CN109192719B

Movatterモバイル変換

Info

Publication number: CN109192719B
Application number: CN201811034385.8A
Authority: CN
Inventors: 奚鹏博; 曹梓毅; 林振祺
Original assignee: AU Optronics Corp
Current assignee: AUO Corp
Priority date: 2018-06-21
Filing date: 2018-09-05
Publication date: 2020-06-02
Anticipated expiration: 2038-09-05
Also published as: TW202001387A; CN109192719A; TWI684053B

Abstract

Translated fromChinese

一种显示装置及其制造方法，显示装置包括基板与微型发光元件。基板具有多个子区域，其中子区域中的至少一者包括驱动电路、开关电路、绝缘层、至少二第一电极、至少二第二电极与粘着层。绝缘层具有突起部且设置于基板上。第一电极分离设置于绝缘层的突起部上且分别连接于驱动电路与开关电路。第二电极分离设置于绝缘层上，且第二电极中的一者电性连接于驱动电路。粘着层设置于绝缘层上且覆盖第一电极的一部分并暴露第一电极的另一部分。微型发光元件设置于粘着层上且对应于绝缘层的突起部，其中微型发光元件的底面接触第一电极的另一部分。

A display device and a manufacturing method thereof. The display device includes a substrate and a micro-light-emitting element. The substrate has a plurality of sub-regions, wherein at least one of the sub-regions includes a driving circuit, a switching circuit, an insulating layer, at least two first electrodes, at least two second electrodes and an adhesive layer. The insulating layer has protrusions and is disposed on the substrate. The first electrodes are separately arranged on the protrusions of the insulating layer and are respectively connected to the driving circuit and the switching circuit. The second electrodes are separately provided on the insulating layer, and one of the second electrodes is electrically connected to the driving circuit. The adhesive layer is disposed on the insulating layer and covers a portion of the first electrode and exposes another portion of the first electrode. The micro-light-emitting element is disposed on the adhesive layer and corresponds to the protruding portion of the insulating layer, wherein the bottom surface of the micro-light-emitting element contacts another part of the first electrode.

Description

Display device and method for manufacturing the same

Technical Field

The present invention relates to a display device and a method for manufacturing the same, and more particularly, to a display device having a micro light emitting device and a method for manufacturing the same.

Background

Various types of display fields are currently emerging, such as: a liquid crystal display panel, a self-luminous display panel, and the like. However, in the self-luminous display panel, if the self-luminous element is transferred onto the receiving plate by the transposing process, the problems of poor alignment and incapability of performing electrical and/or optical measurement on the self-luminous element after transposing are easily caused, so that the quality and process yield of the self-luminous display panel are poor.

Disclosure of Invention

The invention provides a display device and a manufacturing method thereof, which can improve the problem of poor alignment, and further can perform electrical and/or optical measurement on a post-rotation element, so that the display device has good quality and process yield.

An embodiment of the invention provides a display device, which includes a substrate, at least one adhesive layer, at least one micro light emitting device, at least one signal line, at least one readout line, at least one control line, and at least two power supply lines. The substrate has a plurality of sub-regions, wherein at least one of the sub-regions comprises at least one driving circuit, at least one switching circuit, at least one insulating layer, at least two first electrodes and at least two second electrodes. The driving circuit is arranged on the substrate. The switch circuit is arranged on the substrate and is separated from the driving circuit. The insulating layer is arranged on the substrate and covers a part of the driving circuit and a part of the switch circuit, wherein the insulating layer is provided with at least one protruding part. The first electrode is separately arranged on the protruding part of the insulating layer and is respectively connected with the driving circuit and the switch circuit. The second electrodes are separately arranged on the insulating layer, and one of the second electrodes is electrically connected to the driving circuit. The adhesive layer is arranged on the insulating layer and covers one part of each first electrode, one part of each second electrode, the driving circuit and the switching circuit, and the adhesive layer respectively exposes the other part of each first electrode and the other part of each second electrode. The micro light-emitting element is arranged on the adhesive layer and corresponds to the protruding part of the insulating layer, wherein the bottom surface of the micro light-emitting element is contacted with the other part of each first electrode, the micro light-emitting element comprises at least two semiconductor layers, and the semiconductor layers are respectively and electrically connected with the other part of the second electrode. The signal line is arranged on the substrate and electrically connected to the driving circuit. The reading line and the control line are separately arranged on the substrate and electrically connected with the switch circuit. The power supply lines are separately arranged on the substrate and are respectively electrically connected with the micro light-emitting element and the driving circuit, wherein the power supply lines respectively have different electric potentials when electrified.

An embodiment of the invention provides a method for manufacturing a display device, which includes the following steps. A display device as described above is provided. Two separately disposed third electrodes are formed on the corresponding semiconductor layers, wherein one of the third electrodes is disposed on one of the semiconductor layers that is not in contact with the first electrode. Enabling the driving circuit and the switch circuit to electrically connect the first electrodes with each other through the micro light-emitting device, thereby determining whether the micro light-emitting device is successfully transferred onto the first electrode.

In view of the above, in the display device and the manufacturing method thereof according to the above embodiments of the present invention, the micro light emitting elements are disposed on the adhesive layer and correspond to the protruding portions of the insulating layer, wherein the bottom surfaces of the micro light emitting elements contact another portion of each of the first electrodes. Therefore, when the driving circuit and the switch circuit are enabled, the first electrodes can be electrically connected with each other through the micro light-emitting element, so that whether the micro light-emitting element is successfully transferred onto the first electrode is determined, the problem of poor alignment is further solved, furthermore, the electrical and/or optical measurement can be carried out on the element after the rotation, and the display device has good quality and process yield.

The invention is described in detail below with reference to the drawings and specific examples, but the invention is not limited thereto.

Drawings

Fig. 1 is a schematic cross-sectional view of a display device according to an embodiment of the invention.

Fig. 2A and 2B are circuit diagrams of a display device according to an embodiment of the invention.

Fig. 3A and 3B are circuit diagrams of a display device according to another embodiment of the invention.

Fig. 4A to 4C are schematic cross-sectional views illustrating a method of manufacturing a display device according to an embodiment of the invention.

Wherein, the reference numbers:

100: display device

S: substrate

ADL: adhesive layer

MLED: micro light-emitting device

SL: signal line

GL: scanning line

DL: data line

RL: reading line

CL: control wire

SR: sub-area

DC: driving circuit

SC: switching circuit

And SE: switching element

IL1, IL 2: insulating layer

E1: a first electrode

E2: second electrode

E3: third electrode

T1, T2: active element

C: capacitor with a capacitor element

PP: protrusion part

SE1, SE 2: semiconductor layer

AL: active layer

CE: connecting electrode

G1, G2, SG: control terminal

S1, S2, SS: first end

D1, D2, SD: second end

C1, C2, C3, C4: contact window

A. B: endpoint

VSS, VDD: power supply line

Detailed Description

The invention will be described in detail with reference to the following drawings, which are provided for illustration purposes and the like:

the present invention will now be described more fully hereinafter with reference to the accompanying drawings of the embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The thickness of layers and regions in the drawings may be exaggerated for clarity. The same or similar reference numbers refer to the same or similar elements, and the following paragraphs will not be repeated. In addition, directional terms mentioned in the embodiments, for example: up, down, left, right, front or rear, etc., are referred to only in the direction of the attached drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

In the drawings, the thickness of layers, films, panels, regions, etc. have been exaggerated for clarity. Like reference numerals refer to like elements throughout the specification. It will 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 can be directly on or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connections. However, "electrically connected" or "coupled" may mean that there are additional elements between the two elements.

As used herein, "about", "approximately" or "substantially" includes the stated value and the average value within an acceptable range of deviation of the specified value as determined by one of ordinary skill in the art, taking into account the measurement in question and the specified amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" may mean within one or more standard deviations of the stated value, or within ± 30%, ± 20%, ± 10%, ± 5%. Further, as used herein, "about", "approximately" or "substantially" may be selected based on optical properties, etch properties, or other properties, with a more acceptable range of deviation or standard deviation, and not all properties may be applied with one standard deviation.

Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present invention and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to cross-sectional views that are schematic illustrations of idealized embodiments. Thus, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, the embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region shown or described as flat may generally have rough and/or nonlinear features. Further, the acute angles shown may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the claims.

Fig. 1 is a schematic cross-sectional view of a display device according to an embodiment of the invention. Fig. 2A and 2B are circuit diagrams of a display device according to an embodiment of the invention. Fig. 3A and 3B are circuit diagrams of a display device according to another embodiment of the invention.

Referring to fig. 1, fig. 2A and fig. 2B, thedisplay device 100 may include a substrate S, at least one adhesive layer ADL, at least one micro light emitting device MLED, at least one signal line SL (e.g., a scan line GL or a data line DL), at least one readout line RL, at least one control line CL, and at least two power supply lines VSS and VDD.

In the present embodiment, the substrate S has a plurality of sub regions SR. In the present embodiment, the sub-region SR in fig. 1 is taken as an example, but not limited thereto. In other embodiments, there may be more than one sub-region SR. At least one of the sub-regions SR may include at least one driving circuit DC, at least one switching circuit SC, at least one insulating layer IL1, at least two first electrodes E1, and at least two second electrodes E2.

The driving circuit DC may be disposed on the substrate S. The driving circuit DC of the present embodiment is illustrated by including two active devices T1 and T2 and a capacitor C (which may be represented as 2T1C) (as shown in fig. 2B), but the invention is not limited thereto. In other embodiments, the driving circuit DC may also include three active elements and one or two capacitors C (which may be denoted as 3T1C/2C), four active elements and one or two capacitors C (which may be denoted as 4T1C/2C), five active elements and one or two capacitors C (which may be denoted as 5T1C/2C), six active elements and one or two capacitors C (which may be denoted as 6T1C/2C), or other suitable wiring configurations. In some embodiments, at least one of the active elements T1, T2 may employ a Thin Film Transistor (TFT), such as a bottom gate transistor, a top gate transistor, a solid-state transistor, or other suitable transistor. The grid of the bottom grid transistor is positioned below the semiconductor layer, the grid of the top grid transistor is positioned above the semiconductor layer, and the channel of the semiconductor layer of the three-dimensional transistor is not extended and positioned on a plane. The semiconductor layer may be a single layer or a multilayer structure, and its material includes amorphous silicon, microcrystalline silicon, nanocrystalline silicon, polycrystalline silicon, single crystal silicon, an organic semiconductor material, an oxide semiconductor material, carbon nanotubes/rods, perovskite, or other suitable materials or combinations of the foregoing.

The switch circuit SC may be disposed on the substrate S, and the switch circuit SC is separated from the driving circuit DC. The switch circuit SC may include at least one switch element SE, wherein the switch circuit SC of the present embodiment is described by including one switch element SE (as shown in fig. 1), but the present invention is not limited thereto. In other embodiments, the switching circuit SC may also include a plurality of switching elements SE or other elements with which a suitable number of switching elements SE cooperate. In the present embodiment, the switching element SE may be an active element (e.g., a thin film transistor), a diode, or other suitable elements. The switching element SE may be of the active element type and/or semiconductor material, and may be substantially the same or different.

The insulating layer IL1 may be disposed on the substrate S and cover a portion of the driving circuit DC and a portion of the switching circuit SC, wherein the insulating layer IL1 may have at least one protrusion PP. The insulating layer IL1 may be a single layer or a multi-layer structure, and its material may be an inorganic dielectric material, an organic dielectric material, or other suitable materials, or a combination of the foregoing. The inorganic dielectric material may be silicon oxide, silicon nitride, silicon oxynitride, or other suitable material, or a combination of at least two of the foregoing; the organic dielectric material may be a photoresist, a polyimide-based resin, an epoxy-based resin, an acryl-based resin, or other suitable materials, or a combination of at least two of the foregoing. In the embodiment, the height of the protrusion PP is about 2 μm, for example, but the invention is not limited thereto. In other embodiments, the height of the protrusion PP can be adjusted according to the design, but it should be noted that the height of the protrusion PP is not too high, so as to avoid that the thickness of the adhesive layer ADL mentioned below is too thick to be beneficial for the slim design of the display panel.

The first electrode E1 may be separately disposed on the protrusion PP of the insulating layer IL1 and connected to the driving circuit DC and the switching circuit SC, respectively. In the present embodiment, the first electrode E1 can be connected to the driving circuit DC and the switch circuit SC through the contact windows C1 and C2 respectively disposed in the insulating layer IL1, but is not limited thereto. The first electrode E1 may be a single layer or a multilayer structure, and its material may be a non-transparent conductive material, a transparent or semi-transparent conductive material, an organic conductive material, or other suitable conductive material, or a combination of at least two of the foregoing. The non-transparent conductive material comprises a metal, an alloy, or other suitable material, an oxide of the foregoing, a nitride of the foregoing, an oxynitride of the foregoing, or a combination of at least two of the foregoing. Transparent or translucent conductive materials include indium tin oxide, indium zinc oxide, indium gallium oxide, metals or alloys having a thickness of less than 60 angstroms, carbon nanotubes/rods, or other suitable materials, or combinations of at least two of the foregoing. The organic conductive material comprises particles of organic material mixed with non-transparent conductive material and/or transparent or semi-transparent conductive material, intrinsically conductive polymer (or conjugated conductive polymer), polymer coupled metal, or other suitable material, or a combination of at least two of the foregoing.

The second electrode E2 may be separately disposed on the insulating layer IL1, and one of the second electrodes E2 is electrically connected to the driving circuit DC. In the present embodiment, one of the second electrodes E2 may be electrically connected to the driving circuit DC through a contact C3 disposed in the insulating layer IL1, but is not limited thereto. The second electrode E2 can be a single-layer or multi-layer structure, and the material can be selected from the materials described above for the first electrode E1, and they can be substantially the same or different. In some embodiments, the other of the second electrodes E2 is electrically connected to the power supply line VDD, for example: the other of the second electrodes E2 may be electrically connected to the power supply line VDD through a contact C4 disposed in the insulating layer IL1, but is not limited thereto.

The adhesion layer ADL may be disposed on the insulating layer IL1 and cover a portion of each first electrode E1, a portion of each second electrode E2, the driving circuit DC and the switching circuit SC, and the adhesion layer ADL exposes another portion of each first electrode E1 and another portion of each second electrode E2, respectively. The adhesion layer ADL itself preferably has a substantially insulating effect (such as, but not limited to, a resistivity greater than 108 ohm cm), and may be a single layer or a multi-layer structure, and the material thereof may be an insulating material, such as acrylic resin (acryl resin), epoxy resin (epoxy), glass cement (glass frit), or other suitable materials, or a combination of the foregoing materials.

The micro light emitting elements MLED are disposed on the adhesive layer ADL and substantially correspond to the protrusions PP of the insulating layer IL1, wherein the bottom surfaces of the micro light emitting elements MLED contact another portion of each first electrode E1 (e.g., the portion exposed by the adhesive layer ADL), and the micro light emitting elements MLED may include at least two semiconductor layers SE1 and SE2, wherein the semiconductor layers SE1 and SE2 may be respectively electrically connected to another portion of the second electrode E2. Wherein, the size of the micro light-emitting element is less than 100 microns and more than 0 micron. Preferably, the size of the micro light emitting device is less than 50 microns and greater than 0 micron. When the driving circuit DC and the switching circuit SC are enabled, the first electrodes E1 can be electrically connected to each other through the micro light emitting device MLED, so as to determine whether the micro light emitting device MLED is successfully transferred to the first electrode E1, thereby improving the problem of poor alignment, and providing the display device with good quality and process yield. For example, when the micro light emitting device MLED is successfully transferred onto the first electrode E1, the separately disposed first electrodes E1 may be electrically connected to each other through the micro light emitting device MLED; when the micro light emitting device MLED is not successfully transferred onto the first electrode E1, the first electrodes E1, which are separately disposed, cannot be electrically connected to each other through the micro light emitting device MLED. Therefore, the foregoing process can be considered as an electrical measurement of whether the micro light emitting device MLED is connected to the first electrode E1 or not.

In addition, before forming a connection line (e.g., the connection electrode CE shown in fig. 1) for electrically connecting the second electrode E2, the first electrode E1 can be used to confirm whether the transfer of the micro light-emitting device MLED is successful, so that the process yield can be accurately determined after a large amount of transfer processes, and the micro light-emitting device MLED which is not successfully transferred can be repaired, thereby improving the quality and process yield of the display device. In some embodiments, the method for repairing the micro light emitting device MLED that has not been successfully transferred is, for example, to remove the micro light emitting device MLED that has not been successfully transferred, and then to transfer a new micro light emitting device MLED to replace the micro light emitting device MLED that has not been successfully transferred, but the invention is not limited thereto. In addition, since it is not necessary to confirm whether or not the transfer of the micro light-emitting device MLED onto the substrate S is successful by lighting the micro light-emitting device MLED, even if the micro light-emitting device MLED is not formed with the third electrode E3, which will be described later, it is possible to confirm whether or not the transfer of the micro light-emitting device MLED is successful by the first electrode E1.

In some embodiments, there is no adhesive layer ADL between the bottom surface of the micro light emitting device MLED and the first electrode E1 on the protrusion PP, so that the first electrode E1 and the micro light emitting device MLED have good electrical contact to avoid the occurrence of erroneous interpretation.

In some embodiments, the contact area of the micro light emitting elements MLED and the adhesive layer ADL may be larger than the contact area of the micro light emitting elements MLED and the first electrode E1, such that the micro light emitting elements MLED can be stably fixed on the adhesive layer ADL, but is not limited thereto. In other embodiments, the contact area between the micro light emitting elements MLED and the adhesive layer ADL may be larger than the forward projection area of the protrusion PP of the insulating layer IL1 on the micro light emitting elements MLED, so that the micro light emitting elements MLED can be more stably fixed on the adhesive layer ADL, but not limited thereto.

In some embodiments, the size of the micro light emitting device MLED may be greater than or substantially equal to 100 μm2 and less than or substantially equal to 10000 μm2, but is not limited thereto. In other embodiments, the size of the micro light emitting device MLED may be greater than or substantially equal to 100 μm2 and less than or substantially equal to 400 μm2, but is not limited thereto.

In some embodiments, the semiconductor layer SE1 and the semiconductor layer SE2 may have opposite electrical properties. For example, the semiconductor layer SE1 is one of a P-type doped semiconductor layer and an N-type doped semiconductor layer; the semiconductor layer SE2 is the other of the P-type doped semiconductor layer and the N-type doped semiconductor layer. The P-type doped semiconductor layer may be a single layer or a multi-layer structure, and the material thereof is, for example, P-type gallium nitride (P-GaN), P-type gallium arsenide (GaAs), P-type silicon carbide (SiC), P-type gallium phosphide (GaP), P-type zinc selenide (ZnSe), P-type zinc sulfide (ZnS), P-type organic semiconductor material, or other suitable material. The N-type doped semiconductor layer may be a single layer or a multi-layer structure, and a material thereof is, for example, N-type gallium nitride (N-GaN), N-type gallium arsenide (GaAs), N-type silicon carbide (SiC), N-type gallium phosphide (GaP), N-type zinc selenide (ZnSe), N-type zinc sulfide (ZnS), N-type organic semiconductor material, or other suitable material.

In the present embodiment, the micro light emitting element MLED may optionally include an active layer AL disposed between the semiconductor layer SE1 and the semiconductor layer SE2, but is not limited thereto. In some embodiments, the active layer AL may be a Multiple Quantum Well (MQW) layer formed by alternately stacking a plurality of well layers (well layers) and barrier layers (barrier layers), but the invention is not limited thereto. Wherein the barrier layer can restrict electrons and holes from combining in the well layer to emit photons in case the well layer has a lower energy gap relative to the barrier layer. In other embodiments, the active layer AL may also have a structure of a junction region formed by the intersection of the electron holes of the semiconductor layer SE1 and thesemiconductor layer SE 2. In other embodiments, the active layer AL may also be a Single Quantum Well (SQW), but is not limited thereto. In the present embodiment, the active layer AL may be a multiple quantum well layer, wherein a well layer in the multiple quantum well layer may be an indium gallium nitride (InGaN) layer, and a barrier layer in the multiple quantum well layer may be a gallium nitride (GaN) layer, for example, but is not limited thereto.

In the present embodiment, the micro light emitting device MLED may optionally further include an insulating layer IL2, but is not limited thereto. The insulating layer IL2 may be formed on a portion of the surface and sidewalls of the semiconductor layer SE1, a portion of the surface and sidewalls of the semiconductor layer SE2, and sidewalls of the active layer AL (if optionally present), so as to ensure that electrons and holes are combined in the active layer AL, thereby improving the light emitting efficiency. The insulating layer IL2 may be a single layer or a multi-layer structure, and its material may preferably be an inorganic dielectric material, such as silicon oxide, silicon nitride, silicon oxynitride, other suitable materials, or a combination thereof, but is not limited thereto.

In this embodiment, the semiconductor layer SE1 and the semiconductor layer SE2 do not partially overlap or may be referred to as the semiconductor layer SE1 and the semiconductor layer SE2 partially overlap. In some embodiments, the micro light emitting device MLED may further include two third electrodes E3 separately disposed on the corresponding semiconductor layers SE1 andSE 2. The micro light emitting device MLED of the present embodiment is illustrated by using a horizontal light emitting diode as an example, and the invention is not limited thereto. In other embodiments, the micro light emitting device MLED may also use other suitable light emitting diodes according to the design. The third electrode E3 may be a single-layer or multi-layer structure, and the material thereof may be selected from the aforementioned conductive materials.

In some embodiments, a probe may be used to contact one of the third electrodes E3 to inspect the micro light-emitting device MLED, thereby confirming whether the micro light-emitting device MLED emits light. For example, the probe may contact the third electrode E3 disposed on the semiconductor layer SE2 and drive the micro light emitting element MLED through the first electrode E1 and/or the third electrode E3, thereby optically testing the micro light emitting element MLED. In addition to the electrical tests (e.g., the first electrodes E1 are electrically connected to each other through the micro light-emitting devices MLED), in some embodiments, the optical tests can be used to determine whether the micro light-emitting devices MLED are bright, so as to accurately determine the process yield and improve the quality of the display device.

In some embodiments, after the electrical test, a connection line for electrically connecting the second electrode E2 and the third electrode E3 may be formed, but the invention is not limited thereto. In other embodiments, the electrical test and/or the optical test may be performed after forming the connection line for electrically connecting the second electrode E2 and the third electrode E3. In other embodiments, the electrical test and/or the optical test may be performed before and after the connection line for electrically connecting the second electrode E2 and the third electrode E3 is formed.

In some embodiments, after the electrical test and the optical test, a connection line for electrically connecting the second electrode E2 and the third electrode E3 is formed. In the present embodiment, the connection line may be, for example, a connection electrode CE (as shown in fig. 1) which will be mentioned later.

In some embodiments, another portion of the second electrode E2 (e.g., the portion exposed by the adhesion layer ADL) can be electrically connected to the corresponding semiconductor layers SE1 and SE2 through the third electrode E3. For example, thedisplay device 100 may further include at least two connection electrodes CE, and another portion of the second electrode E2 may be electrically connected to the corresponding semiconductor layers SE1 and SE2 through the connection electrode CE and the third electrode E3, respectively. The connection electrode CE may have a single-layer or multi-layer structure, and the material thereof may be selected from the aforementioned conductive materials.

In the present embodiment, the signal line SL may be disposed on the substrate S and electrically connected to the driving circuit DC. For example, the signal lines SL may include scan lines GL and data lines DL disposed on the substrate S and electrically connected to the driving circuit DC (as shown in fig. 2A), but is not limited thereto. In other embodiments, the signal line SL may also include other required lines, such as: a common electrode line, or other suitable line.

In the present embodiment, the readout line RL and the control line CL are separately disposed on the substrate S and electrically connected to the switch circuit SC. For example, the readout line RL and the control line CL can be separately disposed on the substrate S and respectively connected to the second terminal SD and the control terminal SG of the switching element SE (as shown in fig. 2B).

In the present embodiment, the power supply lines VSS and VDD are separately disposed on the substrate S, wherein the power supply line VDD and the power supply line VSS are electrically connected to the micro light emitting device MLED and the driving circuit DC (as shown in fig. 2B), respectively, and when the power supply line VDD and the power supply line VSS have different potentials, respectively.

Hereinafter, the connection relationship among the driving circuit DC, the switching circuit SC, the signal line SL (e.g., the scanning line GL and the data line DL), the readout line RL, the control line CL, the first electrode E1, the second electrode E2, the third electrode E3, the micro light emitting element MLED, and the power supply lines VSS and VDD will be described by way of example with reference to fig. 1, 2A and 2B, but the present invention is not limited thereto. In other embodiments, the connection relationship between the above elements can be adjusted according to the design.

Referring to fig. 1, fig. 2A and fig. 2B, the driving circuit DC may include an active device T1, an active device T2 and a capacitor C (which may be denoted as 2T1C), and the signal line SL may include at least one scan line GL and at least one data line DL, wherein each of the active devices T1 and T2 includes at least one control terminal G1, G2, at least one first terminal S1, S2 and at least one second terminal D1, D2. For example, the active device T1 may include a control terminal G1, a first terminal S1, and a second terminal D1; the active device T2 may include a control terminal G2, a first terminal S2 and a second terminal D2. In some embodiments, the control line CL and the scan line GL may be electrically connected to the same scan signal source, but the invention is not limited thereto. In other embodiments, the control lines CL and the scan lines GL may be electrically connected to different scan signal sources.

In the present embodiment, the control terminals G1 and G2 of one of the active devices T1 and T2 can be electrically connected to the scan line GL; the first terminal S1 of one of the active devices T1 and T2 may be electrically connected to the data line DL. The control terminals G1 and G2 of the other one of the active devices T1 and T2 may be electrically connected to the second terminals D1 and D2 of the other one of the active devices T1 and T2. For example, the control terminal G1 of the active device T1 may be electrically connected to the scan line GL, and the first terminal S1 of the active device T1 may be electrically connected to the data line DL; the control terminal G2 of the active device T2 may be electrically connected to the second terminal D1 of the active device T1, but is not limited thereto.

In the present embodiment, the first ends S1 and S2 of the other of the active elements T1 and T2 can be electrically connected to one of the third electrodes E3, one of the first electrodes E1, and one of the second electrodes E2 of the micro light emitting device MLED. The second terminals D1 and D2 of the other of the active devices T1 and T2 may be electrically connected to one of the power supply lines VSS and VDD, and one of the third electrodes E3 of the micro light emitting device MLED may be electrically connected to the other of the power supply lines VSS and VDD. For example, the first end S2 of the active device T2 can be electrically connected to the third electrode E3 disposed on the semiconductor layer SE2, the second electrode E2 electrically connected to the third electrode E3 (e.g., the second electrode E2 at the position of [ - ] shown in FIG. 1), and the first electrode E1 corresponding to the terminal A shown in FIG. 2B (e.g., [ A ] shown in FIG. 1), wherein the third electrode E3 disposed on the semiconductor layer SE2 is electrically connected to the power supply line VDD (e.g., [ + ] shown in FIG. 1); the second end D2 of the active device T2 may be electrically connected to the power supply line VSS (e.g., "-" shown in FIG. 1).

In this embodiment, the switch circuit SC may include a switch element SE, and the switch element SE may include at least one control terminal SG, at least one first terminal SS, and at least one second terminal SD. For example, as shown in fig. 2B, the switching element SE may include a control terminal SG, a first terminal SS and a second terminal SD. The first terminal SS of the switching element SE may be electrically connected to the other of the first electrodes E1; the second end SD of the switching element SE is electrically connected to the readout line RL. For example, the first terminal SS of the switching element SE can be electrically connected to the first electrode E1 corresponding to the terminal B shown in FIG. 2B (e.g.: at [ B ] shown in FIG. 1); the second end SD of the switching element SE is electrically connected to the readout line RL.

Based on the above, since the micro light emitting elements MLED are disposed on the adhesive layer ADL and correspond to the protrusion portions PP of the insulating layer IL1, and the bottom surfaces of the micro light emitting elements MLED contact the first electrode E1. In this way, when the driving circuit DC and the switching circuit SC are enabled, the first electrodes E1 can be electrically connected to each other through the micro light emitting device MLED, so as to confirm whether the micro light emitting device MLED is successfully transferred, thereby improving the problem of poor alignment, and thedisplay device 100 has good quality and process yield.

Fig. 3A and 3B are circuit diagrams of a display device according to another embodiment of the invention, wherein the circuit diagrams shown in fig. 3A and 3B are similar to the circuit diagrams shown in fig. 2A and 2B, except that the active device T2 shown in fig. 2A and 2B is a P-type TFT, and the active device T2 shown in fig. 3A and 3B is an N-type TFT, so the same or similar components are denoted by the same or similar reference numerals, and the connection relationship, materials and processes of the remaining components have been described in detail in the foregoing, and thus will not be repeated herein.

Referring to fig. 3A and 3B, in this embodiment, the first end S2 of the active device T2 can be electrically connected to the third electrode E3 disposed on the semiconductor layer SE1, the second electrode E2 electrically connected to the third electrode E3 (e.g., [ - ] the second electrode E2 shown in fig. 1), and the first electrode E1 corresponding to the terminal a shown in fig. 3B, wherein the third electrode E3 disposed on the semiconductor layer SE1 is electrically connected to the power supply line VDD; the second end D2 of the active device T2 is electrically connected to the power supply line VSS. In other embodiments, one of the active devices T1, T2 may be an N-type TFT, and the other of the active devices T1, T2 may be a P-type TFT. In the foregoing embodiments, the switching element SE is determined to be an N-type TFT or a P-type TFT according to the polarity types of the active elements T1 and T2 of the embodiments, but is not limited thereto. In other embodiments, the switching element SE may also select the appropriate TFT polarity type according to design requirements.

Hereinafter, the method of manufacturing thedisplay device 100 shown in fig. 1 will be exemplified by fig. 4A to 4C, but is not limited thereto. In other embodiments, the adjustment may be made according to design. It should be noted that the same or similar elements have the same or similar reference numerals, and the connection, materials, functions and processes thereof have been described in detail in the foregoing, and thus are not repeated herein.

First, referring to fig. 4A, a driving circuit DC, a switching circuit SC, and power supply lines VSS and VDD are formed on a substrate S. Next, an insulating layer IL1 covering the driving circuit DC, the switching circuit SC, and the power supply lines VSS and VDD is formed on the substrate S, wherein the insulating layer IL1 has a protrusion PP. In some embodiments, the insulating layer IL1 may be formed by forming an insulating material layer covering the driving circuit DC, the switching circuit SC, and the power supply lines VSS and VDD on the substrate S, and then performing a patterning process on the insulating material layer to form the insulating layer IL1 having the protrusion PP. The patterning process is, for example, a photolithography process and/or an etching process, but the present invention is not limited thereto.

Then, a first electrode E1 and a second electrode E2 are formed over the insulating layer IL1, wherein the first electrode E1 is formed over and separated from the protrusion PP of the insulatinglayer IL 1; and the second electrode E2 is formed on the insulating layer IL1 and separated from each other. In the present embodiment, the first electrode E1 can be electrically connected to the driving circuit DC and the switch circuit SC through the contact windows C1 and C2, respectively; the second electrode E2 is electrically connected to the driving circuit DC and the power supply lines VSS and VDD through the contact windows C3 and C4, respectively. The first electrode E1, the second electrode E2, and the contact windows C1 to C4 may be formed by forming the contact windows C1 to C4 in the insulating layer IL1 in advance. Then, a conductive material is formed on the insulating layer IL1 and filled into the contact windows C1-C4. Then, a patterning process is performed on the conductive material on the insulating layer IL1 to form a first electrode E1, a second electrode E2, and contact windows C1 to C4. In the embodiment, the first electrode E1 and the second electrode E2 may be formed by the same patterned conductive layer, but the invention is not limited thereto.

Next, referring to fig. 4B, a portion covering each first electrode E1, each second electrode E2, the driving circuit DC and the switching circuit SC is formed on the insulating layer IL1, and the adhesion layer ADL exposes another portion of each first electrode E1.

Then, referring to fig. 4C, the micro light emitting device MLED is transferred onto the adhesive layer ADL and corresponds to the protrusion PP of the insulating layer IL1 to provide a display device. In the present embodiment, thedisplay device 100 has not formed the third electrode E3 or the connection line for connecting the second electrode E2 and the third electrode E3 on the micro light emitting element MLED, but the invention is not limited thereto. In other embodiments, the third electrode E3 may be formed on the corresponding semiconductor layers SE1 and SE2 before the micro light-emitting device MLED is transferred to the adhesive layer ADL, so that the process is simple and the influence of the process on other components on the substrate S can be avoided. In some embodiments, micro-mechanical devices (e.g., vacuum suction heads or other suitable devices) or stamp transfer methods may be used to transfer the micro-light emitting elements MLEDs. In some embodiments, the following steps may be used to form and transfer the micro light-emitting elements MLED onto the adhesive layer ADL. First, the micro light emitting devices MLED can be epitaxially formed on a growth substrate (e.g., a sapphire substrate, a silicon substrate, or other suitable substrate), and then the micro light emitting devices MLED are transferred onto the adhesion layer ADL by using a micro pick-up array.

The bottom surface of the micro light emitting element MLED may contact another portion of each of the first electrodes E1, wherein the micro light emitting element MLED may include semiconductor layers SE1, SE2, and the semiconductor layers SE1 and SE2 are electrically connected to the second electrodes E2, respectively. In the present embodiment, the micro light emitting element MLED may further include an active layer AL formed between the semiconductor layer SE1 and thesemiconductor layer SE 2.

Then, referring to fig. 4C, the micro light-emitting device MLED is tested to determine whether the micro light-emitting device MLED is successfully transferred to the first electrode E1. In the present embodiment, the driving circuit DC and the switching circuit SC are enabled, so that the first electrodes E1 are electrically connected to each other through the micro light emitting device MLED, thereby confirming whether the micro light emitting device MLED is successfully transferred.

Then, two separately disposed third electrodes E3 are formed on the corresponding semiconductor layers SE1, SE2, wherein one of the third electrodes E3 is disposed on one of the semiconductor layers SE1, SE2 which is not in contact with the first electrode E1. In some embodiments, after the third electrode E3 is formed, the micro light emitting device MLED may be electrically tested as described above. In some embodiments, a probe may be provided to contact one of the third electrodes E3 to inspect the micro light-emitting device MLED, thereby confirming whether the micro light-emitting device MLED emits light (optical detection).

Then, a connecting electrode CE is formed on a portion of the adhesive layer ADL and a portion of the micro light emitting device MLED to form thedisplay device 100 shown in fig. 1. In the embodiment, the adhesive layer ADL covers a portion of the second electrode E2 and exposes another portion of the second electrode E2, wherein the another portion of the second electrode E2 can be electrically connected to the semiconductor layer SE1 and the semiconductor layer SE2, respectively. For example, another portion of the second electrode E2 may be electrically connected to the corresponding semiconductor layers SE1 and SE2 through the connecting electrode CE and the third electrode E3, respectively. In the display device completed as described above, the current flows through the semiconductor layers SE1 and SE2 of the micro light-emitting element MLED and is easily transmitted through the connection path between the connection electrode CE and the third electrode E3.

In summary, in the display device and the manufacturing method thereof according to the above embodiments, the micro light emitting elements are disposed on the adhesive layer and correspond to the protruding portions of the insulating layer, and the bottom surfaces of the micro light emitting elements contact another portion of each first electrode. Therefore, when the driving circuit and the switch circuit are enabled, the first electrodes can be electrically connected with each other through the micro light-emitting element, so that whether the micro light-emitting element is successfully transferred or not is confirmed, the problem of poor alignment is further solved, and furthermore, the electrical and/or optical measurement can be carried out on the element after the rotation, so that the display device has good quality and process yield.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.