CN115763679A

CN115763679A - Light emitting diode array substrate

Info

Publication number: CN115763679A
Application number: CN202211410925.4A
Authority: CN
Inventors: 李冠谊; 陈韦洁; 杨智钧; 白佳蕙
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2022-04-01
Filing date: 2022-11-11
Publication date: 2023-03-07

Abstract

The invention discloses a light-emitting diode array substrate which comprises a substrate, an adhesive layer and a plurality of light-emitting diode elements. The adhesive layer is arranged on the substrate. The adhesive layer includes a plurality of adhesive structures. Each of the adhesion structures has a first protrusion and a second protrusion spaced apart from each other. The plurality of adhesion structures are positioned between the plurality of light emitting diode elements and the substrate. The first electrode and the second electrode of each light-emitting diode element are respectively connected to the first bulge and the second bulge of the corresponding adhesive structure.

Description

Light emitting diode array substrate

Technical Field

The present invention relates to an array substrate, and more particularly, to a light emitting diode array substrate.

Background

The light emitting diode display panel comprises a driving backboard and a plurality of light emitting diode elements which are transposed on the driving backboard. The characteristics of the light emitting diode are inherited, and the light emitting diode display panel has the advantages of electricity saving, high efficiency, high brightness, quick response time and the like. In addition, compared with the organic light emitting diode display panel, the light emitting diode display panel also has the advantages of easy color adjustment, long light emitting life, no image branding and the like. Therefore, the led display panel is considered as the next generation display technology.

In the manufacturing process of the led display panel, a large number of led devices on the temporary storage substrate need to be transferred to the driving backplane, and the electrodes of the led devices are electrically connected to the pads of the driving backplane. Before transferring a large number of led elements to the driving backplane, the adhesive structures on the led elements need to be removed to expose the electrodes of the led elements. However, the adhesive structure is easy to remain on the led device, which may cause poor bonding between the led device and the driving backplane. If a severe dry etching process condition is used to clean the adhesion structure, the led device may be damaged and cracked during the dry etching process.

Disclosure of Invention

The invention provides a light-emitting diode array substrate which is high in joint yield with a driving back plate of a light-emitting diode display panel.

The invention discloses a light emitting diode array substrate, which comprises a substrate, an adhesion layer and a plurality of light emitting diode elements. The adhesion layer is arranged on the substrate. The adhesive layer includes a plurality of adhesive structures. Each of the adhesion structures has a first protrusion and a second protrusion spaced apart from each other. The plurality of adhesion structures are positioned between the plurality of light emitting diode elements and the substrate. The first electrode and the second electrode of each light-emitting diode element are respectively connected to the first bulge and the second bulge of one corresponding adhesion structure.

The invention discloses a light emitting diode array substrate, which comprises a substrate, an adhesion layer, a plurality of light emitting diode elements and a plurality of adhesion structures. The adhesive layer is arranged on the substrate. The plurality of light emitting diode elements are arranged on the adhesive layer. The plurality of adhesion structures are respectively arranged on the plurality of light emitting diode elements. Each adhesion structure is provided with a first surface facing the adhesion layer, and the first surface is provided with a first bulge and a second bulge which are separated from each other. Each light emitting diode element is provided with a first electrode and a second electrode, and the first electrode and the second electrode are respectively connected to the first bulge and the second bulge of one of the plurality of adhesion structures.

Drawings

Fig. 1A to fig. 1F are schematic cross-sectional views illustrating a manufacturing process of an led array substrate according to an embodiment of the invention;

FIG. 2 is a schematic top view of an LED device according to an embodiment of the present invention;

fig. 3A to 3C are schematic cross-sectional views illustrating a manufacturing process of a first temporary storage substrate according to an embodiment of the invention;

FIG. 4 is a schematic top view of an LED chip according to an embodiment of the present invention;

FIG. 5 is an enlarged view of an alignment mark of an LED chip according to an embodiment of the present invention;

FIG. 6 is a schematic top view of an adhesive layer of a first temporary storage substrate according to an embodiment of the invention.

Description of the symbols

10. 20, 30 light emitting diode array substrate

100 light emitting diode chip

110 growth substrate

110a element region

110b non-device region

120 light emitting diode element

121 first type semiconductor layer

122 second type semiconductor layer

123 active layer

124 insulating layer

124a first contact window

124b second contact window

125 first electrode

126 second electrode

130. 223 alignment mark

200 first temporary storage substrate

210. 310 base

220. 320 adhesive layer

220' adhesive material layer

222 adhesive structure

222a first bump

222b second projection

222c platform

222s upper surface

222s1 first surface

222s2 second surface

300 second temporary storage substrate

g1 first air gap

g2 second air gap

g3 third air gap

H1, H2 height

M-gray scale photomask

Ma first region

Mb second region

Third zone of Mc

S semiconductor structure

Wx125, wy125, wx222a width

x is the first direction

y is the second direction

Δ H height deviation

Detailed Description

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

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 physically and/or electrically connected. Further, "electrically connected" or "coupled" may mean that there are additional elements between the 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, given the particular number of measurements and errors associated with the measurements in question (i.e., the limitations of the measurement system). For example, "about" can 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 with respect to optical properties, etching properties, or other properties, with a more acceptable range of deviation or standard deviation, and not one standard deviation may apply to all properties.

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.

Fig. 1A to fig. 1F are schematic cross-sectional views illustrating a manufacturing process of an led array substrate according to an embodiment of the invention. Fig. 2 is a schematic top view of an led device according to an embodiment of the invention.

Referring to fig. 1A and fig. 2, first, an led chip 100 is provided, wherein the led chip 100 includes a growth substrate 110 and a plurality of led devices 120 formed on the growth substrate 110. Each led element 120 includes a first electrode 125 and a second electrode 126 spaced apart from each other. In detail, each of the led devices 120 further includes a first type semiconductor layer 121, a second type semiconductor layer 122, an active layer 123 and an insulating layer 124, wherein the active layer 123 is disposed between the first type semiconductor layer 121 and the second type semiconductor layer 122, the first type semiconductor layer 121, the second type semiconductor layer 122 and the active layer 123 form a semiconductor structure S, the insulating layer 124 is disposed on the semiconductor structure S and has a first contact window 124a and a second contact window 124b, the first contact window 124a and the second contact window 124b of the insulating layer 124 are respectively overlapped with the first type semiconductor layer 121 and the second type semiconductor layer 122, and the first electrode 125 and the second electrode 126 are electrically connected to the first type semiconductor layer 121 and the second type semiconductor layer 122 through the first contact window 124a and the second contact window 124b of the insulating layer 124, respectively.

Referring to fig. 1A, a first temporary substrate 200 is provided. The first temporary substrate 200 includes a base 210 and an adhesive layer 220 disposed on the base 210. The adhesive layer 220 includes a plurality of adhesive structures 222. Each of the adhesion structures 222 has a first protrusion 222a and a second protrusion 222b spaced apart from each other. In the present embodiment, each of the adhesion structures 222 further has a platform 222c, the first protrusion 222a and the second protrusion 222b are disposed on the platform 222c, and the platform 222c is located between the first protrusion 222a and the substrate 210 and between the second protrusion 222b and the substrate 210. In the present embodiment, the plurality of platforms 222c of the plurality of adhesion structures 222 are disconnected from each other.

Fig. 3A to 3C are schematic cross-sectional views illustrating a manufacturing process of a first temporary storage substrate according to an embodiment of the invention. The method for manufacturing the first temporary substrate 200 is illustrated with reference to fig. 3A to 3C.

Referring to fig. 3A, in detail, in the present embodiment, an adhesive material layer 220' may be formed on the substrate 210. Referring to fig. 3B and 3C, the adhesive material layer 220' is patterned by using the gray-scale photomask M as a mask to form an adhesive layer 220 having a plurality of adhesive structures 222. For example, in the present embodiment, the adhesive material layer 220 'may be a negative photoresist, the gray-scale photomask M has a first region Ma, a second region Mb and a third region Mc, the light transmittance of the first region Ma is 0%, the light transmittance of the second region Mb is 100%, and the light transmittance of the third region Mc is greater than 0% and less than 100%, the adhesive material layer 220' can be broken into a plurality of adhesive structures 222 separated from each other by using the first region Ma of the gray-scale photomask M, and each of the adhesive structures 222 can have a height difference Δ H by using the second region Mb and the third region Mc of the gray-scale photomask M, wherein the height difference Δ H refers to a difference between a maximum height H1 of the adhesive structure 222 and a height H2 of a platform 222c of the adhesive structure 222. In the embodiment, the light transmittance of the third region Mc is, for example, in a range of 5% to 35%, the maximum height H1 of the adhesive structure 222 is, for example, in a range of 2 μm to 6 μm, and the adhesive structure 222 has a height difference Δ H in a range of 0.4 μm to 2.8 μm, for example, but the invention is not limited thereto.

Referring to fig. 1A and fig. 2, in the present embodiment, an area of any one of the first protrusion 222a and the second protrusion 222b of the adhesion structure 222 may be greater than or equal to an area of any one of the first electrode 125 and the second electrode 126 of the light emitting diode element 120. Further, the first direction x and the second direction y are parallel to the base 210 of the first temporary substrate 200 and perpendicular to each other, a width Wx222a of the upper surface 222s of any one of the first protrusion 222a and the second protrusion 222b in the first direction x may be greater than or equal to a width Wx125 of any one of the first electrode 125 and the second electrode 126 of the led device 120 in the first direction x, and a width (not labeled) of the upper surface 222s of any one of the first protrusion 222a and the second protrusion 222b in the second direction y may be greater than or equal to a width Wy125 (labeled in fig. 2) of any one of the first electrode 125 and the second electrode 126 of the led device 120 in the second direction y. For example, in the present embodiment, a width Wx222a of an upper surface 222s of any one of the first bump 222a and the second bump 222b in the first direction x may be substantially equal to a width Wx125 of any one of the first electrode 125 and the second electrode 126 of the led device 120 in the first direction x, and a width (not labeled) of an upper surface 222s of any one of the first bump 222a and the second bump 222b in the second direction y may be substantially equal to a width Wy125 (labeled in fig. 2) of any one of the first electrode 125 and the second electrode 126 of the led device 120 in the second direction y. However, the invention is not limited thereto, and in another embodiment, the width Wx222a may be greater than the width Wx125 (for example, but not limited to, 2 μm greater), and a width (not labeled) of the upper surface 222s of any one of the first protrusion 222a and the second protrusion 222b in the second direction y may be greater than the width Wy125 (for example, but not limited to, 2 μm greater) of any one of the first electrode 125 and the second electrode 126 of the led device 120 in the second direction y; the upper surface 222s of any one of the first and

second protrusions

222a and 222b may be about 10 μm ² . In yet another embodiment, the width Wx222a of the upper surface 222s of any one of the first protrusion 222a and the second protrusion 222b in the first direction x may also be smaller than that of any one of the first electrode 125 and the second electrode 126 of the led device 120The width Wx125 in the first direction x, and the width (not labeled) of the upper surface 222s of any one of the first protrusion 222a and the second protrusion 222b in the second direction y may also be smaller than the width Wy125 of any one of the first electrode 125 and the second electrode 126 of the light emitting diode device 120 in the second direction y.

Fig. 4 is a schematic top view of an led chip according to an embodiment of the invention. Fig. 4 shows the growth substrate 110 and the alignment marks 130, and other components of the led chip 100 are omitted. Fig. 5 is an enlarged schematic view of the alignment mark of the led chip according to an embodiment of the invention. FIG. 6 is a schematic top view of an adhesive layer of a first temporary storage substrate according to an embodiment of the invention.

Referring to fig. 1B, the first electrode 125 and the second electrode 126 of the led device 120 of the led chip 100 are connected to the first bump 222a and the second bump 222B of the adhesion structure 222 of the first temporary storage substrate 200, respectively.

Referring to fig. 1B, fig. 4 and fig. 5, in the present embodiment, the growth substrate 110 of the light emitting diode wafer 100 has an element region 110a and a non-element region 110B outside the element region 110a, the plurality of light emitting diode devices 120 are disposed in the element region 110a, the light emitting diode wafer 100 further has an alignment mark 130, and the alignment mark 130 is disposed in the non-element region 110B. Referring to fig. 1B and fig. 6, in the present embodiment, the adhesion layer 220 of the first temporary substrate 200 further includes alignment marks 223 outside the adhesion structures 222. Referring to fig. 1B, fig. 5 and fig. 6, in the connection process of the led device 120 and the adhesive structure 222, the first electrode 125 and the second electrode 126 of the led device 120 can be aligned with the first bump 222a and the second bump 222B of the adhesive structure 222 respectively through the alignment mark 130 of the led chip 100 and the alignment mark 223 of the first temporary substrate 200, so that the first electrode 125 and the second electrode 126 of the led device 120 can be accurately connected with the first bump 222a and the second bump 222B of the adhesive structure 222.

Referring to fig. 1B and fig. 1C, the growth substrate 110 of the led chip 100 is removed, and the led elements 120 are left on the first temporary storage substrate 200 to form the led array substrate 10. For example, in the embodiment, the growth substrate 110 and the led element 120 may be separated by Laser lift-off (LLO), but the invention is not limited thereto.

Referring to fig. 1C, the led array substrate 10 includes a substrate 210, an adhesive layer 220 and a plurality of led elements 120. The adhesive layer 220 is disposed on the substrate 210. The adhesive layer 220 includes a plurality of adhesive structures 222. Each of the adhesion structures 222 has a first protrusion 222a and a second protrusion 222b spaced apart from each other. The plurality of adhesion structures 222 are located between the plurality of led elements 120 and the substrate 210. The first electrode 125 and the second electrode 126 of each led device 120 are respectively connected to the first protrusion 222a and the second protrusion 222b of the corresponding adhesive structure 222.

In the present embodiment, a first air gap g1 exists between the insulating layer 124 of the led device 120 and the platform 222c of the adhesive structure 222. The first air gap g1 is located between the first electrode 125 and the second electrode 126 of the led device 120 and between the first protrusion 222a and the second protrusion 222b of the adhesive structure 222. That is to say, the first air gap g1 is an open space surrounded by the first electrode 125 of the led element 120, the insulating layer 124 of the led element 120, the second electrode 126 of the led element 120, the second protrusion 222b of the adhesive structure 222, the platform 222c of the adhesive structure 222, and the first protrusion 222a of the adhesive structure 222.

In the present embodiment, a second air gap g2 exists between the insulating layer 124 of the led device 120 and the platform 222c of the adhesive structure 222, and the first electrode 125 of the led device 120 and the first bump 222a of the adhesive structure 222 are located between the first air gap g1 and the second air gap g 2. In the present embodiment, a third air gap g3 exists between the insulating layer 124 of the led device 120 and the platform 222c of the adhesive structure 222, and the second electrode 126 of the led device 120 and the second bump 222b of the adhesive structure 222 are located between the first air gap g1 and the third air gap g3.

Referring to fig. 1D, a second temporary storage substrate 300 is provided, wherein the second temporary storage substrate 300 includes a base 310 and an adhesive layer 320 disposed on the base 310. In the embodiment, the adhesive layer 320 may cover the substrate 310 entirely, but the invention is not limited thereto.

Referring to fig. 1D and fig. 1E, the led elements 120 and the adhesive structures 222 of the led array substrate 10 are selectively transferred onto the adhesive layer 320 of the second temporary storage substrate 300 to form another led array substrate 20. The arrangement of the plurality of light emitting diode elements 120 of the light emitting diode array substrate 10 is different from the arrangement of the plurality of light emitting diode elements 120 of another light emitting diode array substrate 20. The arrangement of the led elements 120 of the led array substrate 20 is determined according to the positions of the pads of the driving back plate of the led display panel (not shown) to be formed.

Referring to fig. 1D and fig. 1E, in the present embodiment, a Laser lift-off (LLO) technique may be used to separate the adhesion structure 222 from the base 210 of the first temporary storage substrate 200, so that the adhesion structure 222 and the led device 120 are disposed on the adhesion layer 320 of the second temporary storage substrate 300 to form another led array substrate 20.

Referring to fig. 1E, the led array substrate 20 includes a substrate 310, an adhesive layer 320, a plurality of led elements 120, and a plurality of adhesive structures 222. The adhesive layer 320 is disposed on the substrate 310. The plurality of led elements 120 are disposed on the adhesive layer 320. The plurality of adhesive structures 222 are respectively disposed on the plurality of led elements 120. Each of the adhesive structures 222 has a first surface 222s1 facing the adhesive layer 320, and the first surface 222s1 has a first protrusion 222a and a second protrusion 222b spaced apart from each other. Each of the led elements 120 has a first electrode 125 and a second electrode 126, and the first electrode 125 and the second electrode 126 are respectively connected to the first protrusion 222a and the second protrusion 222b of a corresponding one of the adhesive structures 222.

In the present embodiment, each of the adhesion structures 222 has a second surface 222s2 facing away from the adhesion layer 320, and the roughness of the second surface 222s2 is less than that of the first surface 222s 1. Specifically, in the present embodiment, the first surface 222s1 of each adhesion structure 222 facing the adhesion layer 320 is an undulating surface having the first protrusions 222a and the second protrusions 222b, and the second surface 222s2 of each adhesion structure 222 facing away from the adhesion layer 320 is substantially a plane. However, the invention is not limited thereto, and in another embodiment, the second surface 222s2 of the adhesion structure 222 facing away from the adhesion layer 320 may also be slightly damaged during the laser lift-off process corresponding to fig. 1D, so as to form a plane-like surface with micro-defects.

In the present embodiment, the first protrusion 222a and the second protrusion 222b of the adhesive structure 222 are located between the platform 222c of the adhesive structure 222 and the adhesive layer 320. In the present embodiment, the plurality of platforms 222c of the plurality of adhesive structures 222 of the led array substrate 20 are disconnected from each other. In the present embodiment, after the led device 120 and the adhesive structure 222 connected to each other are transferred to the adhesive layer 320 of the second temporary substrate 300, the first air gap g1, the second air gap g2 and the third air gap g3 still exist between the insulating layer 124 of the led device 120 and the platform 222c of the adhesive structure 222.

Referring to fig. 1E and fig. 1F, the adhesive structure 222 on the led device 120 is removed by a dry etching process to expose the first electrode 125 and the second electrode 126 of the led device 120, and the led array substrate 30 is completed, wherein the led device 120 on the led array substrate 30 is electrically connected to a driving back plate of an led display panel (not shown).

It should be noted that at least a first air gap g1 exists between the insulating layer 124 of the led device 120 and the platform 222c of the adhesive structure 222; in the dry etching process corresponding to FIG. 1E, the plasma (not shown) used to remove the adhesive structure 222 can etch the adhesive structure 222 from the first air gap g1 in addition to etching the adhesive structure 222 from the second surface 222s2 of the adhesive structure 222. Therefore, the adhesive structure 222 can be removed without over-etching, thereby reducing the probability of damage to the led device 120 during the etching process.

In addition, since the adhesive structures 222 on the led elements 120 can be removed without over-etching, the bonding yield between the led elements 120 of the led array substrate 30 and the driving back plate of the led display panel (not shown) is high.

Moreover, in the present embodiment, the plasma for etching can also etch the adhesive structure 222 from the second air gap g2 and the third air gap g3. The second air gap g2 and the third air gap g3 also help to reduce the probability of damage to the led device 120 during the etching process.

Claims

1. A light emitting diode array substrate comprising:

a substrate;

an adhesive layer disposed on the substrate, wherein the adhesive layer includes a plurality of adhesive structures, and each of the adhesive structures has a first protrusion and a second protrusion spaced apart from each other; and

and a plurality of light emitting diode elements, wherein the adhesive structures are located between the light emitting diode elements and the substrate, and a first electrode and a second electrode of each of the light emitting diode elements are respectively connected to the first protrusion and the second protrusion of one of the adhesive structures.

2. The light emitting diode array substrate of claim 1, wherein each of the plurality of adhesive structures further comprises a platform, the first bump and the second bump are disposed on the platform, and the platform is located between the first bump and the substrate and between the second bump and the substrate.

3. The light emitting diode array substrate of claim 2, wherein the plurality of mesas of the adhesive structures are disconnected from each other.

4. The light emitting diode array substrate of claim 2, wherein each of the light emitting diode elements comprises:

a first type semiconductor layer;

a second type semiconductor layer;

an active layer disposed between the first type semiconductor layer and the second type semiconductor layer, wherein the first type semiconductor layer, the second type semiconductor layer and the active layer form a semiconductor structure; and

an insulating layer disposed on the semiconductor structure and having a first contact window and a second contact window respectively overlapped with the first type semiconductor layer and the second type semiconductor layer, wherein the first electrode and the second electrode are electrically connected to the first type semiconductor layer and the second type semiconductor layer through the first contact window and the second contact window of the insulating layer, respectively;

a first air gap exists between the insulating layer and the platform of one of the adhesive structures.

5. The light emitting diode array substrate of claim 4, wherein the first air gap is located between the first electrode and the second electrode and between the first protrusion and the second protrusion.

6. The light emitting diode array substrate of claim 5, wherein a second air gap is further present between the insulating layer and the platform of the one of the adhesive structures, and the first electrode and the first protrusion are located between the first air gap and the second air gap.

7. The light emitting diode array substrate of claim 6, wherein a third air gap is further present between the insulating layer and the mesa of the one of the plurality of adhesive structures, and the second electrode and the second protrusion are located between the first air gap and the third air gap.

8. The light emitting diode array substrate of claim 1, wherein the adhesive layer further comprises alignment marks outside the adhesive structures.

9. A light emitting diode array substrate comprising:

a substrate;

an adhesive layer disposed on the substrate;

a plurality of light emitting diode elements arranged on the adhesive layer; and

a plurality of adhesive structures respectively arranged on the light emitting diode elements, wherein each of the adhesive structures has a first surface facing the adhesive layer, and the first surface has a first protrusion and a second protrusion which are separated from each other; each of the light emitting diode elements has a first electrode and a second electrode, and the first electrode and the second electrode are respectively connected to the first protrusion and the second protrusion of one of the adhesive structures.

10. The light emitting diode array substrate of claim 9, wherein each of the adhesive structures further has a platform, and the first bump and the second bump are located between the platform and the adhesive layer.

11. The light emitting diode array substrate of claim 10, wherein the plurality of mesas of the adhesive structures are disconnected from each other.

12. The light emitting diode array substrate of claim 10, wherein each of the light emitting diode elements comprises:

a first type semiconductor layer;

a second type semiconductor layer;

13. The light emitting diode array substrate of claim 12, wherein the first air gap is located between the first electrode and the second electrode and between the first protrusion and the second protrusion.

14. The light emitting diode array substrate of claim 13, wherein a second air gap is further present between the insulating layer and the mesa of the one of the plurality of adhesive structures, and the first electrode and the first protrusion are located between the first air gap and the second air gap.

15. The light emitting diode array substrate of claim 14, wherein a third air gap is further present between the insulating layer and the mesa of the one of the adhesive structures, and the second electrode and the second protrusion are located between the first air gap and the third air gap.

16. The light emitting diode array substrate of claim 9, wherein each of the adhesive structures has a second surface facing away from the adhesive layer, and the roughness of the second surface is less than that of the first surface.

17. The light emitting diode array substrate of claim 9, wherein each of the adhesive structures has a second surface facing away from the adhesive layer, and the second surface is substantially planar.