Display chip and manufacturing method thereof

Abstract

The invention discloses a display chip and a manufacturing method thereof. The display chip at least comprises a connecting electrode, a first light-emitting unit and a second light-emitting unit, each light-emitting unit comprises a light-emitting functional layer, a first electrode and a second electrode; the first electrode and the second electrode of the first light-emitting unit are located on the side facing the second light-emitting unit, the first electrode of the second light-emitting unit is located on the side away from the first light-emitting unit, and the second electrode of the second light-emitting unit is located on the side close to the first light-emitting unit. The first electrode of the first light-emitting unit is connected with the second electrode of the second light-emitting unit, and the second electrode of the first light-emitting unit extends to the side, away from the first light-emitting unit, of the second light-emitting unit through the connecting electrode. Therefore, the display chip has the characteristics of low current and high voltage, and the area of the display chip can be reduced. And the bonding process of the display chip can be simplified.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of display technology, and in particular to a display chip and a manufacturing method thereof. Background Art

[0002] Micro-LED, or micro light-emitting diode, is an LED that is further reduced in size to the micron level based on the traditional light-emitting diode (LED). As a new generation of core display technology, Micro-LED has excellent characteristics such as low power consumption, high integration, high display effect, and long life, and is showing a booming development trend. Compared with traditional low-voltage Micro-LED, high-voltage Micro-LED chips have two major advantages: small driving current and low AC / DC conversion power loss, as well as simple and stable circuit design, high voltage conversion efficiency, and low energy loss. In the traditional preparation process of high-voltage Micro-LED chips, a large-size chip can be divided into multiple small light-emitting units, and then the light-emitting units are connected in series through electrodes to achieve a low-current, high-voltage Micro-LED. At this time, the size of the high-voltage Micro-LED chip is relatively large, which is not conducive to the realization of Micro-LED. Summary of the invention

[0003] The invention provides a display chip and a manufacturing method thereof, so as to reduce the size of the display chip.

[0004] In a first aspect, an embodiment of the present invention provides a display chip, comprising at least a connecting electrode and a first light-emitting unit and a second light-emitting unit arranged in a stacked manner; each light-emitting unit comprises a light-emitting functional layer, a first electrode and a second electrode; the first electrode and the second electrode of the first light-emitting unit are located on a side facing the second light-emitting unit, the first electrode of the second light-emitting unit is located on a side away from the first light-emitting unit, and the second electrode of the second light-emitting unit is located on a side close to the first light-emitting unit; the first electrode of the first light-emitting unit is connected to the second electrode of the second light-emitting unit, and the second electrode of the first light-emitting unit extends to a side of the second light-emitting unit away from the first light-emitting unit through the connecting electrode.

[0005] Optionally, the connecting electrode includes a first connecting electrode and a second connecting electrode, the first connecting electrode is arranged on one side of the light-emitting functional layer of the second light-emitting unit, the second connecting electrode is arranged on a side of the second light-emitting unit away from the first light-emitting unit, the first connecting electrode and the second connecting electrode are connected, and the second electrode of the first light-emitting unit is connected to the first connecting electrode.

[0006] Optionally, a surface of the first electrode of the first light-emitting unit close to the second light-emitting unit and a surface of the second electrode close to the second light-emitting unit are not in the same plane, and / or,

[0007] A surface of the second connecting electrode away from the second light emitting unit and a surface of the first electrode of the second light emitting unit away from the first light emitting unit are not in the same plane.

[0008] Optionally, along a first direction, two electrodes on the same side of a light-emitting unit both have protrusions relative to the light-emitting functional layer; wherein the first direction is a stacking direction of the light-emitting unit.

[0009] Optionally, the light-emitting functional layer comprises a first semiconductor layer, a quantum well layer, a second semiconductor layer and an ohmic contact layer stacked in sequence; the stacking order of the light-emitting functional layer of the first light-emitting unit is opposite to the stacking order of the light-emitting functional layer of the second light-emitting unit;

[0010] A surface of the first semiconductor layer close to the quantum well layer is at least partially exposed; the first electrode is disposed on a surface of the first semiconductor layer close to the quantum well layer and is insulated from the quantum well layer, the second semiconductor layer and the ohmic contact layer; and the second electrode is disposed on a surface of the ohmic contact layer away from the second semiconductor layer.

[0011] Optionally, the light-emitting unit also includes an insulating layer, which covers the ohmic contact layer and partially exposes the surface of the ohmic contact layer away from the second semiconductor layer, and the insulating layer covers the quantum well layer, the second semiconductor layer and the side of the ohmic contact layer close to the first electrode.

[0012] Optionally, the insulating layer includes a first dielectric layer and a second dielectric layer that are periodically arranged, and the first dielectric layer and the second dielectric layer form a distributed Bragg reflector.

[0013] Optionally, the display chip further includes a bonding layer, wherein the bonding layer is disposed between adjacent light-emitting units; a gap is provided between the first electrode and the insulating layer, and the bonding layer extends into the gap.

[0014] In a second aspect, an embodiment of the present invention further provides a method for manufacturing a display chip, which is used to manufacture the display chip described in the first aspect. The method for manufacturing the display chip includes:

[0015] A first light-emitting unit and a second light-emitting unit are provided; the first electrode and the second electrode of the first light-emitting unit are located on a side facing the second light-emitting unit, the first electrode of the second light-emitting unit is located on a side away from the first light-emitting unit, and the second electrode of the second light-emitting unit is located on a side close to the first light-emitting unit;

[0016] The first light emitting unit and the second light emitting unit are bonded together to form the display chip.

[0017] Optionally, the second light emitting unit further includes a substrate; bonding the first light emitting unit and the second light emitting unit comprises:

[0018] Bonding the first light-emitting unit and the second light-emitting unit;

[0019] removing the substrate of the second light emitting unit;

[0020] A portion of the connecting electrode and the first electrode are formed on a side of the second light emitting unit away from the first light emitting unit.

[0021] The technical solution of the embodiment of the present invention can make the display chip have the characteristics of low current and high voltage by arranging the first light-emitting unit and the second light-emitting unit arranged in a stacked manner and connected in series, and can also reduce the area of ​​the display chip. Moreover, the light-emitting units connected in series have both the first electrode and the second electrode on one side surface, which can simplify the manufacturing process of the display chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a display chip provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of the structure of another display chip provided by an embodiment of the present invention;

[0024] Figure 3 A schematic flow chart of a method for manufacturing a display chip provided by an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of the structure of a display chip in step S110 provided by an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of a structure with multiple light-emitting units on the same substrate provided by an embodiment of the present invention;

[0027] Figure 6 A schematic diagram of a structure of bonding adjacent light-emitting units provided by an embodiment of the present invention;

[0028] Figure 7A schematic diagram of a structure in which a substrate is removed after bonding adjacent light-emitting units according to an embodiment of the present invention;

[0029] Figure 8 A schematic diagram of a structure in which adjacent light-emitting units are bonded to form an electrode according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] Figure 1 FIG. 1 is a schematic diagram of a display chip provided by an embodiment of the present invention. Figure 1 As shown, the display chip at least includes a connecting electrode 20 and a first light-emitting unit 11 and a second light-emitting unit 12 which are stacked; each light-emitting unit includes a light-emitting functional layer 110, a first electrode 120 and a second electrode 130; the first electrode 120 and the second electrode 130 of the first light-emitting unit 11 are located on a side facing the second light-emitting unit 12, the first electrode 120 of the second light-emitting unit 12 is located on a side away from the first light-emitting unit 11, and the second electrode 130 of the second light-emitting unit 12 is located on a side close to the first light-emitting unit 11; the first electrode 120 of the first light-emitting unit 11 is connected to the second electrode 130 of the second light-emitting unit 12, and the second electrode 130 of the first light-emitting unit 11 extends to a side of the second light-emitting unit 12 away from the first light-emitting unit 11 through the connecting electrode 20.

[0032] Specifically, Figure 1 exemplarily shows that the display chip includes a first light-emitting unit 11 and a second light-emitting unit 12 stacked, and the light-emitting colors of the first light-emitting unit 11 and the second light-emitting unit 12 are the same or different. Each light-emitting unit includes a light-emitting functional layer 110, a first electrode 120 and a second electrode 130. When the display chip includes only the first light-emitting unit 11 and the second light-emitting unit 12, the display chip has a connecting electrode 20, which is arranged on one side of the second light-emitting unit 12. Along the first direction X, the first light-emitting unit 11 is Figure 1 The lower light emitting unit in the second light emitting unit 12 is Figure 1The display chip may further include a plurality of light-emitting units. On the side of the second light-emitting unit 12 away from the first light-emitting unit 11, a third light-emitting unit, a fourth light-emitting unit may be sequentially stacked. When the display chip includes a driving circuit board, the connecting electrode 20 and the first electrode 120 on the side of the second light-emitting unit 12 away from the first light-emitting unit 11 are connected to the driving circuit board, so that the driving circuit board can drive the first light-emitting unit 11 and the second light-emitting unit 12. At this time, the light-emitting surface of the display chip is the surface of the first light-emitting unit 11 away from the second light-emitting unit 12.

[0033] Since the first electrode 120 and the second electrode 130 of the first light-emitting unit 11 are located on the side facing the second light-emitting unit 12, and the first electrode 120 of the second light-emitting unit 12 is located on the side away from the first light-emitting unit 11, the first electrode 120 of the first light-emitting unit 11 can be directly connected to the second electrode 130 of the second light-emitting unit 12, so that the first light-emitting unit 11 and the second light-emitting unit 12 are connected in series. At the same time, the second electrode 130 of the first light-emitting unit 11 extends to the side of the second light-emitting unit 12 away from the first light-emitting unit 11 through the connecting electrode 20, so that the side of the second light-emitting unit 12 away from the first light-emitting unit 11 has the first electrode 120 and the connecting electrode 20, so that the first light-emitting unit 11 and the second light-emitting unit 12 can be connected in series, and the surface of the second light-emitting unit 12 away from the first light-emitting unit 11 has the first electrode 120 and the second electrode 130 of the display chip. Similarly, when the display chip includes a third light-emitting unit, the second electrode 130 of the third light-emitting unit can be directly connected to the first electrode 120 of the second light-emitting unit 12. At the same time, the connecting electrode 20 on the side of the second light-emitting unit 12 away from the first light-emitting unit 11 extends to the side of the third light-emitting unit away from the second light-emitting unit 12, so that the side of the third light-emitting unit away from the second light-emitting unit 12 has both the first electrode 120 and the connecting electrode 20, so that the three light-emitting units can be connected in series, and the surface of the third light-emitting unit away from the second light-emitting unit 12 has the first electrode 120 and the second electrode 130 of the display chip. By analogy, when the display chip includes multiple light-emitting units, the above process can be repeated, so that the multiple light-emitting units are connected in series, and the last light-emitting unit has the first electrode 120 and the second electrode 130 on the side away from the first light-emitting unit 11, so that when the light-emitting units connected in series are connected to the driving circuit board, the connection process can be simplified. Exemplarily, the driving circuit board can be connected to the light-emitting units connected in series by a bonding process. Thus, when at least two light-emitting units are stacked, different light-emitting units can be connected in series. The display chip has the characteristics of low current and high voltage, and the area of ​​the display chip can be reduced.

[0034] The technical solution of this embodiment can make the display chip have the characteristics of low current and high voltage by arranging the first light-emitting unit and the second light-emitting unit in a stacked arrangement and connecting them in series, and can also reduce the area of ​​the display chip. Moreover, the light-emitting units connected in series have both the first electrode and the second electrode on one side surface, which can simplify the manufacturing process of the display chip.

[0035] Continue to refer Figure 1 The connecting electrode 20 includes a first connecting electrode 210 and a second connecting electrode 220. The first connecting electrode 210 is arranged on one side of the light-emitting functional layer 110 of the second light-emitting unit 12, and the second connecting electrode 220 is arranged on a side of the second light-emitting unit 12 away from the first light-emitting unit 11. The first connecting electrode 210 and the second connecting electrode 220 are connected, and the second electrode 130 of the first light-emitting unit 11 is connected to the first connecting electrode 210.

[0036] Specifically, in the process of manufacturing the display chip, the light-emitting units can be formed on different substrates respectively, and then the different light-emitting units are bonded to form the display chip. When the first electrode 120 and the second electrode 130 of the light-emitting unit are located on both sides of the light-emitting functional layer 110, when the light-emitting unit is formed on the substrate, the second electrode 130 on the side of the light-emitting functional layer 110 away from the substrate can be formed, and then after the different light-emitting units are bonded, the substrate of the second light-emitting unit 12 is removed, and then the first electrode 120 is formed on the surface of the light-emitting functional layer 110 of the light-emitting unit away from the second electrode 130, so that the first electrode 120 and the second electrode 130 of the light-emitting unit are respectively located on both sides of the light-emitting functional layer 110. The first connecting electrode 210 is arranged on one side of the light-emitting functional layer 110 of the second light-emitting unit 12, and the first connecting electrode 210 can be formed simultaneously when the light-emitting functional layer 110 of the light-emitting unit is formed on the substrate. The second connecting electrode 220 is arranged on the side of the second light-emitting unit 12 away from the first light-emitting unit 11, and after the substrate of the second light-emitting unit 12 is removed, it can be formed simultaneously with the first electrode 120 of the second light-emitting unit 12. The second electrode 130 of the first light-emitting unit 11 is connected to the first connection electrode 210, and the first connection electrode 210 is connected to the second connection electrode 220. Exemplarily, the second electrode 130 of the first light-emitting unit 11 is bonded to the first connection electrode 210, and the first connection electrode 210 is in contact with the second connection electrode 220. Thus, the second electrode 130 of the first light-emitting unit 11 can be extended to the side of the second light-emitting unit 12 away from the first light-emitting unit 11 through the connection electrode 20, so that the display chip has the first electrode 120 and the second electrode 130 on the same side, so that it can be connected to the driving circuit board through a bonding process, simplifying the manufacturing process of the display chip.

[0037] It should be noted that when the display chip includes a plurality of light-emitting units, the connection electrode 20 includes a plurality of first connection electrodes 210 and a plurality of second connection electrodes 220. Between adjacent light-emitting units, along the first direction X, the second electrode 130 of the previous light-emitting unit is extended to the side of the next light-emitting unit away from the previous light-emitting unit through a first connection electrode 210 and a second connection electrode 220, so that the second electrode 130 of the first light-emitting unit 11 can be extended to the side of the last light-emitting unit away from the first light-emitting unit 11 through the plurality of first connection electrodes 210 and the plurality of second connection electrodes 220, so that the display chip has the first electrode 120 and the second electrode 130 on the same side.

[0038] Continue to refer Figure 1 , a surface 121 of the first electrode 120 of the first light-emitting unit 11 close to the second light-emitting unit 12 and a surface 131 of the second electrode 130 close to the second light-emitting unit 12 are not in the same plane.

[0039] Specifically, Figure 1 As shown, the surface 121 of the first electrode 120 of the first light-emitting unit 11 close to the second light-emitting unit 12 is the end face of the first electrode 120 of the first light-emitting unit 11 facing the second light-emitting unit 12. The surface 131 of the second electrode 130 of the first light-emitting unit 11 close to the second light-emitting unit 12 is the end face of the second electrode 130 of the first light-emitting unit 11 facing the second light-emitting unit 12. By setting the surface 121 of the first electrode 120 of the first light-emitting unit 11 close to the second light-emitting unit 12 and the surface 131 of the second electrode 130 close to the second light-emitting unit 12 not to be in the same plane, the end face of the first electrode 120 of the first light-emitting unit 11 facing the second light-emitting unit 12 and the end face of the second electrode 130 of the first light-emitting unit 11 facing the second light-emitting unit 12 have a height difference as the first height difference. Therefore, when different light-emitting units are connected by a bonding process, the alignment difficulty and the bonding difficulty of different light-emitting units in the bonding process can be improved, and the bonding yield between different light-emitting units and the yield of the display chip are improved.

[0040] It should be noted that when the end faces of the first electrode 120 and the second electrode 130 of the first light-emitting unit 11 away from the first light-emitting unit 11 are not on the same plane, the surface of the second electrode 130 of the second light-emitting unit 12 close to the first light-emitting unit 11 and the surface of the connecting electrode 20 close to the first light-emitting unit 11 are not on the same plane, that is, the end face of the second electrode 130 of the second light-emitting unit 12 facing the first light-emitting unit 11 and the end face of the connecting electrode 20 facing the first light-emitting unit 11 have a height difference as the second height difference. The first height difference is complementary to the second height difference, so that the two electrodes can be bonded synchronously when the first light-emitting unit 11 and the second light-emitting unit 12 are bonded. For example, as Figure 1 As shown, the distance between the end face of the first electrode 120 of the first light-emitting unit 11 facing the second light-emitting unit 12 and the surface of the light-emitting functional layer 110 of the first light-emitting unit 11 is smaller than the distance between the end face of the second electrode 130 of the first light-emitting unit 11 facing the second light-emitting unit 12 and the surface of the light-emitting functional layer 110 of the first light-emitting unit 11, and the distance between the end face of the second electrode 130 of the second light-emitting unit 12 facing the first light-emitting unit 11 and the surface of the light-emitting functional layer 110 of the second light-emitting unit 12 is greater than the distance between the end face of the connecting electrode 20 facing the first light-emitting unit 11 and the surface of the light-emitting functional layer 110 of the second light-emitting unit 12, so that when the first light-emitting unit 11 and the second light-emitting unit 12 are bonded, the first electrode 120 of the first light-emitting unit 11 can be connected to the second electrode 130 of the second light-emitting unit 12, and the second electrode 130 of the first light-emitting unit 11 can be connected to the connecting electrode 20 at the same time.

[0041] In some embodiments, continue to refer to Figure 1 , the surface of the second connection electrode 220 away from the second light-emitting unit 12 is the end face of the second connection electrode 220 away from the first connection electrode 210, and the surface of the first electrode 120 of the second light-emitting unit 12 away from the first light-emitting unit 11 is the end face of the first electrode 120 of the second light-emitting unit 12 away from its own light-emitting functional layer 110. When the display chip only includes the first light-emitting unit 11 and the second light-emitting unit 12, the surface of the second connection electrode 220 away from the second light-emitting unit 12 and the surface of the first electrode 120 of the second light-emitting unit 12 away from the first light-emitting unit 11 are located in the same plane. At this time, the two electrodes of the second light-emitting unit 12 away from the first light-emitting unit 11 can be used as the two electrodes of the display chip and directly connected to the driving circuit board to ensure bonding reliability.

[0042] In some embodiments, the surface of the second connection electrode 220 away from the second light emitting unit 12 and the surface of the first electrode 120 of the second light emitting unit 12 away from the first light emitting unit 11 may not be in the same plane.

[0043] Specifically, when the display chip includes a plurality of light-emitting units, the display chip may include a first light-emitting unit 11 and a plurality of second light-emitting units 12. The number of the first connection electrodes 210 and the number of the second connection electrodes 220 in the connection electrode 20 are both the number of the second light-emitting units 12. Each first connection electrode 210 is arranged on one side of a second light-emitting unit 12, and each second connection electrode 220 is arranged on one side of a second light-emitting unit 12 away from the first light-emitting unit 11. At this time, the end faces of the first second connection electrode 220 to the n-1 second connection electrode 220 away from the first connection electrode 210 in the same connection electrode 20 may be arranged to be not in the same plane as the end faces of the corresponding first electrode 120 away from the side of its own light-emitting functional layer 110, so that when the plurality of light-emitting units are bonded in sequence, the electrodes between the adjacent light-emitting units have a height difference, which can improve the alignment difficulty and the bonding difficulty of different light-emitting units in the bonding process, and improve the bonding yield between different light-emitting units and the yield of the display chip. Exemplarily, when the display chip includes two second light-emitting units 12, the connecting electrode 20 includes two first connecting electrodes 210 and two second connecting electrodes 220, and the first second connecting electrode 220 is arranged on the side of the first second light-emitting unit 12 away from the first light-emitting unit 11. At this time, the end face of the first second connecting electrode 220 away from the first first connecting electrode 210 and the end face of the first electrode 120 of the second light-emitting unit 12 away from the light-emitting functional layer 110 of the second light-emitting unit 12 can be set to be not in the same plane. When bonding the first second light-emitting unit 12 and the second second light-emitting unit 12, the alignment difficulty and the bonding difficulty of different light-emitting units in the bonding process can be improved, thereby improving the bonding yield between different light-emitting units and the yield of the display chip.

[0044] In other embodiments, when the display chip includes a plurality of light-emitting units, the display chip may include one first light-emitting unit 11 and a plurality of second light-emitting units 12. The number of the first connection electrodes 210 in the connection electrode 20 is the number of the second light-emitting units 12, and the number of the second connection electrode 220 may be one. Each first connection electrode 210 is disposed on one side of a second light-emitting unit 12, and the second connection electrode 220 is disposed on the side of the last second light-emitting unit 12 away from the first light-emitting unit 11.

[0045] Continue to refer Figure 1 Along the first direction X, the two electrodes on the same side of a light-emitting unit have protrusions relative to the light-emitting functional layer 110; wherein the first direction X is the stacking direction of the light-emitting unit.

[0046] Specifically, Figure 1As shown, the light-emitting unit includes a first light-emitting unit 11 and a second light-emitting unit 12, and the two electrodes located on the same side of the first light-emitting unit 11 are the first electrode 120 and the second electrode 130 of the first light-emitting unit 11. At this time, the first electrode 120 and the second electrode 130 of the first light-emitting unit 11 both have protrusions relative to the light-emitting functional layer 110 of the first light-emitting unit 11, and a groove can be formed on the surface of the light-emitting functional layer 110. When the first light-emitting unit 11 and the second light-emitting unit 12 are bonded, the bonding material can be arranged in the groove, so as to facilitate the bonding process and improve the bonding yield. Similarly, the two electrodes located on the same side of the second light-emitting unit 12 are the connecting electrode 20 and the first electrode 120 of the second light-emitting unit 12. At this time, the connecting electrode 20 and the first electrode 120 of the second light-emitting unit 12 can be arranged to have protrusions relative to the light-emitting functional layer 110 of the second light-emitting unit 12, and a groove can also be formed on the surface of the light-emitting functional layer 110 of the second light-emitting unit 12. When the second light-emitting unit 12 is bonded to other light-emitting units or a driving circuit board, the bonding material can also be arranged in the groove, so as to facilitate the bonding process and improve the bonding yield.

[0047] Continue to refer Figure 1 The light-emitting functional layer 110 includes a first semiconductor layer 111, a quantum well layer 112, a second semiconductor layer 113 and an ohmic contact layer 114 which are stacked in sequence; the stacking order of the light-emitting functional layer 110 of the first light-emitting unit 11 is opposite to the stacking order of the light-emitting functional layer 110 of the second light-emitting unit 12; a surface of the first semiconductor layer 111 close to the quantum well layer 112 is at least partially exposed, and the first electrode 120 is arranged on a surface of the first semiconductor layer 111 close to the quantum well layer 112, and is insulated from the quantum well layer 112, the second semiconductor layer 113 and the ohmic contact layer 114; the second electrode 130 is arranged on a surface of the ohmic contact layer 114 away from the second semiconductor layer 113.

[0048] Specifically, Figure 1It is exemplarily shown that the first semiconductor layer 111 is an n-type semiconductor layer, and the second semiconductor layer 113 is a p-type semiconductor layer. In this case, the first electrode 120 is an n-electrode, and the second electrode 130 is a p-electrode. The quantum well layer 112, the second semiconductor layer 113 and the ohmic contact layer 114 partially cover the first semiconductor layer 111, so that the surface of the first semiconductor layer 111 is at least partially exposed. In this case, the first electrode 120 can be directly arranged on the exposed surface of the first semiconductor layer 111, avoiding etching of the light-emitting functional layer 110, and simplifying the manufacturing process of the display chip. At the same time, the first electrode 120 is insulated from the quantum well layer 112, the second semiconductor layer 113 and the ohmic contact layer 114, avoiding short-circuit connection between the first electrode 120 and the quantum well layer 112, the second semiconductor layer 113 and the ohmic contact layer 114. The material of the ohmic contact layer 114 can be a transparent conductive material, such as indium tin oxide. The stacking order of the light-emitting functional layer 110 of the first light-emitting unit 11 is opposite to the stacking order of the light-emitting functional layer 110 of the second light-emitting unit 12, so that the first electrode 120 of the first light-emitting unit 11 is disposed adjacent to the second electrode 130 of the second light-emitting unit 12, and the second electrode 130 of the first light-emitting unit 11 is disposed adjacent to the connecting electrode 20, so that the first light-emitting unit 11 and the second light-emitting unit 12 can be connected by bonding. When the display chip includes at least two second light-emitting units 12, the stacking order of the light-emitting functional layers 110 of different second light-emitting units 12 is the same, and the second electrode 130 of the second light-emitting unit 12 can also be disposed adjacent to the first electrode 120 of the adjacent second light-emitting unit 12, which is conducive to simplifying the series connection between different second light-emitting units 12. In addition, the second electrode 130 is in contact with and connected to the ohmic contact layer 114, and then extends to the side of the last second light-emitting unit 12 away from the first light-emitting unit 11 through the connecting electrode 20, so that the connecting electrode 20 serves as the second electrode of the display chip, and the first electrode 120 of the last second light-emitting unit 12 serves as the first electrode of the display chip, so that the two electrodes of the display chip are located on the same side of the display chip, and when the display chip is connected to the driving circuit board, they can be connected through a bonding process.

[0049] It should be noted that, in some embodiments, the first semiconductor layer 111 may be a p-type semiconductor layer, and the second semiconductor layer 113 may be an n-type semiconductor layer. In this case, the first electrode 120 is a p-electrode, and the second electrode 130 is an n-electrode. The specific process is similar to the above process and will not be repeated here.

[0050] Continue to refer Figure 1The light-emitting unit also includes an insulating layer 140, which covers the ohmic contact layer 114 and partially exposes the surface of the ohmic contact layer 114 away from the second semiconductor layer 113. The insulating layer 140 covers the quantum well layer 112, the second semiconductor layer 113 and the side of the ohmic contact layer 114 close to the first electrode 120.

[0051] Specifically, Figure 1 As shown, the material of the insulating layer 140 can be silicon dioxide or a transparent resin, etc. By arranging the insulating layer 140 on the ohmic contact layer 114, and the insulating layer 140 covers the quantum well layer 112, the second semiconductor layer 113 and the side of the ohmic contact layer 114 close to the first electrode 120, the insulation reliability of the first electrode 120 and the quantum well layer 112, the second semiconductor layer 113 and the ohmic contact layer 114 can be ensured. In addition, the insulating layer 140 can also have adhesion. By arranging the insulating layer 140 between adjacent light-emitting units, the bonding material between the adjacent light-emitting units can be better adhered to the surface of the light-emitting unit, thereby improving the bonding yield.

[0052] In some embodiments, the insulating layer includes a first dielectric layer and a second dielectric layer that are periodically arranged, and the first dielectric layer and the second dielectric layer form a distributed Bragg reflector.

[0053] Specifically, the material of the first dielectric layer may be silicon dioxide, and the material of the second dielectric layer may be titanium dioxide. By arranging the first dielectric layer and the second dielectric layer periodically along the first direction, a distributed Bragg reflector (DBR) may be formed on the side of the light-emitting unit away from the light-emitting surface, so that the light emitted by the light-emitting functional layer in the light-emitting unit is reflected at the DBR to the light-emitting surface, thereby improving the light-emitting efficiency of the light-emitting unit, and further improving the light-emitting efficiency of the display chip.

[0054] It should be noted that when the first dielectric layer of the insulating layer is a silicon dioxide layer and the second dielectric layer is a titanium dioxide layer, the silicon dioxide layer and the titanium dioxide layer can be arranged periodically, and the silicon dioxide layer is located at the outermost side of the light-emitting unit, thereby ensuring the surface adhesion of the insulating layer, which is used to improve the adhesion between the light-emitting unit and the bonding material and improve the bonding yield.

[0055] Figure 2 FIG. 1 is a schematic diagram of the structure of another display chip provided by an embodiment of the present invention. Figure 2 As shown, the display chip further includes a bonding layer 30 , which is disposed between adjacent light-emitting units; there is a gap between the first electrode 120 and the insulating layer 140 , and the bonding layer 30 extends into the gap.

[0056] Specifically, there is a gap between the first electrode 120 and the insulating layer 140. When bonding adjacent light-emitting units, the bonding material of the bonding layer 30 can flow into the gap, and the side bonding connection of the light-emitting unit can be realized, thereby improving the stability of the display chip. At the same time, the gap can serve as a receiving space, and the excess bonding material of the bonding layer 30 can flow into the receiving space to avoid the bonding material from squeezing the electrodes on both sides, further improving the stability and reliability of the display chip, and improving the bonding yield of the display chip. Among them, when the display chip only includes the first light-emitting unit 11 and the second light-emitting unit 12, the adjacent light-emitting units are the first light-emitting unit 11 and the second light-emitting unit 12. When the display chip includes at least two second light-emitting units 12, the adjacent light-emitting units also include adjacent second light-emitting units 12.

[0057] An embodiment of the present invention further provides a method for manufacturing a display chip, which is used to manufacture the display chip provided by any embodiment of the present invention. Figure 3 The present invention provides a flow chart of a method for manufacturing a display chip. Figure 3 As shown, the method includes:

[0058] S110, providing a first light-emitting unit and a second light-emitting unit; the first electrode and the second electrode of the first light-emitting unit are located on a side facing the second light-emitting unit, the first electrode of the second light-emitting unit is located on a side away from the first light-emitting unit, and the second electrode of the second light-emitting unit is located on a side close to the first light-emitting unit.

[0059] Specifically, the light-emitting unit can be formed by epitaxially growing a light-emitting functional layer on a substrate and forming a first electrode and a second electrode, thereby forming a light-emitting unit. Figure 4 A schematic diagram of the structure of a display chip in step S110 provided by an embodiment of the present invention. Figure 4 As shown, the first light emitting unit can be Figure 4 The lower light emitting unit in the second light emitting unit may be Figure 4 The two light-emitting units both have a substrate 40, and the side of the second light-emitting unit has a first connection electrode 210 connected to the electrode 20, the first connection electrode 210 can be arranged in the isolation groove between adjacent light-emitting units on the same substrate 40, and the side of the second light-emitting unit close to the first light-emitting unit has a second electrode 130. Exemplarily, Figure 5 A schematic diagram of a structure with multiple light-emitting units on the same substrate provided by an embodiment of the present invention. Figure 5As shown, the substrate 40 is exemplarily shown to include three second light-emitting units. An isolation groove A is provided between adjacent second light-emitting units to electrically and / or optically isolate different second light-emitting units. The first connection electrode 210 is disposed in the isolation groove A, so that the first connection electrode 210 is disposed on one side of the second light-emitting unit, which can avoid etching the second light-emitting unit, simplify the preparation process of the display chip, and save the preparation cost of the display chip.

[0060] S120, bonding the first light emitting unit and the second light emitting unit to form a display chip.

[0061] The technical solution of this embodiment can make the display chip have the characteristics of low current and high voltage by arranging the first light-emitting unit and the second light-emitting unit in a stacked arrangement and connecting them in series, and can also reduce the area of ​​the display chip. Moreover, the light-emitting units connected in series have both the first electrode and the second electrode on one side surface, which can simplify the manufacturing process of the display chip.

[0062] In some embodiments, the second light emitting unit is disposed on the substrate. Bonding the first light emitting unit to the second light emitting unit comprises:

[0063] Bonding the first light-emitting unit to the second light-emitting unit;

[0064] Specifically, Figure 6 A schematic diagram of a structure of bonding adjacent light-emitting units provided by an embodiment of the present invention, such as Figure 6 As shown, after the upper light-emitting unit and the lower light-emitting unit are bonded, the second electrode of the upper light-emitting unit is connected to the first electrode of the lower light-emitting unit. The connecting electrode is located on the substrate and is arranged on the same side as the light-emitting functional layer, and the connecting electrode is connected to the second electrode of the lower light-emitting unit.

[0065] removing the substrate of the second light emitting unit;

[0066] Specifically, Figure 7 A schematic diagram of a structure in which adjacent light-emitting units are bonded and then the substrate is removed according to an embodiment of the present invention, such as Figure 7 As shown, after the upper light-emitting unit and the lower light-emitting unit are bonded, the substrate of the upper light-emitting unit is removed.

[0067] A portion of the connecting electrode and the first electrode are formed on a side of the second light emitting unit away from the first light emitting unit.

[0068] Specifically, Figure 8 A schematic diagram of a structure of an electrode formed by bonding adjacent light-emitting units provided by an embodiment of the present invention. Figure 8As shown, after removing the substrate of the upper light-emitting unit, a second connecting electrode and a first electrode are formed on a side of the upper light-emitting unit away from the lower light-emitting unit, so that the second connecting electrode is connected to the second electrode of the lower light-emitting unit through the first connecting electrode, thereby forming a first electrode and a second electrode on a side of the upper light-emitting unit away from the lower light-emitting unit as electrodes of the display chip.

[0069] When the display chip includes a plurality of light-emitting units, the above process can be repeated, that is, Figures 5 to 7 The process continues, and other light-emitting units are bonded on the side of the upper light-emitting unit away from the lower light-emitting unit until all the light-emitting units are bonded to form a display chip.

[0070] In some embodiments, after the plurality of light-emitting units are bonded and connected, the method for manufacturing a display chip may further include: removing or thinning a substrate of a first light-emitting unit.

[0071] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A display chip, characterized in that: At least includes a connecting electrode and a first light-emitting unit and a second light-emitting unit arranged in a stacked manner; each light-emitting unit includes a light-emitting functional layer, a first electrode and a second electrode; the first electrode and the second electrode of the first light-emitting unit are located on a side facing the second light-emitting unit, the first electrode of the second light-emitting unit is located on a side away from the first light-emitting unit, and the second electrode of the second light-emitting unit is located on a side close to the first light-emitting unit; the first electrode of the first light-emitting unit is connected to the second electrode of the second light-emitting unit, and the second electrode of the first light-emitting unit extends to a side of the first light-emitting unit away from the first light-emitting unit through the connecting electrode.

2. The display chip according to claim 1, characterized in that: The connecting electrode includes a first connecting electrode and a second connecting electrode, the first connecting electrode is arranged on one side of the light-emitting functional layer of the second light-emitting unit, the second connecting electrode is arranged on a side of the second light-emitting unit away from the first light-emitting unit, the first connecting electrode and the second connecting electrode are connected, and the second electrode of the first light-emitting unit is connected to the first connecting electrode.

3. The display chip according to claim 2, characterized in that: The surface of the first electrode of the first light-emitting unit close to the second light-emitting unit and the surface of the second electrode close to the second light-emitting unit are not in the same plane, and / or, A surface of the second connecting electrode away from the second light emitting unit and a surface of the first electrode of the second light emitting unit away from the first light emitting unit are not in the same plane.

4. The display chip according to any one of claims 1 to 3, characterized in that: Along a first direction, two electrodes on the same side of a light-emitting unit both have protrusions relative to the light-emitting functional layer; wherein the first direction is a stacking direction of the light-emitting unit.

5. The display chip according to claim 4, characterized in that: The light-emitting functional layer comprises a first semiconductor layer, a quantum well layer, a second semiconductor layer and an ohmic contact layer stacked in sequence; the stacking order of the light-emitting functional layer of the first light-emitting unit is opposite to the stacking order of the light-emitting functional layer of the second light-emitting unit; A surface of the first semiconductor layer close to the quantum well layer is at least partially exposed; the first electrode is disposed on a surface of the first semiconductor layer close to the quantum well layer and is insulated from the quantum well layer, the second semiconductor layer and the ohmic contact layer; and the second electrode is disposed on a surface of the ohmic contact layer away from the second semiconductor layer.

6. The display chip according to claim 5, characterized in that: The light-emitting unit also includes an insulating layer, which covers the ohmic contact layer and partially exposes the surface of the ohmic contact layer away from the second semiconductor layer. The insulating layer covers the quantum well layer, the second semiconductor layer and the side of the ohmic contact layer close to the first electrode.

7. The display chip according to claim 6, characterized in that: The insulating layer includes a first dielectric layer and a second dielectric layer that are periodically arranged, and the first dielectric layer and the second dielectric layer form a distributed Bragg reflector.

8. The display chip according to claim 6, characterized in that: It also includes a bonding layer, which is arranged between adjacent light-emitting units; there is a gap between the first electrode and the insulating layer, and the bonding layer extends into the gap.

9. A method for manufacturing a display chip, characterized in that: Used to manufacture the display chip according to any one of claims 1 to 8, the manufacturing method of the display chip comprising: A first light-emitting unit and a second light-emitting unit are provided; the first electrode and the second electrode of the first light-emitting unit are located on a side facing the second light-emitting unit, the first electrode of the second light-emitting unit is located on a side away from the first light-emitting unit, and the second electrode of the second light-emitting unit is located on a side close to the first light-emitting unit; The first light emitting unit and the second light emitting unit are bonded together to form the display chip.

10. The method for manufacturing a display chip according to claim 9, characterized in that: The second light emitting unit further includes a substrate; bonding the first light emitting unit and the second light emitting unit includes: Bonding the first light-emitting unit and the second light-emitting unit; removing the substrate of the second light emitting unit; A portion of the connecting electrode and the first electrode are formed on a side of the second light emitting unit away from the first light emitting unit.

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