohmic contact with the second conductive type semiconductor layer 104. The contact electrode 105 can include a transparent conductive layer. The transparent conductive layer can further include at least one of a light-transmitting conductive oxide such as indium tin oxide, zinc oxide, indium zinc oxide, indium zinc oxide, zinc tin oxide, indium gallium tin oxide, indium gallium oxide, zinc gallium oxide, aluminum-doped zinc oxide, fluorine-doped tin oxide, etc., and a light-transmitting metal layer such as Ni / Au. The conductive oxide can also include various dopants. Preferably, the thickness of the contact electrode 105 is 50 to 300 nanometers. The surface contact resistance of the contact electrode 105 with the second conductive type semiconductor layer 104 is preferably lower than the surface contact resistance of the metal electrode with the second conductive type semiconductor layer 104, so that the forward voltage (Vf) can be reduced and the light emission efficiency can be improved.

[0068] The insulating dielectric layer 106 covers the top surface and sidewalls of the semiconductor light-emitting sequence and the second region of the first surface of the transparent substrate 100. Specifically, when there is a contact electrode 105, the contact electrode 105 and the top surface and sidewalls of the semiconductor light-emitting sequence not covered by the contact electrode 105 are all covered by the insulating dielectric layer 106. And the insulating dielectric layer 106 can further at least partially or completely cover the second region exposed on the first surface of the transparent substrate, which can ensure its more stable coverage on the sidewalls of the semiconductor light-emitting sequence, and at the same time prevent water vapor from entering the periphery of the semiconductor light-emitting sequence and reduce the leakage risk.

[0069] Preferably, the insulating dielectric layer 106 is an insulating reflective layer that covers the top surface and sidewalls of the semiconductor light-emitting sequence. When the light radiated by the light-emitting layer reaches the surface of the insulating dielectric layer 106 through the contact electrode 105, most of the light can be reflected back into the semiconductor light-emitting sequence by the insulating dielectric layer 106, and most of the light passes through the second surface side of the transparent substrate and exits the light, reducing the light loss caused by the light exiting from the surface and sidewalls of the semiconductor light-emitting sequence. Preferably, the insulating dielectric layer 106 can reflect at least 80% or further at least 90% of the light intensity of the light radiated by the light-emitting layer reaching its surface. Specifically, the insulating dielectric layer 106 can include a Bragg reflector. The Bragg reflector can be formed by repeating the stacking of at least two insulating dielectrics with different refractive indices, and can be formed into 4 to 20 pairs. For example, the insulating dielectric layer can include TiO2 , SiO 2 , HfO 2 , ZrO 2 , Nb 2 O 5 , MgF 2 etc. In some embodiments, the insulating dielectric layer 106 may be formed by alternately depositing TiO 2 layers / SiO 2 layers.

[0070] Each layer of the Bragg reflector may have an optical thickness of 1 / 4 of the peak wavelength of the emission band of the light-emitting layer. The uppermost layer of the Bragg reflector may be formed of SiNx. The layer formed of SiNx has excellent moisture resistance and can protect the light-emitting diode from the influence of moisture.

[0071] When the insulating dielectric layer 106 includes a Bragg reflector, the lowermost layer of the insulating dielectric layer 106 may have a bottom layer or an interface layer that improves the film quality of the distributed Bragg reflector. For example, the insulating dielectric layer 106 may include an interface layer formed of SiO 2 with a thickness of about 0.2 to 1.0 micrometers and TiO 2 / SiO 2 stacked on the interface layer according to a specific period.

[0072] The insulating dielectric layer 106 may also be just a single insulating dielectric layer. Preferably, the reflectivity is generally lower than that of the Bragg reflector layer, and at least 40% of the light is emitted from the insulating dielectric layer 106. Preferably, the thickness is at least 1 micrometer or more preferably 2 micrometers or more, such as SiO 2 , which has excellent moisture resistance and can protect the light-emitting diode from the influence of moisture.

[0073] The insulating dielectric layer 106 has at least one first opening 1061 and one second opening 1062. The first electrode 107 and the second electrode 108 are formed on the surface of the insulating dielectric layer 106. The first electrode 107 is in electrical contact with the first electrode electrical contact region of the first conductive type semiconductor layer 102 through the first opening 1061 to form an electrical connection. The second electrode 108 is in electrical connection with the contact electrode 105 on the surface of the second conductive type semiconductor layer 102 through the second opening 1062. The contact electrode 105 may also have an opening, and the second electrode 108 may partially contact the surface of the second conductive type semiconductor layer 104 through the said opening of the contact electrode 105. Preferably, the resistance between the second electrode 108 and the second conductive type semiconductor layer 104 is higher than the resistance between the contact electrode 105 and the second conductive type semiconductor layer 104 to minimize the crowding of current directly at the position where the second electrode contacts the second conductive type semiconductor layer 104.

[0074] Such asFigure 4 As shown in the figure, when looking down from the top surface of the semiconductor light-emitting sequence, the periphery of the semiconductor light-emitting sequence sequentially includes a first edge E1, a second edge E2, a third edge E3, and a fourth edge E4 along a surrounding direction.

[0075] The second region of the first surface of the transparent substrate 100 has four widths, defined as W1, W2, W3, and W4, respectively, around the first edge E1, the second edge E2, the third edge E3, and the fourth edge E4 of the semiconductor light-emitting sequence. Here, the width is defined as the horizontal width. Preferably, the side length of the first edge E1 is greater than or equal to the side length of the second edge E2, and the side length of the third edge E3 is greater than or equal to the side length of the fourth edge E4.

[0076] According to the existing manufacturing process of light-emitting diodes, the separation of the transparent substrate usually adopts the scribing and cleavage process. W1 + W3 and W2 + W4 are the widths of the scribe lanes on the exposed first surface of the transparent substrate between adjacent semiconductor light-emitting sequences before the separation of the transparent substrate, and W1 + W3 and W2 + W4 are between 10 and 50 microns.

[0077] For small-sized light-emitting diodes, in order to obtain the first electrode contact region, it is necessary to etch the second conductive-type semiconductor layer and the light-emitting layer to expose a part of the surface of the first conductive-type semiconductor layer. Among them, the mesa formation process has a larger proportion of the light-emitting area than the opening process, which can increase the proportion of the light-emitting area and improve the light-emitting brightness. Therefore, in the present invention, the first electrode electrical connection region is formed at the edge position of the semiconductor light-emitting sequence instead of the middle position of the semiconductor light-emitting sequence stack layer, and a mesa light-emitting area composed of the light-emitting layer and the second conductive-type semiconductor layer is formed.

[0078] The first electrode electrical connection region of the first conductive-type semiconductor layer 102 is set to be located at a part of the first edge E1 and at least a part of the second edge E2, that is, the first electrode electrical connection position is set at the edge position of the semiconductor light-emitting sequence, which is beneficial to the diffusion distribution of current between the first electrode and the second electrode.

[0079] As an embodiment, as Figure 4 shown, the first electrode electrical connection region of the first conductive-type semiconductor layer 102 is an exposed region and is only located at a part of the first edge E1 and a part of the second edge E2. That is, the first electrode electrical connection region of the first conductive-type semiconductor layer does not extend to the third edge and the fourth edge.

[0080] As a preferred embodiment, there is one mesa.

[0081] For example Figure 4The small-sized light-emitting diodes supported by a transparent substrate as shown. Since the area of the light-emitting region formed by the mesa accounts for a relatively small proportion, and the proportion of the second region of the first surface of the substrate around the mesa is relatively large. In order to reduce the light loss caused by light absorption or reflection when the light radiated from the sidewalls around the mesa reaches the second region of the first surface of the substrate, the following improvements are provided in this embodiment: The second region of the first surface of the transparent substrate has the following width relationship along the four edges around the semiconductor light-emitting sequence: W1 is greater than W3 and / or W2 is greater than W4. By reducing the width of W3 and / or W4, the area proportion of the second region of the first surface of the transparent substrate around the mesa is reduced. The proportion of light absorption or reflection when the light passes through the insulating dielectric layer from the sidewalls around the mesa to the second region of the first surface of the transparent substrate will be reduced, and the proportion of direct light output will increase, thereby achieving the purpose of improving the light output brightness on the second surface side of the transparent substrate.

[0082] As a preferred embodiment, according to the size of the cutting channel required by the current laser scribing process, W1 or W2 is greater than or equal to 10 microns, and more preferably, it is between 10 and 30 microns.

[0083] As a preferred embodiment, W2 or W4 is less than or equal to 20 microns, or further preferably less than or equal to 5 microns.

[0084] As a preferred embodiment, the ratio of the width of the second region of the first surface of the transparent substrate around the first edge to the width of the second region of the first surface of the transparent substrate around the third edge is 2 to 40 times, such as 2 to 10 times, or 10 to 20 times, or 20 to 40 times.

[0085] As a preferred embodiment, the ratio of the width of the second region of the first surface of the transparent substrate around the second edge to the width of the second region of the first surface of the transparent substrate around the fourth edge is 2 to 10 times, or 10 to 40 times, or 10 to 20 times, or 20 to 40 times.

[0086] The manufacturing process of the light-emitting diodes in this embodiment will be described in detail below.

[0087] As Figure 6 shown, the first surface of the transparent substrate 100 includes a first conductive-type semiconductor layer 102, a light-emitting layer 103, and a second conductive-type semiconductor layer 104 stacked in sequence.

[0088] The contact electrode 105 is ITO and covers the surface of the second conductive-type semiconductor layer 104.

[0089] As Figures 7 - 8As shown, a mask is formed by one photomask or two photomasks, etching part of the contact electrode 105, part of the second-conductive-type semiconductor layer 104, and the light-emitting layer 103, exposing part of the first-conductive-type semiconductor layer 102 and forming several mesa structures. The several mesa structures include the light-emitting layer 103, the second-conductive-type semiconductor layer 104, and the contact electrode 105.

[0090] As shown in FIGS. 8-9, a mask is formed by one photomask, etching along the first-conductive-type semiconductor layer 102 between adjacent mesa structures to expose part of the first surface of the transparent substrate 100, forming multiple independent semiconductor light-emitting sequences. A dicing channel region is formed around the first surface of the transparent substrate 100 exposed by each semiconductor light-emitting sequence, and each semiconductor light-emitting sequence includes an edge defining four different directions along a circumferential direction, namely a first edge E1, a second edge E2, a third edge E3, and a fourth edge E4.

[0091] The first-conductive-type semiconductor layer of each semiconductor light-emitting sequence includes a first surface and an opposite second surface. The first surface includes a mesa coverage region and a first electrode electrical connection region. The first electrode electrical connection region is located at part of the first edge E1 and part of the second edge E2 of the semiconductor light-emitting sequence.

[0092] As Figure 11 shown, the insulating dielectric layer 106 is deposited to cover the surface, sidewalls of the contact electrode 105 and the exposed semiconductor light-emitting sequence, and a second region covering the first surface of the transparent substrate 100. In the existing coating process, such as evaporation coating or sputtering coating, due to the shadow effect, the thickness of the insulating dielectric layer 106 on the sidewalls of the semiconductor light-emitting sequence is usually lower than that on the top surface of the semiconductor light-emitting sequence and the second region of the first surface of the transparent substrate, resulting in the thickness on the sidewalls of the semiconductor light-emitting sequence being 40-90% of the thickness on the top surface of the semiconductor sequence.

[0093] If the insulating dielectric layer 106 is an insulating reflective layer, due to the thickness difference, the reflectivity on the sidewalls of the semiconductor light-emitting sequence is likely to be lower than that on the top surface of the semiconductor sequence. The light radiated by the light-emitting layer easily transmits through the sidewalls of the mesa structure, reaches the second region of the first surface of the transparent substrate, and is reflected, resulting in light output brightness loss on the second surface of the transparent substrate 100.

[0094] The insulating dielectric layer 106 makes a first opening in the first electrode electrical connection region of the first-conductive-type semiconductor layer 102 and makes a second opening on the surface of the contact electrode 105.

[0095] As Figures 12 - 13As shown, a first electrode 107 and a second electrode 108 are respectively fabricated on the surface of the insulating dielectric layer 106. The first electrode 107 and the second electrode 108 are respectively in contact with the contact electrode 105 and the first electrode electrical connection region of the first-conductivity-type semiconductor layer 102 through the first opening and the second opening. The first electrode 107 and the second electrode 108 include a contact layer and a eutectic layer, and both the contact layer and the eutectic layer are made of metal. The minimum horizontal spacing between the first electrode 107 and the second electrode 108 on the insulating dielectric layer 106 is preferably 5 micrometers.

[0096] As Figures 13 - 14 shown, a part of the first surface of the transparent substrate 100 covered by the insulating dielectric layer 106 between adjacent semiconductor light-emitting sequences serves as a dicing street, and the width of the dicing street is between 10 and 50 micrometers. On the dicing street, a laser beam is scanned from the dotted line position of the dicing street in the figure to form several modified explosion points inside the transparent substrate below the dicing street. A cleavage knife is used to cleave the transparent substrate 100 along the dicing street, and the modified explosion points formed inside the transparent substrate below the dotted line in the figure will form a fracture surface to obtain each independent light-emitting diode.

[0097] Taking the width of the dicing street as 20 micrometers as an example, a laser beam is scanned along the dotted lines in the X and Y directions as the scanning paths to form multiple modified explosion points inside the substrate. Among them, as shown in the figure X the laser scanning path at the dotted line position in the Y direction deviates 5 micrometers to the right from the center position of the dicing street, and the laser scanning path at the dotted line position in the

[0098] As Figure 16 shown, the structure is Figure 14A light-emitting diode circled in the figure. By controlling the position of the laser beam scanning, the second region of the first surface of the transparent substrate 100 that is not covered by the semiconductor light-emitting sequence has four widths W1, W2, W3, and W4 along the four edges E1, E2, E3, and E4 of the semiconductor light-emitting sequence respectively. Taking the width of the scribe line as 20 microns as an example, taking the width of W1 as 5 microns as an example, the width of W2 is 15 microns, taking the width of W3 as 5 microns as an example, and the width of W4 is 15 microns. Through the above design, when looking down from the side of the second-conductive-type semiconductor layer 104, the electrical contact region of the first electrode is located at the first edge E1 and the second edge E2 of the mesa. The horizontal side lengths of the mesa at the first edge E1 and the second edge E2 are lower than the horizontal side lengths of the mesa at the third edge E3 and the fourth edge E4. The light-emitting ratio of the side walls around the mesa at the third edge E3 and the fourth edge E4 is greater than that around the mesa at the first edge E1 and the second edge E2. Therefore, by designing W3 and W4 of the second region of the first surface of the transparent substrate to be smaller, the light reflection or light absorption loss caused by the light passing through the side walls around the mesa at the third edge E3 and the fourth edge E4 and reaching the second region of the transparent substrate around the mesa can be effectively reduced, promoting the light to be directly radiated after emitting from the side walls, and improving the light-emitting ratio on the side of the second surface of the transparent substrate and enhancing the brightness.

[0099] Preferably, the widths of W1 and W3 are less than or equal to 20 microns. Or further, the widths of W1 and W3 are less than or equal to 5 microns, and the separation position deviates from the center of the scribe line and is closer to the semiconductor light-emitting sequence. By virtue of the stress generated by the semiconductor light-emitting sequence on the transparent substrate, the efficiency of die separation can be improved. The width of W1 is at least 1 micron, and the width of W3 is at least 1 micron. If W1 and W3 are too small, the stealth cutting laser beam will be too close to the semiconductor light-emitting sequence, which will disadvantageously damage the layer structure of the semiconductor light-emitting sequence.

[0100] The small-sized light-emitting diode provided by the present invention can be widely applied to the packages or applications of displays or backlights, and can particularly meet the high-brightness requirements of backlight products.

[0101] Specifically, this embodiment provides a package as shown in Figure 17 At least one light-emitting diode is mounted on the mounting substrate 30. The mounting substrate 30 is an insulating substrate, such as a package module substrate for an RGB display screen or a module substrate for a backlight display. One surface of the mounting substrate 30 has an electrically isolated first electrode 301 and a second electrode 302. The light-emitting diode is located on one surface of the mounting substrate 30. The first electrode 307 and the second electrode 308 of the light-emitting diode are respectively connected to the first electrode 301 and the second electrode 302 through a first bonding portion 303 and a second bonding portion 304. The first bonding portion 303 and the second bonding portion 304 include but are not limited to solder, such as eutectic solder or reflow solder.

[0102] The package of the small-sized light-emitting diode of this embodiment can be widely used in modules for backlight and modules for RGB display. For example, in order to achieve the display effect of high dynamic range (HDR) images on LCD displays, a backlight module with a small-sized light-emitting diode arranged directly below is used. By controlling the lighting and closing of a single position of the backlight module, the dynamic contrast of the screen is improved to obtain a better display effect. At the same time, by increasing the brightness of a single light-emitting diode, the brightness of the entire backlight module can also be increased.

[0103] like Figure 18 The structure shown is the structure of the first embodiment. Figure 4 An alternative structure of the light-emitting diode shown, the first electrode electrical connection area on the surface of the first conductive semiconductor layer extends to part of the first edge E1, all of the second edge E2 and part of the third edge E3 of the semiconductor light-emitting sequence, and does not extend to the fourth edge E4. The setting position of the electrical connection area of ​​the first electrode is suitable for a structure with a large length-to-width ratio of the side length of the semiconductor light-emitting sequence, so as to facilitate the uniform diffusion of current. The side length of the first edge E1 is greater than the side length E2 of the second edge, preferably, the side length of the first edge E1 is greater than three times the side length of the second edge E2. The width W2 of the second area of ​​the first surface of the transparent substrate around the second edge E2 of the semiconductor light-emitting sequence is greater than the width W4 around the fourth edge E4. Through this design, the loss caused by the light emitted from the side wall of the mesa corresponding to the fourth edge of the semiconductor light-emitting sequence and then reaching the surface of the second area of ​​the first surface of the substrate and being reflected or absorbed can be effectively reduced. Preferably, W1+W3 and W2+W4 are between 10 and 50 microns. Preferably, W4 is less than or equal to 20 microns, or more preferably, less than or equal to 5 microns; W4 is between 10 and 30 microns.

[0104] Preferably, the first electrode contact area is a square area on the surface of the first conductive semiconductor layer, and the relationship between W2 and W4 does not need to be specifically limited, W2 may be greater than or equal to W4 or W2 may be less than W4; or more preferably, W2=W4.

[0105] Since the size of the single-chip packaging module for backlight or display screen made of small-sized light-emitting diodes supported by transparent substrates is limited, it is necessary to use a backlight packaging module or an RGB module for further splicing to obtain an RGB display screen or a backlight display backlight source.

[0106] This embodiment further provides a display device for backlighting, such as a television, comprising a backlight source, the backlight source comprising a back plate, the back plate adopting a conventional SECC (electrolytic sub-lead galvanized steel plate) material substrate, Or use an aluminum substrate, Figures 19 - 20The multiple backlight modules shown are spliced and fixed on the backplane. Figure 19 Shown is a schematic structural diagram of a backlight source obtained by splicing multiple blue light emitting diode modules 30 on a backlight panel, along X the direction, on the mounting substrates of two modules, there are multiple columns of light emitting diodes in the module. When splicing along X the direction, on the edges of the two modules, there is one column of the closest light emitting diodes arranged respectively. The distance between the two closest columns of light emitting diodes is defined as D1. Due to the gap existing between the edges of the mounting substrates, when the two modules are spliced on the adjacent side, D1 and the distance W1 between two adjacent columns of light emitting diodes in one module, usually the former is greater than the latter, and it is easy to have the problem of splicing dark lines. The same problem also exists when RGB modules are spliced into a display screen.

[0107] As an implementation manner, this embodiment also provides a packaging module for backlight display (liquid crystal display) as follows. As Figure 19 shown, the module includes a mounting substrate 30. The mounting substrate 30 has four side edges, namely two horizontal and two vertical side edges, and multiple rows and multiple columns of light emitting diodes are mounted on the mounting substrate 30; all the light emitting diodes are blue light emitting diodes, and the blue light emitting diodes all adopt flip-chip light emitting diodes, or one row of blue light emitting diodes, one row of red light emitting diodes and one row of green light emitting diodes are included in the multiple columns of light emitting diodes. The light emission of the three-color light emitting diodes can be mixed to form white light.

[0108] The light-emitting diodes mounted on the mounting substrate 30 have the following structural features: a transparent substrate, a semiconductor light-emitting sequence, an insulating dielectric layer, a first electrode, and a second electrode; the transparent substrate has a first surface, and the first surface includes an inner first region and a peripheral second region; the semiconductor light-emitting sequence includes a first-conductive-type semiconductor layer, a light-emitting layer, and a second-conductive-type semiconductor layer stacked from the first surface of the transparent substrate, covering the first region of the first surface of the transparent substrate; one surface of the first-conductive-type semiconductor layer includes a region covered by the light-emitting layer and the second-conductive-type semiconductor layer and a region electrically connected to the first electrode; the insulating dielectric layer at least covers the semiconductor light-emitting sequence and has a first opening and a second opening; the first electrode and the second electrode are electrically connected to the first-conductive-type semiconductor layer and the second-conductive-type semiconductor layer through the first opening and the second opening respectively; the second region of the first surface of the transparent substrate has four widths respectively around the first edge, the second edge, the third edge, and the fourth edge of the semiconductor light-emitting sequence, defined as W1, W2, W3, and W4; the light-emitting diodes in the column closest to the longitudinal side of the mounting substrate have the third edge of the semiconductor light-emitting sequence parallel to and closest to the side of the mounting substrate compared with other edges, and W1 is greater than W3. Among them, W1 + W3 and W2 + W4 are between 10 and 50 microns. Preferably, W3 is less than or equal to 20 microns, or more preferably, less than or equal to 5 microns; W1 is between 10 and 30 microns.

[0109] Or further, the light-emitting diodes in the row closest to the horizontal side of the mounting substrate have the third edge of the semiconductor light-emitting sequence parallel to and closest to the side of the mounting substrate compared with other edges, and W2 is greater than W4. Preferably, W3 is less than or equal to 20 microns, or more preferably, less than or equal to 5 microns; W1 is between 10 and 30 microns.

[0110] As Figure 20 shown, the light-emitting diode can be the light-emitting diode in Embodiment 1 Figure 4 shown. With the third edge and the fourth edge of the semiconductor light-emitting sequence close to the horizontal side and the longitudinal side of the mounting substrate, by reducing the widths of W3 and / or W4 in the second region of the first surface of the transparent substrate, the light absorption or light reflection loss of the light reaching the second region of the first surface of the transparent substrate with widths of W3 and W4 is reduced, the light brightness around the third edge side and the fourth edge side of the semiconductor light-emitting sequence is increased, and the splicing problem is improved.

[0111] Or as Figure 21 shown, the light-emitting diode can be the light-emitting diode in Embodiment 2. With the third edge and the fourth edge of the semiconductor light-emitting sequence close to the edge of the mounting substrate, and W1 is greater than W3, and W2 is greater than W4.

[0112] Or as Figure 22As shown, the light-emitting diodes on the mounting substrate 30 have a structure different from Figure 4 the structure of the light-emitting diodes shown. The structure of the light-emitting diodes can be referred to Figures 23 - 24 , including: a transparent substrate 100, a semiconductor light-emitting sequence (102-104), an insulating dielectric layer 106, a first electrode 107, and a second electrode 108. There are second regions with different widths around the four edges of the semiconductor light-emitting sequence on the first surface side of the transparent substrate 100. The semiconductor light-emitting sequence has first, second, third, and fourth edges in sequence along a surrounding direction. The widths of the second regions exposing the first surface of the transparent substrate 100 around the first to fourth edges are different, being W1, W2, W3, and W4 respectively. The width of W1 + W3 is 10 to 50 micrometers, and the width of W2 + W4 is 10 to 50 micrometers, where W1 is greater than W3 or further W2 is greater than W4. Different from Figure 4 the light-emitting diodes shown is that: the first electrode electrical connection region exposed by the first-conductive-type semiconductor layer 102 is formed by opening a hole on the surface of the second-conductive-type semiconductor layer 104 to expose a part of the first-conductive-type semiconductor layer 102, and there is no need to define the positional relationship between the first electrode electrical connection region and the first and second edges of the semiconductor light-emitting sequence. The insulating dielectric layer 106 covers the inner sidewall of the hole, and the insulating dielectric layer 106 has a first opening exposing the surface of the first-conductive-type semiconductor layer 102 at the bottom of the hole. The first electrode 107 contacts the first-conductive-type semiconductor layer 102 through the first opening of the insulating dielectric layer 106.

[0113] To solve the problem of the splicing dark lines of the RGB display screen, as an alternative embodiment, as Figures 19 - 22 shown, each module is an RGB module for a display screen, including a mounting substrate 30 and at least three columns of light-emitting diodes mounted on the mounting substrate 30; the at least three columns of light-emitting diodes at least include a column of red light-emitting diodes R, a column of green light-emitting diodes G, and a column of blue light-emitting diodes B. The red light-emitting diodes, green light-emitting diodes, and blue light-emitting diodes all adopt flip-chip light-emitting diodes. At the same time, every three trichromatic light-emitting diodes are adjacent, and the trichromatic light can be mixed to form white light and constitute a pixel.

[0114] The above embodiments only illustrate the principles and effects of the present invention by way of example, rather than limiting the present invention. Those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A light-emitting diode, which comprises: a transparent substrate, a semiconductor light-emitting sequence, an insulating dielectric layer, a first electrode and a second electrode; the transparent substrate has a first surface, and the first surface includes an inner first region and a peripheral second region; the semiconductor light-emitting sequence includes a first-conductive-type semiconductor layer, a light-emitting layer and a second-conductive-type semiconductor layer stacked from the first surface of the transparent substrate, covering the first region of the first surface of the transparent substrate; one surface of the first-conductive-type semiconductor layer includes: a region covered by the light-emitting layer and the second-conductive-type semiconductor layer and a region electrically connected to the first electrode; the insulating dielectric layer covers at least the semiconductor light-emitting sequence and has a first opening and a second opening; the first electrode and the second electrode are respectively electrically connected to the first-conductive-type semiconductor layer and the second-conductive-type semiconductor layer through the first opening and the second opening; when looking down from the second-conductive-type semiconductor layer, the periphery of the semiconductor light-emitting sequence sequentially includes a first edge, a second edge, a third edge and a fourth edge along a surrounding direction; the second region of the first surface of the transparent substrate has four widths respectively around the first edge, the second edge, the third edge and the fourth edge of the semiconductor light-emitting sequence, defined as W1, W2, W3 and W4; characterized in that: the first electrode electrical connection region of the first-conductive-type semiconductor layer is located at a part of the first edge and a part of the second edge, and W3 is between 0 and 20 microns or W4 is between 0 and 20 microns.

2. A light-emitting diode according to claim 1, characterized in that: W1 + W3 is 10 to 50 microns.

3. A light-emitting diode according to claim 1, characterized in that: the side length of the first edge of the semiconductor light-emitting sequence is greater than or equal to the side length of the second edge.

4. A light-emitting diode according to claim 1 or 3, characterized in that: W1 is 10 to 30 microns.

5. A light-emitting diode according to claim 1 or 3, characterized in that: W1:W3 is (2 to 40):

1.

6. A light-emitting diode according to claim 1, characterized in that: the first electrode electrical connection region of the first-conductive-type semiconductor layer is not located at the third edge and the fourth edge, W1 is greater than W3; W2 is greater than or equal to W4.

7. A light-emitting diode according to claim 1, characterized in that: W2 is 10 to 30 microns.

8. A light-emitting diode according to claim 1, characterized in that: W4 is between 0 and 5 or 5 and 20 microns.

9. A light-emitting diode according to claim 1, characterized in that: W2:W4 is (2 to 40):

1.

10. A light-emitting diode according to claim 1, characterized in that: the side length of the edge of the first surface of the transparent substrate is between 200 and 300 microns or 100 and 200 microns or 40 and 100 microns, and the transparent substrate includes a second surface, opposite to the first surface, and the second surface is the main light-emitting surface.

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