TWI757141B - Display device and method for manufacturing the same - Google Patents

Abstract

A display device includes a circuit substrate and a light-emitting element. The light-emitting element is electrically connected to the circuit substrate and has an opening. The opening is located at one side of the light-emitting element adjacent to or away from the circuit substrate. A method for manufacturing a display device is also provided.

Description

Display device and method of manufacturing the same

The present invention relates to a display device and a manufacturing method thereof, and in particular, to a miniature light emitting diode display device and a manufacturing method thereof.

Due to the extremely small size of the micro-LEDs, the current method of manufacturing the micro-LED display devices is to use the Mass Transfer technology, that is, to use the micro-electromechanical array technology to pick and place the micro-LED grains. In order to transport a large number of micro light-emitting diode crystal grains to the driving substrate with pixel circuit at one time. At present, various new mass transfer technologies have been published, among which laser transfer technology is favored due to its efficiency advantages.

The laser transfer technology realizes the separation of the die by the light-matter reaction between the laser and the connecting material, and the impact force or driving force generated at the same time can dislodge the die and push the die to transfer to the target substrate. However, when the light-matter reaction occurs, due to the uneven distribution of the impact force or the driving force, the direction of detachment of the crystal grains is not fixed, so that the crystal grains cannot be accurately transferred to the target substrate.

The present invention provides a display device with accurately transferred light-emitting elements.

The present invention provides a method of manufacturing a display device, which can accurately transfer light-emitting elements.

An embodiment of the present invention provides a display device, including: a circuit substrate; and a light-emitting element, which is electrically connected to the circuit substrate and has an opening, wherein the opening is located on a side of the light-emitting element adjacent to or away from the circuit substrate.

In an embodiment of the present invention, the orthographic projection of the opening on the circuit board overlaps the orthographic projection of the center of gravity of the light-emitting element on the circuit board.

In an embodiment of the present invention, the above-mentioned light-emitting element includes two electrodes, and the opening is at least partially located outside the two electrodes.

In an embodiment of the present invention, the above-mentioned light-emitting element includes two electrodes, and the opening is located between the two electrodes.

In an embodiment of the present invention, the above-mentioned opening is located on the light-emitting surface or the non-light-emitting surface of the light-emitting element.

In an embodiment of the present invention, the above-mentioned opening penetrates the light-emitting element.

In an embodiment of the present invention, the cross section of the above-mentioned opening has a normal trapezoid or an inverted trapezoid.

In an embodiment of the present invention, the above-mentioned opening has lateral blind holes.

In an embodiment of the present invention, the aperture of the above-mentioned opening is less than 1/3 of the width of the light-emitting element.

In an embodiment of the present invention, the diameter of the above-mentioned opening is less than or equal to 3 μm.

In an embodiment of the present invention, the depth of the above-mentioned opening is greater than or equal to 1 μm.

In an embodiment of the present invention, the above-mentioned circuit substrate includes an active element array.

In an embodiment of the present invention, the above-mentioned display device further includes a connecting column, and the connecting column is at least partially located in the opening.

In an embodiment of the present invention, the above-mentioned connecting column includes a plurality of layers, and the plurality of layers have different concentrations, light absorption rates or light transmittances.

One embodiment of the present invention provides a method for manufacturing a display device, which includes: providing a light-emitting element, the light-emitting element is located on a first carrier; forming an opening on a surface of the light-emitting element away from the first carrier; forming a connection layer on the surface, and the connection layer is filled in the opening; the second carrier is fixed on the connection layer, so that the light-emitting element is located between the first carrier and the second carrier; the first carrier is removed; the connection layer is removed and the opening is retained forming a connection column with a connection layer between the second carrier and the second carrier; providing a third carrier, and aligning the light-emitting element and the third carrier, wherein the light-emitting element is located between the second carrier and the third carrier; and The laser beam is focused on the connecting column to separate the light-emitting element and the second carrier, so that the light-emitting element is transferred to the third carrier.

In an embodiment of the present invention, the above-mentioned opening is located on the light-emitting surface or the non-light-emitting surface of the light-emitting element.

In an embodiment of the present invention, the orthographic projection of the above-mentioned opening on the surface overlaps the orthographic projection of the center of gravity of the light-emitting element on the surface.

In an embodiment of the present invention, the above-mentioned opening penetrates the light-emitting element.

In an embodiment of the present invention, the above-mentioned third carrier is a circuit substrate.

In an embodiment of the present invention, the above-mentioned connecting layer includes multiple layers, and the multiple layers have different concentrations, light absorption rates or light transmittances.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, the following embodiments are given and described in detail with the accompanying drawings as follows.

FIG. 1A to FIG. 1I are schematic cross-sectional views of the steps of a manufacturing method of a display device 10 according to an embodiment of the present invention. First, referring to FIG. 1A , a light-emitting element 120 grown on the source substrate 110 is provided. The light-emitting element 120 includes a first-type semiconductor layer 121 , a second-type semiconductor layer 122 , and the first-type semiconductor layer 121 and the second-type semiconductor layer 122 The light emitting layer 123 therebetween, and a plurality of electrodes 121a and 122a electrically connected to the first type semiconductor layer 121 and the second type semiconductor layer 122, respectively. In this embodiment, the plurality of electrodes 121 a and 122 a are located on the same side of the first type semiconductor layer 121 . That is to say, the light emitting diode element 120 is a horizontal type (Lateral) miniature light emitting diode.

In this embodiment, pads 121b and 122b are formed on the electrodes 121a and 122a, respectively, wherein the pad 121b is electrically connected to the electrode 121a, the pad 122b is electrically connected to the electrode 122a, and the top surface of the pad 121b is electrically connected to the electrode 121a. The top surfaces of the pads 122b are cut to be flush, but not limited to this. The material of the pads 121b and 122b is metal, but the present invention is not limited thereto. In other embodiments, the pads 121b and 122b may also use other conductive materials, such as alloys, nitrides of metal materials, oxides of metal materials, oxynitrides of metal materials, graphene, stacked layers of metal materials or is a stack of other conductive materials.

1B , a carrier C1 coated with an adhesive layer 130 is provided, and the light-emitting element 120 is attached to the adhesive layer 130 , and the light-emitting element 120 can be located between the source substrate 110 and the carrier C1 . Then, the source substrate 110 is removed to expose the surface 121S of the first type semiconductor layer 121 away from the carrier C1. The method of removing the source substrate 110 can be, for example, a laser lift off process, but the invention is not limited thereto.

Next, referring to FIG. 1C , an opening O1 is formed on the surface 121S of the first-type semiconductor layer 121 . In this embodiment, the opening O1 may be completely located in the first-type semiconductor layer 121 and may be located on the light-emitting surface of the light-emitting element 120 . In addition, the orthographic projection of the opening O1 on the surface 121S may overlap the orthographic projection of the center of gravity of the light-emitting element 120 on the surface 121S, but the invention is not limited to this. In this embodiment, the cross-section of the opening O1 may present a regular trapezoid with a narrow top and a wide bottom, but the present invention is not limited thereto. In some embodiments, the opening O1 may further extend downward to penetrate the first type semiconductor layer 121 or deeper. The method of forming the opening O1 may use a lithography etching process. For example, in the present embodiment, the opening O1 with a normal trapezoidal cross-section can be formed by a dry etching process and a wet etching process.

Next, referring to FIG. 1D , a connection layer 150 is formed on the light-emitting element 120 and the adhesive layer 130 , and the connection layer 150 is filled in the opening O1 . The material of the connection layer 150 is a material that can be decomposed (eg, ablated) by reacting with laser light. In this embodiment, the connection layer 150 may have viscosity, but the invention is not limited thereto. In some embodiments, when the connection layer 150 is not adhesive, an adhesive layer may be formed on the connection layer 150 .

Next, referring to FIG. 1E , a carrier C2 is attached on the connection layer 150 , and the light-emitting element 120 is located between the carrier C1 and the carrier C2 at this time. After that, the carrier C1 is removed. For example, the removal of the carrier C1 may be performed by heating, but the present invention is not limited thereto.

Next, referring to FIG. 1F , the adhesive layer 130 is removed to expose the pads 121b and 122b. The method of removing the adhesive layer 130 may be a wet etching process, but the invention is not limited thereto.

Next, referring to FIG. 1G , most of the connection layer 150 is removed, but a part of the connection layer 150 between the opening O1 and the carrier C2 is left to form the connection column 150a, and the connection column 150a is at least partially located in the opening O1. The method of removing the connection layer 150 may adopt a wet etching process, but the invention is not limited thereto.

1H, a circuit substrate 170 is provided, and the circuit substrate 170 may include a plurality of pads 170a, 170b, and the light-emitting element 120 and the circuit substrate 170 are aligned so that the light-emitting element 120 is located between the carrier C2 and the circuit substrate 170 between. Specifically, in this embodiment, the alignment step is to align the pads 121b and 122b of the light-emitting element 120 with the pads 170a and 170b of the circuit substrate 170 respectively, but the invention is not limited to this, and other suitable alignments can also be used. bit mode.

After that, the laser beam LB emitted by the laser 180 is focused on the connecting column 150a. Specifically, the connecting post 150a may include a neck portion NP outside the opening O1 and a bottom portion BP inside the opening O1. In this embodiment, the laser beam LB can be focused on the neck NP of the connecting column 150a, so that the neck NP of the connecting column 150a reacts with the laser beam LB to be decomposed, and the bottom BP of the connecting column 150a can remain in the inside the opening O1. When the neck NP of the connecting column 150a is decomposed and broken, the light-emitting element 120 can fall vertically downward in a manner similar to a free fall, and is accurately transferred to the circuit substrate 170, so that the pads 121b and 122b can respectively contact Pads 170a, 170b, as shown in FIG. 1I. At this time, in the formed display device 10 , the electrodes 121 a and 122 a of the light-emitting element 120 may be located between the first-type semiconductor layer 121 and the circuit substrate 170 .

In some embodiments, the laser beam LB can be focused on the bottom BP of the connecting column 150a, so that the bottom BP of the connecting column 150a reacts with the laser beam LB to generate an impact force or a driving force. In detail, the lateral impact force or driving force generated by the reaction between the bottom BP of the connecting column 150a and the laser beam LB can cancel each other by acting on the sidewall of the opening O1, so that the net impact force or driving force is longitudinally downward. the combined force. The resultant downward force can make the light-emitting element 120 move directly downward and be accurately transferred to the circuit substrate 170 , so that the contact pads 121b and 122b can be respectively connected to the contact pads 170a and 170b.

In some embodiments, after the aforementioned steps, it may further include electrically connecting the pads 121b of the light-emitting element 120 and the pads 170a of the circuit substrate 170 , and electrically connecting the pads 122b of the light-emitting element 120 and the circuit substrate 170 170b. The method of electrically connecting the pads 121b and the pads 170a and the pads 122b and the pads 170b can be eutectic bonding or other similar methods, but the invention is not limited thereto.

Referring to FIG. 1I , in this embodiment, the display device 10 includes a circuit substrate 170 and a light-emitting element 120 . The light-emitting element 120 is electrically connected to the circuit substrate 170 and has an opening O1 , and the opening O1 is located on a side of the light-emitting element 120 away from the circuit substrate 170 . By adjusting the action range of the laser beam during the laser transfer process through the opening O1 of the light-emitting element 120 , the light-emitting element 120 can be accurately transferred to the circuit substrate 170 , so that the display device 10 has an accurate mass transfer of light-emitting elements 120 arrays.

In some embodiments, the circuit substrate 170 may include a bottom plate 171 , an element layer 172 and a plurality of pads 170 a and 170 b. The element layer 172 including the array of active elements T (eg, a thin film transistor array) can be formed on the base plate 171 by a thin film deposition process, a masking process and an etching process. After the element layer 172 is formed, a plurality of electrodes 170 a and 170 b may be formed on the element layer 172 by using the thin film deposition process, the masking process and the etching process.

The position of the opening O1 on the light-emitting element 120 is not particularly limited. In the display device 10 , the orthographic projection of the opening O1 on the circuit substrate 170 may overlap the orthographic projection of the center of gravity of the light emitting element 120 on the circuit substrate 170 , but the invention is not limited thereto. Specifically, the position of the center of gravity of the light-emitting element 120 can be obtained by calculating the area and density distribution of each layer of the light-emitting element 120 . Using the orthographic projection of the opening O1 on the circuit substrate 170 to overlap with the orthographic projection of the center of gravity of the light-emitting element 120 on the circuit substrate 170 , the light-emitting element 120 can be kept ideal when the light-emitting element 120 is suspended from the carrier C2 by the connecting column 150 a balance, as shown in Figure 1H.

The shape of the opening O1 is not particularly limited. In this embodiment, the cross-section of the opening O1 has a regular trapezoid shape with an upper narrow and a lower width, but the invention is not limited to this. In some embodiments, the cross-section of the opening O1 may also have an inverted trapezoid shape that is wide at the top and narrow at the bottom. In other embodiments, by further forming lateral blind holes in the opening O1, the cross-section of the opening O1 can have a burr-like shape.

The size of the opening O1 can be as small as possible so as not to affect the optical properties and electrical properties of the light emitting element 120 , but the invention is not limited to this. In this embodiment, the diameter Da of the opening O1 may be smaller than 1/3 of the width W of the light-emitting element 120 , that is, Da<1/3W. In some embodiments, the diameter Da of the opening O1 may be less than or equal to 3 μm, for example, the diameter Da is 3 μm, 2 μm or 1.5 μm, and an appropriate diameter Da can be selected as required.

The opening O1 may have a sufficient depth to, for example, ensure that the net impact or driving force generated by the reaction of the connecting post 150a with the laser beam LB is a downwardly directed force. In some embodiments, the depth Dt of the opening O1 may be greater than or equal to 1 μm, for example, the depth Dt is 1 μm, 2 μm or 3 μm or more, but the present invention is not limited thereto. In some embodiments, a portion of the connection post 150a may remain in the opening O1.

2A to FIG. 2G are schematic cross-sectional views illustrating the steps of a method for manufacturing the display device 20 according to an embodiment of the present invention. Element numbers and related contents of the embodiments in FIG. 1A to FIG. 1I are used below, wherein the same numbers are used to represent the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted part, reference may be made to the embodiments of FIGS. 1A to 1I , which will not be repeated in the following description.

First, referring to FIG. 2A , a light-emitting element 220 grown on the source substrate 110 is provided. The light-emitting element 220 includes a first-type semiconductor layer 121 , a second-type semiconductor layer 122 , the first-type semiconductor layer 121 and the second-type semiconductor layer 122 . The light emitting layer 123 therebetween, and a plurality of electrodes 121a and 122a electrically connected to the first type semiconductor layer 121 and the second type semiconductor layer 122, respectively.

Next, referring to FIG. 2B , an opening O2 is formed in the electrode 122 a and the second-type semiconductor layer 122 . In this embodiment, the opening O2 is located in the electrode 122a and the second-type semiconductor layer 122, but the invention is not limited thereto. In some embodiments, the opening O2 may also penetrate through the light emitting layer 123 and extend to the first type semiconductor layer 121 .

In this embodiment, at least two lateral blind holes may be further formed in the opening O2, so that the opening O2 has a burr-like shape, so as to improve the supporting force of the connecting post 150a formed in the opening O2 subsequently, and further improve the The stability of the connection post 150a when the light-emitting element 220 is suspended. For example, the lateral blind holes B1 , B2 , B3 , and B4 may be formed in the opening O2 , but the invention is not limited thereto.

The formation of the burr-like openings O2 may be achieved by using multiple etching processes. For example, in this embodiment, two etching processes may be used to form the main part of the opening O2 first, wherein the two etching processes use an etchant that can selectively etch the electrode 122 a and the second-type semiconductor layer 122 , respectively. After that, the lateral blind holes B1 and B2 may be formed using an etchant that is selective for the specific lattice orientation of the electrode 122 a , and then the etchant that is selective to the specific lattice orientation of the second-type semiconductor layer 122 may be used to form the lateral blind holes B1 and B2 . Lateral blind holes B3 and B4 are formed. In other embodiments, an etchant with selectivity to a specific material may be selected in sequence according to actual requirements to form openings O2 of various shapes.

Next, referring to FIG. 2C , a connection layer 150 is formed on the light-emitting element 220 and the source substrate 110 , and the connection layer 150 is filled in the opening O2 .

Next, referring to FIG. 2D , the carrier C3 is attached on the connection layer 150 , and the light emitting element 220 is located between the source substrate 110 and the carrier C3 at this time, and then the source substrate 110 is removed. The source substrate 110 can be removed by, for example, laser lift-off, but the invention is not limited thereto.

Next, referring to FIG. 2E , most of the connection layer 150 is removed, but a part of the connection layer 150 between the opening O2 and the carrier C3 is retained to form the connection post 150 a , and the connection post 150 a fills the opening O2 and has a thorn-like shape sectional shape. In this way, the bristle-shaped connecting post 150a can have an improved supporting force to stably hang the light-emitting element 220 . In this embodiment, the method of removing the connection layer 150 can be, for example, a wet etching process, but the invention is not limited thereto.

Next, referring to FIG. 2F, a circuit substrate 170 is provided, and the circuit substrate 170 may include a plurality of pads 170a, 170b on its surface. The light emitting element 220 and the circuit substrate 170 are aligned so that the light emitting element 220 is located between the carrier C3 and the circuit substrate 170 , and the orthographic projection of the light emitting element 220 on the circuit substrate 170 is located between the pads 170 a and 170 b of the circuit substrate 170 . After that, the laser beam LB emitted by the laser 180 is focused on the bottom BP of the connecting column 150a, so that the light-emitting element 220 is moved directly downward and accurately transferred to the circuit board 170.

Next, referring to FIG. 2G , connecting wires 121 c and 122 c are formed, wherein the connecting wire 121 c connects the electrode 121 a of the light emitting element 220 and the pad 170 a of the circuit substrate 170 , and the connecting wire 122 c connects the electrode 122 a of the light emitting element 220 and the connecting pad 170 of the circuit substrate 170 . The pad 170b can complete the display device 20 of this embodiment.

Compared with the display device 10 shown in FIG. 1I , the display device 20 shown in FIG. 2G is different in that: in the display device 20 , the opening O2 has a burr-like shape and is located on the non-light-emitting surface of the light-emitting element 220 . , the first-type semiconductor layer 121 of the light-emitting element 220 is located between the electrodes 121a, 122a and the circuit substrate 170, and the electrodes 121a, 122a of the light-emitting element 220 are respectively connected to the pads 170a, 170b of the circuit substrate 170 through the connecting wires 121c, 122c .

3A to FIG. 3H are schematic cross-sectional views of the steps of a method for manufacturing the display device 30 according to an embodiment of the present invention. Element numbers and related contents of the embodiments in FIG. 1A to FIG. 1I are used below, wherein the same numbers are used to represent the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted part, reference may be made to the embodiments of FIGS. 1A to 1I , which will not be repeated in the following description.

First, referring to FIG. 3A , a light-emitting element 320 grown on the source substrate 110 is provided. The light-emitting element 320 includes a first-type semiconductor layer 321 , a second-type semiconductor layer 322 , a first-type semiconductor layer 321 and a second-type semiconductor layer 322 . The light-emitting layer 323 in between, and a plurality of electrodes 321a and 322a electrically connected to the first-type semiconductor layer 321 and the second-type semiconductor layer 322, respectively. In this embodiment, the light-emitting diode element 320 may be a flip-chip micro light-emitting diode.

Next, referring to FIG. 3B , a carrier C4 coated with an adhesive layer 330 is provided, and the first-type semiconductor layer 321 of the light-emitting element 320 is attached to the adhesive layer 330 . At this time, the light-emitting element 320 can be located between the source substrate 110 and the carrier. between C4. Then, the source substrate 110 is removed to expose the electrodes 321a and 322a of the light emitting element 320, and there is an opening O3 between the electrodes 321a and 322a. The method of removing the source substrate 110 can be, for example, a laser lift off process, but the invention is not limited thereto.

Next, referring to FIG. 3C , a connection layer 350 is formed on the light-emitting element 320 and the adhesive layer 330 , and the connection layer 350 fills the opening O3 between the electrodes 321 a and 322 a. In this embodiment, the connection layer 350 may include multiple layers. For example, the connection layer 350 may include a first layer 351, a second layer 352 and a third layer 353, wherein the second layer 352 is located between the first layer 351 and the third layer 353, but the invention is not limited thereto . In this embodiment, the first layer 351 , the second layer 352 and the third layer 353 may have sequentially increasing light transmittances with respect to the subsequently used laser beam LB. In some embodiments, the first layer 351 , the second layer 352 and the third layer 353 may have sequentially decreasing light transmittances with respect to the subsequently used laser beam LB. In some embodiments, the first layer 351 , the second layer 352 and the third layer 353 may have light absorption rates that increase and then decrease with respect to the subsequently used laser beam LB. In some embodiments, the first layer 351 , the second layer 352 , and the third layer 353 may have a decreasing and then increasing light absorptivity with respect to the subsequently used laser beam LB. In some embodiments, the first layer 351 , the second layer 352 and the third layer 353 may also include a laser light absorbing material, and the laser light absorbing material in the first layer 351 , the second layer 352 and the third layer 353 Concentrations can be sequentially increasing, sequentially decreasing, first increasing and then decreasing, or first decreasing and then increasing.

The material of the connection layer 350 is a material that can be decomposed by reacting with laser light. The connection layer 350 may have viscosity, but the invention is not limited thereto. In some embodiments, when the third layer 353 of the connection layer 350 is not adhesive, an adhesive layer may be formed on the third layer 353 .

Next, referring to FIG. 3D , the carrier C5 is attached on the connection layer 350 , and the light-emitting element 320 is located between the carrier C5 and the carrier C4 at this time, and then the carrier C4 is removed. In some embodiments, the adhesive layer 330 may also be removed together with the removal of the carrier C4. The carrier C4 and the adhesive layer 330 can be removed by heating, for example, but the invention is not limited thereto.

Next, referring to FIG. 3E , most of the connection layer 350 is removed, but part of the connection layer 350 between the opening O3 and the carrier C5 is retained, and a connection column 350 a is formed, wherein the connection column 350 a includes the first layer 351 a, the second layer 350 a The layer 352a and the third layer 353a, and the connection post 350a is at least partially located in the opening O3. In this embodiment, the first layer 351a, the second layer 352a and the third layer 353a may have sequentially increasing light transmittances with respect to the laser beam LB.

In some embodiments, the first layer 351a, the second layer 352a, and the third layer 353a may have sequentially decreasing light transmittances with respect to the laser beam LB. In some embodiments, the first layer 351a, the second layer 352a, and the third layer 353a may have light absorption rates that increase and then decrease with respect to the laser beam LB. In some embodiments, the first layer 351a, the second layer 352a, and the third layer 353a may have a decreasing and then increasing light absorptivity with respect to the laser beam LB. In some embodiments, the first layer 351a, the second layer 352a and the third layer 353a may also include a laser absorbing material, and the laser absorbing material in the first layer 351a, the second layer 352a and the third layer 353a Concentrations can be sequentially increasing, sequentially decreasing, first increasing and then decreasing, or first decreasing and then increasing. With the above-mentioned increasing or decreasing light transmittance, light absorptivity or the concentration of the laser absorbing material, the breaking position of the connecting post 350a after reacting with the laser beam LB can be adjusted, so that the mass transfer of the light-emitting element 320 can be optimally change.

In some embodiments, when the light-emitting element 320 is viewed in a plan view from the carrier C5 toward the light-emitting element 320, the distance D1 between the electrodes 321a, 322a may be smaller than the length of the electrodes 321a, 322a in the direction perpendicular to the distance D1, At this time, the opening O3 can be a long groove located between the electrodes 321a and 322a, so that the connecting column 350a has a long top-view shape. In this case, the connecting column 350a in the middle section of the opening O3 can be retained, and the opening O3 can be completely removed The remaining part of the connecting column 350a, so that the connecting column 350a has an approximately cylindrical shape.

Next, referring to FIG. 3F , a carrier C6 is provided, and one surface of the carrier C6 is coated with an adhesive layer 340 , and the light-emitting element 320 is placed on the adhesive layer 340 , and the light-emitting element 320 is located on the carrier C6 and the carrier C5 between. Then, the laser beam LB emitted by the laser 180 is focused on the first layer 351a of the connecting column 350a, so that the first layer 351a of the connecting column 350a reacts with the laser beam LB to generate a downward net impact force or The driving force causes the light-emitting element 320 to advance directly downward and is transferred to the carrier C6, as shown in FIG. 3G . In this embodiment, since the third layer 353a and the second layer 352a have higher light transmittance than the first layer 351a, a relatively large part of the laser beam LB can penetrate the third layer 353a and the first layer 351a. The second layer 352a reaches the first layer 351a, thereby improving the light utilization rate of the laser beam LB acting on the first layer 351a.

Next, referring to FIG. 3H, a circuit substrate 170 is provided, and the circuit substrate 170 may include a plurality of pads 170a and 170b. After that, the light-emitting element 320 is placed on the circuit substrate 170 , and the electrodes 321 a and 322 a of the light-emitting element 320 are connected to the pads 170 a and 170 b of the circuit substrate 170 , respectively.

In some embodiments, after the aforesaid steps, it may further include connecting the electrode 321a of the light emitting element 320 and the pad 170a of the circuit substrate 170 , and electrically connecting the electrode 322a of the 320 and the pad 170b of the circuit substrate 170 . The method for electrically connecting the electrode 321a and the pad 170a and the method for electrically connecting the electrode 322a and the pad 170b include, for example, eutectic bonding or other similar methods, but the invention is not limited thereto.

Compared with the display device 10 shown in FIG. 1I, the display device 30 shown in FIG. 3H is different in that: in the display device 30, the opening O3 is located on the side of the light-emitting element 320 adjacent to the circuit substrate 170, and the opening O3 is Because of the space between the electrodes 321 a and 322 a , the opening O3 does not need to be formed by an additional lithography etching process, and the opening O3 is located on the non-light-emitting surface of the light-emitting element 320 .

4A to FIG. 4G are schematic cross-sectional views of the steps of a method for manufacturing the display device 40 according to an embodiment of the present invention. Element numbers and related contents of the embodiments in FIGS. 2A to 2G are used below, wherein the same numbers are used to represent the same or similar elements, and the description of the same technical contents is omitted. For the description of the omitted part, reference may be made to the embodiments of FIGS. 2A to 2G , which will not be repeated in the following description.

First, referring to FIG. 4A , a light-emitting element 420 grown on the source substrate 110 is provided. The light-emitting element 420 includes a first-type semiconductor layer 421 , a second-type semiconductor layer 422 , the first-type semiconductor layer 421 and the second-type semiconductor layer 422 . The light emitting layer 423 therebetween, and a plurality of electrodes 421a and 422a electrically connected to the first type semiconductor layer 421 and the second type semiconductor layer 422, respectively. In this embodiment, the plurality of electrodes 421a and 422a are located on opposite sides of the light emitting layer 423, respectively. That is to say, the light emitting element 420 is a vertical micro light emitting diode.

4B, an opening O4 is formed in the electrode 421a, the first type semiconductor layer 421, the light emitting layer 423, the second type semiconductor layer 422 and the electrode 422a. In this embodiment, the opening O4 penetrates through each layer of the light emitting element 420 and has a deeper depth. In this way, the supporting force of the connecting column 450a formed in the opening O4 to the light-emitting element 420 can be increased, thereby improving the stability of the connecting column 450a when the light-emitting element 420 is suspended. The formation of the opening O4 can be achieved by using multiple etching processes, and an etchant having selectivity for each layer of the light emitting element 420 can be sequentially selected to form the opening O4 according to actual needs.

Next, referring to FIG. 4C , a connection layer 450 is formed on the light-emitting element 420 and the source substrate 110 , and the connection layer 450 is filled in the opening O4 . In this embodiment, the first layer 451 , the second layer 452 , the third layer 453 and the fourth layer 454 can be sequentially formed to form the connection layer 450 , wherein the light absorption rate of the third layer 453 is greater than that of the fourth layer 454 The light absorptivity of the fourth layer 454 is greater than that of the second layer 452 , and the light absorptivity of the second layer 452 is greater than that of the first layer 451 . In the connection layer 450, at least the third layer 453 or the fourth layer 454 is a material that can react with laser light to be decomposed.

In this embodiment, the connection layer 450 can completely fill the opening O4, but the invention is not limited to this. In some embodiments, the connection layer 450 may also be filled in the partial opening O4. The fourth layer 454 of the connection layer 450 may have viscosity, but the invention is not limited thereto. In some embodiments, when the fourth layer 454 of the connection layer 450 is not adhesive, an adhesive layer may be formed on the fourth layer 454 .

Next, referring to FIG. 4D , the carrier C7 is attached on the connection layer 450 , and the light emitting element 420 is located between the source substrate 110 and the carrier C7 at this time, and then the source substrate 110 is removed.

Next, referring to FIG. 4E , most of the connection layer 450 is removed, but part of the connection layer 450 between the opening O4 and the carrier C7 is retained, and a connection column 450 a is formed, wherein the connection column 450 a includes the first layer 451 a, the second layer 450 a Layer 452a, third layer 453a, and fourth layer 454a.

Next, referring to FIG. 4F, a circuit substrate 170 is provided, and the circuit substrate 170 may include a plurality of pads 170a, 170b on the surface thereof. Then, the light emitting element 420 is aligned with the circuit substrate 170 so that the light emitting element 420 is located between the carrier C7 and the circuit substrate 170 , and the orthographic projection of the light emitting element 420 on the circuit substrate 170 overlaps the pad 170 b of the circuit substrate 170 . After that, the laser beam LB emitted by the laser 180 is focused on the third layer 453a of the connecting column 450a, for example, to burn the third layer 453a, so that the light-emitting element 420 can be dropped directly downward and transferred to the circuit substrate 170, And the electrode 422a of the light-emitting element 420 directly contacts the pad 170b. Since the third layer 453a of the connection pillar 450a has the largest light absorption rate in the connection pillar 450a, the laser beam LB can easily decompose the third layer 453a by reacting with the third layer 453a.

In some embodiments, after the foregoing steps, it may further include electrically connecting the electrodes 422 a of the light emitting element 420 and the pads 170 b of the circuit substrate 170 . The method for electrically connecting the electrode 422a of the light emitting element 420 and the pad 170b of the circuit substrate 170 includes, for example, eutectic bonding or other similar methods, but the invention is not limited thereto.

Next, referring to FIG. 4G , the insulating layer IS can be formed on the side of the electrode 422a and the pad 170b close to the pad 170a first, and then the connecting wire 421c can be formed to complete the display device 40 of this embodiment. In this embodiment, the connecting wire 421c connects the electrode 421a of the light emitting element 420 and the pad 170a of the circuit substrate 170, and the insulating layer IS can prevent the connecting wire 421c from being short-circuited with the electrode 422a or the pad 170b.

Compared with the display device 20 shown in FIG. 2G , the display device 40 shown in FIG. 4G is different in that: in the display device 40 , the light-emitting element 420 is a vertical miniature light-emitting diode; the opening O4 penetrates the light-emitting element The electrode 421a, the first-type semiconductor layer 421, the light-emitting layer 423, the second-type semiconductor layer 422, and the electrode 422a of 420 do not have lateral blind holes; and the connecting column 450a includes a plurality of layers. In addition, the electrode 421a of the light emitting element 420 is connected to the pad 170a of the circuit substrate 170 through the connecting wire 421c, and the electrode 422a of the light emitting element 420 is directly connected to the pad 170b of the circuit substrate 170 .

To sum up, in the display device of the embodiment of the present invention, the opening in the light-emitting element is used to adjust the action range of the laser beam during the laser transfer process, so that the light-emitting element can be accurately transferred to the circuit substrate, thereby enabling the display The device has an array of light-emitting elements that are accurately mass-transferred.

Although the present invention has been disclosed above by the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the scope of the appended patent application.

10, 20, 30, 40: Display device 110: Source substrate 120, 220, 320, 420: light-emitting elements 121, 321, 421: first type semiconductor layer 121a, 321a, 421a: Electrodes 121b: Pad 121c, 421c: connecting wires 121S: Surface 122, 322, 422: the second type semiconductor layer 122a, 322a, 422a: Electrodes 122b: Pad 122c: Connecting wires 123, 323, 423: light-emitting layer 130, 330, 340: Adhesive layer 150, 350, 450: connection layer 150a, 350a, 450a: connecting posts 170: circuit substrate 170a, 170b: pads 171: Bottom Plate 172: Component layer 180: Laser 351, 351a, 451, 451a: first floor 352, 352a, 452, 452a: Second layer 353, 353a, 453, 453a: Tier 3 454, 454a: Fourth floor B1, B2, B3, B4: lateral blind holes BP: Bottom C1, C2, C3, C4, C5, C6, C7: carrier board D1: Spacing Da: caliber Dt: depth IS: insulating layer LB: Laser Beam NP: neck O1, O2, O3, O4: Opening T: Active element W: width

FIG. 1A to FIG. 1I are schematic cross-sectional views of the steps of a manufacturing method of a display device 10 according to an embodiment of the present invention. 2A to FIG. 2G are schematic cross-sectional views illustrating the steps of a method for manufacturing the display device 20 according to an embodiment of the present invention. 3A to FIG. 3H are schematic cross-sectional views of the steps of a method for manufacturing the display device 30 according to an embodiment of the present invention. 4A to FIG. 4G are schematic cross-sectional views of the steps of a method for manufacturing the display device 40 according to an embodiment of the present invention.

10: Display device

120: Light-emitting element

121: first type semiconductor layer

121a: Electrodes

121b: Pad

122: the second type semiconductor layer

122a: Electrodes

122b: Pad

123: Light-emitting layer

150a: connecting column

170: circuit substrate

170a, 170b: pads

171: Bottom Plate

172: Component layer

Da: caliber

Dt: depth

O1: Opening

T: Active element

W: width

Claims (19)

A display device, comprising: a circuit substrate; a light-emitting element electrically connected to the circuit substrate and having an opening, wherein the opening is located on a side of the light-emitting element adjacent to or away from the circuit substrate; and a connecting column, the The connecting post is located at least partially in the opening. The display device according to claim 1, wherein the orthographic projection of the opening on the circuit substrate overlaps the orthographic projection of the center of gravity of the light-emitting element on the circuit substrate. The display device of claim 1, wherein the light-emitting element includes two electrodes, and the opening is at least partially located outside the two electrodes. The display device of claim 1, wherein the light-emitting element includes two electrodes, and the opening is located between the two electrodes. The display device according to claim 1, wherein the opening is located on a light-emitting surface or a non-light-emitting surface of the light-emitting element. The display device according to claim 1, wherein the cross section of the opening has a normal trapezoid or an inverted trapezoid. The display device according to claim 1, wherein the aperture of the opening is smaller than 1/3 of the width of the light-emitting element. The display device according to claim 1, wherein the aperture of the opening is less than or equal to 3 μm. The display device of claim 1, wherein the depth of the opening is greater than or equal to 1 μm. The display device of claim 1, wherein the circuit substrate includes an active element array. The display device of claim 1, wherein the connection pillar includes a plurality of layers, and the plurality of layers have different concentrations, light absorption rates, or light transmittances. A display device, comprising: a circuit substrate; and a light-emitting element, which is electrically connected to the circuit substrate and has an opening, wherein the opening is located on a side of the light-emitting element adjacent to or away from the circuit substrate, and wherein the The opening penetrates the light emitting element. A display device, comprising: a circuit substrate; and a light-emitting element, which is electrically connected to the circuit substrate and has an opening, wherein the opening is located on a side of the light-emitting element adjacent to or away from the circuit substrate, and wherein the There are lateral blind holes in the opening. A manufacturing method of a display device, comprising: providing a light-emitting element, the light-emitting element is located on a first carrier; forming an opening on a surface of the light-emitting element away from the first carrier; forming a connection layer on the surface , and the connection layer is filled in the opening; the second carrier is fixed on the connection layer, so that the light-emitting element is located between the first carrier and the second carrier; removing the first carrier board; removing the connection layer, and leaving the connection layer between the opening and the second carrier board to form a connection column; providing a third carrier board, and connecting the alignment of the light-emitting element and the third carrier, wherein the light-emitting element is located between the second carrier and the third carrier; and focusing a laser beam on the connecting post to separate the the light-emitting element and the second carrier, and the light-emitting element is transferred to the third carrier. The method for manufacturing a display device according to claim 14, wherein the opening is located on a light-emitting surface or a non-light-emitting surface of the light-emitting element. The method for manufacturing a display device according to claim 14, wherein the orthographic projection of the opening on the surface overlaps the orthographic projection of the center of gravity of the light-emitting element on the surface. The method of manufacturing a display device according to claim 14, wherein the opening penetrates the light-emitting element. The method for manufacturing a display device according to claim 14, wherein the third carrier is a circuit substrate. The method for manufacturing a display device according to claim 14, wherein the connection layer includes a plurality of layers, and the plurality of layers have different concentrations, light absorption rates, or light transmittances.

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