CN102569559B - Method for manufacturing an array of light emitting elements - Google Patents

Abstract

The invention discloses a method for manufacturing a light-emitting element array, which comprises the following steps: providing a substrate; forming a light emitting stack on the substrate, wherein the light emitting stack comprises: a first semiconductor layer located on the substrate; a light emitting layer on the first semiconductor layer; and a second semiconductor layer located on the light-emitting layer; forming at least one groove on the substrate, wherein the groove exposes part of the substrate and separates the light-emitting laminated layer into at least one first light-emitting element and at least one second light-emitting element; and forming an insulating layer on the light-emitting laminated layer and the groove, wherein the width of the groove is not more than twice the thickness of the insulating layer, and the insulating layer seals the groove to form at least one cavity in the groove.

Description

Method for manufacturing an array of light emitting elements

This application is a divisional application of the invention patent application with the application number 200810169439.1 and the invention title "Method for Manufacturing Light-Emitting Element Array".

technical field

The invention relates to a method for manufacturing a light-emitting element array, in particular to a light-emitting element array with grooves closed by an insulating layer.

Background technique

A light emitting diode (Light Emitting Diode; LED) is a solid-state physical semiconductor component. A light emitting diode array (LED Array) has multiple LEDs, which can be connected in series or in parallel as required. Before connecting in series or in parallel, it is necessary to form a groove to separate each LED, then form an insulating layer between the groove and the LED to electrically insulate each LED, and then form an electrical connection line on the insulating layer and electrically connect each LED. electrodes for series or parallel connection. However, due to the influence of the size of the trench, for example, the depth of the trench is too deep, disconnection or poor electrical connection may occur when electrical connection lines are formed on the sidewall of the trench. The known solution is to increase the thickness of the electrical connection line to fill the trench or completely cover the sidewall of the trench to achieve good electrical connection; but increasing the thickness of the electrical connection line also increases the production cost .

Contents of the invention

A method of manufacturing a light-emitting element array, comprising: providing a substrate; forming a light-emitting stack on the substrate, wherein the light-emitting stack includes: a first semiconductor layer located on the substrate; a light-emitting layer located on the first semiconductor layer layer; and a second semiconductor layer, located on the light-emitting layer; forming at least one groove on the substrate, wherein the groove exposes a portion of the substrate, and separates the light-emitting stack into at least one first light-emitting an element and a second light-emitting element; and forming an insulating layer on the light-emitting stack and the trench, the width of the trench is not greater than twice the thickness of the insulating layer.

A method of manufacturing a light-emitting element array, comprising providing a substrate; forming a light-emitting stack on the substrate, wherein the light-emitting stack includes a first semiconductor layer and is located on the substrate; a light-emitting layer is located on the first semiconductor layer; and The second semiconductor layer is located on the light emitting layer. Part of the light-emitting stack is removed to form at least one groove, wherein the groove exposes part of the substrate, and the light-emitting stack is divided into a first light-emitting element and a second light-emitting element. removing part of the second semiconductor layer and the light emitting layer of the first light emitting element and the second semiconductor layer and the light emitting layer of the second light emitting element to expose part of the first semiconductor layer of the first light emitting element and the first semiconductor of the second light emitting element layer. Then forming a second electrode on the second semiconductor layer, and a first electrode on the exposed first semiconductor layer. An insulating layer is formed on the light emitting stack and the trench, the insulating layer substantially closes the trench to form at least one cavity in the trench, and exposes the first electrode and the second electrode. An electrical connection line is formed to electrically connect the first electrode of the first light-emitting element and the second electrode of the second light-emitting element.

A light-emitting element array, comprising a substrate; a first light-emitting element located on the substrate; a second light-emitting element located on the substrate; at least one groove separating the first light-emitting element and the second light-emitting element; and an insulating layer roughly The trench is closed to form at least one cavity in the trench.

Description of drawings

FIG. 1 is a cross-sectional view showing a manufacturing process of a light emitting element array according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a trench according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a trench according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a trench according to another embodiment of the present invention.

FIG. 5 is a schematic diagram showing a light source generating device composed of an array of light emitting elements according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing a backlight module composed of an array of light emitting elements according to an embodiment of the present invention.

Explanation of reference signs

1: Light-emitting element array 10: Substrate

12: Light emitting stack 122: The first semiconductor layer

124: Light-emitting layer 126: Second semiconductor layer

14: Groove 142, 144, 146: Hollow

16: insulating layer 15: first electrode

17: Second electrode 11: First light emitting element

13: Second light-emitting element 2: Light source generating device

21: Light source 22: Power supply system

23: Control element 3: Backlight module

31: Optical components 18: Electrical connection wires

w: width t: thickness

Detailed ways

As shown in FIG. 1 , a wafer of light-emitting diodes 1 is provided, including a substrate 10; a light-emitting stack 12 is formed on the substrate 10, wherein the light-emitting stack 12 includes at least a first semiconductor layer 122, an active layer 124, and a second semiconductor layer. 126. Removing part of the light-emitting stack 12 to form a trench 14, wherein the trench 14 exposes part of the substrate 10, and separates the light-emitting stack 12 into a first light-emitting element 11 and a second light-emitting element 13. The removal method includes but is not limited to etch. Removing part of the second semiconductor layer 126 and the light emitting layer 124 of the first light emitting element 11 and the second light emitting element 13 to expose part of the first semiconductor layer 122, wherein the removal method includes but not limited to inductively coupled plasma etching (InductivelyCoupled Plasma; ICP). At this time, the upper surfaces of the first semiconductor layer 122 on both sides of the trench 14 are approximately at the same level, that is, the distance between the upper surface of the first semiconductor layer 122 of the first light-emitting element 11 and the substrate 10 is the same as that of the first light-emitting element 13 . The distance between the upper surface of the semiconductor layer 122 and the substrate 10 is about the same, or the heights of the sidewalls on both sides of the trench 14 are about the same. Then the first electrode 15 is formed on the upper surface of the first semiconductor layer 122 , and the second electrode 17 is formed on the upper surface of the second semiconductor layer 126 . Next, an insulating layer 16 is formed on the trench 14, the first light-emitting element 11 and the second light-emitting element 13, but the first electrode 15 and the second electrode 17 are exposed, wherein the insulating layer 16 is formed in a manner including but not limited to electron beam Evaporation (E-Gun), sputtering (Sputtering) or plasma enhanced chemical vapor deposition (PECVD). Finally, an electrical connection line 18 is formed on the insulating layer 16 to electrically connect the first electrode 15 of the first light-emitting element 11 and the second electrode 17 of the second light-emitting element 13, wherein the formation method of the electrical connection line 18 includes evaporation, Electroless or electroplating, such as physical vapor deposition (PVD), chemical vapor deposition (CVD), metalorganic chemical vapor deposition (MOCVD), electron beam evaporation (E-Gun) or plasma enhanced chemical vapor deposition (PECVD). As shown in FIG. 2 , the insulating layer 16 substantially closes the trench 14 to form a cavity 142 in the trench 14, wherein the width w of the trench 14 is not greater than twice the thickness t of the insulating layer 16 on the first semiconductor layer 122 . The insulating layer has a characteristic of lateral growth during formation, in other words, the growth rate of the insulating layer material in the horizontal direction is greater than the growth rate in the vertical direction, so that the insulating layer 16 can roughly close the trench 14 when it is formed, preventing the formation of the electrical connection line 18 On the sidewalls of the trench 14 , avoid disconnection or poor electrical connection.

The material of the substrate 10 includes but not limited to copper (Cu), tungsten (W), aluminum nitride (AlN), metal matrix composite (Metal Matrix Composite; MMC), ceramic matrix composite (Ceramic Matrix Composite; CMC), silicon carbide (SiC), aluminum (Al), silicon (Si), diamond (Diamond), gallium aluminum arsenide (AlGaAs), gallium phosphide (GaP), aluminum nitride (AlN), lithium aluminum oxide (LiAlO ₂ ), carbide Silicon (SiC), zinc oxide (ZnO), indium phosphide (InP), aluminum nitride (AlN), sapphire (Sapphire), glass (Glass), other transparent materials or a combination of these materials. The material of the substrate 10 is preferably an electrically insulating material. If it is a conductive material, an electrically insulating layer (not shown) is formed between the substrate 10 and the light-emitting stack 12 to electrically insulate the first light-emitting element 11 and the second light-emitting element 13 .

The material of the light emitting stack 12 includes but not limited to one or more substances, such as gallium (Ga), aluminum (Al), indium (In), arsenic (As), phosphorus (P), nitrogen (N) or Silicon (Si). The material of the insulating layer 16 is an electrical insulating material, such as polyimide (PI), perfluorocyclobutane (PFCB), spin-on-glass, Su8, benzocyclobutene (BCB), epoxy resin (Epoxy), Acrylic resin (Acrylic Resin), cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide ( Polyetherimide), Fluorocarbon Polymer, Silicone, Glass, Aluminum Oxide (Al ₂ O ₃ ), Silicon Nitride (SiN _x ), Silicon Oxide (SiO ₂ ), Titanium Oxide (TiO ₂ ), the above combination of materials or other transparent insulating materials. The material of the electrical connection wire 18 is a conductive material, such as gold (Au), copper (Cu), nickel (Ni) or a combination of the above materials.

As shown in FIG. 3 and FIG. 4 , the trench 14 may include a plurality of sub-trenches, covered by the insulating layer 16 and substantially closing its opening to form a plurality of cavities 142, 144 and 146, wherein the width of each sub-trench is w Not more than twice the thickness t of the insulating layer 16 on the first semiconductor layer 122 .

FIG. 5 shows a schematic diagram of a light source generating device. The light source generating device 2 may be a lighting device, such as a street lamp, a car lamp, or an indoor lighting source, or a traffic sign, or a backlight source of a backlight module in a flat-panel display. The light source generating device 2 includes a light source 21 , which can be an array of light emitting elements in any embodiment of the present invention, a power supply system 22 for supplying current to the light source 21 , and a control element 23 for controlling the power supply system 22 .

FIG. 6 is a schematic cross-sectional view of the backlight module. The backlight module 3 includes the light source generating device 2 in the foregoing embodiments, and an optical element 31 . The optical element 31 can process the light emitted by the light source generating device 2 to be applied to a flat panel display, for example, diffuse the light emitted by the light source generating device 2 .

However, the above-mentioned embodiments are only for illustrating the principles and effects of the present invention, rather than limiting the present invention. Any person skilled in the art can modify and change the above-mentioned embodiments without violating the technical principle and spirit of the present invention. Therefore, the protection scope of the present invention is as listed in the following claims.

Claims (9)

1. A method of manufacturing an array of light-emitting elements, comprising: Provide the substrate; forming a light-emitting stack on the substrate, wherein the light-emitting stack includes: a first semiconductor layer located on the substrate; a light emitting layer located on the first semiconductor layer; and a second semiconductor layer located on the light-emitting layer; forming at least one groove on the substrate, wherein the groove exposes a portion of the substrate, and separates the light emitting stack into at least a first light emitting element and a second light emitting element; and forming an insulating layer over the light-emitting stack and the trench, the width of the trench being no greater than twice the thickness of the insulating layer, Wherein the insulating layer seals the trench to form at least one cavity in the trench. 2. The method for manufacturing a light-emitting element array as claimed in claim 1, further comprising: removing part of the second semiconductor layer and the light emitting layer of the first light emitting element and the second light emitting element to expose part of the first semiconductor layer; forming a second electrode on each of the second semiconductor layers; forming a first electrode on each of the exposed first semiconductor layers; and An electrical connection line is formed on the insulating layer to electrically connect the first electrode of the first light-emitting element with the second electrode of the second light-emitting element. 3. The method for manufacturing a light-emitting device array as claimed in claim 1, wherein the insulating layer is formed by a method selected from the group consisting of electron beam evaporation, sputtering and plasma enhanced chemical vapor deposition. 4. The method for manufacturing a light-emitting device array as claimed in claim 1, after forming the insulating layer on the light-emitting stack and the trench, further comprising forming electrical connection lines on the insulating layer. 5. The method for manufacturing a light-emitting element array as claimed in claim 4, wherein the method for forming the electrical connection line is selected from the group consisting of physical vapor deposition, chemical vapor deposition, electroless plating, and electroplating. 6. The method for manufacturing a light-emitting element array as claimed in claim 5, wherein the chemical vapor deposition method is a metalorganic chemical vapor deposition method and a plasma enhanced chemical vapor deposition method. 7. The method for manufacturing a light-emitting element array as claimed in claim 5, wherein the physical vapor deposition method is an electron beam evaporation method. 8. The method for manufacturing a light-emitting element array as claimed in claim 1, further comprising: A subtrench is formed in the trench. 9. The method of manufacturing a light-emitting element array as claimed in claim 8, wherein the width of the sub-trench is not greater than twice the thickness of the insulating layer.