CN111799205B

CN111799205B - Method for manufacturing electronic device

Info

Publication number: CN111799205B
Application number: CN201911273714.9A
Authority: CN
Inventors: 王惠洁; 谢朝桦; 林芳莹
Original assignee: Innolux Display Corp
Current assignee: Innolux Corp
Priority date: 2019-04-08
Filing date: 2019-12-12
Publication date: 2024-02-09
Anticipated expiration: 2039-12-12
Also published as: TW202038377A; CN111799205A

Abstract

The invention discloses a method for manufacturing an electronic device. First, a plurality of light emitting elements are provided on a first substrate. At least one of the light emitting elements is then transferred from the first substrate to the second substrate via the transfer joint. The transfer joint includes an electrode and a cantilever that supports the electrode and has a U-shaped portion.

Description

Method for manufacturing electronic device

Technical Field

The present invention relates to a method for manufacturing an electronic device, and more particularly, to a method for manufacturing an electronic device by transferring a light emitting element using a transfer joint.

Background

Elements in electronic devices, such as light emitting diodes, have been moving toward miniaturization. As the number of microelements in electronic devices increases, transfer techniques have been developed to transfer the microelements in large quantities. However, the conventional transfer technology has a number of disadvantages, such as poor freedom of movement of the transfer joint, which is liable to cause poor pick-up, or damage of the micro-device.

Disclosure of Invention

According to an embodiment of the present invention, a method of manufacturing an electronic device is disclosed. First, a plurality of light emitting elements are provided on a first substrate. At least one of the light emitting elements is then transferred from the first substrate to the second substrate via the transfer joint. The transfer joint includes an electrode and a cantilever that supports the electrode and has a U-shaped portion.

According to another embodiment of the present invention, another method of making an electronic device is disclosed. First, a plurality of light emitting elements are provided on a first substrate. At least one of the light emitting elements is then transferred from the first substrate to the second substrate via the transfer joint. The transfer joint comprises an electrode and a cantilever, the cantilever supports the electrode, the electrode comprises a first sub-electrode and a second sub-electrode, and the first sub-electrode and the second sub-electrode are staggered.

Drawings

Fig. 1 to 3 are schematic diagrams illustrating a method for manufacturing an electronic device according to a first embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view of a transfer fitting according to an alternative embodiment of the first embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view of an electronic device according to an embodiment of the invention;

FIG. 6 is a schematic top view of a connector unit according to a first embodiment of the present invention;

FIG. 7 is a schematic top view of a connector unit according to a second embodiment of the present invention;

FIG. 8 is a schematic top view of a connector unit according to a third embodiment of the present invention;

FIG. 9 is a schematic top view of a fourth embodiment of a connector unit of the present invention; and

fig. 10 is a schematic top view of a joint unit according to a fifth embodiment of the present invention.

Reference numerals illustrate: 1. 1 A-An electronic device; 102-a first substrate; 104-a light emitting element; 104 A-A semiconductor body; 104b, 104 c-pads; 106. 106 a-transfer linker; 106S-picking up the surface; 108. 208, 308, 408, 508-linker units; 110. 310-electrode; 110E1, 110E2, 310E1, 310E 2-sub-electrodes; 110S, 114S-surfaces; 112. 412-cantilever; 112a, 112b, 212a, 212b, 312a, 312b, 412a, 412b, 412c, 412d, 512a, 512 b-sub-cantilevers; 112L-L shaped portion; 112U, 212U, 512U-U shape; 114. 126-a substrate; 116-connecting elements; IN1, IN2, IN 3-insulating layers; 116a, OP-openings; 118-a dielectric layer; 120-a second substrate; 122-a protective layer; 124. CL1, CL 2-conductive layers; 128-a circuit structure layer; 130. 132-electrodes; 134-a first electrode; 136-a second electrode; 138-a first semiconductor layer; 140-a light emitting layer; 142-a second semiconductor layer; CP 1-connection; d1—a first direction; d2—a second direction; DE-drain; g-spacing; a GE-gate; an ML-material layer; a PDL-pixel definition layer; s1, S2-sides; an SC-semiconductor layer; SE-source; SP-subfraction; a TFT-thin film transistor; VD-top view direction; w1, W2, W3, W4, W5-width; A-A' -profile; t1, T2-thickness; US1, US2, US 3-upper surface; CP-bend; c1, C2, C3-junctions.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments and attached drawings, which are potentially simplified schematic illustrations and elements therein may not be drawn to scale in order to make the content of the present invention more clear and understandable. The number and size of the elements in the drawings are illustrative only and are not intended to limit the scope of the invention.

Certain terms are used throughout the description and following claims to refer to particular components. Those skilled in the art will appreciate that electronic device manufacturers may refer to a same component by different names, and that there is no intent to distinguish between components that function identically but are not necessarily named identically. In the following description and in the claims, the terms "include," comprise, "and" have "are open-ended terms, and thus should be interpreted to mean" include, but not limited to ….

Directional terms mentioned herein, such as: "upper", "lower", "front", "rear", "left", "right", etc., are merely directions with reference to the drawings. Thus, the directional terminology is used for purposes of illustration and is not intended to be limiting of the invention. In the drawings, the various drawings depict general features of methods, structures and/or materials used in particular embodiments. However, these drawings should not be construed as defining or limiting the scope or nature of what is covered by these embodiments. For example, the relative dimensions, thicknesses, and locations of various layers, regions, and/or structures may be reduced or exaggerated for clarity.

When a corresponding element such as a film or region is referred to as being "on" another element, it can be directly on the other element or other elements can be present therebetween. On the other hand, when an element is referred to as being "directly on" another element, there are no elements therebetween. In addition, when a component is referred to as being "on" another component, the two are in a top-down relationship in the top-down direction, and the component may be above or below the other component, and the top-down relationship depends on the orientation of the device.

It will be understood that when an element or film is referred to as being "connected to" another element or film, it can be directly connected to the other element or film or intervening elements or films may be present therebetween. When an element is referred to as being "directly connected to" another element or film, there are no intervening elements or films present therebetween. In addition, when an element is referred to as being "coupled to" (or a variant thereof) another element, it can be directly connected to the other element or be indirectly connected (e.g., electrically connected) to the other element(s) through one or more elements.

The terms "about," "equal to," or "same," or "substantially" are generally construed to be within 20% of a given value or range, or to be within 10%, 5%, 3%, 2%, 1% or 0.5% of a given value or range.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise, nor do it represent a sequential order of a given claim element from another, or a method of manufacture, by which the use of such ordinals merely serves to distinguish one claim element from another element having the same name.

It should be noted that the technical solutions provided in the following different embodiments may be replaced, combined or mixed with each other to form another embodiment without departing from the spirit of the present invention.

The electronic device of the present invention may include a display apparatus, a light emitting device, a sensing device or a splicing device, other suitable devices, or a combination of the above devices, but is not limited thereto. The display device may be a bendable or flexible display device.

Fig. 1 to 3 are schematic diagrams illustrating a method for manufacturing an electronic device according to a first embodiment of the present invention. Referring to fig. 1 to 3, fig. 6 is a schematic top view of a joint unit according to a first embodiment of the present invention, wherein the joint unit 108 shown in fig. 1 to 3 may be, for example, but not limited to, a schematic cross-sectional view along a line A-A' of fig. 6. As shown in fig. 1, a plurality of light emitting elements 104 are first provided on a first substrate 102. In the methods shown in fig. 1 to 3, three light emitting elements 104 are taken as an example, but not limited thereto. The light emitting element 104 may include a Light Emitting Diode (LED), a micro-LED (mini-LED) or micro-LED), a Quantum Dots (QDs) material, a Quantum Dot Light Emitting Diode (QDLED), a fluorescent (fluorescence) material, a phosphorescent (phosphor) material, other suitable materials, or a combination thereof, but is not limited thereto. The light emitting element 104 may emit red light, green light, blue light or other suitable wavelength band light, but is not limited thereto. The detailed lamination of the light emitting element 104 will be described later with reference to fig. 5. In some embodiments, the pad 104b and the pad 104c may be used as an anode and a cathode of the light emitting device 104, respectively, and the pad 104b and the pad 104c are disposed on the same side of the semiconductor body 104a, such as a side of the semiconductor body 104a adjacent to the first substrate 102, but not limited thereto. In some embodiments, the first substrate 102 may, for example, serve as a substrate that temporarily carries the light emitting elements 104. The material of the first substrate 102 includes, but is not limited to, glass, quartz, ceramic, sapphire, polyimide (PI), polyethylene terephthalate (polyethylene terephthalate, PET), other suitable materials, or a combination thereof. In some embodiments, the first substrate 102 may include a hard substrate, a soft substrate, or a flexible substrate. In some embodiments, the light emitting element 104 may include a conductive pattern (in this embodiment, the conductive pattern may be compared to the semiconductor layer body 104 a) for contacting the transfer joint 106.

Next, as shown in fig. 1 to 3, at least one of the light emitting elements 104 is transferred from the first substrate 102 to the second substrate 120 through the transfer joint 106. In some embodiments, the transfer joint 106 may include a plurality of joint units 108 for picking up the corresponding light emitting elements 104, respectively. The present embodiment uses a connector unit 108 to pick up a corresponding light emitting element 104, but is not limited thereto. In other embodiments (not shown), one connector unit 108 picks up a plurality of light emitting elements 104, for example. In detail, the transfer joint 106 (e.g., joint unit 108) may include an electrode 110 and a cantilever 112, wherein the cantilever 112 connects the electrode 110 and is used to support the electrode 110. In some embodiments, the electrode 110 of the connector unit 108 may, for example, have a pick-up surface 106S, which pick-up surface 106S picks up the light-emitting element 104, for example, towards the electrode 110. In some embodiments, the electrode 110 may include two sub-electrodes (e.g., the sub-electrode 110E1 and the sub-electrode 110E 2), and the sub-electrode 110E1 (which may correspond to one of the first sub-electrode and the second sub-electrode in the claims) and the sub-electrode 110E2 (which may correspond to the other of the first sub-electrode and the second sub-electrode in the claims) are staggered, but not limited thereto. In some embodiments (not shown), the electrode 110 may be divided into two sub-electrodes (i.e. the first sub-electrode and the second sub-electrode), for example, without limitation, the electrode 110 may be a unitary structure.

Referring to fig. 1-3, in some embodiments, electrode 110 and cantilever 112 may comprise, for example, the same material, but are not limited thereto. In other words, the electrode 110 and the cantilever 112 may be integrally formed, for example. In some embodiments, the material of the electrode 110 and/or the cantilever 112 includes, but is not limited to, a semiconductor material, a transparent conductive material, a metal conductive material, or a combination thereof. The semiconductor material includes, for example, silicon, germanium, or a combination of the above, but is not limited thereto. In some embodiments, electrode 110 and/or cantilever 112 may comprise a single layer of material or multiple layers of material, but is not limited thereto. In some embodiments, electrode 110 and/or cantilever 112 are formed, for example, from a layer of material ML (e.g., a semiconductor material), which may be doped, for example, with dopants, such that layer of material ML may have conductive properties. In some embodiments, an external line (not shown) may provide a voltage to cantilever 112, and the voltage may be transmitted to electrode 110, for example, though cantilever 112, but not limited thereto. In some embodiments, the dopants may include, for example, but are not limited to, N-type dopants, P-type dopants, or other suitable materials.

Referring to fig. 1-3, the transfer joint 106 may include, but is not limited to, a substrate 114, a connecting element 116, and/or a dielectric layer 118. In some embodiments, the substrate 114 may be, for example, a soft substrate or a hard substrate. In some embodiments, the substrate 114 may optionally include circuitry thereon for transmitting a voltage to the electrode 110, but is not limited thereto. In some embodiments, the connection element 116 is disposed between the joint unit 108 and the substrate 114, for example. In some embodiments, connecting element 116 may be connected to or in contact with cantilever 112, for example, to secure cantilever 112 to substrate 114 via connecting element 116, but is not limited thereto. In some embodiments, openings 116a may be formed between adjacent connecting elements 116. In some embodiments, the electrode 110 and/or the cantilever 112 may overlap the opening 116a in the top view VD, for example, so that the electrode 110 and a portion of the cantilever 112 hang over the opening 116a to increase the freedom of movement of the electrode 110 and the cantilever 112. Thus, the pick-up surface 106S of the electrode 110 can have a degree of freedom of movement or a degree of freedom of rotation in multiple directions, and the pick-up surface 106S is improved to pick up the light emitting element 104. In some embodiments, the material of the connection element 116 includes, for example, an insulating material, which may include, for example, silicon oxide, other suitable materials, or a combination thereof, but is not limited thereto. In some embodiments, the transfer connector 106 may optionally include a circuit board (not shown) via which the electrode 110 and/or cantilever 112 are electrically connected to a control element (or power source). In some embodiments (not shown), vias (via) may be formed in the substrate 114, such as with conductive material disposed therein, and the cantilever 112 may be electrically connected to a control element (or power source), such as via the conductive material disposed in the vias. In some embodiments (not shown), the cantilever 112 may be electrically connected to an external circuit (not shown) via other electrically conductive lines.

Referring to fig. 1-3, in some embodiments, the dielectric layer 118 may be disposed on a portion of a surface 114S of the substrate 114, such as a surface adjacent to the tab unit 108. In some embodiments, dielectric layer 118 may be disposed on cantilever 112. In some embodiments, dielectric layer 118 on surface 114S and dielectric layer 118 on tab unit 108 (including cantilever 112 and electrode 110) may be connected to each other, but are not limited thereto. In other words, the dielectric layer 118 on the surface 114S and the dielectric layer 118 on the connector unit 108 may be formed in the same process, but is not limited thereto. In some embodiments, the dielectric layer 118 may be fabricated, for example, by atomic layer deposition (atomic layer deposition, ALD) techniques or other suitable methods. In some embodiments, the dielectric layer 118 may cover the connection element 116, and/or the tab unit 108. In some embodiments, the electrode 110 and the light emitting element 104 may be insulated from each other when the transfer joint 106 is in contact with the light emitting element 104 by disposing a dielectric layer 118 over the electrode 110 of the transfer joint 106.

In some embodiments, the electrode 110 includes a sub-electrode 110E1 and a sub-electrode 110E2, and by applying different voltages (e.g., voltages of different polarities) to the sub-electrode 110E1 and the sub-electrode 110E2, respectively, an electric field (e.g., a boundary electric field) is generated between the sub-electrode 110E1 and the sub-electrode 110E2, so that electrostatic induction (electrostatic induction) is generated between the electrode 110 and the light emitting element 104. When electrostatic induction is generated between the electrode 110 and the light emitting element 104, an induced charge is generated between the light emitting element 104 and the transfer connector 106, for example, so as to attract or pick up the light emitting element 104. In some embodiments, the range of the voltage difference applied between the sub-electrode 110E1 and the sub-electrode 110E2 may be greater than 0V and less than or equal to 110V (0V < voltage difference. Ltoreq.110V), but is not limited thereto. In some embodiments, the range of the voltage difference applied between the sub-electrode 110E1 and the sub-electrode 110E2 may be greater than or equal to 10V and less than or equal to 80V (10V. Ltoreq. Voltage difference. Ltoreq.80V), but is not limited thereto.

In some embodiments, the material of the dielectric layer 118 may include an insulating material, such as a high-k dielectric material or other suitable material. The material of the dielectric layer 118 may include, for example, aluminum oxide, silicon oxide, other suitable materials, or combinations thereof, but is not limited thereto.

Referring to fig. 1-3 and 6, in some embodiments, the thickness of electrode 110 is, for example, greater than the thickness of cantilever 112 in cross-section, but is not limited thereto. In some embodiments, where electrode 110 and cantilever 112 are formed, for example, from the same material layer (e.g., material layer ML), electrode 110 may be defined as a thicker portion of material layer ML, and cantilever 112 may be defined as a thinner portion of material layer ML. In some embodiments (as shown in fig. 1-6), electrode 110 may correspond substantially to the middle portion when electrode 110 and cantilever 112 are formed, for example, from the same material layer (e.g., material layer ML). By designing the thickness of the electrode 110 to be greater than the thickness of the cantilever 112, when the transfer joint 106 contacts the light emitting element 104, the electrode 110 can be closer to the light emitting element 104 than the cantilever 112, and the electrode 110 picks up the corresponding light emitting element 104, so that the alignment accuracy of transferring the light emitting element 104 to the second substrate is improved. In other words, by designing the thickness of the electrode 110 to be larger than the thickness of the cantilever 112, the situation in which the light emitting element 104 is erroneously picked up by the cantilever 112 can be reduced. In some embodiments, the thickness T1 of electrode 110 may differ from the thickness T2 of cantilever 112 by greater than or equal to 20 μm and less than or equal to 70 μm (20 μm. Ltoreq.T1-T2. Ltoreq.70 μm), but is not limited thereto. In some embodiments, the thickness T1 of electrode 110 may differ from the thickness T2 of cantilever 112 by greater than or equal to 30 μm and less than or equal to 60 μm (30 μm. Ltoreq.T1-T2. Ltoreq.60 μm), but is not limited thereto. In other embodiments (not shown), the thickness T1 of the electrode 110 is, for example, substantially equal to or greater than the thickness T2 of the cantilever 112 in the cross-sectional view, and the material of the electrode 110 is, for example, more conductive than the material of the cantilever 112.

Referring to fig. 4, a schematic cross-sectional view of a transfer joint according to a variation of the first embodiment of the present invention is shown. The transfer connector of fig. 4 shows a connector unit, but is not limited thereto. The transfer joint 106a shown in fig. 4 differs from the transfer joint 106 shown in fig. 1 in that the transfer joint 106a further comprises a conductive layer 124, the conductive layer 124 being disposed between the upper surface 110S of the electrode 110 and the dielectric layer 118, for example. In detail, in some embodiments, when the material of the electrode 110 includes a semiconductor material and is not doped with a dopant, the conductive layer 124 may be disposed to generate electrostatic induction between the conductive layer 124 and the light emitting element 104. In some embodiments, conductive layer 124 may be disposed between at least a portion of cantilever 112 and dielectric layer 118. In some embodiments, a conductive layer 124 may be disposed between the connection element 116 and the dielectric layer 118.

Please continue to refer to fig. 1-3. The step of transferring the light emitting element 104 from the first substrate 102 to the second substrate 120 is described in detail below. As shown in fig. 1, the transfer joint 106 is moved so that the pick-up surfaces 106S of the different electrodes 110 of the transfer joint 106 are respectively in contact with the light emitting elements 104 to be picked up. In some embodiments, the upper surfaces of the different light emitting elements 104 (e.g., the surfaces remote from the first substrate 102) may be, for example, not located on the same horizontal plane. The horizontal plane is, for example, a surface substantially parallel to the surface of the first substrate 102. For example, as shown in fig. 1, the upper surface US1 of the leftmost light emitting element 104 and the upper surface US2 of the middle light emitting element 104 are not located on the same horizontal plane, for example. In some embodiments, the upper surface US3 of the light emitting element 104 (e.g., the rightmost light emitting element 104) may be, for example, an inclined surface (or a surface having an arc shape), i.e., the upper surface US3 may be, for example, not parallel to the surface of the first substrate 102. In some embodiments, the cantilever 112 may have a bending portion for improving the freedom of movement of the pick-up surface 106S of the electrode 110, and the detailed bending portion will be described with reference to fig. 6. By the design of the bending part of the cantilever 112, when the transfer joint 106 contacts the light emitting element 104, the different pick-up surfaces 106S can be more freely matched with the upper surface of the light emitting element 104, so that the contact area between the pick-up surfaces 106S and the corresponding light emitting element 104 is increased, and the probability of picking up the light emitting element 104 is increased. As shown in fig. 2, the light emitting element 104 is, for example, adsorbed on the pick-up surface 106S of the electrode 110 of the transfer joint 106, and the light emitting element 104 may be separated from the first substrate 102 later.

As shown in fig. 3, the transfer connector 106 is moved onto the second substrate 120, and then the voltage on the electrode 110 is removed, so that the light emitting element 104 can be separated from the transfer connector 106 and located on the second substrate 120. As in the steps of fig. 1 to 3, the electronic device 1 of the present embodiment is formed, but not limited thereto, and steps may be added or deleted according to the requirement.

Referring to fig. 5, a schematic cross-sectional view of an electronic device according to an embodiment of the invention is shown. After the light emitting element 104 is disposed on the second substrate 120, the protection layer 122 may be selectively disposed on the light emitting element 104 and the second substrate 120. In some embodiments, the second substrate 120 may include, for example, but not limited to, a thin film transistor substrate or a circuit board. For example, the second substrate 120 may include a substrate 126 and a circuit structure layer 128, and the circuit structure layer 128 is used to transmit signals to the light emitting devices 104 disposed on the second substrate 120. The substrate 126 may include a hard substrate or a flexible substrate, and the material of the substrate may include, for example, glass, ceramic, quartz, sapphire, polyimide (PI), polycarbonate (PC), or polyethylene terephthalate (polyethylene terephthalate, PET), or a combination of the foregoing, but is not limited thereto. In some embodiments, the substrate 126 may include a rigid substrate, a flexible substrate, or a flexible substrate. IN some embodiments, the circuit structure layer 128 may include a conductive layer CL1 for forming a gate electrode GE and/or a scan line (not shown), an insulating layer IN1, a semiconductor layer SC, an insulating layer IN2, and a conductive layer CL2 for forming a source electrode SE, a drain electrode DE, and/or a data line (not shown), but is not limited thereto. The conductive layer CL1, the insulating layer IN1, the semiconductor layer SC, the insulating layer IN2, and the conductive layer CL2 may form a plurality of thin film transistors TFTs, and the light emitting element 104 may be electrically connected to the thin film transistors TFTs. The type of the thin film transistor TFT is not limited to the bottom gate type as shown in fig. 5, but may also include a top gate type, a double gate type, or other suitable type, but is not limited thereto. In some embodiments, the protection layer 122 may include an inorganic material layer, an organic material layer, or a combination thereof, for example, to reduce the influence of moisture or oxygen. In some embodiments, the protective layer 122 comprises, for example, a single layer or a multi-layer structure.

IN some embodiments, the second substrate 120 may include an electrode 130, an electrode 132, and an insulating layer IN3, the insulating layer IN3 is disposed on the circuit structure layer 128, the electrode 130 and the electrode 132 are disposed on the insulating layer IN3, and the electrode 130 is electrically connected to the TFT through a hole of the insulating layer IN 3. In some embodiments, the semiconductor layer SC may include, for example, metal oxide, amorphous silicon, low temperature polysilicon (low-temperature polysilicon, LTPS), or low temperature poly-oxide (low-temperature polycrystalline oxide, LTPO), but is not limited thereto. In some embodiments, different thin film transistors TFTs may include the semiconductor layers SC of different materials described above, but are not limited thereto. IN some embodiments, the second substrate 120 may include a pixel defining layer PDL disposed on the insulating layer IN3, and the pixel defining layer PDL has a plurality of openings OP, and the light emitting element 104 may be disposed IN the openings OP and electrically connected to the electrode 130 and the electrode 132.

In some embodiments, the light emitting element 104 (e.g., the semiconductor layer body 104 a) may include, but is not limited to, a first electrode 134, a second electrode 136, a first semiconductor layer 138, a light emitting layer 140, and a second semiconductor layer 142. The first electrode 134 is connected between the first semiconductor layer 138 and the pad 104b, and the second electrode 136 is connected between the second semiconductor layer 142 and the pad 104 c. For example, the first semiconductor layer 138 may include one of a P-type semiconductor material and an N-type semiconductor material, and the second semiconductor layer 142 may include the other of the P-type semiconductor material and the N-type semiconductor material, but is not limited thereto. In some embodiments, the second semiconductor layer 142 may be a conductive pattern for contact with the transfer joint, but is not limited thereto.

It should be noted that, although not shown in fig. 1 to 3, the cantilever 112 of the present embodiment may have at least one bending portion (the bending portion CP shown in fig. 6) in the top view VD. In some embodiments, cantilever 112 may include an L-shaped portion, a U-shaped portion, or other suitable shape portion in top view VD. By the above-described design, the degree of freedom of movement between the cantilever 112 and the connected electrode 110 or the degree of freedom of rotation of the electrode 110 (e.g., the pick-up surface 106S) can be improved. For example, when the surfaces of the light emitting elements 104 are different (i.e. located at different horizontal planes) or have inclined surfaces, by the design of the cantilever 112 as described above, when the pick-up surface 106S of the transfer connector 106 contacts the light emitting element 104 (e.g. the surface of the light emitting element 104), the pick-up surface 106S of the transfer connector 106 can be modulated according to the corresponding surface condition of the light emitting element 104, for example, the inclination of the pick-up surface 106S of the transfer connector 106 or the distance between the pick-up surface 106S and the substrate 114 is modulated, so as to increase the contact area between the pick-up surface 106S of the electrode 110 and the corresponding light emitting element 104, and increase the pick-up probability.

Referring to fig. 6, fig. 6 is a schematic top view of the joint unit of the first embodiment, wherein the joint unit 108 shown in fig. 1 to 3 or the joint unit 108 shown in fig. 4 may be, for example, a schematic cross-sectional view along a line A-A' of fig. 6, but is not limited thereto. The joint unit 108 shown in fig. 1 to 3 is described below as an example. As shown in FIG. 6, cantilever 112 may include at least two sub-cantilevers (e.g., sub-cantilever 112a, sub-cantilever 112 b), sub-cantilever 112a and sub-cantilever 112b are connected to sub-electrode 110E1 and sub-electrode 110E2, respectively, for supporting sub-electrode 110E1 and sub-electrode 110E2 via sub-cantilever 112a and sub-cantilever 112b, respectively. In some embodiments, sub-cantilevers 112a, 112b may be connected to opposite sides of electrode 110, respectively, for example, but are not limited thereto. In some embodiments, the sub-cantilever 112a, the electrode 110, and the sub-cantilever 112b may be sequentially arranged, for example, along the first direction D1, but are not limited thereto. In some embodiments (not shown), the connector unit 108 may include at least one sub-cantilever connected to at least one side of the electrode 110. In some embodiments (not shown), the sub-electrodes 110E1 and 110E2 may have arcuate edges.

In some embodiments, the sub-cantilever 112a and/or the sub-cantilever 112b may have at least one bending portion in the top view VD. Specifically, sub-cantilever 112a and/or sub-cantilever 112b may include at least two bending portions CP to form at least one U-shaped portion 112U (or ㄩ -shaped portion). In some embodiments (not shown), the bending portion CP may be designed to have an arc-shaped edge according to the requirement. In the joint unit 108 shown in fig. 6, the sub-cantilever 112a and/or the sub-cantilever 112b may have two U-shaped portions 112U, for example, two U-shaped portions 112U respectively facing in opposite directions, for example, an opening of one U-shaped portion 112U faces upward, and an opening of the other U-shaped portion 112U faces downward, but is not limited thereto. Wherein two U-shaped portions 112U may be connected to each other, for example, to form a serpentine shape, without being limited thereto, and two U-shaped portions 112U have a connection point C3, for example. In some embodiments, at least one of the sub-cantilever 112a and the sub-cantilever 112b may optionally include an L-shaped portion 112L connected between the U-shaped portion 112U and the corresponding sub-electrode 110E1 (or sub-electrode 110E 2), but is not limited thereto. In some embodiments, sub-boom 112a is rotated approximately 180 degrees to form sub-boom 112b, but is not limited thereto. In some embodiments (not shown), sub-cantilever 112a and sub-cantilever 112b may be, for example, mirror symmetrical, but are not limited thereto. In some embodiments (not shown), sub-cantilever 112a and sub-cantilever 112b may be, for example, asymmetric. In some embodiments, the length and/or shape of sub-cantilever 112a and sub-cantilever 112b may be the same or different, but is not limited thereto.

In some embodiments, the junction C1 of sub-cantilever 112a and sub-electrode 110E1 may be located on a different horizontal line, e.g., parallel to first direction D1, than the junction C2 of sub-cantilever 112b and sub-electrode 110E2. In some embodiments (not shown), the junction C1 of sub-cantilever 112a and sub-electrode 110E1 may be on the same horizontal line as the junction C2 of sub-cantilever 112b and sub-electrode 110E2, for example. In some embodiments, in the first direction D1, the width W2 of the sub-cantilever 112a and/or the width W3 of the sub-cantilever 112b may be greater than or equal to 50 μm and less than or equal to 200 μm (50 μm. Ltoreq.W2. Ltoreq.200 μm;50 μm. Ltoreq.W3. Ltoreq.200 μm), but is not limited thereto. In some embodiments, in the first direction D1, the width W2 of sub-cantilever 112a (and/or the width W3 of sub-cantilever 112 b) may be greater than or equal to 80 μm and less than or equal to 170 μm (80 μm.ltoreq.W2.ltoreq.170 μm;80 μm.ltoreq.W3.ltoreq.170 μm), but is not limited thereto. In some embodiments, width W2 and width W3 may be the same or different.

In some embodiments, the sub-electrode 110E1 and/or the sub-electrode 110E2 may have a spiral shape when viewed in the top view VD direction, but is not limited thereto. In some embodiments, the shape of the sub-electrode 110E1 and/or the sub-electrode 110E2 may be comb-shaped or other suitable shape when viewed in the top view VD direction. In some embodiments, the patterned outline (e.g., a thick dashed box) that frames the outer edges of the electrodes 110, as viewed in the top-down direction VD, may include, for example, a rectangle, circle, polygon, arc, or other suitable shape. The pattern profile shown in fig. 6 is exemplified by a rectangle, and the sub-electrode 110E1 and/or the sub-electrode 110E2 may include a plurality of sub-portions having different lengths, which are sequentially connected in a spiral shape, but is not limited thereto. In some embodiments, the number of sub-portions of sub-electrodes 110E1 and 110E2 may be the same or different.

In some embodiments, sub-electrode 110E1 and sub-electrode 110E2 are offset from each other. In some embodiments, the sub-electrode 110E1 and the sub-electrode 110E2 may have a pitch G1 and a pitch G2 therebetween. The pitch G1 is, for example, a minimum distance between the sub-electrode 110E1 and the sub-electrode 110E2 in the first direction D1, and the pitch G2 is, for example, a minimum distance between the sub-electrode 110E1 and the sub-electrode 110E2 in the second direction D2, wherein the first direction D1 and the second direction D2 are different (both may be substantially perpendicular), but is not limited thereto. In some embodiments, the pitch G1 and the pitch G2 may be the same or different. In some embodiments, the side S1 of the sub-electrode 110E1 is adjacent to the side S2 of the sub-electrode 110E2, and an electric field (e.g., fringe field) is formed between the side S1 of the sub-electrode 110E1 and the side S2 of the sub-electrode 110E2 when different voltages are applied between the sub-electrode 110E1 and the sub-electrode 110E2. In some embodiments, the longer the sides S1 and S2, the higher the electric field, so that the adsorption force of the electrode 110 to the light emitting element 104 is increased. In some embodiments, the spacing G1 (and/or the spacing G2) may be greater than or equal to 3 μm and less than or equal to 500 μm (3 μm. Ltoreq.G1. Ltoreq.500 μm;3 μm. Ltoreq.G2. Ltoreq.500 μm), but is not limited thereto. In some embodiments, the spacing G1 (and/or the spacing G2) may be greater than or equal to 10 μm and less than or equal to 400 μm (10 μm.ltoreq.G1.ltoreq.400 μm;10 μm.ltoreq.G2.ltoreq.400 μm), but is not limited thereto. In some embodiments, the spacing G1 (and/or the spacing G2) may be greater than or equal to 100 μm and less than or equal to 300 μm (100 μm.ltoreq.G1.ltoreq.300 μm;100 μm.ltoreq.G2.ltoreq.300 μm), but is not limited thereto.

In some embodiments, the width W4 of the sub-electrode 110E1 and the width W5 of the sub-electrode 110E2 may be, for example, the same or different. The width W4 may be, for example, a maximum width measured in an extending direction of a vertical sub-portion (one of the sub-portions 110E 1), and the width W5 may be, for example, a maximum width measured in an extending direction of a vertical sub-portion (one of the sub-portions 110E 2). In some embodiments, the width W4 (and/or the width W5) may be greater than or equal to 1 μm and less than or equal to 500 μm (1 μm.ltoreq.W4.ltoreq.500 μm;1 μm.ltoreq.W5.ltoreq.500 μm). In some embodiments, the width W4 (and/or the width W5) may be greater than or equal to 5 μm and less than or equal to 300 μm (5 μm.ltoreq.W4.ltoreq.300 μm;5 μm.ltoreq.W5.ltoreq.300 μm). In some embodiments, the width W1 of the electrode 110 in the first direction D1 may be substantially the same as the width of the light emitting element 104, for example, but is not limited thereto. In some embodiments, in the first direction D1, the width W1 of the electrode 110 may be, for example, greater than the width of the light emitting element 104. In some embodiments, in the first direction D1, the width W1 of the electrode 110 may be, for example, smaller than the width of the light emitting element 104. In some embodiments, the area of the electrode 110 may be substantially the same as the area of the light emitting element 104, for example, in the top view VD. In some embodiments, the area of the electrode 110 may be, for example, larger than the area of the light emitting element 104 in the top view VD. In some embodiments, the area of the electrode 110 may be, for example, smaller than the area of the light emitting element 104 in the top view VD.

Fig. 7 is a schematic top view of a connector unit according to a second embodiment of the present invention. As shown in fig. 7, the difference between the joint unit 208 and the joint unit of fig. 6 is that the sub-electrode 110E1 and/or the sub-electrode 110E2 may be connected to two sub-cantilevers (e.g. the sub-cantilever 212a and the sub-cantilever 212 b), respectively, but is not limited thereto. In other embodiments, the number of sub-cantilevers to which the sub-electrodes are connected may be adjusted as desired. In some embodiments, the sub-cantilever 212a and/or the sub-cantilever 212b may be connected to, for example, but not limited to, a middle portion of a side portion of the sub-electrode E1 (and/or the sub-electrode E2).

In some embodiments, the sub-cantilever 212a and/or the sub-cantilever 212b may include two U-shaped portions 212U, and the openings of the two U-shaped portions 212U may be oriented in different directions, respectively, but not limited thereto.

In some embodiments, the sub-cantilever 212a and the sub-cantilever 212b connected to the same sub-electrode (e.g., the sub-electrode 110E1 or the sub-electrode 110E 2) may be symmetrical to each other with respect to the first direction D1, but is not limited thereto.

Fig. 8 is a schematic top view of a joint unit according to a third embodiment of the present invention. As shown in fig. 8, the difference between the joint unit 308 and the joint unit of the embodiment of fig. 6 or 7 is that the shape of the sub-electrode 310E1 and/or the sub-electrode 310E2 in the top view VD may be, for example, comb-shaped. Specifically, the sub-electrode 310E1 and/or the sub-electrode 310E2 may have a plurality of sub-portions SP and connection portions CP1, respectively. In some embodiments, in the sub-electrode 310E1 and/or the sub-electrode 310E2, the connection portion CP1 is connected with a plurality of sub-portions SP, for example, to form a comb shape. In some embodiments, the sub-portions SP of the sub-electrode 310E1 and the sub-portions SP of the sub-electrode 310E2 may be alternately or alternatively (alternatively) arranged along the first direction D1, so that an electric field may be formed between the sub-portions SP of the sub-electrode 310E1 and the sub-portions SP of the sub-electrode 310E2 to enhance the adsorption force of the electrode 310. In some embodiments, the sub-cantilever 312a and the sub-cantilever 312b that connect the same sub-electrode (e.g., sub-electrode 310E1 or sub-electrode 310E 2) may be symmetrical to each other with respect to the sub-electrode (e.g., sub-electrode 310E1 or sub-electrode 310E 2). In some embodiments, the sub-cantilever 312a of the connector electrode 310E1 and the sub-cantilever 312a of the connector electrode 310E2 may be symmetrical to each other. In some embodiments, the sub-cantilever 312b of the connector electrode 310E1 and the sub-cantilever 312b of the connector electrode 310E2 may be symmetrical to each other.

Fig. 9 is a schematic top view of a joint unit according to a fourth embodiment of the present invention. As shown in fig. 9, the difference between the joint unit 408 and the joint unit of the first embodiment is that the cantilever 412 may include four sub-cantilevers (e.g. sub-cantilever 412a, sub-cantilever 412b, sub-cantilever 412c and sub-cantilever 412 d) respectively connected to four sides of the electrode 110, but is not limited thereto.

In some embodiments, the shape of sub-cantilever 412a, sub-cantilever 412b, sub-cantilever 412c, and/or sub-cantilever 412d may be, for example, U-shaped (ㄩ -shaped) or L-shaped in the top view direction VD. In some embodiments, the openings of sub-cantilever 412a, sub-cantilever 412b, sub-cantilever 412c, and/or sub-cantilever 412d may be, for example, oriented toward electrode 110. In some embodiments, at least one end of sub-cantilever 412a, sub-cantilever 412b, sub-cantilever 412c, and/or sub-cantilever 412d may be connected to electrode 110. For example, one end of the sub-cantilever 412a may be connected to the sub-electrode 110E1, while the other end is spaced apart from the sub-electrode 110E1. One end of the sub-cantilever 412b may be connected to the sub-electrode 110E2, and the other end is spaced apart from the sub-electrode 110E2. In some embodiments, both ends of the sub-cantilever 412c may be connected to the sub-electrode 110E1. In some embodiments, both ends of the sub-cantilever 412d may be connected to the sub-electrode 110E2.

Fig. 10 is a schematic top view of a joint unit according to a fifth embodiment of the present invention. As shown in fig. 10, the tab unit 508 is different from the tab unit of the above embodiment in that the sub-cantilevers 512a and 512b connected to the sub-electrodes 110E1 and 110E2, respectively, may include a plurality of U-shaped portions 512U, and the openings of the U-shaped portions 512U face left and right, respectively. In some embodiments, the U-shaped portions 512U of the sub-cantilevers 512a and/or 512b may be connected, for example, to form a serpentine shape, and to connect the corresponding sub-electrode 110E1 and/or sub-electrode 110E2 at one end. In some embodiments, multiple sub-cantilevers may be connected to different corners of the electrode as desired. In some embodiments (not shown), different sub-cantilevers may be disposed on opposite sides of the electrode, respectively, for example, but not limited thereto. In some embodiments (not shown), different sub-cantilevers may be disposed, for example, on adjacent sides of the electrode, respectively.

In summary, the transfer joint of the present invention has the bent sub-cantilever, so that the electrode supported by the cantilever can not only move in the vertical direction, but also have a rotational degree of freedom, thereby improving the degree of freedom of the contact between the pick-up surface of the corresponding electrode and the micro-device. Therefore, when the surfaces of different microelements are different in height or are provided with inclined surfaces, the pick-up surface of the transfer joint can be matched with the surface of the corresponding microelement, so that the contact area with the corresponding microelement is increased, the pick-up success rate is increased, or the damage to the microelement is reduced. In addition, the invention can increase the length of the corresponding side edges (namely the length of the fringe electric field area) of the sub-electrodes by patterning the electrodes, so that when a voltage difference is applied between the sub-electrodes, the adsorption force provided by the electrodes can be improved, and the pick-up defect or omission can be reduced.

The above description is only an example of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method of making an electronic device, comprising the steps of:

providing a plurality of light emitting elements on a first substrate; and

transferring at least one of the plurality of light emitting elements from the first substrate to a second substrate through a transfer joint;

wherein the transfer joint comprises an electrode, a cantilever, and a dielectric layer, the cantilever supports the electrode, and the cantilever has a U-shaped part,

wherein the electrode comprises a first sub-electrode and a second sub-electrode,

wherein the first sub-electrode and the second sub-electrode have an upper surface facing the at least one of the plurality of light emitting elements and picking up the at least one of the plurality of light emitting elements by the electrode, respectively, and a lower surface opposite to the upper surface, respectively, and the dielectric layer contacts the upper surface and the lower surface of the first sub-electrode and the second sub-electrode, respectively, and a portion of the dielectric layer contacting the first sub-electrode and another portion of the dielectric layer contacting the second sub-electrode are not in contact with each other.

2. The method of manufacturing an electronic device according to claim 1, wherein the cantilever further has another U-shaped portion.

3. The method of making an electronic device of claim 1, wherein the first sub-electrode and the second sub-electrode are staggered.

4. A method of fabricating an electronic device according to claim 3, wherein the cantilever comprises a first sub-cantilever and a second sub-cantilever, the first sub-cantilever supporting the first sub-electrode and the second sub-cantilever supporting the second sub-electrode.

5. The method of claim 1, wherein the at least one of the plurality of light emitting elements includes a conductive pattern for contacting the transfer connector.

6. A method of making an electronic device, comprising the steps of:

providing a plurality of light emitting elements on a first substrate; and

wherein the transfer joint comprises an electrode, a cantilever and a dielectric layer, the cantilever supports the electrode, the electrode comprises a first sub-electrode and a second sub-electrode, the first sub-electrode and the second sub-electrode are staggered,