Display substrate, manufacturing method thereof and display device

Abstract

The present invention discloses a display substrate, a manufacturing method thereof and a display device, comprising: a driving backplane, the driving backplane comprising a plurality of connection electrodes; a plurality of light-emitting chips, each light-emitting chip being bonded and connected to a corresponding group of connection electrodes; an insulating layer, located on a side of a layer where the plurality of light-emitting chips are located away from the driving backplane; and a color conversion layer, located on a side of the insulating layer away from the driving backplane, the color conversion layer being in direct contact with the insulating layer.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display substrate, a manufacturing method thereof, and a display device. Background Art

[0002] Micro-LED (Light Emitting Diode) display device is a traditional LED structure that is miniaturized and matrixed to achieve display. Due to its advantages of small size, high resolution, high brightness, high luminous efficiency, and low power consumption, it has become a research focus in the display field. Summary of the invention

[0003] The embodiment of the present invention provides a display substrate, a manufacturing method thereof and a display device, which are used to improve the light crosstalk problem in an LED display device.

[0004] Specifically, an embodiment of the present invention provides a display substrate, comprising:

[0005] A driving backplane, the driving backplane comprising a plurality of groups of connecting electrodes;

[0006] A plurality of light-emitting chips, each of which is bonded and connected to a group of the connecting electrodes;

[0007] An insulating layer, located on a side of the layer where the plurality of light-emitting chips are located away from the driving backplane;

[0008] The color conversion layer is located on a side of the insulating layer away from the driving backplane, and the color conversion layer is in direct contact with the insulating layer.

[0009] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the insulating layer includes a buffer layer.

[0010] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the insulating layer further includes an inorganic planarization layer located between the buffer layer and the color conversion layer.

[0011] Optionally, in the above-mentioned display substrate provided in an embodiment of the present invention, each of the light-emitting chips includes one first light-emitting unit, one second light-emitting unit and one third light-emitting unit, and the first light-emitting unit, the second light-emitting unit and the third light-emitting unit share a first pole, and the first pole is an anode or a cathode.

[0012] Optionally, in the above-mentioned display substrate provided in an embodiment of the present invention, in each of the light-emitting chips, when the second pole of the first light-emitting unit, the second pole of the second light-emitting unit, the second pole of the third light-emitting unit, and any two of the first pole are in the same row or column, the distance between the two is 20μm-40μm, and the second pole of the first light-emitting unit, the second pole of the second light-emitting unit, and the second pole of the third light-emitting unit are all anodes or cathodes, and are different from the first pole.

[0013] Optionally, in the display substrate provided by an embodiment of the present invention, in each of the light-emitting chips, the second electrode of the first light-emitting unit is arranged in the same row as the first electrode and in the same column as the second electrode of the third light-emitting unit, and the second electrode of the second light-emitting unit is arranged in the same row as the second electrode of the third light-emitting unit and in the same column as the first electrode;

[0014] The area of ​​the light emitting chip is equal to (D+a+a R ) 2 、(D+b R +b B ) 2 、(D+a G +a B ) 2 、(D+b+b G ) 2 The maximum value in ;

[0015] Among them, a R is the length of the second electrode of the first light-emitting unit in the row direction, b R is the width of the second electrode of the first light-emitting unit in the column direction, a G is the length of the second electrode of the second light-emitting unit in the row direction, b G is the width of the second electrode of the second light-emitting unit in the column direction, a B is the length of the second electrode of the third light-emitting unit in the row direction, b B is the width of the second pole of the third light-emitting unit in the column direction, a is the length of the first pole in the row direction, b is the width of the first pole in the column direction, and D is the distance between the second pole of the first light-emitting unit and the first pole, the second pole of the first light-emitting unit and the second pole of the third light-emitting unit, the second pole of the second light-emitting unit and the first pole, and the second pole of the second light-emitting unit and the second pole of the third light-emitting unit.

[0016] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the insulating layer completely covers a side of the light-emitting chip away from the driving backplane, and the insulating layer has a hollow structure at a gap between the light-emitting chips.

[0017] Optionally, the display substrate provided in the embodiment of the present invention further includes: a black dam filled between the light-emitting chips.

[0018] Optionally, in the above-mentioned display substrate provided by an embodiment of the present invention, the color conversion layer includes a black matrix and a plurality of color conversion parts; wherein the black matrix has a plurality of openings, and a color conversion part is disposed at each of the openings;

[0019] Each of the color conversion units is arranged corresponding to one of the first light-emitting unit, the second light-emitting unit or the third light-emitting unit, and the color conversion unit is configured to directly transmit the emission light corresponding to the first light-emitting unit, the second light-emitting unit or the third light-emitting unit, or to convert the emission light corresponding to the first light-emitting unit, the second light-emitting unit or the third light-emitting unit into a target color.

[0020] Optionally, in the display substrate provided by an embodiment of the present invention, in a direction perpendicular to the driving backplane, the cross-sectional shape of the black matrix is ​​an inverted trapezoid that is wide at the top and narrow at the bottom, and the cross-sectional shape of the color conversion portion is a regular trapezoid that is narrow at the top and wide at the bottom.

[0021] Optionally, in the above-mentioned display substrate provided by the embodiment of the present invention, it further includes a color filter layer located on a side of the color conversion layer away from the insulating layer.

[0022] Based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing the above-mentioned display substrate, comprising:

[0023] A driving backplane and a light-emitting component are provided; wherein the driving backplane includes a plurality of groups of connecting electrodes, and the light-emitting component includes a sapphire substrate, a buffer layer disposed on the entire surface of the sapphire substrate, and a plurality of light-emitting chips on a side of the buffer layer away from the sapphire substrate;

[0024] Bonding and connecting the plurality of light-emitting chips to the plurality of groups of connecting electrodes;

[0025] Removing the sapphire substrate by laser lift-off;

[0026] A color conversion layer is formed on the buffer layer, the color conversion layer being in direct contact with the insulating layer including the buffer layer.

[0027] Optionally, in the above manufacturing method provided by the embodiment of the present invention, after removing the sapphire substrate by laser lift-off and before forming the color conversion layer on the buffer layer, the method further includes:

[0028] The buffer layer at the gaps between the light-emitting chips is removed, and a black dam is filled at the gaps between the light-emitting chips.

[0029] Optionally, in the above manufacturing method provided by the embodiment of the present invention, after removing the buffer layer at the gaps between the light-emitting chips and filling the gaps between the light-emitting chips with black dams, and before forming the color conversion layer on the buffer layer, the method further includes:

[0030] An inorganic flat layer is formed entirely on the buffer layer and the black dam.

[0031] Based on the same inventive concept, an embodiment of the present invention further provides a display device, comprising the above-mentioned display substrate.

[0032] The beneficial effects of the present invention are as follows:

[0033] The display substrate, the manufacturing method thereof and the display device provided by the embodiment of the present invention include: a driving backplane, the driving backplane includes a plurality of connection electrodes; a plurality of light-emitting chips, each light-emitting chip is bonded and connected to a corresponding group of connection electrodes; an insulating layer, located on the side of the layer where the plurality of light-emitting chips are located away from the driving backplane; a color conversion layer, located on the side of the insulating layer away from the driving backplane, and the color conversion layer is in direct contact with the insulating layer. Since there is a sapphire substrate between the insulating layer and the color conversion layer in the prior art, the emitted light of the light-emitting chip is reflected on the sapphire substrate, resulting in poor light crosstalk. In the present invention, the insulating layer is in direct contact with the color conversion layer, so there is no sapphire substrate in the present invention, thereby avoiding light crosstalk caused by the emitted light of the light-emitting chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the structure of a display substrate provided by an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of another structure of a display substrate provided by an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of the structure of a light-emitting chip provided by an embodiment of the present invention;

[0037] Figure 4 A schematic diagram of splicing multiple display substrates provided by an embodiment of the present invention;

[0038] Figures 5 to 11 The embodiments of the present invention are respectively provided Figure 2 The figure shows a schematic diagram of the structure of the display substrate during the manufacturing process. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the drawings of the embodiment of the present invention. It should be noted that the size and shape of the figures in the drawings do not reflect the actual proportion, and the purpose is only to illustrate the content of the present invention. And the same or similar numbers throughout represent the same or similar elements or elements with the same or similar functions. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0040] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar terms used in the specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Inside", "outside", "upper", "lower" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] Usually, after completing the production of multiple LED light-emitting chips on the sapphire substrate, independent LED light-emitting chips are obtained by cutting, and then the independent LED light-emitting chips are bonded to the connection electrodes (Pad) on the driver backplane by means of ejector pins. During the bonding process using ejector pins, the sapphire substrate can prevent the LED light-emitting chip from being damaged. However, since the sapphire substrate is relatively thick, the emitted light from different light-emitting units is reflected on the sapphire substrate, which will cause great light crosstalk between adjacent light-emitting units.

[0042] In order to at least solve the above problems existing in the related art, an embodiment of the present invention provides a display substrate, such as Figure 1 As shown, it may include:

[0043] A driving back plate BP, the driving back plate BP comprises a plurality of groups of connecting electrodes 101;

[0044] A plurality of light emitting chips 102, each light emitting chip 102 is bonded and connected to a group of connecting electrodes 101;

[0045] The insulating layer 103 is located on a side of the layer where the plurality of light emitting chips 102 are located away from the driving backplane BP;

[0046] The color conversion layer 104 is located on a side of the insulating layer 103 away from the driving backplane BP, and the color conversion layer 104 is in direct contact with the insulating layer 103 .

[0047] In the present invention, the multiple light-emitting chips 102 on the sapphire substrate can be first transferred to the driving backplane BP for bonding, and then the sapphire substrate can be removed, so that the insulating layer 103 is located on the side of the layer where the multiple light-emitting chips 102 are located away from the driving backplane BP, and the insulating layer 103 can be in direct contact with the color conversion layer 104 manufactured subsequently. Therefore, there is no sapphire substrate in the present invention, thereby avoiding light crosstalk caused by the emission light of the light-emitting chip being reflected on the sapphire substrate.

[0048] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 1 As shown, the insulating layer 103 may include a buffer layer 1031. When the light emitting chip 102 is a green light emitting chip or a blue light emitting chip, the material of the buffer layer 1031 may be GaN; when the light emitting chip 102 is a red light emitting chip, the material of the buffer layer 1031 may be GaP. Figure 2 As shown, the insulating layer 103 may further include an inorganic flat layer 1032 between the buffer layer 1031 and the color conversion layer 104. The inorganic flat layer 1032 may provide a flat surface for the color conversion layer 104, and the inorganic flat layer 1032 may have a large adhesion to the color conversion layer 104. In a specific implementation, a layer of SiNx material with a thickness of about 1 μm may be deposited on the buffer layer 1031 as the inorganic flat layer 1032.

[0049] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 1 and Figure 2 As shown, each light emitting chip 102 may include a first light emitting unit 1021, a second light emitting unit 1022 and a third light emitting unit 1023. The first light emitting unit 1021, the second light emitting unit 1022 and the third light emitting unit 1023 share a first electrode C, which may be an anode or a cathode.

[0050] Since the display substrate in the related art has a sapphire substrate, in order to avoid light crosstalk, it is generally necessary to set the interval between adjacent light-emitting units to be larger. For example, when the thickness of the sapphire substrate is 60μm, the interval between adjacent light-emitting units is greater than 100μm to prevent crosstalk, which results in a low utilization rate of the light-emitting chip 102. In the present invention, since there is no sapphire substrate, the poor crosstalk can be effectively improved. Therefore, when the light-emitting chip 102 includes multiple light-emitting units, the interval between the light-emitting units in the present invention can be smaller than the interval between the light-emitting units in the related art, thereby effectively improving the utilization rate of the light-emitting chip 102. In addition, the reduction of the interval between the light-emitting units, on the one hand, helps to improve the resolution (PPI), and on the other hand, it is conducive to further reducing the area of ​​the light-emitting chip 102, and the current density required to achieve the same brightness level increases. According to the micro-LED efficiency curve, as the current density increases, the light-emitting chip 102 can work in the high-efficiency area.

[0051] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 3 As shown, in each light-emitting chip 102, when any two of the second pole A1 of the first light-emitting unit, the second pole A2 of the second light-emitting unit, the second pole A3 of the third light-emitting unit, and the first pole C are in the same row or column, the distance D therebetween can be 20μm-40μm, and the second pole A1 of the first light-emitting unit, the second pole A2 of the second light-emitting unit, and the second pole A3 of the third light-emitting unit are all anodes or cathodes, and are different from the first pole C.

[0052] In some embodiments, Figure 1 As shown, a group of connection electrodes 101 includes four connection electrodes (Pads) 101, and the second pole A1 of the first light-emitting unit, the second pole A2 of the second light-emitting unit, the second pole A3 of the third light-emitting unit, and the first pole C of the light-emitting chip 102 are respectively electrically connected to a corresponding connection electrode 101. In a specific implementation, the second pole A1 of the first light-emitting unit, the second pole A2 of the second light-emitting unit, the second pole A3 of the third light-emitting unit, and the first pole C can be electrically connected to the corresponding connection electrode 101 through solder paste 105. Of course, the second pole A1 of the first light-emitting unit, the second pole A2 of the second light-emitting unit, the second pole A3 of the third light-emitting unit, and the first pole C can also be electrically connected to the corresponding connection electrode 101 through metal bonding, anisotropic conductive adhesive (ACF), etc., which is not specifically limited here.

[0053] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 2As shown, in each light-emitting chip 102, the second pole A1 of the first light-emitting unit can be arranged in the same row as the first pole C and in the same column as the second pole A3 of the third light-emitting unit, and the second pole A2 of the second light-emitting unit can be arranged in the same row as the second pole A3 of the third light-emitting unit and in the same column as the first pole C;

[0054] The area of ​​the light emitting chip 102 may be equal to (D+a+a R ) 2 、(D+b R +b B ) 2 、(D+a G +a B ) 2 、(D+b+b G ) 2 The maximum value in ;

[0055] Among them, a R is the length of the second electrode A1 of the first light emitting unit in the row direction, b R is the width of the second electrode A1 of the first light emitting unit in the column direction, a G is the length of the second electrode A2 of the second light emitting unit in the row direction, b G is the width of the second electrode A2 of the second light emitting unit in the column direction, a B is the length of the second electrode A3 of the third light emitting unit in the row direction, b B is the width of the second pole A3 of the third light-emitting unit in the column direction, a is the length of the first pole C in the row direction, b is the width of the first pole C in the column direction, and D is the distance between the second pole A1 of the first light-emitting unit and the first pole C, the second pole A1 of the first light-emitting unit and the second pole A3 of the third light-emitting unit, the second pole A2 of the second light-emitting unit and the first pole C, and the second pole A2 of the second light-emitting unit and the second pole A3 of the third light-emitting unit.

[0056] It can be seen from the above formula that the size of the light-emitting chip 102 provided by the present invention is only related to the second pole A1 of the first light-emitting unit, the second pole A2 of the second light-emitting unit, the second pole A3 of the third light-emitting unit, the first pole C, and the distance D between the second pole A1 of the first light-emitting unit and the first pole C, the second pole A1 of the first light-emitting unit and the second pole A3 of the third light-emitting unit, the second pole A2 of the second light-emitting unit and the first pole C, and the second pole A2 of the second light-emitting unit and the second pole A3 of the third light-emitting unit. Since there is no sapphire substrate in the present invention, the D value can be smaller than the value in the related art; and in the related art, it is necessary to cut the multiple light-emitting chips on the sapphire substrate into independent light-emitting chips by cutting, so the area of ​​each light-emitting chip needs to reserve a cutting area, while in the present invention, all the light-emitting chips on the sapphire substrate are transferred centrally, so the area of ​​each light-emitting chip does not need to reserve a cutting area. Combining the above two factors, the size of the light-emitting chip 102 in the present invention can be smaller.

[0057] In some embodiments, the first light emitting unit 1021, the second light emitting unit 1022 and the third light emitting unit 1023 can all be blue light mini-leds, and are converted into red light and green light by the color conversion layer 104. In this case, the above area formula of the light emitting chip 102 can be implemented in the following manner:

[0058] First, according to the preset red light color coordinates (x R ,y R ,z R ), green light color coordinates (x G ,y G ,z G ), blue light color coordinates (x B ,y B ,z B ), white light color coordinates (x W ,y W ,z W ), determine the absolute proportionality coefficient γ of red light R , the absolute proportional coefficient of green light γ G and the absolute proportionality coefficient of blue light γ B ; Among them, z R =1-x R -y R ;

[0059] z G =1-x G -y G ;

[0060] z B =1-x B -y B ;

[0061] z W =1-x W -y W ;

[0062]

[0063]

[0064] Second, according to the absolute proportionality coefficient γ of red light R , the absolute proportional coefficient of green light γ G and the absolute proportionality coefficient of blue light γ B , determine the relative proportionality coefficient ε of red light R 、The relative proportion coefficient of green light ε G The relative ratio coefficient of blue light ε B ;in,

[0065]

[0066] Third, according to the relative proportional coefficient ε of red light R 、The relative proportion coefficient of green light ε G The relative ratio coefficient of blue light ε B , the conversion efficiency of red light conversion material P R 、Luminous efficiency of red light E R , the conversion efficiency of green light conversion materials P G 、Luminous efficiency of green light E G , luminous efficiency of blue light E B , determine the aperture ratio K of red light R , the aperture ratio of green light K G And the preset aperture ratio K of blue light B The relationship between

[0067] E R =P R* E B ;

[0068] E G =P G* E B ;

[0069] K B =ε R* K R* P R / ε B =ε G* K G* P G / ε B ;

[0070] Fourth, according to the aperture ratio K of red light R, the aperture ratio of green light K G And the preset aperture ratio K of blue light B The relationship between the blue light and the preset aperture ratio K B , the aperture ratio K of red light is obtained R and the aperture ratio K of green light G ;

[0071] Fifth, according to the preset area S1 of the sub-pixel and the aperture ratio K of the red light R , the aperture ratio of green light K G And the preset aperture ratio of blue light K B , get the red light emitting area A R (which can be equivalent to the area of ​​the second pole A1 of the first light-emitting unit), the green light emitting area A G The area of ​​the second pole A2 of the second light-emitting unit and the blue light emitting area A B (which may be equivalent to the area of ​​the second pole A3 of the third light-emitting unit); wherein,

[0072] A R =S1*K R ;

[0073] A G =S1*K G ;

[0074] A B =S1*K B ;

[0075] Sixth, according to the luminous area A of red light R The area of ​​green light emission area A G The area of ​​blue light emission area A B The area S of the light emitting chip 102 is determined to be equal to (D+a+a R ) 2 、(D+b R +b B ) 2 、(D+a G +a B ) 2 、(D+b+b G ) 2 The maximum value in .

[0076] It should be noted that the above content is described by taking the light emitting chip 102 as a square. In some embodiments, the light emitting chip 102 may also be a rectangle, a circle, a regular polygon, etc., which is not specifically limited here.

[0077] The size design of the light emitting chip 102 provided by the present invention is further described below in conjunction with two specific embodiments, but it should be understood that the present invention is not limited to the following specific embodiments. In addition, it should be noted that a light emitting chip 102 provided by the present invention is equivalent to a sub-pixel in the following.

[0078] Example 1: The sub-pixel size (pitch) is set according to the 55-inch 4k display standard, the design pitch is 318μm*318μm, the R color coordinates are (0.695, 0.302), the G color coordinates are (0.137, 0.79), the B color coordinates are (0.131, 0.066), and the target W color coordinates are (0.28, 0.29). The aperture ratio is adjusted to make the current density and luminous efficiency of the three B light-emitting units (B-LED) consistent. The color conversion material is CdSe material, and the R / B brightness ratio of CdSe is P R =0.62, the G / B brightness ratio of CdSe is P G =1.74, then according to the above formula (with ε R =30%, ε G =60%, ε B =10% as an example), the aperture ratio of R / G / B can be set to 2.3%, 1.8%, and 0.6%, and the corresponding light-emitting area of ​​R is 48μm*48μm, the corresponding light-emitting area of ​​G is 43μm*43μm, and the corresponding light-emitting area of ​​B is 25μm*25μm. In addition, for the same area, the chip design pattern can be circular, rectangular, hexagonal, etc. The distance between different light-emitting areas is set to 20μm-40μm, the shared first pole C is 30μm*30μm, and the chip size is 98μm*98μm-118μm*118μm. Compared with the pitch of 318μm*318μm, there is 200μm-220μm of space on both sides, which can be used for splicing display, such as Figure 4 shown.

[0079] Example 2: The sub-pixel size (pitch) is set according to the 98-inch 8k display standard. The design pitch is 282.5μm*282.5μm, the R color coordinates are (0.695, 0.302), the G color coordinates are (0.137, 0.79), the B color coordinates are (0.131, 0.066), and the target W color coordinates are (0.28, 0.29). The aperture ratio is adjusted to make the current density and luminous efficiency of the three B LEDs consistent. The color conversion material is CdSe material, and the R / B brightness ratio of CdSe is P R is 0.62, and the G / B brightness ratio of CdSe is P G is 1.74, then according to the above formula (with ε R =30%, ε G =60%, εB =10% as an example), the opening ratio of R / G / B can be set to 2.3%, 1.8%, and 0.6%, and the corresponding light-emitting area of ​​R is 43μm*43μm, the corresponding light-emitting area of ​​G is 38μm*38μm, and the corresponding light-emitting area of ​​B is 22μm*22μm. In addition, for the same area, the chip design pattern can be circular, rectangular, hexagonal, etc. The distance between different light-emitting areas is set to 20μm-30μm, the shared first pole C is 30μm*30μm, and the size of the light-emitting chip 102 is 93μm*93μm-103μm*103μm. Compared with the pitch of 282.5μm*282.5μm, there is 179.5μm-199.5μm of space on both sides that can be used for splicing display.

[0080] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 1 and Figure 2 As shown, the insulating layer 103 completely covers the side of the light-emitting chip 102 away from the driving backplane BP, and the insulating layer 103 has a hollow structure in the gap between each light-emitting chip 102. In other words, the insulating layer 103 can be only arranged at the position of the light-emitting chip 102. This arrangement facilitates the subsequent filling of the black dam 106 in the gap between each light-emitting chip 102, thereby avoiding light crosstalk between adjacent light-emitting chips 102.

[0081] Optionally, in the above display substrate provided by an embodiment of the present invention, Figure 1 and Figure 2 As shown, the color conversion layer 104 may include a black matrix (BM) 1041 and a plurality of color conversion portions 1042; wherein the black matrix 1041 has a plurality of openings, and a color conversion portion 1042 is disposed at each opening;

[0082] Each color conversion unit 1042 is disposed corresponding to a first light-emitting unit 1021, a second light-emitting unit 1022 or a third light-emitting unit 1023, and the color conversion unit 1042 is configured to directly transmit the emission light of the corresponding first light-emitting unit 1021, the second light-emitting unit 1022 or the third light-emitting unit 1023, or to convert the emission light of the corresponding first light-emitting unit 1021, the second light-emitting unit 1022 or the third light-emitting unit 1023 into a target color.

[0083] In some embodiments, the first light-emitting unit 1021, the second light-emitting unit 1022 or the third light-emitting unit 1023 can all be blue light mini-leds, and can be used in conjunction with corresponding color conversion materials to achieve RGB color display. Compared with the solution of using R, G, and B three-color mini-leds to achieve color display, it helps to achieve a higher PPI and avoid the problem of poor stability of red light chips. Figure 1 and Figure 2As shown, the color conversion unit 1042 corresponding to the first light-emitting unit 1021 may mainly include scattering particles (SiO2 or TiO2, with a central particle size of 200nm-300nm), organic resin, a photosensitive unit for converting blue light into red light (such as red quantum dots R-QD), a photosensitizer and a dispersant. The color conversion unit 1042 corresponding to the first light-emitting unit 1021 may convert the blue light emitted by the first light-emitting unit 1021 into the desired red light; the color conversion unit 1042 corresponding to the second light-emitting unit 1022 may mainly include scattering particles (SiO2 or TiO2, with a central particle size of 200nm-300nm), an organic resin, a photosensitive unit for converting blue light into red light (such as red quantum dots R-QD), a photosensitizer and a dispersant. nm), organic resin, a photosensitive unit that converts blue light into green light (such as green quantum dots G-QD), a photosensitive agent and a dispersant, then the color conversion unit 1042 corresponding to the second light-emitting unit 1022 can convert the blue light emitted by the second light-emitting unit 1022 into the desired green light; the color conversion unit 1042 corresponding to the third light-emitting unit 1023 can mainly include scattering particles (SiO2 or TiO2, with a central particle size of 200nm-300nm), organic resin, a photosensitive agent and a dispersant, then the color conversion unit 1042 corresponding to the third light-emitting unit 1023 can directly transmit the blue light emitted by the third light-emitting unit 1023. In some embodiments, in order to achieve a better RGB light-emitting effect, the thickness of the color conversion unit 1042 in the direction perpendicular to the driving backplane BP can be approximately 12μm-20μm. In addition, the thickness of the black matrix 1041 can also be approximately 12μm-20μm to provide a flat surface for the production of subsequent film layers, which is conducive to the production of subsequent film layers.

[0084] In some embodiments, a black negative photoresist may be used to make the black matrix 1041. During the exposure process, less light reaches the bottom of the black negative photoresist, so that the bottom of the black negative photoresist cannot be completely cured. During the development process, the uncured black negative photoresist portion at the bottom will be developed away. Figure 1 As shown, in the direction perpendicular to the driving backplane BP, the cross-sectional diagram of the black matrix 1041 presents an inverted trapezoid that is wide at the top and narrow at the bottom, while the color conversion portion 1042 is filled in the opening of the black matrix 1041, so that the cross-sectional diagram of the color conversion portion 1042 presents a regular trapezoid that is narrow at the top and wide at the bottom.

[0085] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 1 and Figure 2 As shown, a color filter layer 107 may also be included on the side of the color conversion layer 104 away from the insulating layer 103. The color filter layer 107 may prevent the light that has not been converted by the color conversion unit 104 from being emitted, thereby ensuring a better color mixing effect of the RGB three colors.

[0086] In some embodiments, in the above display substrate provided by the embodiments of the present invention, Figure 1and Figure 2 As shown, it may also include a passivation layer 108, an encapsulation layer 109, a planarization layer 110, a driving circuit board 100, etc. Among them, the material of the passivation layer 108 may be an inorganic insulating material, the material of the encapsulation layer 109 may be an epoxy resin, the material of the planarization layer 110 may be an organic insulating material (OC), and the driving circuit board 100 may include components such as a substrate, a transistor, and a capacitor. The transistor may be a low temperature polysilicon transistor (LTPS TFT), an oxide transistor (Oxide TFT) or an amorphous silicon transistor (a-Si TFT).

[0087] Based on the same inventive concept, the embodiment of the present invention also provides a method for manufacturing the above-mentioned display substrate. Since the principle of solving the problem by the manufacturing method is similar to the principle of solving the problem by the above-mentioned display substrate, the implementation of the manufacturing method provided by the embodiment of the present invention can refer to the implementation of the above-mentioned display substrate provided by the embodiment of the present invention, and the repeated parts will not be repeated.

[0088] Specifically, an embodiment of the present invention further provides a method for manufacturing the above-mentioned display substrate, which may include the following steps:

[0089] A driving backplane and a light-emitting component are provided; wherein the driving backplane includes a plurality of groups of connecting electrodes, and the light-emitting component includes a sapphire substrate, a buffer layer disposed on the entire surface of the sapphire substrate, and a plurality of light-emitting chips on a side of the buffer layer away from the sapphire substrate;

[0090] Bonding and connecting a plurality of light-emitting chips to a plurality of groups of connecting electrodes;

[0091] The sapphire substrate is removed by laser lift-off;

[0092] A color conversion layer is formed on the buffer layer, the color conversion layer being in direct contact with the insulating layer including the buffer layer.

[0093] In order to better understand the technical solution of the manufacturing method provided by the present invention, the following Figure 2 The manufacturing process of the display substrate is described in detail.

[0094] The first step, such as Figure 5 As shown, a driving back plate BP is provided, and the driving back plate BP includes a plurality of connection electrodes 101 .

[0095] The second step is, Figure 6As shown, an insulating layer 103 including a buffer layer 1031 and a plurality of (e.g., 50,000-60,000) light-emitting chips 102 are sequentially fabricated on a sapphire substrate 111 to obtain a light-emitting component. The light-emitting chip 102 includes a first light-emitting unit 1021, a second light-emitting unit 1022, and a third light-emitting unit 1023, and all three light-emitting units emit blue light, and each light-emitting unit includes a first semiconductor layer 102a (e.g., n-GaN), a quantum well layer 102b (e.g., AlInGaN), and a second semiconductor layer 102c (e.g., n-GaN).

[0096] The third step is Figure 7 As shown, the light emitting chip 102 is bonded to the connecting electrode 101 of the driving backplane through solder paste 105 .

[0097] The fourth step is Figure 8 As shown, the sapphire substrate 111 is peeled off using a laser lift-off (LLO) method.

[0098] Step 5: Fig. 9 As shown, the buffer layer 1031 at the gaps between the light emitting chips 102 is removed, that is, the buffer layer 1031 only exists in the area where the light emitting chips 102 are located.

[0099] Step 6: Fig.10 As shown, a black dam material is printed at the gaps between the light emitting chips 102 by means of IJP, and the black dam material is cured, so that a black dam 106 is formed between the light emitting chips 102 .

[0100] Step 7: Fig.11 As shown, an inorganic flat layer 1032 is formed on the entire surface of the buffer layer 1031 and the black dam 106, and the insulating layer 103 includes the inorganic flat layer 1032 and the buffer layer 1031. The inorganic flat layer 1032 can modify the surface of the buffer layer 1031, thereby improving the surface flatness of the buffer layer 1031 and the black dam 106, and the adhesion between the buffer layer 1031 and the subsequently formed color conversion layer 104.

[0101] Step 8: Figure 2 As shown, a color conversion layer 104, an encapsulation layer 109, a color filter layer 107 and a flat layer 110 are sequentially formed on the insulating layer 103. The color conversion layer 104 includes a black matrix 1041 and a color conversion portion 1042. In some embodiments, the black matrix 1041 can be made of a black negative photoresist. Since less light reaches the bottom of the black negative photoresist during the exposure process, the bottom of the black negative photoresist cannot be completely cured. During the development process, the uncured black negative photoresist portion at the bottom will be developed away. Figure 2As shown, in the direction perpendicular to the driving backplane BP, the cross-sectional diagram of the black matrix 1041 presents an inverted trapezoid that is wide at the top and narrow at the bottom, while the color conversion portion 1042 is filled in the opening of the black matrix 1041, so that the cross-sectional diagram of the color conversion portion 1042 presents a regular trapezoid that is narrow at the top and wide at the bottom.

[0102] So far, it is completed Figure 2 The fabrication of the display substrate is shown.

[0103] It should be noted that in the above-mentioned manufacturing method provided in the embodiment of the present invention, the patterning process involved in forming each layer structure may include not only deposition, photoresist coating, masking, exposure, development, etching, photoresist stripping and other partial or complete process, but also other process, which is subject to the pattern of the required composition formed in the actual manufacturing process and is not limited here. For example, a post-baking process may also be included after development and before etching.

[0104] Among them, the deposition process can be chemical vapor deposition, plasma enhanced chemical vapor deposition or physical vapor deposition, which is not limited here; the mask plate used in the mask process can be a half tone mask (Half Tone Mask), a single slit diffraction mask (Single Slit Mask) or a gray tone mask (Gray Tone Mask), which is not limited here; the etching can be dry etching or wet etching, which is not limited here.

[0105] Based on the same inventive concept, an embodiment of the present invention further provides a display device, including the above-mentioned display substrate provided by the embodiment of the present invention. Since the principle of solving the problem by the display device is similar to the principle of solving the problem by the above-mentioned display substrate, the implementation of the display device provided by the embodiment of the present invention can refer to the implementation of the above-mentioned display substrate provided by the embodiment of the present invention, and the repeated parts will not be repeated.

[0106] In some embodiments, the display device may be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a laptop computer, a digital photo frame, a navigator, a smart watch, a fitness wristband, a personal digital assistant, etc. The display device includes but is not limited to components such as a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply. Those skilled in the art will appreciate that the structure of the above-mentioned display device does not constitute a limitation on the display device, and the display device may include more or less of the above-mentioned components, or a combination of certain components, or different component arrangements. In the embodiments of the present application, the display device includes but is not limited to a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, etc.

[0107] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A display substrate, characterized in that: include: A driving backplane, the driving backplane comprising a plurality of groups of connecting electrodes; A plurality of light-emitting chips, each of which is bonded and connected to a group of the connecting electrodes; An insulating layer, located on a side of the layer where the plurality of light-emitting chips are located away from the driving backplane; The color conversion layer is located on a side of the insulating layer away from the driving backplane, and the color conversion layer is in direct contact with the insulating layer.

2. The display substrate according to claim 1, wherein: The insulating layer includes a buffer layer.

3. The display substrate according to claim 2, wherein: The insulating layer further includes an inorganic planarization layer between the buffer layer and the color conversion layer.

4. The display substrate according to claim 1, wherein: Each of the light-emitting chips includes a first light-emitting unit, a second light-emitting unit and a third light-emitting unit. The first light-emitting unit, the second light-emitting unit and the third light-emitting unit share a first electrode, which is an anode or a cathode.

5. The display substrate according to claim 4, wherein: In each of the light-emitting chips, when any two of the second pole of the first light-emitting unit, the second pole of the second light-emitting unit, the second pole of the third light-emitting unit, and the first pole are in the same row or column, the distance between the two is 20μm-40μm, and the second pole of the first light-emitting unit, the second pole of the second light-emitting unit, and the second pole of the third light-emitting unit are all anodes or cathodes, and are different from the first pole.

6. The display substrate according to claim 4, wherein: In each of the light-emitting chips, the second electrode of the first light-emitting unit is arranged in the same row as the first electrode and in the same column as the second electrode of the third light-emitting unit, and the second electrode of the second light-emitting unit is arranged in the same row as the second electrode of the third light-emitting unit and in the same column as the first electrode; The area of ​​the light emitting chip is equal to (D+a+a R ) 2 、(D+b R +b B ) 2 、(D+a G +a B ) 2 、(D+b+b G ) 2 The maximum value in ; Among them, a R is the length of the second electrode of the first light-emitting unit in the row direction, b R is the width of the second electrode of the first light-emitting unit in the column direction, a G is the length of the second electrode of the second light-emitting unit in the row direction, b G is the width of the second electrode of the second light-emitting unit in the column direction, a B is the length of the second electrode of the third light-emitting unit in the row direction, b B is the width of the second pole of the third light-emitting unit in the column direction, a is the length of the first pole in the row direction, b is the width of the first pole in the column direction, and D is the distance between the second pole of the first light-emitting unit and the first pole, the second pole of the first light-emitting unit and the second pole of the third light-emitting unit, the second pole of the second light-emitting unit and the first pole, and the second pole of the second light-emitting unit and the second pole of the third light-emitting unit.

7. The display substrate according to claim 4, wherein: The insulating layer completely covers the side of the light emitting chip away from the driving backplane, and the insulating layer has a hollow structure at the gap between the light emitting chips.

8. The display substrate according to claim 7, wherein: Also includes: A black dam is filled between the light emitting chips.

9. The display substrate according to claim 4, wherein: The color conversion layer includes a black matrix and a plurality of color conversion parts; wherein the black matrix has a plurality of openings, and a color conversion part is disposed at each of the openings; Each of the color conversion units is arranged corresponding to one of the first light-emitting unit, the second light-emitting unit or the third light-emitting unit, and the color conversion unit is configured to directly transmit the emission light corresponding to the first light-emitting unit, the second light-emitting unit or the third light-emitting unit, or to convert the emission light corresponding to the first light-emitting unit, the second light-emitting unit or the third light-emitting unit into a target color.

10. The display substrate according to claim 9, wherein: In a direction perpendicular to the driving backplane, the cross-sectional shape of the black matrix is ​​an inverted trapezoid that is wide at the top and narrow at the bottom, and the cross-sectional shape of the color conversion portion is a regular trapezoid that is narrow at the top and wide at the bottom.

11. The display substrate according to any one of claims 1 to 10, characterized in that: It also includes a color filter layer located on the side of the color conversion layer away from the insulating layer.

12. A method for manufacturing a display substrate according to any one of claims 1 to 11, characterized in that: include: A driving backplane and a light-emitting component are provided; wherein the driving backplane includes a plurality of groups of connecting electrodes, and the light-emitting component includes a sapphire substrate, a buffer layer disposed on the entire surface of the sapphire substrate, and a plurality of light-emitting chips on a side of the buffer layer away from the sapphire substrate; Bonding and connecting the plurality of light-emitting chips to the plurality of groups of connecting electrodes; Removing the sapphire substrate by laser lift-off; A color conversion layer is formed on the buffer layer, the color conversion layer being in direct contact with the insulating layer including the buffer layer.

13. The method according to claim 12, characterized in that: After removing the sapphire substrate by laser lift-off and before forming a color conversion layer on the buffer layer, the method further includes: The buffer layer at the gaps between the light-emitting chips is removed, and a black dam is filled at the gaps between the light-emitting chips.

14. The method according to claim 13, characterized in that: After removing the buffer layer at the gaps between the light-emitting chips and filling the gaps between the light-emitting chips with black dams, and before forming a color conversion layer on the buffer layer, the method further includes: An inorganic flat layer is formed entirely on the buffer layer and the black dam.

15. A display device, characterized in that: Comprising the display substrate as described in any one of claims 1-11.

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