Micro light emitting diode substrate and manufacturing method therefor

Abstract

A micro light emitting diode substrate and a manufacturing method therefor. The micro light emitting diode substrate comprises a base substrate, a driving circuit layer, a plurality of micro light emitting diodes, a plurality of connecting via holes, and a plurality of conductive structures. The driving circuit layer is located on a first side of the base substrate, the plurality of micro light emitting diodes are located on a second side of the base substrate, the second side and the first side are two opposite sides of the base substrate, the plurality of connecting via holes run through the base substrate, and the plurality of conductive structures are located in the plurality of connecting via holes and are arranged in one-to-one correspondence with the plurality of connecting via holes. The plurality of connecting via holes comprise a plurality of first connecting via holes, the plurality of conductive structures comprise a plurality of first conductive structures, the plurality of first conductive structures are located in the plurality of first connecting via holes, and the plurality of micro light emitting diodes are electrically connected to the driving circuit layer by means of the plurality of first conductive structures. The driving circuit layer and the micro light emitting diodes are located on two sides of the base substrate, and thus seamless tiling can be achieved, the repair yield can be increased, and foreign matter growth on the substrate will not affect light emitting or display.

Description

Micro light-emitting diode substrate and manufacturing method thereof

[0001] This application claims priority to Chinese Patent Application No. 202310807146.6 filed on June 30, 2023. The contents of the above-mentioned Chinese patent application disclosure are hereby incorporated by reference in their entirety as a part of this application. Technical Field

[0002] Embodiments of the present disclosure relate to a micro-light emitting diode substrate and a method for manufacturing the same. Background Art

[0003] Liquid crystal display (LCD) is the earliest popular and most mature display technology. Organic light-emitting diode (OLED) display technology is the next generation display technology after LCD and is already very mature.

[0004] In recent years, with the rapid development of the micro-light-emitting diode (MLED) industry, its application has become increasingly widespread. MLEDs include sub-millimeter light-emitting diodes (Mini LED) and micro-light-emitting diodes (Micro LED). MLEDs offer superior performance, including lower power consumption, faster response, longer lifespan, and higher color saturation and contrast. With technological breakthroughs, Mini LED and Micro LED displays are poised to become the next generation of display technology after LCD and OLED. With the widespread adoption of 4K ultra-high definition in the 5G era, Mini LED and Micro LED panels are expected to rapidly replace traditional panels, with penetration rates increasing rapidly and presenting enormous market potential.

[0005] Summary of the Invention

[0006] The disclosed embodiments provide a micro-LED substrate and a method for manufacturing the same. This micro-LED substrate enables seamless splicing between substrates, reducing seams at the joints. This improves the yield rate during micro-LED repair, and prevents foreign matter growth on the substrate from affecting the light emission or display of the micro-LED.

[0007] At least one embodiment of the present disclosure provides a micro-LED substrate, comprising: a substrate, a driving circuit layer, located on a first side of the substrate; a plurality of micro-LEDs, located on a second side of the substrate, the second side and the first side being opposite sides of the substrate; a plurality of connecting vias, passing through the substrate; and a plurality of conductive structures, located within the plurality of connecting vias and arranged in a one-to-one correspondence with the plurality of connecting vias, the plurality of connecting vias including a plurality of first connecting vias, the plurality of conductive structures including a plurality of first conductive structures, the plurality of first conductive structures being located within the plurality of first connecting vias, and the plurality of micro-LEDs being electrically connected to the driving circuit layer through the plurality of first conductive structures.

[0008] For example, in the micro-LED substrate provided in one embodiment of the present disclosure, each of the micro-LEDs includes a first pole and a second pole, one end of each of the first conductive structures is connected to the driving circuit layer, and the other end of each of the first conductive structures is exposed on the second side of the substrate to serve as a soldering pad, and the soldering pad is configured to be connected to the first pole or the second pole.

[0009] For example, in the micro-LED substrate provided in one embodiment of the present disclosure, at least one of the first connecting vias includes: a first sub-portion; and a second sub-portion, located on the side of the first sub-portion close to the driving circuit layer, and the average aperture of the second sub-portion is larger than the average aperture of the first sub-portion.

[0010] For example, in the micro-LED substrate provided by an embodiment of the present disclosure, in the direction along the substrate pointing to the driving circuit layer, the aperture of the first sub-section remains unchanged, and the aperture of the second sub-section gradually becomes smaller, and the maximum aperture of the second sub-section is larger than the aperture of the first sub-section.

[0011] For example, in the micro LED substrate provided by an embodiment of the present disclosure, the cross section of the first sub-portion along the plane perpendicular to the substrate includes a rectangle, and the cross section of the second sub-portion along the plane perpendicular to the substrate includes a trapezoid.

[0012] For example, in a micro-LED substrate provided by an embodiment of the present disclosure, the substrate includes a base substrate and a first passivation layer, the first sub-portion is located on the base substrate, and the second sub-portion is located on the first passivation layer.

[0013] For example, in the micro-LED substrate provided in one embodiment of the present disclosure, at least one of the first conductive structures includes: a first conductive part, a second conductive part, located on the side of the first conductive part close to the driving circuit layer, and the average radial dimension of the second conductive part is greater than the average radial dimension of the first conductive part.

[0014] For example, in the micro-LED substrate provided by an embodiment of the present disclosure, in the direction along the substrate pointing to the driving circuit layer, the radial dimension of the first conductive part remains unchanged, and the radial dimension of the second conductive part gradually decreases, and the maximum radial dimension of the second conductive part is greater than the radial dimension of the first conductive part.

[0015] For example, in a micro-LED substrate provided by an embodiment of the present disclosure, the first conductive portion includes a rectangular cross-section along a plane perpendicular to the substrate, and the second conductive portion includes a trapezoidal cross-section along a plane perpendicular to the substrate.

[0016] For example, in a micro-LED substrate provided in an embodiment of the present disclosure, the substrate includes a base substrate and a first passivation layer, the first conductive portion is located on the base substrate, and the second conductive portion is located on the first passivation layer.

[0017] For example, in the micro-LED substrate provided in an embodiment of the present disclosure, the driving circuit layer includes multiple signal lines and multiple connecting lines, and the micro-LED is connected to the signal lines through the first conductive structure and the connecting lines.

[0018] For example, a micro-LED substrate provided in an embodiment of the present disclosure further includes: a plurality of light-emitting units, each of the light-emitting units including a plurality of micro-LEDs; and a plurality of first micro-driver chips, arranged corresponding to the plurality of light-emitting units, each of the first micro-driver chips being configured to drive the corresponding light-emitting unit to emit light, the plurality of connection vias further including a plurality of second connection vias, the plurality of conductive structures further including a plurality of second conductive structures, the plurality of second conductive structures being located within the plurality of second connection vias, the plurality of first micro-driver chips being connected to the driver circuit layer via the plurality of second conductive structures, the plurality of signal lines including a driving voltage line, a ground line, an operating voltage line, and a source address line, the micro-LEDs being connected to the driving voltage line via the first conductive structures and the connection lines, the first micro-driver chips being respectively connected to the ground line, the operating voltage line, and the source address line via the second conductive structures and the connection lines, or the first micro-driver chips being respectively connected to the ground line, the operating voltage line, and the source address line via the second conductive structures, the first micro-driver chip including an output terminal, the micro-LEDs being connected to the output terminal via the first conductive structures and the connection lines.

[0019] For example, in the micro-LED substrate provided in an embodiment of the present disclosure, the driving circuit layer includes: a first conductive layer, a second passivation layer, located on the side of the first conductive layer away from the substrate; an insulating layer, located on the side of the second passivation layer away from the first conductive layer; a third passivation layer, located on the side of the insulating layer away from the second passivation layer; a second conductive layer, located on the side of the third passivation layer away from the insulating layer; and a plurality of first vias, passing through the second passivation layer, the insulating layer and the three passivation layers, the first conductive layer includes a plurality of connecting lines, the second conductive layer includes a plurality of signal lines, the plurality of micro-LEDs are connected to the plurality of connecting lines of the first conductive layer through the plurality of first conductive structures, and the plurality of connecting lines of the first conductive layer are connected to the plurality of signal lines of the second conductive layer through the plurality of first vias.

[0020] For example, the micro-LED substrate provided in an embodiment of the present disclosure further includes: a plurality of light-emitting units, each of the light-emitting units including a plurality of micro-LEDs; and a plurality of first micro-driving chips, which are arranged corresponding to the plurality of light-emitting units, each of the micro-driving chips being configured to drive the corresponding light-emitting unit to emit light, the plurality of connection vias further including a plurality of second connection vias, the plurality of conductive structures further including a plurality of second conductive structures, the plurality of second conductive structures being located within the plurality of second connection vias, the plurality of first micro-driving chips being connected to the drive circuit layer through the second conductive structures, the plurality of signal lines including a drive voltage line, a ground line, an operating voltage line, and a source address line, the micro-LEDs being connected to the drive voltage lines through the connecting lines between the first conductive structures and the first conductive layer, the first micro-driving chip being respectively connected to the ground line, the operating voltage line, and the source address line through the connecting lines between the second conductive structures and the first conductive layer, the first micro-driving chip including an output end, and the micro-LEDs being connected to the output end through the connecting lines.

[0021] For example, the micro-LED substrate provided in an embodiment of the present disclosure also includes a plurality of pixel units; and a plurality of second micro-driving chips, which are arranged corresponding to the plurality of pixel units, and each of the second micro-driving chips is configured to drive the corresponding pixel unit for display, and the plurality of micro-LEDs include a first micro-LED, a second micro-LED and a third micro-LED, the first micro-LED is configured to emit light of a first color, the second micro-LED is configured to emit light of a second color, and the third micro-LED is configured to emit light of a third color, each of the pixel units includes the first micro-LED, the second micro-LED and the third micro-LED, the plurality of connecting vias also include a plurality of second connecting vias, the plurality of conductive structures also include a plurality of second conductive structures, the plurality of second conductive structures are located in the plurality of second connecting vias, and the plurality of second micro-driving chips are connected to the driving circuit layer through the plurality of second conductive structures.

[0022] For example, in the micro-LED substrate provided in an embodiment of the present disclosure, the multiple signal lines include a first signal line, a second signal line, a ground line, an operating voltage line and a data line. The micro-LED is connected to the first signal line or the second signal line through the connecting line of the first conductive structure and the first conductive layer. The second micro-driving chip is respectively connected to the ground line, the operating voltage line and the data line through the connecting line of the second conductive structure and the first conductive layer. The second micro-driving chip includes three output terminals, and the three output terminals are respectively connected to the first micro-LED, the second micro-LED and the third micro-LED of the corresponding pixel units.

[0023] For example, the micro-LED substrate provided in one embodiment of the present disclosure further includes: a fourth passivation layer located on the first side of the substrate and on the side of the driving circuit layer away from the substrate; and a second via hole penetrating the fourth passivation layer to expose the driving circuit layer.

[0024] At least one embodiment of the present disclosure further provides a display device comprising any of the above-mentioned micro-LED substrates.

[0025] At least one embodiment of the present disclosure also provides a method for manufacturing a micro-LED substrate, including: providing a substrate; forming a driving circuit layer on a first side of the substrate; forming a plurality of connecting vias penetrating the substrate on the substrate; forming a conductive structure in the connecting vias; and forming a plurality of micro-LEDs on a second side of the substrate, wherein the first side and the second side are opposite sides of the substrate, the plurality of connecting vias include a plurality of first connecting vias, the plurality of conductive structures include a plurality of first conductive structures, the plurality of first conductive structures are located in the plurality of first connecting vias, and the plurality of micro-LEDs are electrically connected to the driving circuit layer through the plurality of first conductive structures.

[0026] For example, in a manufacturing method provided in an embodiment of the present disclosure, providing a substrate includes: providing a base substrate; and forming a passivation layer on a side of the base substrate close to the driving circuit layer.

[0027] For example, in the manufacturing method provided in one embodiment of the present disclosure, forming multiple connecting vias on the substrate includes: forming a blind hole on the base substrate using a laser process; and etching the unpunched portion of the base substrate and the passivation layer along the extension direction of the blind hole using an etching process to form a first sub-portion passing through the base substrate and a second sub-portion passing through the passivation layer, and the first connecting via includes the first sub-portion and the second sub-portion.

[0028] For example, in the manufacturing method provided in one embodiment of the present disclosure, the average pore size of the second sub-portion is greater than the average pore size of the first sub-portion.

[0029] For example, in the manufacturing method provided in one embodiment of the present disclosure, in the direction from the substrate to the driving circuit layer, the aperture of the first sub-section remains unchanged, and the aperture of the second sub-section gradually becomes smaller, and the maximum aperture of the second sub-section is larger than the aperture of the first sub-section.

[0030] For example, in a manufacturing method provided by an embodiment of the present disclosure, the cross-section of the first sub-portion along a plane perpendicular to the substrate includes a rectangle, and the cross-section of the second sub-portion along a plane perpendicular to the substrate includes a trapezoid.

[0031] For example, in the manufacturing method provided in one embodiment of the present disclosure, the thickness of the non-perforated portion of the base substrate has a value range of 0.05-0.15 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limiting the present disclosure.

[0033] FIG1 is a schematic diagram of a copper wire blistering and corrosion caused by foreign matter growth;

[0034] FIG2 is a schematic diagram of a splicing of a micro-LED product;

[0035] FIG3A is a cross-sectional schematic diagram of a micro-LED substrate provided in one embodiment of the present disclosure;

[0036] FIG3B is a cross-sectional schematic diagram of another micro-LED substrate provided by an embodiment of the present disclosure;

[0037] FIG3C is a schematic cross-sectional view of another micro-LED substrate provided in an embodiment of the present disclosure;

[0038] FIG4 is a schematic diagram of a partial structure of the first connecting via shown in FIG3A ;

[0039] FIG5 is a schematic diagram of a partial structure of the first conductive structure shown in FIG3A ;

[0040] FIG6 is a schematic diagram of drilling a hole in a substrate using a laser process according to an embodiment of the present disclosure;

[0041] FIG7 is a schematic diagram of etching holes in a film layer using a dry etching process according to an embodiment of the present disclosure;

[0042] FIG8 is a schematic diagram of wiring of a micro-LED substrate provided by an embodiment of the present disclosure;

[0043] FIG9 is a schematic cross-sectional view of the micro-LED substrate shown in FIG8 ;

[0044] FIG10 is a schematic diagram of wiring of another micro-LED substrate provided by an embodiment of the present disclosure;

[0045] FIG11 is a schematic cross-sectional view of the micro-LED substrate shown in FIG10 ;

[0046] FIG12 is a schematic diagram of wiring of another micro-LED substrate provided by an embodiment of the present disclosure;

[0047] FIG13 is a schematic cross-sectional view of the micro-LED substrate shown in FIG12 ;

[0048] FIG14 is a schematic diagram of a display device provided by an embodiment of the present disclosure;

[0049] FIG15A is a schematic diagram of a structure for drilling a hole in a substrate using a laser;

[0050] FIG15B is a structural diagram of a micro-LED product;

[0051] FIG16 is a flow chart of a method for manufacturing a micro-LED substrate according to an embodiment of the present disclosure;

[0052] 17A to 17C are schematic flow charts of a method for forming a connecting via on a substrate according to an embodiment of the present disclosure;

[0053] 18A to 18H are schematic flow charts of a method for manufacturing the micro-LED substrate shown in FIG. 8 ; and

[0054] 19A to 19L are schematic flow charts of a method for manufacturing the micro-LED substrate shown in FIG. 10 . DETAILED DESCRIPTION

[0055] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0056] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by persons of ordinary skill in the field to which this disclosure belongs. The words "first", "second" and similar terms used in this disclosure 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 preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0057] Unless otherwise defined, the features such as "parallel", "perpendicular" and "same" used in the embodiments of the present disclosure include the cases of "parallel", "perpendicular", "same" in a strict sense, as well as the cases of "approximately parallel", "approximately perpendicular", "approximately the same" and the like which contain certain errors. For example, the above-mentioned "approximately" may mean that the difference between the compared objects is 10% of the average value of the compared objects, or within 5%. When the number of a component or element is not specifically indicated below in the embodiments of the present disclosure, it means that the component or element may be one or more, or may be understood as at least one. "At least one" refers to one or more, and "multiple" refers to at least two. The "same-layer arrangement" in the embodiments of the present disclosure refers to the relationship between multiple film layers formed by the same material after the same step (for example, a one-step patterning process). The "same layer" here does not always mean that the thickness of multiple film layers is the same or the height of multiple film layers in the cross-sectional view is the same.

[0058] Mini LED and Micro LED backlighting have been gradually adopted in televisions and gaming monitors, and are gradually expanding into smaller sizes like tablets. Depending on the substrate, Mini LED and Micro LED products can be categorized as glass substrates or printed circuit boards (PCBs). Currently, the mainstream market, especially for smaller products, uses PCBs. Glass substrates do not suffer from poor heat dissipation and can share the same wiring as TFT products, offering greater potential. Mini LED and Micro LED displays can serve as an upgrade to LCD and OLED displays and are gradually gaining adoption in display products.

[0059] During long-term reliability testing, Mini LED and Micro LED products are prone to reliability issues such as solder pad corrosion, weak LED brightness, and LED failure, impacting product stability. There are two main causes of corrosion: one is the precipitation and growth of Na and Ga components in the glass itself, which causes film cracking, corrosion, and related defects. The other is the growth of foreign matter introduced during the coating process, which causes film cracking, corrosion, and related defects. Both types of foreign matter growth can lead to circuit short circuits. Figure 1 is a schematic diagram of a foreign matter growth causing copper wire bubbling and corrosion. Figure 1(b) is a cross-sectional view of the selected area in Figure 1(a) along the extension direction of the copper wire, and Figure 1(c) is a partial enlarged view of the selected area in Figure 1(b). As shown in Figure 1, precipitates 11 on the underlying substrate 10 cause copper wire 12 to bubble and corrode, resulting in circuit short circuits, pad corrosion, and other defects.

[0060] During the design process for Mini LED and Micro LED products, the driver circuit layer and micro-LEDs are located on the same side of the substrate, resulting in a bonding area on the display side. This makes it impossible to achieve seamless splicing of the substrate in all directions due to the presence of the bonding area. Figure 2 shows a schematic diagram of the splicing of a micro-LED product. As shown in Figure 2, due to the presence of the bonding area 14 on the display side 13 of this micro-LED product, seamless splicing in all directions is impossible, and only left-right splicing is possible.

[0061] The embodiments of the present disclosure provide a micro-LED substrate and a method for manufacturing the same. The micro-LED substrate includes a substrate, a driving circuit layer, a plurality of micro-LEDs, a plurality of connection vias, and a plurality of conductive structures. The driving circuit layer is located on a first side of the substrate, the plurality of micro-LEDs are located on a second side of the substrate, the second side and the first side being opposite sides of the substrate, the plurality of connection vias penetrate the substrate, the plurality of conductive structures are located within the plurality of connection vias, and are arranged in a one-to-one correspondence with the plurality of connection vias. The plurality of connection vias include a plurality of first connection vias, the plurality of conductive structures include a plurality of first conductive structures, the plurality of first conductive structures are located within the plurality of first connection vias, and the plurality of micro-LEDs are electrically connected to the driving circuit layer through the plurality of first conductive structures.

[0062] In the micro-LED substrate provided in the disclosed embodiments, the driver circuit layer and micro-LEDs are located on both sides of the substrate. The side where the micro-LEDs are located is the display side, and the side where the driver circuit layer is located is the non-display side. Consequently, the bonding area is also located on the non-display side. This allows for seamless splicing between the substrates, reduces the seam at the splicing point, and improves the display quality after splicing. Compared to conventional die-bonding structures, the micro-LEDs are fixed to the substrate via a first conductive structure within a first connecting via. During rework of the micro-LEDs, less copper is thinned from the first conductive structure, improving the yield rate during a second die-bonding process. Furthermore, during the rework process, the first connecting via has a leveling effect, concentrating more copper within the first connecting via. This reduces the copper thinning of the first conductive structure during the rework process, further improving the yield rate. The micro-LEDs on the display side are directly assembled onto the display side of the substrate, while the driver circuit layer is located on the non-display side. This ensures that foreign matter growth on the substrate does not affect the light emission or display of the micro-LEDs, improving the corrosion resistance and other properties of the product. The micro-LEDs and driver circuit layers are located on both sides of the substrate, which reduces the overall voltage and current, thereby improving circuit corrosion. Furthermore, placing the micro-LEDs and driver circuit layers on both sides of the substrate allows for greater layout space for the micro-LEDs, increasing their density. It should be noted that the "micro-LEDs" mentioned herein are unpackaged and consist solely of the PN junction, the light-emitting layer, and other functional layers that assist in light emission. They are not typical single LEDs.

[0063] The micro-LED substrate and the manufacturing method thereof provided by the embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0064] One embodiment of the present disclosure provides a micro-LED substrate. Figure 3A is a cross-sectional schematic diagram of a micro-LED substrate provided in one embodiment of the present disclosure. As shown in Figure 3A, the micro-LED substrate 200 includes a substrate 100, a driving circuit layer 110, a plurality of micro-LEDs 120, a plurality of connecting vias 130, and a plurality of conductive structures 140. The driving circuit layer 110 is located on a first side S1 of the substrate 100, the plurality of micro-LEDs 120 are located on a second side S2 of the substrate 100, and the second side S2 and the first side S1 are opposite sides of the substrate 100. The plurality of connecting vias 130 penetrates the substrate 100, and the plurality of conductive structures 140 are located within the plurality of connecting vias 130 and are arranged in a one-to-one correspondence with the plurality of connecting vias 130. The multiple connection vias 130 include multiple first connection vias 131, the multiple conductive structures 140 include multiple first conductive structures 141, the multiple first conductive structures 141 are located in the multiple first connection vias 131, and the multiple micro-LEDs 120 are electrically connected to the driving circuit layer 110 through the multiple first conductive structures 141.

[0065] In the micro-LED substrate provided in the embodiments of the present disclosure, the driver circuit layer 110 and micro-LED 120 are located on opposite sides of the substrate 100. The side where the micro-LED 120 is located is the display side, and the side where the driver circuit layer 110 is located is the non-display side. Consequently, the bonding area is also located on the non-display side. This allows for seamless splicing between the substrates 100, reduces the seam at the splice, and improves the display quality after splicing. Compared to conventional designs where the micro-LED 120 is secured via solder pads on copper wires, the micro-LED 120 is secured to the substrate 100 via the first conductive structure 141 within the first connection via 131. During rework of the micro-LED 120, less copper is removed from the first conductive structure 141, resulting in improved product yield during the second die bonding process. Furthermore, during the rework process, the first connection via 131 has a leveling effect, concentrating more copper within the first connection via 131. This reduces the copper removal from the first conductive structure 141 during the rework process, further improving product yield. The display-side micro-LEDs 120 are directly assembled onto the display side of the substrate 100, while the driver circuit layer 110 is located on the non-display side. This prevents foreign matter growth on the substrate from affecting the light emission or display of the micro-LEDs 120, improving the product's corrosion resistance and other properties. With the micro-LEDs 120 and driver circuit layer 110 located on opposite sides of the substrate 100, the overall voltage and current are reduced, thereby also improving circuit corrosion issues. Furthermore, placing the micro-LEDs 120 and driver circuit layer 110 on opposite sides of the substrate 100 allows for greater layout space for the micro-LEDs 120, increasing their density.

[0066] For example, the “micro light-emitting diode 120” in this article may not be packaged, and may only include a PN junction, a light-emitting layer, and other functional layers that assist in luminescence. Of course, the embodiments of the present disclosure are not limited to this.

[0067] 3A , each micro LED 120 includes a first electrode 121 and a second electrode 122 , each of which is connected to the driving circuit layer 110 via a different first conductive structure 141 . For example, each micro LED 120 further includes a light-emitting functional layer 123 .

[0068] Figure 3B is a cross-sectional schematic diagram of another micro-LED substrate provided in accordance with an embodiment of the present disclosure. As shown in Figure 3B , each micro-LED 120 includes a first electrode 121 and a second electrode 122. One end of each first conductive structure 141 is connected to the driver circuit layer 110, while the other end of each first conductive structure 141 is exposed on the second side S2 of the substrate 100 to serve as a soldering pad. The soldering pad is configured to connect to the first or second electrode of the micro-LED 120. This allows for more convenient and efficient connection between the micro-LED 120 and the first conductive structure 141, improving the die bonding efficiency and yield rate of the micro-LED 120.

[0069] Figure 3C is a schematic cross-sectional view of another micro-LED substrate according to an embodiment of the present disclosure. As shown in Figure 3C , the section line only cuts through the first electrode 121 or the second electrode 122 of the micro-LED 120, and only one of the first electrode 121 or the second electrode 122 of the micro-LED 120 is shown connected to the first conductive structure 141.

[0070] In some examples, as shown in Figures 3A to 3C, at least one first connection via 131 includes a first sub-portion 132 and a second sub-portion 133. The second sub-portion 133 is located on a side of the first sub-portion 132 closer to the drive circuit layer 110. The average pore size of the second sub-portion 133 is larger than the average pore size of the first sub-portion 132, thereby improving the contact adhesion between the first conductive structure 141 within the first connection via 131 and the drive circuit layer 110, thereby enhancing performance stability. In this case, the overall cross-sectional shape of the first connection via 131 can be approximately anchor-shaped, and the overall cross-sectional shape of the first conductive structure 141 within the first connection via 131 can be approximately anchor-shaped. The anchor-shaped design of the first connection via 131 and the first conductive structure 141 can improve the contact adhesion between the first conductive structure 141 within the first connection via 131 and the drive circuit layer 110, thereby improving performance stability.

[0071] In some examples, as shown in Figures 3A to 3C , along the direction from substrate 100 toward driver circuit layer 110, the aperture of first sub-portion 132 remains substantially constant, while the aperture of second sub-portion 133 gradually decreases, with the maximum aperture of second sub-portion 133 being larger than the aperture of first sub-portion 132. Consequently, the shape of first connection via 131 can be approximately anchor-shaped, and the first conductive structure 141 within first connection via 131 can also be approximately anchor-shaped. The anchor-shaped design of first connection via 131 and first conductive structure 141 can improve the contact adhesion between first conductive structure 141 within first connection via 131 and driver circuit layer 110, thereby enhancing performance stability.

[0072] In some examples, as shown in Figures 3A to 3C, the first sub-portion 132 includes a rectangle in a cross-section along a plane perpendicular to the substrate 100, and the second sub-portion 133 includes a trapezoid in a cross-section along a plane perpendicular to the substrate 100, with the bottom side of the trapezoid connected to the rectangle.

[0073] In some examples, as shown in Figures 3A to 3C, substrate 100 includes a base substrate 101 and a first passivation layer 102, a first sub-portion 132 is located on base substrate 101, and a second sub-portion 133 is located on first passivation layer 102. First sub-portion 132 is a via formed on base substrate 101, and second sub-portion 133 is a via formed on first passivation layer 102.

[0074] FIG4 is a schematic diagram of the partial structure of the first connecting via shown in FIG3A . As shown in FIG3A and FIG4 , the aperture of the first sub-portion 132 is D1, the maximum aperture of the second sub-portion 133 is D2, the minimum aperture of the second sub-portion 133 is D3, the thickness of the first passivation layer 102 is H, and the angle between the side of the second sub-portion 133 and the bottom surface of the base substrate 101 is θ1. For example, the relationship between D1 and D3 can satisfy: D3 ≥ D1. For example, the relationship between D1, D2, and D3 can satisfy: D2 ≥ D3 + 2H / tanθ1. Of course, the first connecting vias of FIG3B and FIG3C also satisfy the above relationship, which will not be repeated here.

[0075] In some examples, as shown in Figures 3A to 3C, at least one first conductive structure 141 includes a first conductive portion 142 and a second conductive portion 143, with the second conductive portion 143 being located on a side of the first conductive portion 142 closer to the driving circuit layer 110. The average radial dimension of the second conductive portion 143 is greater than the average radial dimension of the first conductive portion 142. Thus, the shape of the first conductive structure 141 can be approximately anchor-shaped, thereby improving the contact adhesion between the first conductive structure 141 and the driving circuit layer 110 and enhancing performance stability.

[0076] In some examples, as shown in Figures 3A to 3C , along the direction from substrate 100 to driving circuit layer 110, the radial dimension of first conductive portion 142 remains substantially constant, while the radial dimension of second conductive portion 143 gradually decreases, with the maximum radial dimension of second conductive portion 143 being greater than the radial dimension of first conductive portion 142. Thus, the shape of first conductive structure 141 can be approximately anchor-shaped, thereby improving the contact adhesion between first conductive structure 141 and driving circuit layer 110 and enhancing performance stability.

[0077] In some examples, as shown in FIG. 3A to FIG. 3C , the cross-section of the first conductive portion 142 along the plane perpendicular to the substrate 100 includes a rectangle, and the cross-section of the second conductive portion 143 along the plane perpendicular to the substrate 100 includes a trapezoid.

[0078] In some examples, as shown in Figures 3A to 3C, substrate 100 includes a base substrate 101 and a first passivation layer 102. First conductive portion 142 is located in a via hole of base substrate 101, for example, the via hole is first sub-portion 132. Second conductive portion 143 is located in a via hole of first passivation layer 102, for example, the via hole is second sub-portion 133.

[0079] FIG5 is a schematic diagram of a partial structure of the first conductive structure shown in FIG3A . As shown in FIG3A and FIG5 , the radial dimension of the first conductive portion 142 is D10, the maximum radial dimension of the second conductive portion 143 is D20, the minimum radial dimension of the second conductive portion 143 is D30, the thickness of the first passivation layer 102 is H, and the angle between the side of the second conductive portion 143 and the bottom surface of the base substrate 101 is θ2. For example, the relationship between D10 and D30 can satisfy: D30 ≥ D10. For example, the relationship between D10, D20, and D30 can satisfy: D20 ≥ D30 + 2H / tanθ2. Of course, the first conductive structures of FIG3B and FIG3C also satisfy the above relationship, which will not be repeated here.

[0080] In some examples, as shown in Figures 4 and 5, the aperture D1 of the first sub-portion 132 is equal to the radial dimension D10 of the first conductive portion 142, the maximum aperture D2 of the second sub-portion 133 is equal to the maximum radial dimension D20 of the second conductive portion 143, the minimum aperture D3 of the second sub-portion 133 is equal to the minimum radial dimension D30 of the second conductive portion 143, and the angle θ1 between the side of the second sub-portion 133 and the bottom surface of the base substrate 101 is equal to the angle θ2 between the side of the second conductive portion 143 and the bottom surface of the base substrate 101.

[0081] Figure 6 is a schematic diagram of a laser-processed substrate drilling method according to one embodiment of the present disclosure. As shown in Figure 6, from left to right, it can be seen that when the laser process is used to drill the substrate 20, as the depth of the hole 21 increases, the profile of the hole 21 remains essentially unchanged, and the sides of the hole 21 are approximately perpendicular to the surface of the substrate 20. Thus, the laser process can be used to form the first sub-portion 132 of the first connecting via 131 described above on the substrate. Of course, the present embodiment does not limit the process for forming the first sub-portion 132.

[0082] FIG7 is a schematic diagram of a method for etching a hole in a membrane layer using a dry etching process according to an embodiment of the present disclosure. As shown in FIG7(a), when etching the membrane layer 22 using a dry etching process, the dry etching parameters can be adjusted so that the angle θ between the profile of the hole 23 and the bottom surface of the membrane layer 22 is approximately 30 degrees. As shown in FIG7(b), the angle θ between the profile of the hole 23 and the bottom surface of the membrane layer 22 is approximately 80 degrees. Thus, the angle θ between the profile of the hole 23 and the bottom surface of the membrane layer 22 can be adjusted between 30 degrees and 80 degrees. This angle corresponds to the angle θ1 in the aforementioned embodiment. Thus, the second sub-portion 133 of the first connecting via 131 can be formed using a dry etching process, and holes with different profiles can be etched according to design requirements. Of course, the embodiment of the present disclosure does not limit the formation process of the first sub-portion 132.

[0083] For example, as shown in Figures 3A to 3C, Figures 6 and 7, a blind hole can be first formed on the base substrate 101 using a laser process, and then the unetched portion of the base substrate 101 and the first passivation layer 102 are etched using an etching process, thereby forming a first sub-portion 132 on the base substrate 101 and a second sub-portion 133 on the first passivation layer 102.

[0084] In some examples, as shown in Figures 3A to 3C , the micro-LED substrate further includes multiple micro-driver chips 150, each configured to drive a corresponding micro-LED 120 to emit light or display. The multiple connection vias 130 further include multiple second connection vias 134, and the multiple conductive structures 140 further include multiple second conductive structures 144. The multiple second conductive structures 144 are located within the multiple second connection vias 134. The multiple micro-driver chips 150 are connected to the driver circuit layer 110 via the multiple second conductive structures 144. The display-side micro-driver chips 150 are directly assembled onto the display side of the substrate 100, while the driver circuit layer 110 is located on the non-display side. This prevents foreign matter growth from affecting the micro-driver chips 150, improving the product's corrosion resistance and other performance. Furthermore, the micro-driver chips 150 and the micro-LED 120 are located on the same side of the substrate 100, facilitating assembly of the micro-driver chips 150 and the micro-LED 120. It should be noted that the second connecting via 134 may also include a first sub-portion 132 and a second sub-portion 133, and the second conductive structure 144 may also include a first conductive portion 142 and a second conductive portion 143. The design of the dimensions and other parameters of the second connecting via 134 is similar to that of the first connecting via 131, and the design of the dimensions and other parameters of the second conductive structure 144 is similar to that of the first conductive structure 141. Thus, the second conductive structure 144 can have the same beneficial effects as the first conductive structure 141, which will not be described in detail here. It should be noted that Figures 3A to 3C only schematically illustrate the connection between the micro-drive chip 150 and the second conductive structure 144. For example, the micro-drive chip 150 may include multiple terminals, such as multiple input terminals and multiple output terminals. The multiple terminals of the micro-drive chip 150 are connected to the second conductive structure 144 to achieve connection with the drive circuit layer 110.

[0085] In some examples, as shown in Figures 3A to 3C , the micro-LED substrate further includes a passivation layer 119 and a via V1. The passivation layer 119 is located on the first side S1 of the substrate 100 and on the side of the driver circuit layer 110 away from the substrate 100. The via V1 penetrates the passivation layer 119 to expose the driver circuit layer 110. Thus, the driver circuit board and the flexible circuit board can be arranged on the first side S1 of the substrate 100, i.e., the non-display side. One end of the flexible circuit board can be connected to the driver circuit layer 110 through the via V1, and the other end of the flexible circuit board can be connected to the driver circuit board, thereby achieving seamless splicing between the substrates 100, reducing the splicing seam at the splicing location, and improving the display effect after splicing.

[0086] In some examples, the substrate 100 includes but is not limited to a glass substrate, a printed circuit board, a resin substrate, etc. For example, the base substrate 101 includes but is not limited to a glass substrate, etc.

[0087] Figure 8 is a schematic diagram of the wiring of a micro-LED substrate provided in one embodiment of the present disclosure; Figure 9 is a schematic cross-sectional view of the micro-LED substrate shown in Figure 8. As shown in Figures 8 and 9, the driving circuit layer 110 of the micro-LED substrate includes multiple signal lines 200 and multiple connecting lines 210. The micro-LEDs 120 are connected to the signal lines 200 via the first conductive structure 141 and the connecting lines 210. Thus, the signal lines 200 can provide signals to the micro-LEDs 120, causing them to emit light. For example, this micro-LED substrate can be used in the backlight module of a display device.

[0088] In some examples, as shown in Figures 8 and 9 , the micro-LED substrate further includes multiple light-emitting units and multiple first micro-driver chips 151 . Each light-emitting unit includes multiple micro-LEDs 120 . Multiple first micro-driver chips 151 are disposed corresponding to the multiple light-emitting units, and each first micro-driver chip 151 is configured to drive the corresponding light-emitting unit to emit light. Thus, the micro-driver chip can drive the corresponding light-emitting unit to emit light.

[0089] In some examples, as shown in Figures 8 and 9, the multiple connection vias 130 further include multiple second connection vias 134, the multiple conductive structures 140 further include multiple second conductive structures 144, the multiple second conductive structures 144 are located in the multiple second connection vias 134, and the multiple first micro-drive chips 151 are connected to the drive circuit layer 110 through the multiple second conductive structures 144.

[0090] 8 , the plurality of signal lines 200 include a driving voltage line Vled, a ground line GND, an operating voltage line VCC, and a source address line ADDR, etc. For example, the plurality of signal lines 200 may extend along the second direction Y.

[0091] In some examples, as shown in FIG. 8 , the plurality of connection lines 210 may extend along a first direction X or a second direction Y.

[0092] In some examples, as shown in FIG8 , each light-emitting unit includes four micro-LEDs 120, which are connected in series via one connecting line 210 extending along the first direction X and two connecting lines 210 extending along the second direction Y of the first conductive layer 112. Of course, the embodiments of the present disclosure do not limit the number of micro-LEDs 120 included in a light-emitting unit, nor do they limit the serial or parallel connection of the multiple micro-LEDs 120 included in each light-emitting unit.

[0093] In some examples, as shown in FIG. 8 , the micro light emitting diode 120 in the light emitting unit is connected to the driving voltage line Vled through the first conductive structure 141 and the connecting line 210 .

[0094] In some examples, as shown in FIG9 , the micro LED 120 includes a first electrode 121 and a second electrode 122, each of which is connected to a first conductive structure 141. For example, one end of the first conductive structure 141 is exposed on the second side S2 of the substrate 100 to serve as a pad, although this is not a limitation in the present disclosure.

[0095] In some examples, as shown in FIG8 , the first micro-driver chip 151 is connected to the operating voltage line VCC and the source address line ADDR, respectively, via the second conductive structure 144. The first micro-driver chip 151 is also connected to the ground line GND via the second conductive structure 144 and the connection line 210. Of course, the disclosed embodiments do not limit the manner in which the first micro-driver chip 151 is connected to the ground line GND, the operating voltage line VCC, and the source address line ADDR. The first micro-driver chip 151 can be directly connected via the second conductive structure 144 or connected via the second conductive structure 144 and the connection line 210.

[0096] In some examples, as shown in FIG. 8 , the first micro-driving chip 151 further includes an output terminal, and the micro-LED 120 is connected to the output terminal through the first conductive structure 141 and the connecting wire 210 .

[0097] In some examples, as shown in FIG8 , the plurality of micro LEDs 120 in the light-emitting unit are arranged between the driving voltage line Vled and the ground line GND. For example, the first micro driver chip 151 is arranged between the driving voltage line Vled and the ground line GND. For example, in a direction perpendicular to the driving voltage line Vled, the plurality of micro LEDs 120 in the light-emitting unit are arranged between the driving voltage line Vled and the first micro driver chip 151.

[0098] In some examples, as shown in Figure 9, the micro-LED substrate further includes a passivation layer 119 and a via V1. The passivation layer 119 is located on the first side S1 of the substrate 100 and on the side of the driver circuit layer 110 away from the substrate 100. Thus, the driver circuit board and the flexible circuit board can be arranged on the first side S1 of the substrate 100, i.e., the non-display side. One end of the flexible circuit board can be connected to the driver circuit layer 110 via the via V1, and the other end of the flexible circuit board can be connected to the driver circuit board, thereby achieving seamless splicing between the substrates 100, reducing the splicing seam at the splicing location, and improving the display effect after splicing.

[0099] Figure 10 is a schematic diagram of the wiring of another micro-LED substrate provided in an embodiment of the present disclosure; Figure 11 is a schematic cross-sectional view of the micro-LED substrate shown in Figure 10. As shown in Figures 10 and 11, the driving circuit layer 110 of the micro-LED substrate includes a first conductive layer 112, a second passivation layer 113, an insulating layer 114, a third passivation layer 115, a second conductive layer 116, and a plurality of vias V2. The second passivation layer 113 is located on the side of the first conductive layer 112 away from the substrate 100, the insulating layer 114 is located on the side of the second passivation layer 113 away from the first conductive layer 112, the third passivation layer 115 is located on the side of the insulating layer 114 away from the second passivation layer 113, and the second conductive layer 116 is located on the side of the third passivation layer 115 away from the insulating layer 114. The plurality of vias V2 penetrate the second passivation layer 113, the insulating layer 114, and the third passivation layer 115. The first conductive layer 112 includes multiple connecting lines 210, and the second conductive layer 116 includes multiple signal lines 200. Multiple micro-LEDs 120 are connected to the multiple connecting lines 210 of the first conductive layer 112 via multiple first conductive structures 141. The first conductive layer 112 is connected to the multiple signal lines 200 of the second conductive layer 116 via multiple vias V2. For example, this micro-LED substrate can be used in products with more complex circuits and a higher density of micro-LEDs 120. For example, this micro-LED substrate can be used in the backlight module of a display device. It should be noted that Figure 10 only shows the first electrode 121 and the second electrode 122 of the micro-LED 120.

[0100] In some examples, as shown in Figures 10 and 11 , the micro-LED substrate further includes multiple light-emitting units and multiple first micro-driver chips 151 . Each light-emitting unit includes multiple micro-LEDs 120 . Multiple first micro-driver chips 151 are disposed corresponding to the multiple light-emitting units, and each micro-driver chip is configured to drive the corresponding light-emitting unit to emit light. It should be noted that Figure 10 only shows the terminals of the first micro-driver chips 151 .

[0101] In some examples, as shown in Figure 11, the multiple connection vias 130 also include multiple second connection vias 134, the multiple conductive structures 140 also include multiple second conductive structures 144, the multiple second conductive structures 144 are located in the multiple second connection vias 134, and the multiple first micro-drive chips 151 are connected to the drive circuit layer 110 through the multiple second conductive structures 144.

[0102] 10 , the plurality of signal lines 200 include a driving voltage line Vled, a ground line GND, an operating voltage line VCC, and a source address line ADDR. For example, the plurality of signal lines 200 may extend along the second direction Y.

[0103] In some examples, as shown in FIG. 10 , the plurality of connection lines 210 may extend along a first direction X or a second direction Y.

[0104] In some examples, as shown in FIG10 , each light-emitting unit includes six micro-LEDs 120, which are connected in series via a plurality of connecting lines 112 extending along the first direction X and a plurality of connecting lines 112 extending along the second direction Y of the first conductive layer 112. Of course, the embodiments of the present disclosure do not limit the number of micro-LEDs 120 included in a light-emitting unit, nor do they limit the serial or parallel connection of the multiple micro-LEDs 120 included in each light-emitting unit.

[0105] In some examples, as shown in FIG. 10 and FIG. 11 , the micro LED 120 in the light emitting unit is connected to the driving voltage line Vled of the second conductive layer 116 through the first conductive structure 141 and the connecting line 112 of the first conductive layer 112 .

[0106] In some examples, as shown in FIG10 and FIG11 , the first micro-driving chip 151 is respectively connected to the ground line GND, the operating voltage line VCC, and the source address line ADDR through the second conductive structure 144 and the connecting line 112 of the first conductive layer 112 .

[0107] In some examples, as shown in FIG. 10 and FIG. 11 , the first micro-driving chip 151 further includes at least one output terminal 153 , and the micro-LED 120 is connected to the output terminal via the first conductive structure 141 and the connecting wire 112 of the first conductive layer 112 .

[0108] In some examples, as shown in FIG10 , the first micro-driving chip 151 corresponds to four groups of light-emitting units and controls the four groups of light-emitting units to emit light.

[0109] In some examples, as shown in Figure 10, the micro-LED substrate further includes a passivation layer 119 and a via V1. The passivation layer 119 is located on the first side S1 of the substrate 100 and on the side of the driver circuit layer 110 away from the substrate 100. Thus, the driver circuit board and the flexible circuit board can be arranged on the first side S1 of the substrate 100, i.e., the non-display side. One end of the flexible circuit board can be connected to the second conductive layer 116 via the via V1, and the other end of the flexible circuit board can be connected to the driver circuit board. This achieves seamless splicing between the substrates 100, reduces the splicing seam at the splicing location, and improves the display effect after splicing.

[0110] Figure 12 is a schematic diagram of the wiring of another micro-LED substrate provided in an embodiment of the present disclosure; Figure 13 is a schematic cross-sectional view of the micro-LED substrate shown in Figure 12. As shown in Figures 12 and 13, the driving circuit layer 110 of the micro-LED substrate includes a first conductive layer 112, a second passivation layer 113, an insulating layer 114, a third passivation layer 115, a second conductive layer 116, and a plurality of vias V2. The second passivation layer 113 is located on the side of the first conductive layer 112 away from the substrate 100, the insulating layer 114 is located on the side of the second passivation layer 113 away from the first conductive layer 112, the third passivation layer 115 is located on the side of the insulating layer 114 away from the second passivation layer 113, and the second conductive layer 116 is located on the side of the third passivation layer 115 away from the insulating layer 114. Multiple vias V2 penetrate the second passivation layer 113, the insulating layer 114, and the third passivation layer 115. The first conductive layer 112 includes multiple connection lines 210, and the second conductive layer 116 includes multiple signal lines 200. Multiple micro-LEDs 120 are connected to the multiple connection lines 210 of the first conductive layer 112 via multiple first conductive structures 141. The first conductive layer 112 is connected to the multiple signal lines 200 of the second conductive layer 116 via multiple vias V2. For example, the micro-LED substrate can be used in direct display products.

[0111] In some examples, as shown in Figures 12 and 13, the micro LED substrate further includes a plurality of pixel units and a plurality of second micro driving chips 152. The plurality of second micro driving chips 152 are arranged corresponding to the plurality of pixel units, and each second micro driving chip 152 is configured to drive the corresponding pixel unit for display.

[0112] In some examples, as shown in Figures 12 and 13, the plurality of micro-LEDs 120 include a first micro-LED, a second micro-LED, and a third micro-LED. The first micro-LED is configured to emit light of a first color, the second micro-LED is configured to emit light of a second color, and the third micro-LED is configured to emit light of a third color. Each pixel unit includes the first micro-LED, the second micro-LED, and the third micro-LED. It should be noted that the first color, the second color, and the third color are different. For example, the first color is green, the second color is red, and the third color is blue. Of course, the present disclosure includes but is not limited to this, and the first color, the second color, and the third color may also be other colors.

[0113] In some examples, as shown in Figures 12 and 13, the multiple connection vias 130 also include multiple second connection vias 134, the multiple conductive structures 140 also include multiple second conductive structures 144, the multiple second conductive structures 144 are located in the multiple second connection vias 134, and the multiple second micro-driving chips 152 are connected to the driving circuit layer 110 through the multiple second conductive structures 144.

[0114] 12 , the plurality of signal lines 200 include a first signal line VR, a second signal line VGB, a ground line GND, an operating voltage line VCC, and a data line DATA. For example, the plurality of signal lines 200 may extend along the second direction Y.

[0115] In some examples, as shown in FIG. 12 , the plurality of connection lines 210 may extend along a first direction X, or along a second direction Y, or along a direction forming a certain angle with the first direction X.

[0116] In some examples, as shown in FIG. 12 and FIG. 13 , the micro LED 120 is connected to the first signal line VR or the second signal line VGB through the first conductive structure 141 and the connection line 210 of the first conductive layer 112 .

[0117] In some examples, as shown in Figures 12 and 13, the second micro-driving chip 152 is respectively connected to the ground line GND, the operating voltage line VCC, and the data line DATA through the second conductive structure 144 and the connecting line 210 of the first conductive layer 112. The second micro-driving chip 152 also includes three output terminals, which are respectively connected to the first micro-LED, the second micro-LED, and the third micro-LED of the corresponding pixel unit.

[0118] In some examples, as shown in FIG12 , the first conductive layer 112 may further include a plurality of connection blocks 211 . For example, the plurality of connection blocks 211 are located at both ends of the plurality of connection lines 210 to connect to the plurality of signal lines 200 or the plurality of conductive structures 140 . For example, the plurality of connection blocks 211 are provided in a one-to-one correspondence with the plurality of signal lines 200 and are connected through vias V2 . For example, the plurality of connection blocks 211 are provided in a one-to-one correspondence with the plurality of conductive structures 140 . For example, the orthographic projection of the via V2 on the substrate 100 is within the orthographic projection of the corresponding connection block 211 on the substrate 100 . For example, the orthographic projection of the conductive structure 140 on the substrate 100 is within the orthographic projection of the corresponding connection block 211 on the substrate 100 .

[0119] In some examples, as shown in FIG13 , the micro-LED substrate further includes a passivation layer 119 and a via V1. The passivation layer 119 is located on the first side S1 of the substrate 100 and on the side of the driver circuit layer 110 away from the substrate 100. Thus, the driver circuit board and the flexible circuit board can be arranged on the first side S1 of the substrate 100, i.e., the non-display side. One end of the flexible circuit board can be connected to the driver circuit layer 110 via the via V1, and the other end of the flexible circuit board can be connected to the driver circuit board. This achieves seamless splicing between the substrates 100, reduces the splicing seam at the splicing location, and improves the display effect after splicing.

[0120] One embodiment of the present disclosure also provides a display device. Figure 14 is a schematic diagram of a display device provided by one embodiment of the present disclosure. As shown in Figure 14, the display device 300 includes any of the aforementioned micro-LED substrates 200. Thus, the display device 300 exhibits the same benefits as the micro-LED substrate 200, which will not be further elaborated here.

[0121] For example, the display device may be an electronic product with a display function, such as a television, a computer, a navigation system, a car computer, an electronic picture frame, a tablet computer, a mobile phone, or the like.

[0122] On the other hand, when Mini LEDs and Micro LEDs are used in direct display products, the driver circuit layer and micro-LEDs are located on the same side of the glass substrate. The signal lines of the driver circuit layer can be introduced to the back side of the glass substrate through laser-formed vias in the glass substrate. The bonding area, driver circuit layer, and light-emitting device layer are located on opposite sides of the glass substrate. Although this design can achieve seamless splicing in all directions, it has extremely high process requirements and a high process defect rate. It is prone to film peeling, etching residue, and damage to the organic film layer, resulting in poor mass production. Figure 15A is a schematic diagram of a structure using laser drilling for substrates; Figure 15B is a structural diagram of a micro-LED product. As shown in Figure 15A, when laser drilling is used to drill substrate 15, if there is no film layer on the back side of substrate 15, the laser can completely penetrate the substrate to form via 16. However, if there is a film layer 17 on the back side of substrate 15, it is impossible to directly use a laser to drill via 16 while ensuring that the back side film layer 17 is not damaged. As shown in FIG15B , since this product has a film layer on the back side of the substrate, the laser drilling process causes problems such as film damage, film bubbling and separation on the back side of the substrate, resulting in poor mass production. The framed positions in the figure are the locations where the film layer is damaged and the film layer is bubbled and separated.

[0123] In this regard, an embodiment of the present disclosure further provides a method for manufacturing a micro-LED substrate. FIG16 is a flow chart of a method for manufacturing a micro-LED substrate provided by an embodiment of the present disclosure. As shown in FIG16 , the method for manufacturing a micro-LED substrate includes the following steps:

[0124] S110: providing a substrate;

[0125] S120: forming a driving circuit layer on the first side of the substrate;

[0126] S130: forming a plurality of connection vias penetrating the substrate on the substrate;

[0127] S140: forming a conductive structure in the connecting via hole;

[0128] S150: A plurality of micro light-emitting diodes are formed on the second side of the substrate, the first side and the second side are opposite sides of the substrate, the plurality of connection vias include a plurality of first connection vias, the plurality of conductive structures include a plurality of first conductive structures, the plurality of first conductive structures are located in the plurality of first connection vias, and the plurality of micro light-emitting diodes are electrically connected to the driving circuit layer through the plurality of first conductive structures.

[0129] In the method for manufacturing a micro-LED substrate provided in the embodiments of the present disclosure, a driver circuit layer is formed on a first side of the substrate, and a micro-LED is formed on a second side of the substrate. The driver circuit layer and the micro-LED are located on opposite sides of the substrate. The first side where the micro-LED is located is the display side, and the second side where the driver circuit layer is located is the non-display side. Consequently, the bonding area is also located on the non-display side. This allows for seamless splicing between the substrates, reduces the splicing seam at the splicing point, and improves the display quality after splicing. Compared to conventional designs where micro-LEDs are secured via solder pads on copper wires, the micro-LEDs are secured to the substrate via a first conductive structure within a first connecting via. During rework of the micro-LED, less copper is removed from the first conductive structure, resulting in improved product yield during the second die bonding process. Furthermore, during the rework process, the first connecting via has a leveling effect, concentrating more copper within the first connecting via, thereby reducing the copper removed from the first conductive structure during the rework process, further improving product yield. The display-side micro-LEDs are directly assembled onto the display side of the substrate, while the driver circuit layer is located on the non-display side. This prevents foreign matter growth from affecting the micro-LEDs' light emission or display, improving the product's corrosion resistance and other performance. With the micro-LEDs and driver circuit layer located on opposite sides of the substrate, the overall voltage and current are reduced, which also reduces corrosion issues. Furthermore, placing the micro-LEDs and driver circuit layer on opposite sides of the substrate allows for greater layout space for the micro-LEDs, increasing their density.

[0130] In some examples, in the method for manufacturing a micro-LED substrate, providing a substrate includes: providing a base substrate; and forming a passivation layer on a side of the base substrate adjacent to the driving circuit layer. That is, in this example, the substrate includes the base substrate and the passivation layer.

[0131] In some examples, the substrate includes but is not limited to a glass substrate, a printed circuit board, a resin substrate, etc. For example, the base substrate 101 includes but is not limited to a glass substrate, etc.

[0132] Figures 17A to 17C are schematic flow charts of a manufacturing method for forming connecting vias on a substrate provided in an embodiment of the present disclosure. Forming multiple connecting vias on a substrate includes: as shown in Figures 17A and 17B, a blind hole 135 is formed on a base substrate 101 using a laser process; as shown in Figure 17C, an etching process is used to etch the unetched portion of the base substrate 101 and the passivation layer 102 along the extension direction of the blind hole 135 to form a first sub-portion 132 that passes through the base substrate 101 and a second sub-portion 133 that passes through the passivation layer 102. The first connecting via 131 includes a first sub-portion 132 and a second sub-portion 133. In this embodiment, a blind hole 135 is first formed on the base substrate 101 using a laser process, and then an etching process is used to etch the unetched portion of the base substrate 101, so that the laser process will not cause film damage, film bubbling and separation to the passivation layer 102.

[0133] In some examples, as shown in FIG17C , the average pore size of the second sub-portion 133 is larger than the average pore size of the first sub-portion 132. Thus, the shape of the first connection via 131 can be approximately anchor-shaped, and the conductive structure within the first connection via 131 can be approximately anchor-shaped, thereby improving the contact adhesion between the conductive structure within the first connection via 131 and the driving circuit layer 110 and enhancing performance stability.

[0134] In some examples, as shown in Figure 17C, along the direction of the substrate 100 pointing to the driving circuit layer 110, the aperture of the first sub-portion 132 remains unchanged, and the aperture of the second sub-portion 133 gradually becomes smaller, and the maximum aperture of the second sub-portion 133 is larger than the aperture of the first sub-portion 132.

[0135] In some examples, as shown in FIG. 17C , the first sub-portion 132 includes a rectangular shape in a cross-section along a plane perpendicular to the substrate 100 , and the second sub-portion 133 includes a trapezoidal shape in a cross-section along a plane perpendicular to the substrate 100 .

[0136] In some examples, as shown in FIG17B , the thickness dimension T0 of the portion of the base substrate 101 not punched by the laser process ranges from 0.05 to 0.15 mm, thereby ensuring that the laser process does not penetrate the base substrate 101 when punching the base substrate 101 .

[0137] In some examples, as shown in FIG17B , the thickness of the substrate 101 is T1, the thickness of the passivation layer 102 is T2, the depth of the laser drilling process can be set to 0.85*T1, and the remaining thickness of the substrate 101 is 0.15*T1 and etched by the etching process, so that the thickness of the hole etched by the etching process is 0.15T1+T2.

[0138] In some examples, as shown in FIG17C , the plurality of connection vias 130 further include a plurality of second connection vias 134, and the micro-LED substrate further includes a plurality of micro-driver chips, which are connected to the driver circuit layer 110 via the conductive structures within the plurality of second connection vias 134. It should be noted that the manufacturing process of the second connection vias 134 is the same as that of the first connection vias 131, and thus the second connection vias 134 can have the same beneficial effects as the first connection vias 131, which will not be further described here.

[0139] In some examples, the etching process may include dry etching and wet etching. For example, dry etching with special gases (special gases) may be used for etching. The embodiments of the present disclosure do not limit dry etching with special gases.

[0140] Figures 18A to 18H are schematic flow charts of a method for manufacturing a micro-LED substrate as shown in Figure 8. The method for manufacturing the micro-LED substrate includes: as shown in Figure 18A, forming a first passivation layer 102 on a first side S1 of a base substrate 101. For example, the first passivation layer 102 may be a reverse stress layer. For example, the material of the first passivation layer 102 includes, but is not limited to, silicon nitride; as shown in Figure 18B, forming a driving circuit layer 110 on the first passivation layer 102 through a coating process, a yellow light process, and an etching process. For example, the material of the driving circuit layer 110 includes, but is not limited to, copper; as shown in Figure 18C, depositing a passivation layer 119 on the driving circuit layer 110 through a coating device. For example, the material of the passivation layer 119 includes, but is not limited to, silicon nitride; as shown in Figure 18D, drilling a blind hole 135 on a second side S2 of the base substrate 101 using a laser process, and stopping the laser drilling when there is about 0.1 mm of the base substrate 101 remaining; as shown in Figure 18E, On the second side S2 of the substrate 101, dry etching is continued using a special gas etchant to etch the unperforated portion of the substrate 101 and the first passivation layer 102, ultimately forming the first connection via 131 and the second connection via 134 (Figure 18E). As shown in Figure 18F, on the second side S2 of the substrate 101, a first conductive structure 141 is grown within the first connection via 131, and a second conductive structure 144 is grown within the second connection via 134 using electrochemical or gold deposition. As shown in Figure 18G, white ink is printed on the second side S2 of the substrate 101, followed by die bonding, reflow soldering, and adhesive dispensing, to obtain the micro-LEDs 120 and the first micro-driver chip 151 arrayed on the second side S2 of the substrate 101. As shown in Figure 18H, on the first side S1 of the substrate 101, the passivation layer 119 is etched in the bonding area to form a via V1 to expose the driver circuit layer 110, and a bonding process is performed to obtain the final product. For example, this micro-LED substrate can be used for light emission or display. 18A to 18H schematically illustrate only one first connection via 131 and one second connection via 134 , but the embodiment of the present disclosure is not limited thereto.

[0141] Figures 19A to 19L are schematic flow charts of a method for manufacturing a micro-LED substrate shown in Figure 10. The method for manufacturing a micro-LED substrate includes: as shown in Figure 19A, forming a first passivation layer 102 on a first side S1 of a base substrate 101. For example, the first passivation layer 102 may be a reverse stress layer. For example, the material of the first passivation layer 102 includes, but is not limited to, silicon nitride; as shown in Figure 19B, forming a first conductive layer 112 on the first passivation layer 102 through a coating process, a yellow light process, and an etching process. For example, the material of the first conductive layer 112 includes, but is not limited to, copper; as shown in Figure 19C, depositing a second passivation layer on the first conductive layer 112 through a coating device. 113, for example, the material of the second passivation layer 113 includes but is not limited to silicon nitride; as shown in FIG19D , a patterned insulating layer 114 is formed on the second passivation layer 113 by a photolithography process, for example, the material of the insulating layer 114 includes but is not limited to optical adhesive OC; as shown in FIG19E , a third passivation layer 115 and a via V2 are formed by a coating process, a photolithography process, and an etching process; as shown in FIG19F , a second conductive layer 116 is formed on the insulating layer 114 by a coating process, a photolithography process, and an etching process, for example, the material of the second conductive layer 116 includes but is not limited to copper; As shown in FIG19G , a passivation layer 119 is deposited on the driving circuit layer 110 by a coating device. For example, the material of the passivation layer 119 includes but is not limited to silicon nitride, and can also be a composite film layer, for example, a composite film layer of silicon nitride and photoresist OC. As shown in FIG19H , a blind hole 135 is punched on the second side S2 of the substrate 101 using a laser process, and the laser drilling is stopped when there is about 0.1 mm left on the substrate 101. As shown in FIG19I , the unpunched portion of the substrate 101 and the first portion of the substrate 101 are further etched using dry etching gas on the second side S2 of the substrate 101. A passivation layer 102 is formed, ultimately forming the first connection via 131 and the second connection via 134 shown in Figure 19I . As shown in Figure 19J , a first conductive structure 141 is grown within the first connection via 131 and a second conductive structure 144 is grown within the second connection via 134 on the second side S2 of the substrate 101 using electrochemical or gold deposition methods. As shown in Figure 19K , white ink is printed on the second side S2 of the substrate 101, followed by die bonding, reflow soldering, and adhesive dispensing, resulting in an array of micro-LEDs 120 and a first micro-driver chip 151 arranged on the second side S2 of the substrate 101. As shown in Figure 19L , the passivation layer is etched in the bonding area on the first side S1 of the substrate 101 to form vias V1 to expose the driver circuit layer 110, and a bonding process is performed to obtain the final product. For example, this micro-LED substrate can be used for light emission or display. Figures 19A to 19L only schematically illustrate one first connection via 131 and one second connection via 134, but this is not a limitation of the present disclosure.

[0142] For example, the micro-LED substrate shown in FIG12 may also be manufactured using the method shown in FIG19A to FIG19L, which will not be described in detail here.

[0143] There are a few points to note:

[0144] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure, and other structures may refer to conventional designs.

[0145] (2) Unless there is any conflict, the features of the same embodiment and different embodiments of the present disclosure may be combined with each other.

[0146] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A micro light emitting diode substrate, comprising: substrate, A driving circuit layer, located on the first side of the substrate; A plurality of micro light emitting diodes are located on a second side of the substrate, wherein the second side and the first side are two opposite sides of the substrate; A plurality of connecting vias passing through the substrate; as well as A plurality of conductive structures are located within the plurality of connecting vias and are arranged one-to-one corresponding to the plurality of connecting vias. Among them, the multiple connecting vias include multiple first connecting vias, the multiple conductive structures include multiple first conductive structures, the multiple first conductive structures are located in the multiple first connecting vias, and the multiple micro-light-emitting diodes are electrically connected to the driving circuit layer through the multiple first conductive structures.

2. The micro-LED substrate according to claim 1, wherein: Each of the micro-light-emitting diodes includes a first pole and a second pole, one end of each of the first conductive structures is connected to the driving circuit layer, and the other end of each of the first conductive structures is exposed on the second side of the substrate to serve as a pad, and the pad is configured to be connected to the first pole or the second pole.

3. The micro-LED substrate according to claim 1, wherein: At least one of the first connecting vias comprises: The first subdivision; and The second sub-section is located at a side of the first sub-section close to the driving circuit layer, The average pore size of the second sub-section is greater than the average pore size of the first sub-section.

4. The micro-LED substrate according to claim 3, wherein: In a direction from the substrate to the driving circuit layer, the aperture of the first sub-section remains unchanged, and the aperture of the second sub-section gradually decreases, and the maximum aperture of the second sub-section is larger than the aperture of the first sub-section.

5. The micro-LED substrate according to claim 4, wherein: A cross section of the first sub-portion along a plane perpendicular to the substrate includes a rectangular shape, and a cross section of the second sub-portion along a plane perpendicular to the substrate includes a trapezoidal shape.

6. The micro-LED substrate according to any one of claims 3 to 5, wherein: The substrate includes a base substrate and a first passivation layer, the first sub-portion is located on the base substrate, and the second sub-portion is located on the first passivation layer.

7. The micro-LED substrate according to any one of claims 1 to 6, wherein: At least one of the first conductive structures comprises: The first conductive part, The second conductive part is located on a side of the first conductive part close to the driving circuit layer, Wherein, an average radial dimension of the second conductive portion is greater than an average radial dimension of the first conductive portion.

8. The micro-LED substrate according to claim 7, wherein: In a direction from the substrate to the driving circuit layer, the radial dimension of the first conductive portion remains unchanged, and the radial dimension of the second conductive portion gradually decreases, and the maximum radial dimension of the second conductive portion is greater than the radial dimension of the first conductive portion.

9. The micro-LED substrate according to claim 8, wherein: A cross section of the first conductive portion along a plane perpendicular to the substrate includes a rectangular shape, and a cross section of the second conductive portion along a plane perpendicular to the substrate includes a trapezoidal shape.

10. The micro-LED substrate according to claim 7, wherein: The substrate includes a base substrate and a first passivation layer, the first conductive portion is located on the base substrate, and the second conductive portion is located on the first passivation layer.

11. The micro-LED substrate according to any one of claims 1 to 10, wherein: The driving circuit layer includes a plurality of signal lines and a plurality of connecting lines, and the micro light emitting diode is connected to the signal lines through the first conductive structure and the connecting lines.

12. The micro-LED substrate according to claim 11, further comprising: A plurality of light-emitting units, each of which comprises a plurality of micro light-emitting diodes; as well as A plurality of first micro-driving chips are arranged corresponding to the plurality of light-emitting units, and each of the first micro-driving chips is configured to drive the corresponding light-emitting unit to emit light. The plurality of connecting vias further include a plurality of second connecting vias, the plurality of conductive structures further include a plurality of second conductive structures, the plurality of second conductive structures are located in the plurality of second connecting vias, and the plurality of first micro-drive chips are connected to the drive circuit layer through the plurality of second conductive structures. The plurality of signal lines include a driving voltage line, a ground line, an operating voltage line, and a source address line; the micro light emitting diode is connected to the driving voltage line through the first conductive structure and the connecting line; the first micro driving chip is connected to the ground line, the operating voltage line, and the source address line through the second conductive structure and the connecting line, respectively; or the first micro driving chip is connected to the ground line, the operating voltage line, and the source address line through the first conductive structure and the connecting line. Two conductive structures are respectively connected to the ground line, the working voltage line and the source address line, The first micro-driving chip includes an output end, and the micro-light emitting diode is connected to the output end through the first conductive structure and the connecting wire.

13. The micro-LED substrate according to any one of claims 1 to 12, wherein: The driving circuit layer comprises: a first conductive layer, a second passivation layer, located on a side of the first conductive layer away from the substrate; an insulating layer, located on a side of the second passivation layer away from the first conductive layer; a third passivation layer, located on a side of the insulating layer away from the second passivation layer; a second conductive layer, located on a side of the third passivation layer away from the insulating layer; and A plurality of first via holes penetrate the second passivation layer, the insulating layer and the third passivation layer, Among them, the first conductive layer includes multiple connecting lines, the second conductive layer includes multiple signal lines, the multiple micro-light-emitting diodes are connected to the multiple connecting lines of the first conductive layer through the multiple first conductive structures, and the multiple connecting lines of the first conductive layer are connected to the multiple signal lines of the second conductive layer through the multiple first vias.

14. The micro-LED substrate according to claim 13, further comprising: A plurality of light-emitting units, each of which comprises a plurality of micro light-emitting diodes; as well as A plurality of first micro-driving chips are arranged corresponding to the plurality of light-emitting units, and each of the micro-driving chips is configured to drive the corresponding light-emitting unit to emit light. The plurality of connecting vias further include a plurality of second connecting vias, the plurality of conductive structures further include a plurality of second conductive structures, the plurality of second conductive structures are located in the plurality of second connecting vias, and the plurality of first micro-drive chips are connected to the drive circuit layer through the second conductive structures. The plurality of signal lines include a driving voltage line, a ground line, a working voltage line and a source address line, the micro light emitting diode is connected to the driving voltage line through the connecting line of the first conductive structure and the first conductive layer, the first micro driving chip is connected to the ground line, the working voltage line and the source address line respectively through the connecting line of the second conductive structure and the first conductive layer, The first micro-driving chip comprises an output end, and the micro-light emitting diode is connected to the output end through the connecting line.

15. The micro-LED substrate according to claim 13, further comprising: A plurality of pixel units; as well as A plurality of second micro-drive chips are arranged corresponding to the plurality of pixel units, each of the second micro-drive chips The chip is configured to drive the corresponding pixel unit for display. The plurality of micro-LEDs include a first micro-LED, a second micro-LED and a third micro-LED, the first micro-LED is configured to emit light of a first color, the second micro-LED is configured to emit light of a second color, the third micro-LED is configured to emit light of a third color, and each of the pixel units includes the first micro-LED, the second micro-LED and the third micro-LED. The plurality of connection vias further include a plurality of second connection vias, the plurality of conductive structures further include a plurality of second conductive structures, the plurality of second conductive structures are located in the plurality of second connection vias, and the plurality of second micro-drive chips are connected to the drive circuit layer through the plurality of second conductive structures.

16. The micro-LED substrate according to claim 15, wherein: The plurality of signal lines include a first signal line, a second signal line, a ground line, a working voltage line and a data line, The micro-LED is connected to the first signal line or the second signal line through the connecting lines of the first conductive structure and the first conductive layer, the second micro-driving chip is respectively connected to the ground line, the working voltage line and the data line through the connecting lines of the second conductive structure and the first conductive layer, and the second micro-driving chip includes three output terminals, and the three output terminals are respectively connected to the first micro-LED, the second micro-LED and the third micro-LED of the corresponding pixel unit.

17. The micro-LED substrate according to claims 1-16, further comprising: a fourth passivation layer, located on the first side of the substrate and on a side of the driving circuit layer away from the substrate; The second via hole penetrates the fourth passivation layer to expose the driving circuit layer.

18. A display device comprising the micro light emitting diode substrate according to any one of claims 1 to 17.

19. A method for manufacturing a micro light emitting diode substrate, comprising: providing a substrate; forming a driving circuit layer on a first side of the substrate; forming a plurality of connection vias on the substrate that penetrate the substrate; forming a conductive structure in the connecting via; as well as forming a plurality of micro light emitting diodes on the second side of the substrate, The first side and the second side are two opposite sides of the substrate, the plurality of connecting vias include a plurality of first connecting vias, the plurality of conductive structures include a plurality of first conductive structures, and the plurality of A first conductive structure is located in the plurality of first connection vias, and the plurality of micro light emitting diodes are electrically connected to the driving circuit layer through the plurality of first conductive structures.

20. The method according to claim 19, wherein: A substrate is provided comprising: providing a substrate base; and A passivation layer is formed on a side of the base substrate close to the driving circuit layer.

21. The method according to claim 20, wherein: Forming a plurality of connecting vias on the substrate comprises: forming a blind hole on the substrate by using a laser process; and The non-perforated portion of the substrate and the passivation layer are etched along the extension direction of the blind hole by an etching process to form a first sub-portion penetrating the substrate and a second sub-portion penetrating the passivation layer. The first connecting via includes the first sub-portion and the second sub-portion.

22. The method according to claim 21, wherein: An average pore size of the second subsection is larger than an average pore size of the first subsection.

23. The method according to claim 22, wherein: In a direction from the substrate to the driving circuit layer, the aperture of the first sub-section remains unchanged, and the aperture of the second sub-section gradually decreases, and the maximum aperture of the second sub-section is larger than the aperture of the first sub-section.

24. The method according to claim 22, wherein: A cross section of the first sub-portion along a plane perpendicular to the substrate includes a rectangular shape, and a cross section of the second sub-portion along a plane perpendicular to the substrate includes a trapezoidal shape.

25. The method according to claim 21, wherein: The thickness of the non-perforated portion of the substrate has a value ranging from 0.05 to 0.15 mm.

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