Light emitting device

Abstract

A light emitting device includes a circuit substrate, a light emitting element, a first extension pad, a second extension pad, an adhesive layer, a first conductive pattern, and a second conductive pattern. A surface of the circuit substrate is provided with a first electrode and a second electrode. The light emitting element is located on the circuit substrate and includes a first type semiconductor layer, a second type semiconductor layer, a light emitting layer, a first contact pad, and a second contact pad, wherein the second type semiconductor layer is located between the first type semiconductor layer and the circuit substrate. The first extension pad is electrically connected to the first contact pad, and the second extension pad is electrically connected to the second contact pad. The adhesive layer is located between the light emitting element and the circuit substrate and extends at least on a sidewall of the second type semiconductor layer. The first conductive pattern is electrically connected to the first extension pad and the first electrode, and the second conductive pattern is electrically connected to the second extension pad and the second electrode.

Description

Technical Field

[0001] This invention relates to a light-emitting device. Background Technology

[0002] Micro-LED display devices offer advantages such as power saving, high efficiency, high brightness, and fast response time. Due to the extremely small size of Micro-LEDs, the current method for manufacturing Micro-LED display devices mainly employs mass transfer technology, which utilizes microelectromechanical array (MEMS) technology to pick up and place micro-LEDs, thereby transferring a large number of Micro-LEDs onto the circuit board in one go.

[0003] As the size of Micro-LEDs continues to shrink, their luminous efficacy decreases rapidly due to the increasing proportion of surface defects, necessitating the selection of structures with high luminous efficacy. To simplify the bonding structure and improve luminous efficacy, flip-chip Micro-LEDs are expected to offer higher luminous efficacy. However, since flip-chip Micro-LEDs only connect to the circuit board via P / N pads, their bonding yield and reliability have consistently been less than ideal. Furthermore, current flip-chip Micro-LEDs require thermal processes to establish electrical connections with the circuit board. When solder and other connecting materials melt, the Micro-LED, due to its extremely small size and weight, often shifts, further complicating reliability improvement.

[0004] Furthermore, mass transfer technology often results in misalignment of light-emitting elements. One current approach is to use a redundancy architecture, where, when a Micro-LED malfunction is confirmed, the malfunctioning Micro-LED is destroyed, and a new Micro-LED is implanted into the redundancy space. However, the implantation process requires another thermal bridging step, which further increases the possibility of Micro-LED misalignment. Summary of the Invention

[0005] The purpose of this invention is to provide a light-emitting device with improved reliability.

[0006] An embodiment of the present invention provides a light-emitting device, comprising: a circuit substrate having a first electrode and a second electrode disposed on its surface; a light-emitting element located on the circuit substrate and comprising: a first type semiconductor layer; a second type semiconductor layer overlapping the first type semiconductor layer and located between the first type semiconductor layer and the circuit substrate; a light-emitting layer located between the first type semiconductor layer and the second type semiconductor layer; a first pad connecting the first type semiconductor layer and located between the first type semiconductor layer and the circuit substrate; and a second pad connecting the second type semiconductor layer and located between the second type semiconductor layer and the circuit substrate; a first extension pad electrically connected to the first pad; a second extension pad electrically connected to the second pad; an adhesive layer located between the light-emitting element and the circuit substrate and extending at least along the sidewall of the second type semiconductor layer; a first conductive pattern electrically connected to the first extension pad and the first electrode; and a second conductive pattern electrically connected to the second extension pad and the second electrode.

[0007] In one embodiment of the present invention, the first extension pad and the second extension pad are superimposed on the orthogonal projection of the light-emitting element on the circuit board.

[0008] In one embodiment of the present invention, the extension directions of the first extension pad and the second extension pad are opposite or perpendicular to each other.

[0009] In one embodiment of the present invention, at least a portion of the first extension pad or the second extension pad is suspended.

[0010] In one embodiment of the present invention, the first extension pad includes a first extension portion and a first connecting portion. The first extension portion is connected to a first contact pad, and the first connecting portion is connected to the first extension portion and a first conductive pattern. The second extension pad includes a second extension portion and a second connecting portion. The second extension portion is connected to a second contact pad, and the second connecting portion is connected to the second extension portion and a second conductive pattern. The angle between the first extension portion and the first connecting portion is ≥90 degrees, and the angle between the second extension portion and the second connecting portion is ≥90 degrees.

[0011] In one embodiment of the present invention, the first extension pad and the second extension pad described above belong to the same film layer as the first contact pad and the second contact pad, respectively.

[0012] In one embodiment of the present invention, the Young's modulus of the adhesive layer is between 2 and 3.

[0013] In one embodiment of the present invention, the circuit board described above further includes an array of switching elements.

[0014] In one embodiment of the present invention, the light-emitting device further includes a second insulating layer located between the first and second extension pads and the first and second electrodes.

[0015] Another embodiment of the present invention provides a light-emitting device having an adjacent transposed region and a repair region, and comprising: a circuit board having a first electrode and a second electrode disposed on its surface; a plurality of light-emitting elements located on the circuit board, each comprising: a first type semiconductor layer; a second type semiconductor layer overlapping the first type semiconductor layer and located between the first type semiconductor layer and the circuit board; a light-emitting layer located between the first type semiconductor layer and the second type semiconductor layer; a first pad connecting the first type semiconductor layer and located between the first type semiconductor layer and the circuit board; and a second pad connecting the second type semiconductor layer and located between the second type semiconductor layer and the circuit board, wherein the first light-emitting element among the plurality of light-emitting elements is located in the transposed region, and the electrical connection between the first pad of the first light-emitting element and the first electrode is disconnected; the second light-emitting element among the plurality of light-emitting elements is located in the repair region, and the first pad of the second light-emitting element is electrically connected to the first electrode, and the second pad of the second light-emitting element is electrically connected to the second electrode.

[0016] In one embodiment of the present invention, the light-emitting device further includes a first extension pad and a second extension pad, wherein the first extension pad is electrically connected to a first contact pad and the second extension pad is electrically connected to a second contact pad.

[0017] In one embodiment of the present invention, the first extension pad and the second extension pad are superimposed on the orthogonal projection of the light-emitting element on the circuit board.

[0018] In one embodiment of the present invention, the extension directions of the first extension pad and the second extension pad are opposite or perpendicular to each other.

[0019] In one embodiment of the present invention, at least a portion of the first extension pad or the second extension pad is suspended.

[0020] In one embodiment of the present invention, the first extension pad and the second extension pad described above belong to the same film layer as the first contact pad and the second contact pad, respectively.

[0021] In one embodiment of the present invention, the light-emitting device further includes a first conductive pattern and a second conductive pattern, wherein the first conductive pattern is electrically connected to the first extension pad and the first electrode, and the second conductive pattern is electrically connected to the second extension pad and the second electrode.

[0022] In one embodiment of the present invention, the first conductive pattern and the second conductive pattern electrically connected to the first light-emitting element are made of different materials than the first conductive pattern and the second conductive pattern electrically connected to the second light-emitting element.

[0023] In one embodiment of the present invention, the electrical connection between the first pad of the first light-emitting element and the first electrode or the electrical connection between the second pad of the first light-emitting element and the second electrode is broken by forming an opening in the first extension pad, the first conductive pattern, the second extension pad or the second conductive pattern between the electrical connections.

[0024] In one embodiment of the present invention, the light-emitting device further includes an adhesive layer located between the light-emitting element and the circuit substrate, and extending at least to the sidewall of the second type semiconductor layer.

[0025] In one embodiment of the present invention, the Young's modulus of the adhesive layer is between 2 and 3.

[0026] The beneficial effects of this invention are that the light-emitting device of this invention assists in the docking of the light-emitting element and the circuit board through the first extension pad and the second extension pad, while increasing the adhesion of the light-emitting element to the adhesive layer, thereby improving the bonding yield between the light-emitting element and the circuit board and thus improving the reliability of the light-emitting device. In addition, the light-emitting device of this invention forms the first conductive pattern and the second conductive pattern through thin film deposition and photolithography processes, which can avoid the problem of light-emitting element misalignment caused by thermal processes.

[0027] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0028] Figure 1A This is a partial top view of a light-emitting device according to an embodiment of the present invention.

[0029] Figure 1B It is along Figure 1A A schematic diagram of the cross section line A-A'.

[0030] Figure 2A This is a partial top view of a light-emitting device according to an embodiment of the present invention.

[0031] Figure 2B It is along Figure 2A A schematic diagram of the cross section drawn by section line B-B'.

[0032] Figure 3A This is a partial top view of a light-emitting device according to an embodiment of the present invention.

[0033] Figure 3B It is along Figure 3A A schematic diagram of the cross section line C-C'.

[0034] Figure 4A This is a partial top view of a light-emitting device according to an embodiment of the present invention.

[0035] Figure 4B It is along Figure 4A A schematic diagram of the cross section line D-D'.

[0036] Figure 4C It is along Figure 4A A schematic diagram of the cross section drawn by section line E-E'.

[0037] Figure 4D It is along Figure 4A A schematic diagram of the cross section drawn by the section line F-F'.

[0038] The attached figures are labeled as follows:

[0039] 10, 20, 30, 40: Light-emitting devices

[0040] 101: Surface

[0041] 110: Circuit board

[0042] 112: Base Plate

[0043] 114: Driver Circuit Layer

[0044] 120, 123: Light-emitting elements

[0045] 121: First light-emitting element

[0046] 122: Second light-emitting element

[0047] A-A', B-B', C-C', D-D', E-E', F-F': Profile lines

[0048] AH: Adhesive layer

[0049] CP1, CP11, CP12: First conductive pattern

[0050] CP2, CP21, CP22: Second conductive patterns

[0051] E1: First electrode

[0052] E2: Second electrode

[0053] ED1, ED3, ED5, ED7: First extension pad

[0054] ED2, ED4, ED6, ED8: Second extension pads

[0055] EL: Light-emitting layer

[0056] EP1, EP3: First Extension

[0057] EP2, EP4: Second Extension

[0058] Fb: Surface

[0059] I1: Buffer layer

[0060] I2: Gate insulating layer

[0061] I3: Interlayer insulation layer

[0062] I4: Insulating layer

[0063] Ia: Second insulating layer;

[0064] Ib: First insulating layer;

[0065] NP1, NP3: First connecting part

[0066] NP2, NP4: Second connecting parts

[0067] O1, O2: Openings

[0068] P1, P2: Partial

[0069] PD1: First pad

[0070] PD2: Second pad

[0071] RA: Repair Area

[0072] SP1: Type I semiconductor layer

[0073] SP2: Type II Semiconductor Layer

[0074] SS: Semiconductor stack

[0075] T: Switching element

[0076] TA: Transposed area

[0077] TC: Semiconductor layer

[0078] TD: Drain

[0079] TG: Gate

[0080] TS: Source

[0081] t1, t2: Thickness

[0082] VA1, VA2, VA3: Through holes

[0083] VL1, VL2: Power cords

[0084] W1, W2, We: Sidewalls

[0085] X1, X2, X3, X4, X5, X6: Central axis

[0086] θ1, θ2, θ3, θ4: included angle Detailed Implementation

[0087] In the accompanying drawings, the thicknesses of layers, films, panels, regions, etc., are enlarged for clarity. Throughout the specification, the same reference numerals denote the same elements. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected" to another element, it may be directly on or connected to the other element, or intermediate elements may also be present. Conversely, when an element is referred to as being "directly on" or "directly connected" to another element, no intermediate elements are present. As used herein, "connection" can refer to a physical and / or electrical connection. Furthermore, "electrical connection" or "coupling" may mean that other elements exist between the two elements.

[0088] It should be understood that although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or part from another. Therefore, the first “element,” “component,” “region,” “layer,” or “part” discussed below may be referred to as a second element, component, region, layer, or part without departing from the teachings of this document.

[0089] The terminology used herein is for the purpose of describing particular embodiments only and is not restrictive. As used herein, unless the content clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms, including “at least one” or denoteing “and / or.” As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. It should also be understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, areas, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, areas, integrals, steps, operations, elements, components, and / or combinations thereof.

[0090] Furthermore, relative terms such as “down” or “bottom” and “up” or “top” may be used herein to describe the relationship between one element and another, as illustrated in the figures. It should be understood that relative terms are intended to include different orientations of the device beyond those shown in the figures. For example, if a device in one figure is flipped, an element described as being “down” to other elements will be oriented “up” to other elements. Thus, the exemplary term “down” can include both “down” and “up” orientations, depending on the specific orientation of the figure. Similarly, if a device in one figure is flipped, an element described as being “down” or “below” to other elements will be oriented “above” to other elements. Thus, the exemplary terms “down” or “below” can include both “up” and “down” orientations.

[0091] Given the specific number of measurements discussed and the associated errors (i.e., limitations of the measurement system), the terms "about," "approximately," or "substantially" as used herein include the value and the average value within an acceptable range of deviations from the specific value as determined by one of ordinary skill in the art. For example, "about" may mean within one or more standard deviations of the value, or within ±30%, ±20%, ±10%, ±5%. Furthermore, the terms "about," "approximately," or "substantially" as used herein may be chosen based on the optical, etched, or other properties to select a more acceptable range of deviations or standard deviations, rather than applying a single standard deviation to all properties.

[0092] This document describes exemplary embodiments with reference to cross-sectional views, which are schematic diagrams of idealized embodiments. Therefore, variations in shape as a result of, for example, manufacturing techniques and / or tolerances, are expected in the illustrations. Consequently, the embodiments described herein should not be construed as limited to the specific shapes of the regions shown herein, but rather include, for example, shape deviations caused by manufacturing processes. For example, regions shown or described as flat may generally have rough and / or non-linear characteristics. Furthermore, the acute angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to show the precise shapes of the regions, nor are they intended to limit the scope of the claims.

[0093] Figure 1A This is a partial top view of a light-emitting device 10 according to an embodiment of the present invention. Figure 1B It is along Figure 1A A schematic cross-sectional view along section line A-A'. To make the accompanying drawing more concise, Figure 1A Omit Figure 1B Detailed components of the circuit board 110.

[0094] Please refer to the following at the same time Figure 1A and Figure 1BThe light-emitting device 10 includes: a circuit board 110, on which a first electrode E1 and a second electrode E2 are disposed; a light-emitting element 120, located on the circuit board 110, and including: a first type semiconductor layer SP1; a second type semiconductor layer SP2, overlapping the first type semiconductor layer SP1 and located between the first type semiconductor layer SP1 and the circuit board 110; a light-emitting layer EL, located between the first type semiconductor layer SP1 and the second type semiconductor layer SP2; and a first pad PD1, connected to the first type semiconductor layer SP1 and located between the first type semiconductor layer SP1 and the circuit board 110. The device includes a second pad PD2, which is connected to the second semiconductor layer SP2 and located between the second semiconductor layer SP2 and the circuit board 110; a first extension pad ED1, which is electrically connected to the first pad PD1; a second extension pad ED2, which is electrically connected to the second pad PD2; an adhesive layer AH, which is located between the light-emitting element 120 and the circuit board 110 and extends at least to the sidewall W2 of the second semiconductor layer SP2; a first conductive pattern CP1, which is electrically connected to the first extension pad ED1 and the first electrode E1; and a second conductive pattern CP2, which is electrically connected to the second extension pad ED2 and the second electrode E2.

[0095] In a light-emitting device 10 according to an embodiment of the present invention, the first extension pad ED1 and the second extension pad ED2 are used to assist the docking of the light-emitting element 120 and the circuit board 110, and at the same time increase the adhesion of the light-emitting element 120 to the adhesive layer AH, thereby improving the bonding yield of the light-emitting element 120 and the circuit board 110, and thus improving the yield and reliability of the light-emitting device 10.

[0096] The following, in conjunction with Figures 1A to 1B The embodiments of the various components of the light-emitting device 10 will be described further, but the present invention is not limited thereto.

[0097] In this embodiment, the circuit board 110 may include a base plate 112 and a driving circuit layer 114. The base plate 112 of the circuit board 110 may be a transparent substrate, an opaque substrate, a flexible substrate, or a non-flexible substrate, and its material may be a quartz substrate, a glass substrate, a polymer substrate, or other suitable materials. The driving circuit layer 114 may include the components or lines required by the light-emitting device 10, such as driving elements, switching elements, storage capacitors, power lines, driving signal lines, timing signal lines, current compensation lines, detection signal lines, etc. In some embodiments, the driving circuit layer 114 may be formed on the base plate 112 using thin film deposition, photolithography, and etching processes. The driving circuit layer 114 may include at least one insulating layer and at least one conductive layer, and the driving circuit layer 114 may include more insulating layers and conductive layers as needed.

[0098] For example, in this embodiment, the driving circuit layer 114 may include a switching element array, wherein the switching element array includes a plurality of switching elements T arranged in an array, and the switching elements T can be electrically connected to the light-emitting element 120. Specifically, the driving circuit layer 114 may include, for example, switching elements T, power lines VL1, VL2, a first electrode E1, a second electrode E2, a buffer layer I1, a gate insulating layer I2, an interlayer insulating layer I3, and an insulating layer I4. The first electrode E1 and the second electrode E2 may be disposed on the surface 101 of the circuit substrate 110. The switching element T may be composed of a semiconductor layer TC, a gate TG, a source TS, and a drain TD. The region where the semiconductor layer TC overlaps with the gate TG can be considered as the channel region of the switching element T. The buffer layer I1 is located between the base plate 112 and the semiconductor layer TC, used to prevent impurities in the base plate 112 from migrating into the semiconductor layer TC and to enhance the adhesion between the semiconductor layer TC and the base plate 112. The gate insulating layer I2 is located between the gate TG and the semiconductor layer TC. An interlayer insulating layer I3 is disposed between the source electrode TS, drain electrode TD, and power line VL1 and the gate electrode TG and power line VL2. An insulating layer I4 is disposed between the source electrode TS, drain electrode TD, and power line VL1 and the first electrode E1 and the second electrode E2. The first electrode E1 and the second electrode E2 can be electrically connected to the drain electrode TD and the power line VL1 through vias VA1 and VA2 in the insulating layer I4, respectively, and the source electrode TS can be electrically connected to the power line VL2 through via VA3 in the insulating layer I3. When the gate electrode TG receives a signal from, for example, a driving element and turns on the switching element T, the signal received by the source electrode TS from the power line VL2 can be transmitted to the first electrode E1 of the light-emitting element 120. In some embodiments, the second electrode E2 can be electrically connected to the switching element T, and the first electrode E1 can be electrically connected to the power line VL1.

[0099] The semiconductor layer TC can be made of silicon semiconductor materials (such as polycrystalline silicon, amorphous silicon, etc.), oxide semiconductor materials, organic semiconductor materials, but is not limited to these. The gate TG, source TS, drain TD, power lines VL1, VL2, first electrode E1, and second electrode E2 can be made of metals with good conductivity, such as aluminum, molybdenum, titanium, copper, or alloys of the above metals, or stacks of the above metals and alloys, but are not limited to these. For example, the first electrode E1 and the second electrode E2 can be made of sequentially stacked titanium layers, aluminum layers, and titanium layers, or sequentially stacked molybdenum layers, aluminum layers, and molybdenum layers, but are not limited thereto.

[0100] The materials of buffer layer I1, gate insulating layer I2, interlayer insulating layer I3, and insulating layer I4 may include transparent inorganic insulating materials, such as silicon oxide, silicon nitride, silicon oxynitride, or a stack of the above materials, but are not limited thereto. In some embodiments, buffer layer I1, gate insulating layer I2, interlayer insulating layer I3, and insulating layer I4 may each have a single-layer structure or a multi-layer structure. The multi-layer structure is, for example, a stack of any two or more layers of the above insulating materials, and can be combined and varied as needed.

[0101] In this embodiment, the first type semiconductor layer SP1, the second type semiconductor layer SP2, and the light-emitting layer EL of the light-emitting element 120 can constitute a semiconductor stack SS. The first pad PD1 and the second pad PD2 of the light-emitting element 120 are located between the semiconductor stack SS and the circuit substrate 110. Therefore, the light-emitting element 120 can be referred to as a flip-chip light-emitting diode.

[0102] The first type semiconductor layer SP1 and the second type semiconductor layer SP2 of the light-emitting element 120 may include group II-VI materials (e.g., zinc selenide (ZnSe)) or group III-V materials (e.g., gallium nitride (GaN), gallium phosphide (GaP), aluminum nitride (AlN), indium nitride (InN), indium gallium nitride (InGaN), indium gallium phosphide (InGaP), aluminum gallium nitride (AlGaN), aluminum indium gallium nitride (AlInGaN), or aluminum indium gallium phosphide (AlInGaP)). For example, in this embodiment, the first type semiconductor layer SP1 is located on the light-emitting surface, and the first type semiconductor layer SP1 may include a P-type doped semiconductor material, such as P-type gallium phosphide (GaP), but is not limited thereto. The second type semiconductor layer SP2 may include an N-type doped semiconductor layer, such as N-type aluminum indium gallium phosphide (AlInGaP), but is not limited thereto. In this embodiment, the structure of the light-emitting layer EL is, for example, a multiple quantum well (MQW) structure. The multiple quantum well structure includes alternating stacks of multiple indium gallium phosphide (InGaP) and multiple gallium phosphide (GaP). By designing the ratio of indium or gallium in the light-emitting layer EL, the emission wavelength range of the light-emitting layer EL can be adjusted, but the present invention is not limited thereto. The materials of the first pad PD1 and the second pad PD2 may include, for example, metals such as aluminum, molybdenum, titanium, and copper, alloys of the above metals, stacked layers of the above metals and / or alloys, or other suitable conductive materials.

[0103] In this embodiment, the first extension pad ED1 can completely cover the first contact pad PD1 of the light-emitting element 120, and the second extension pad ED2 can completely cover the second contact pad PD2 of the light-emitting element 120, but this is not a limitation. In some embodiments, the first extension pad ED1 can partially overlap the first contact pad PD1, and the second extension pad ED2 can partially overlap the second contact pad PD2. In some embodiments, the first extension pad ED1 and the second extension pad ED2 can extend from the first contact pad PD1 and the second contact pad PD2 of the light-emitting element 120 in opposite directions, respectively. For example, please refer to... Figure 1B The first extension pad ED1 can extend to the right from the first connector pad PD1, while the second extension pad ED2 can extend to the left from the second connector pad PD2. Please refer to... Figure 1A In some embodiments, the central axis X1 of the first extension pad ED1 may also overlap with the central axis X2 of the second extension pad ED2.

[0104] In some embodiments, the orthographic projections of the first extension pad ED1 and the second extension pad ED2 onto the circuit board 110 can partially overlap the orthographic projection of the light-emitting element 120 onto the circuit board 110. In this way, the first extension pad ED1 and the second extension pad ED2 can not only increase the surface area for electrically connecting the first pad PD1 and the second pad PD2, but also increase the adhesion of the light-emitting element 120 to the adhesive layer AH, thereby improving the bonding yield between the light-emitting element 120 and the circuit board 110.

[0105] In some embodiments, at least a portion of the first extension pad ED1 and the second extension pad ED2 may be suspended, meaning that a portion of the first extension pad ED1 and the second extension pad ED2 may not be supported by the adhesive layer AH. Additionally, in some embodiments, the first extension pad ED1 may further include a first extension portion EP1 and a first connecting portion NP1, with the first extension portion EP1 connected to the first contact pad PD1 and the first connecting portion NP1 connected to the first conductive pattern CP1. Simultaneously, the second extension pad ED2 may further include a second extension portion EP2 and a second connecting portion NP2, with the second extension portion EP2 connected to the second contact pad PD2 and the second connecting portion NP2 connected to the second conductive pattern CP2. The angle θ1 between the first extension portion EP1 and the first connecting portion NP1 may be equal to or approximately 90 degrees, and the angle θ2 between the second extension portion EP2 and the second connecting portion NP2 may be equal to or approximately 90 degrees.

[0106] The light-emitting element 120, the first extension pad ED1, and the second extension pad ED2 can be fabricated on the growth substrate and then transferred onto the circuit board 110 via a mass transfer process. The first extension pad ED1 and the second extension pad ED2 can also function as tethers suspending the light-emitting element 120 on the growth substrate. In this embodiment, an adhesive layer AH can be formed first on the surface 101 of the circuit board 110, for example, between the first electrode E1 and the second electrode E2. Then, the light-emitting element 120, the first extension pad ED1, and the second extension pad ED2 are transferred onto the adhesive layer AH. In some embodiments, the adhesive layer AH can also be formed on a portion of the first electrode E1 and / or a portion of the second electrode E2, as long as the adhesive layer AH does not completely cover the first electrode E1 and / or the second electrode E2. The Young's modulus of the adhesive layer AH can be between 2 and 3, but is not limited to this.

[0107] During the transfer of the light-emitting element 120 onto the adhesive layer AH, the adhesive layer AH is squeezed outward due to the downward pressure applied to the light-emitting element 120, causing the adhesive layer AH to extend at least to the sidewall W2 of the second type semiconductor layer SP2. In some embodiments, the adhesive layer AH may also extend to the sidewall We of the light-emitting layer EL. In some embodiments, the adhesive layer AH may further extend to the sidewall W1 of the first type semiconductor layer SP1.

[0108] After the light-emitting element 120 is transferred onto the adhesive layer AH, a first conductive pattern CP1 and a second conductive pattern CP2 can be formed. The first conductive pattern CP1 electrically connects the first extension pad ED1 to the first electrode E1, and the second conductive pattern CP2 electrically connects the second extension pad ED2 to the second electrode E2. In this embodiment, the first conductive pattern CP1 and the second conductive pattern CP2 can be formed using thin-film deposition and photolithography processes, without using a soldering process. This avoids the problem of the light-emitting element 120 easily shifting during thermal processing, thereby improving the bonding yield and reliability of the light-emitting device 10. The materials of the first conductive pattern CP1 and the second conductive pattern CP2 can include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), or other suitable conductive oxides, or a stack of any two or more layers of the above conductive oxides, but are not limited thereto.

[0109] The following uses Figures 2A to 4D Further embodiments of the present invention will be described, and the following will be used... Figures 1A to 1B The component designations and related content of the embodiments are as follows: the same designations are used to represent the same or similar components, and descriptions of identical technical content are omitted. For explanations of the omitted parts, please refer to... Figures 1A to 1BThe embodiments described below will not be repeated.

[0110] Figure 2A This is a partial top view of a light-emitting device 20 according to an embodiment of the present invention. Figure 2B It is along Figure 2A A schematic cross-sectional view along section line B-B'. To make the accompanying drawing more concise, Figure 2A Omit Figure 2B Detailed components of the circuit board 110.

[0111] Please refer to the following at the same time Figure 2A and Figure 2B The light-emitting device 20 includes a circuit board 110, a light-emitting element 120, a first extension pad ED3, a second extension pad ED4, an adhesive layer AH, a first conductive pattern CP1, and a second conductive pattern CP2. A first electrode E1 and a second electrode E2 are disposed on the surface 101 of the circuit board 110. The light-emitting element 120 is located on the circuit board 110 and includes a first type semiconductor layer SP1, a second type semiconductor layer SP2, a light-emitting layer EL located between the first type semiconductor layer SP1 and the second type semiconductor layer SP2, and a connecting layer for the first type semiconductor layer SP1. The semiconductor layer SP1 has a first pad PD1 and a second pad PD2 connected to the second semiconductor layer SP2; the first extension pad ED3 is electrically connected to the first pad PD1; the second extension pad ED4 is electrically connected to the second pad PD2; the adhesive layer AH is located between the light-emitting element 120 and the circuit board 110, and extends at least to the sidewall W2 of the second semiconductor layer SP2; the first conductive pattern CP1 is electrically connected to the first extension pad ED3 and the first electrode E1; and the second conductive pattern CP2 is electrically connected to the second extension pad ED4 and the second electrode E2.

[0112] With Figures 1A to 1B Compared to the light-emitting device 10 shown, Figures 2A to 2B The difference in the light-emitting device 20 shown is that the first extension pad ED3 and the second extension pad ED4 of the light-emitting device 20 can extend in opposite directions, and the central axes of the first extension pad ED3 and the second extension pad ED4 do not need to overlap. For example, please refer to... Figure 2A and Figure 2B The first extension pad ED1 can extend to the right from the first contact pad PD1, while the second extension pad ED2 can extend to the left from the second contact pad PD2. At the same time, the central axis X3 of the first extension pad ED3 and the central axis X4 of the second extension pad ED4 can be parallel to each other, and the central axis X3 of the first extension pad ED3 can be offset upward relative to the central axis X4 of the second extension pad ED4 without overlapping the central axis X4.

[0113] In addition, in this embodiment, the adhesive layer AH can also extend to the sidewall We of the light-emitting layer EL and the sidewall W1 of the first type semiconductor layer SP1. Furthermore, the first extension pad ED3 of the light-emitting device 20 may include a first extension portion EP3 and a first connecting portion NP3. The first extension portion EP3 is connected to the first contact pad PD1, and the first connecting portion NP3 is connected to the first extension portion EP1 and the first conductive pattern CP1. Meanwhile, the second extension pad ED4 may include a second extension portion EP4 and a second connecting portion NP4. The second extension portion EP4 is connected to the second contact pad PD2, and the second connecting portion NP4 is connected to the second extension portion EP4 and the second conductive pattern CP2. The angle θ3 between the first extension portion EP3 and the first connecting portion NP3 may be greater than 90 degrees, and the angle θ4 between the second extension portion EP4 and the second connecting portion NP4 may also be greater than 90 degrees.

[0114] Figure 3A This is a partial top view of a light-emitting device 30 according to an embodiment of the present invention. Figure 3B It is along Figure 3A A schematic cross-sectional view along section line C-C'. To make the accompanying drawing more concise, Figure 3A Omit Figure 3B Detailed components of the circuit board 110.

[0115] Please refer to the following at the same time Figure 3A and Figure 3B The light-emitting device 30 may include a circuit board 110, a light-emitting element 123, a first extension pad ED5, a second extension pad ED6, an adhesive layer AH, a first conductive pattern CP1, and a second conductive pattern CP2. A first electrode E1 and a second electrode E2 are disposed on the surface 101 of the circuit board 110. The light-emitting element 123 is located on the circuit board 110 and includes a first semiconductor layer SP1, a second semiconductor layer SP2, a light-emitting layer EL located between the first semiconductor layer SP1 and the second semiconductor layer SP2, and a connecting layer CP2. A first pad PD1 of a type-1 semiconductor layer SP1 and a second pad PD2 connected to a type-2 semiconductor layer SP2; a first extension pad ED5 electrically connected to the first pad PD1; a second extension pad ED6 electrically connected to the second pad PD2; an adhesive layer AH located between the light-emitting element 123 and the circuit board 110, and extending to the sidewall W2 of the type-2 semiconductor layer SP2; a first conductive pattern CP1 electrically connected to the first extension pad ED5 and the first electrode E1; and a second conductive pattern CP2 electrically connected to the second extension pad ED6 and the second electrode E2.

[0116] With Figures 1A to 1B Compared to the light-emitting device 10 shown, Figures 3A to 3BThe difference in the light-emitting device 30 shown is that the first pad PD1 of the light-emitting element 123 of the light-emitting device 30 can belong to the same film layer as the first extension pad ED5, and the second pad PD2 can belong to the same film layer as the second extension pad ED6. In other words, the first pad PD1 can be integrally formed with the first extension pad ED5, and the second pad PD2 can be integrally formed with the second extension pad ED6.

[0117] Furthermore, in this embodiment, the extending direction of the first extending pad ED5 of the light-emitting device 30 may be perpendicular to the extending direction of the second extending pad ED6. For example, please refer to... Figure 3A The first extension pad ED5 can extend outward and to the right from the light-emitting element 123, while the second extension pad ED6 can extend outward and upward from the light-emitting element 123, such that the central axis X5 of the first extension pad ED5 and the central axis X6 of the second extension pad ED6 are approximately perpendicular to each other.

[0118] In some embodiments, the light-emitting device 30 may further include a second insulating layer Ia, which may be located between the first extension pad ED5 and the second extension pad ED6 and the first electrode E1 and the second electrode E2. For example, the second insulating layer Ia may be formed on the surfaces of the first extension pad ED5 and the second extension pad ED6 opposite to the semiconductor stack SS before the mass transfer process, and the second insulating layer Ia may include portions P1 and P2 with different thicknesses. For example, portion P1 may have a thickness t1, portion P2 may have a thickness t2, and thickness t1 may be greater than thickness t2, so that the side of the first extension pad ED5 and the second extension pad ED6 opposite to the semiconductor stack SS can have a flat surface Fb. In this way, the second insulating layer Ia can assist the light-emitting element 123 to attach to the adhesive layer AH with a larger and flatter surface Fb, thereby increasing adhesion and preventing the light-emitting element 123 from shifting. The material of the second insulating layer Ia may include inorganic insulating materials, such as silicon oxide (SiOx) or silicon nitride (SiNx), but is not limited thereto.

[0119] Figure 4A This is a partial top view of a light-emitting device 40 according to an embodiment of the present invention. Figure 4B It is along Figure 4A A schematic diagram of the cross section line D-D'. Figure 4C It is along Figure 4A A schematic diagram of the cross section drawn by section line E-E'. Figure 4D It is along Figure 4A A schematic diagram of the cross section drawn by the section line F-F'.

[0120] Please refer to the following at the same time Figures 4A to 4DThe light-emitting device 40 has adjacent transpose region TA and repair region RA, and includes: a circuit board 110, on which a first electrode E1 and a second electrode E2 are disposed; a plurality of light-emitting elements 120, located on the circuit board 110, each including: a first type semiconductor layer SP1; a second type semiconductor layer SP2, overlapping the first type semiconductor layer SP1 and located between the first type semiconductor layer SP1 and the circuit board 110; a light-emitting layer EL, located between the first type semiconductor layer SP1 and the second type semiconductor layer SP2; a first pad PD1, connected to the first type semiconductor layer SP1 and located between the first type semiconductor layer SP1 and the circuit board 110; and a second pad PD2, connected to the second type semiconductor layer SP2 and located between the second type semiconductor layer SP2 and the circuit board 110; a first extension pad ED7, electrically connected to the first pad PD1; a second extension pad ED8, electrically connected to the second pad PD2; and an adhesive layer AH, located between the light-emitting element 120 and the circuit board 110, and extending at least to the sidewall W2 of the second type semiconductor layer SP2.

[0121] With Figures 2A to 2B Compared to the light-emitting device 20 shown, Figures 4A to 4D The difference in the illustrated light-emitting device 40 is that the first light-emitting element 121 of the plurality of light-emitting elements 120 in the light-emitting device 40 is located in the transpose region TA, and the first light-emitting element 121 located in the transpose region TA is mainly disposed on the circuit board 110 by a mass transfer process. The first extension pad ED7 of the first light-emitting element 121 could originally be electrically connected to the first electrode E1 through the first conductive pattern CP11. However, due to component malfunction or other factors, the electrical connection between the first pad PD1 of the first light-emitting element 121 and the first electrode E1 can be disconnected. For example, the first conductive pattern CP11 can be disconnected, for example, by forming an opening O1 in the first conductive pattern CP11, so that the first extension pad ED7 cannot be electrically connected to the first electrode E1.

[0122] In some embodiments, the second extension pad ED8 of the first light-emitting element 121 is originally electrically connected to the second electrode E2 via the second conductive pattern CP21. However, due to component malfunction or other factors, the electrical connection between the second pad PD2 of the first light-emitting element 121 and the second electrode E2 can be disconnected. For example, the second extension pad ED8 can be disconnected, for instance, by forming an opening O2 in the second extension pad ED8, such as... Figure 4A As shown, this prevents the second extension pad ED8 from being electrically connected to the second electrode E2. In some embodiments, the abnormal first light-emitting element 121 can also be damaged to ensure that the first light-emitting element 121 does not emit light.

[0123] Furthermore, the second light-emitting element 122 among the plurality of light-emitting elements 120 of the light-emitting device 40 is located in the repair area RA. For example, the second light-emitting element 122 located in the repair area RA can be disposed on the circuit board 110 through a repair process, and the first extension pad ED7 of the second light-emitting element 122 can be electrically connected to the first electrode E1 through the first conductive pattern CP12. For example, the first conductive pattern CP12 can cover the first conductive pattern CP11 and the first electrode E1, so that the first contact pad PD1 of the second light-emitting element 122 can be electrically connected to the first electrode E1. At the same time, the second extension pad ED8 of the second light-emitting element 122 can be electrically connected to the second electrode E2 through the second conductive pattern CP22. For example, the second conductive pattern CP22 can cover the second conductive pattern CP21 and the second electrode E2, so that the second contact pad PD2 of the second light-emitting element 122 can be electrically connected to the second electrode E2. In other words, each pair of first light-emitting elements 121 and second light-emitting elements 122 can use the same pair of first electrodes E1 and second electrodes E2, and the first electrodes E1 and second electrodes E2 are preferably adjacent to the transpose region TA and the repair region RA at the same time.

[0124] In this embodiment, the first conductive pattern CP12 and the second conductive pattern CP22 are formed using thin-film deposition and photolithography processes, rather than welding processes. This avoids the problem of the light-emitting element 120 shifting during thermal processing, thereby improving the reliability of the light-emitting device 40. In some embodiments, the materials of the first conductive pattern CP12 and the second conductive pattern CP22 may be different from those of the first conductive pattern CP11 and the second conductive pattern CP21. For example, the materials of the first conductive pattern CP12 and the second conductive pattern CP22 may include highly conductive metals, such as aluminum, molybdenum, titanium, copper, or alloys of the above metals, or a stack of the above metals or alloys with a transparent conductive material, but are not limited thereto.

[0125] In some embodiments, the light-emitting device 40 may further include a first insulating layer Ib, which may be located between the first extension pad ED7 and the second extension pad ED8 and the adhesive layer AH and the circuit substrate 110. For example, the first insulating layer Ib may be formed on the surfaces of the first extension pad ED7 and the second extension pad ED8 facing away from the semiconductor stack SS before the mass transfer process. In this way, the first insulating layer Ib can assist the light-emitting element 120 in attaching to the adhesive layer AH with a more uniform surface material, thereby improving the adhesion of the light-emitting element 120 to the adhesive layer AH.

[0126] In summary, the light-emitting device of the present invention uses a first extension pad and a second extension pad to assist in the docking of the light-emitting element and the circuit board, while increasing the adhesion of the light-emitting element to the adhesive layer, thereby improving the bonding yield between the light-emitting element and the circuit board and thus improving the reliability of the light-emitting device. Furthermore, the light-emitting device of the present invention forms the first conductive pattern and the second conductive pattern through thin film deposition and photolithography processes, which avoids the problem of light-emitting element misalignment caused by thermal processes.

[0127] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A light emitting device, comprising: a circuit substrate having a first electrode and a second electrode disposed on a surface thereof; a light emitting element disposed on the circuit substrate, and comprising: a first type semiconductor layer; a second type semiconductor layer overlapping the first type semiconductor layer and disposed between the first type semiconductor layer and the circuit substrate; a light emitting layer disposed between the first type semiconductor layer and the second type semiconductor layer; a first connection pad connected to the first type semiconductor layer and disposed between the first type semiconductor layer and the circuit substrate; and a second connection pad connected to the second type semiconductor layer and disposed between the second type semiconductor layer and the circuit substrate; a first extension pad electrically connected to the first connection pad; a second extension pad electrically connected to the second connection pad; an adhesive layer disposed between the light emitting element and the circuit substrate and extending at least on a sidewall of the second type semiconductor layer; a first conductive pattern electrically connected to the first extension pad and the first electrode; and a second conductive pattern electrically connected to the second extension pad and the second electrode; the first extension pad is between the first connection pad and the adhesive layer; the second extension pad is between the second connection pad and the adhesive layer; the first extension pad is between the first conductive pattern and the first electrode, and the first conductive pattern partially contacts the first extension pad and partially contacts the first electrode; the second extension pad is between the second conductive pattern and the second electrode, and the second conductive pattern partially contacts the second extension pad and partially contacts the second electrode; a first insulating layer disposed between the first extension pad and the second extension pad and the adhesive layer and the circuit substrate.

2. The light emitting device of claim 1, wherein a portion of a projection of the first extension pad and the second extension pad on the circuit substrate overlaps a projection of the light emitting element on the circuit substrate.

3. The light emitting device of claim 1, wherein the first extension pad and the second extension pad extend in opposite directions or perpendicular to each other.

4. The light emitting device of claim 1, wherein at least a portion of the first extension pad or the second extension pad is suspended.

5. The light emitting device of claim 1, wherein the first extension pad comprises a first extension portion connecting the first contact pad and a first connection portion connecting the first extension portion with the first conductive pattern, and the second extension pad comprises a second extension portion connecting the second contact pad and a second connection portion connecting the second extension portion with the second conductive pattern. an angle between the first extension portion and the first connection portion is ≥ 90 degrees, and an angle between the second extension portion and the second connection portion is ≥ 90 degrees.

6. The light emitting device of claim 1, wherein the first extension pad and the second extension pad are in the same film layer as the first connection pad and the second connection pad, respectively.

7. The light emitting device of claim 1, wherein a Young's modulus of the adhesive layer is between 2 and 3.

8. The light emitting device of claim 1, wherein the circuit substrate further comprises an array of switching elements.

9. The light emitting device of claim 1, further comprising a second insulating layer disposed between the first extension pad and the second extension pad and the first electrode and the second electrode.

10. A light emitting device having an adjacent transfer region and a repair region, and comprising: a circuit substrate having a first electrode and a second electrode disposed on a surface thereof; A plurality of light emitting elements are located on the circuit substrate and each include: a first type semiconductor layer; a second type semiconductor layer overlapping the first type semiconductor layer and located between the first type semiconductor layer and the circuit substrate; a light emitting layer located between the first type semiconductor layer and the second type semiconductor layer; a first contact pad connected to the first type semiconductor layer and located between the first type semiconductor layer and the circuit substrate; and a second contact pad connected to the second type semiconductor layer and located between the second type semiconductor layer and the circuit substrate, a first extension pad electrically connected to the first contact pad; a second extension pad electrically connected to the second contact pad; the first extension pad is between the first contact pad and the circuit substrate; the second extension pad is between the second contact pad and the circuit substrate; a first conductive pattern and a second conductive pattern; the first extension pad is between the first conductive pattern and the first electrode, and the first conductive pattern partially contacts the first extension pad and partially contacts the first electrode; the second extension pad is between the second conductive pattern and the second electrode, and the second conductive pattern partially contacts the second extension pad and partially contacts the second electrode; wherein a first light emitting element of the plurality of light emitting elements is located in the transpose region, and the electrical connection between the first contact pad of the first light emitting element and the first electrode or the electrical connection between the second contact pad of the first light emitting element and the second electrode is disconnected, and a second light emitting element of the plurality of light emitting elements is located in the repair region, and the first contact pad of the second light emitting element is electrically connected to the first electrode, and the second contact pad of the second light emitting element is electrically connected to the second electrode. an adhesive layer located between the light emitting element and the circuit substrate and extending at least on the sidewall of the second type semiconductor layer; a first insulating layer located between the first extension pad and the second extension pad and the adhesive layer and the circuit substrate.

11. The light emitting device of claim 10, wherein the first extension pad and the second extension pad partially overlap the light emitting element on the circuit substrate in a perspective projection.

12. The light emitting device of claim 10, wherein the first extension pad and the second extension pad extend in opposite directions or perpendicular to each other.

13. The light emitting device of claim 10, wherein at least a portion of the first extension pad or the second extension pad is suspended.

14. The light emitting device of claim 10, wherein the first extension pad and the second extension pad are in the same film layer as the first contact pad and the second contact pad, respectively.

15. The light emitting device of Claim 10, wherein, the first conductive pattern electrically connects the first extension pad and the first electrode, and the second conductive pattern electrically connects the second extension pad and the second electrode.

16. The light emitting device according to claim 15, wherein a material of the first conductive pattern and the second conductive pattern electrically connecting the first light emitting element is different from a material of the first conductive pattern and the second conductive pattern electrically connecting the second light emitting element.

17. The light emitting device according to claim 15, wherein the electrical connection between the first electrode and the first contact pad of the first light emitting element or the electrical connection between the second electrode and the second contact pad of the first light emitting element is disconnected by forming an opening in the first extension pad, the first conductive pattern, the second extension pad, or the second conductive pattern electrically connecting therebetween.

18. The light emitting device according to claim 10, wherein a Young's modulus of the adhesive layer is between 2 and 3.

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