Light-emitting substrate, manufacturing method thereof and backlight module

Abstract

The invention discloses a light-emitting substrate, a manufacturing method thereof and a backlight module, and the light-emitting substrate comprises a substrate which comprises a first surface and a second surface which are oppositely arranged; the substrate further comprises a plurality of via holes; a plurality of light-emitting elements on the first surface; the driving circuit layer is located on the second surface, and the driving circuit layer is electrically connected with the light-emitting elements through the via holes. The light-emitting element and the driving circuit layer are located on the surfaces of the two sides of the substrate respectively, so that the arrangement mode of all the elements on the surface of the side where the light-emitting element is located does not affect the performance of the driving circuit layer, and the arrangement and wiring of all the elements on the two surfaces can be adaptively designed according to requirements.

Description

Technical Field

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

[0002] In submillimeter light-emitting diode (Mini LED) backlight products, Mini LED chips can usually be set on a printed circuit board (Printed Circuit Board, PCB) or a glass substrate. Since the glass substrate has the characteristics of better thermal conductivity, high flatness, and low expansion and contraction coefficient, it can better support the packaging process of Mini LED chips and ensure the packaging quality. It is increasingly used in display products.

[0003] In the packaging process of Mini LED light-emitting substrates, it is usually necessary to reserve a certain window range in the film layer on the substrate for the Mini LED chip. Therefore, it is easy for water vapor to enter the light-emitting substrate and corrode the driving circuit. Summary of the invention

[0004] The invention provides a light-emitting substrate, a manufacturing method thereof and a backlight module, which are used to avoid the adverse effect of the arrangement mode of the light-emitting element on the driving circuit.

[0005] A first aspect of the present invention provides a light-emitting substrate, comprising: a substrate, the substrate comprising a first surface and a second surface arranged opposite to each other; the substrate further comprising a plurality of via holes;

[0006] A plurality of light emitting elements are located on the first surface;

[0007] The driving circuit layer is located on the second surface, and the driving circuit layer is electrically connected to each of the light-emitting elements through each of the via holes.

[0008] In some embodiments of the present invention, the driving circuit layer includes multiple signal lines, and the orthographic projection of at least one of the signal lines located in the edge area of ​​the substrate on the substrate overlaps with the orthographic projection of the light-emitting element adjacent to the signal line on the substrate.

[0009] In some embodiments of the present invention, the light-emitting element includes a light-emitting chip and a packaging structure, and the packaging structure completely covers the light-emitting chip;

[0010] An orthographic projection of at least one of the signal lines located in the edge region of the substrate on the substrate overlaps with an orthographic projection of a packaging structure of the light-emitting element adjacent to the signal line on the substrate;

[0011] Alternatively, the orthographic projection of at least one of the signal lines located in the edge region of the substrate on the substrate overlaps with the orthographic projection of the packaging structure of the light-emitting element and the light-emitting chip adjacent to the signal line on the substrate.

[0012] In some embodiments of the present invention, the diameter of the via hole is larger than the line width of the signal line connected to the via hole.

[0013] In some embodiments of the present invention, the diameter of each via hole is greater than or equal to 0.135 mm.

[0014] In some embodiments of the present invention, a plurality of control chips are further included in an array distributed on the first surface of the substrate, and each of the control chips is connected to the driving circuit layer through the via hole;

[0015] At least one of the light-emitting elements constitutes a light-emitting unit, and the light-emitting unit includes a first end and a second end; one of the control chips correspondingly controls at least one of the light-emitting units;

[0016] The plurality of signal lines include: a plurality of connection lines, a plurality of fixed potential signal lines, a plurality of common potential signal lines, a plurality of power signal lines and a plurality of addressing signal lines;

[0017] The connecting wire is used to connect the control chip and each of the light-emitting units controlled by the control chip, and to connect each of the light-emitting elements in the light-emitting unit;

[0018] The plurality of fixed potential signal lines, the plurality of common potential signal lines, the plurality of power signal lines and the plurality of addressing signal lines extend along a first direction and are arranged at intervals along a second direction to form a plurality of signal line groups, each of the signal line groups comprising one fixed potential signal line, one common potential signal line, one power signal line and one addressing signal line; each of the control chips arranged in a row along the first direction corresponds to one signal line group; the first direction intersects with the second direction;

[0019] The control chip is connected to the connecting line through the via, the first end of each of the light-emitting units is connected to the corresponding connecting line through the via, and the second end of each of the light-emitting units is connected to the fixed potential signal line in the corresponding signal line group through the via; each of the control chips is respectively connected to the addressing signal line, the power signal line and the common potential signal line in the corresponding signal line group through the via.

[0020] In some embodiments of the present invention, an orthographic projection of the fixed potential signal line near one side of the substrate on the substrate and an orthographic projection of a column of light-emitting elements adjacent to the fixed potential signal line on the substrate have an overlapping area;

[0021] And / or, the orthographic projections of the power signal line and the common potential signal line near one side of the substrate on the substrate overlap with the orthographic projections of a column of light-emitting elements adjacent to the power signal line on the substrate.

[0022] In some embodiments of the present invention, further comprising:

[0023] a buffer layer, located between the second surface of the substrate and the driving circuit layer;

[0024] an insulating layer, located on a side of the driving circuit layer facing away from the substrate;

[0025] The reflective layer is located on the first surface of the substrate, and the reflective layer includes a plurality of openings for exposing each of the light-emitting elements.

[0026] In some embodiments of the present invention, the light-emitting chip is a Mini LED chip.

[0027] In some embodiments of the present invention, the driving circuit layer further includes: a binding area, the binding area is located at a side of the second surface in the first direction, the binding area includes a plurality of binding pins, and each of the signal lines is connected to at least one of the binding pins.

[0028] A second aspect of the present invention provides a backlight module, comprising a back plate and at least one of the above-mentioned light-emitting substrates located on the back plate.

[0029] In some embodiments of the present invention, the backlight module includes a plurality of light-emitting substrates spliced ​​together, and the orthographic projections of adjacent signal lines at the splicing points of the light-emitting substrates on the substrate overlap with the orthographic projections of the light-emitting elements adjacent to the signal lines on the substrate.

[0030] In some embodiments of the present invention, the distance between the light-emitting elements on both sides of the adjacent joints of the light-emitting substrates is equal to the distance between the adjacent light-emitting elements in the light-emitting substrates.

[0031] A third aspect of the present invention provides a method for manufacturing a light-emitting substrate, comprising: forming a plurality of via holes at set positions of a substrate; the substrate comprising a first surface and a second surface arranged opposite to each other;

[0032] depositing a conductive material in each of the via holes;

[0033] forming a driving circuit layer on the second surface;

[0034] A plurality of light emitting elements are welded on the first surface; the position of each light emitting element corresponds to a portion of the via holes; and the driving circuit layer is electrically connected to each light emitting element through the conductive material in each via hole.

[0035] In some embodiments of the present invention, before forming the driving circuit layer on the second surface, the manufacturing method further includes:

[0036] forming a buffer material layer on the second surface, and patterning the buffer material layer to expose the conductive material in each of the via holes;

[0037] The step of forming a driving circuit layer on the second surface comprises:

[0038] forming a conductive material layer on the buffer layer, and patterning the conductive material layer to form a plurality of signal lines;

[0039] After forming a driving circuit layer on the second surface, the manufacturing method further includes:

[0040] An insulating material layer is formed on the plurality of signal lines, and the insulating material layer is patterned to expose a portion of the signal lines to form a binding region.

[0041] The beneficial effects of the present invention are as follows:

[0042] The present invention provides a light-emitting substrate, a manufacturing method thereof and a backlight module, wherein the light-emitting substrate comprises: a substrate, the substrate comprises a first surface and a second surface arranged oppositely; the substrate further comprises a plurality of vias; a plurality of light-emitting elements, which are located on the first surface; a driving circuit layer, which is located on the second surface, and the driving circuit layer is electrically connected to each light-emitting element through each via. The light-emitting element and the driving circuit layer are respectively located on both side surfaces of the substrate, so that the arrangement of each element on the side surface where the light-emitting element is located will not affect the performance of the driving circuit layer, and the arrangement and routing of each element on the two surfaces can be adaptively designed according to requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0044] Figure 1 It is a schematic diagram of a partial structure of a light-emitting substrate in the related art;

[0045] Figure 2 A schematic cross-sectional view of a light-emitting substrate provided by an embodiment of the present invention;

[0046] Figure 3 A schematic diagram of a partial structure of a light-emitting substrate provided in an embodiment of the present invention;

[0047] Figure 4 One of the flow charts of the method for manufacturing a light-emitting substrate provided in an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of a process for depositing a conductive material in a via hole of a substrate;

[0049] Figure 6 This is a second flow chart of a method for manufacturing a light-emitting substrate provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and examples. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0051] In the manufacturing process of Mini LED backlight products, a driving circuit is usually formed on the substrate first and then Mini LED is welded on the driving circuit. In order to isolate the driving circuit from the outside air and increase the light utilization rate of the light-emitting substrate, a reflective layer is usually set on the light-emitting substrate. The reflective layer is usually an insulating material. Therefore, it is necessary to hollow out the reflective layer at the position where the Mini LED is located to ensure that the Mini LED and the driving circuit are welded. That is, the reflective layer is provided with a window area at the position corresponding to the position of the Mini LED, and a packaging structure is also provided on the Mini LED. However, it is still difficult to avoid air and water vapor from entering the light-emitting substrate from the interface between the packaging structure and the window area, thereby causing electrochemical corrosion to the driving circuit and affecting the performance of the driving circuit. In addition, during the use of the product, the problem of the packaging structure material falling off or even peeling off the driving circuit may occur due to aging. Therefore, in the related art, the wiring in the driving circuit needs to avoid the window area of ​​the reflective layer as much as possible and avoid the area covered by the packaging structure as much as possible. However, this will expand the area required for the wiring, resulting in a larger side frame size of the product and poor splicing effect of the light-emitting substrate.

[0052] In view of this, an embodiment of the present invention provides a light-emitting substrate, in which the light-emitting element and the driving circuit are respectively disposed on two side surfaces of the substrate, thereby avoiding the above-mentioned problem.

[0053] Figure 1 It is a schematic diagram of the local structure of the light-emitting substrate in the related art.

[0054] Figure 1 FIG. 4 shows an arrangement of a group of signal lines and components connected thereto near the side frame of the light-emitting substrate in the related art, such as Figure 1 As shown, the light-emitting chip 21, the control chip 7 and the signal lines 30 are arranged on the same surface of the substrate 1, and a packaging structure 22 is arranged on the light-emitting chip 21. The signal lines 30 extend along the first direction X, and the light-emitting chips 21 are arranged in an array along the first direction X and the second direction Y. The signal lines 30 near the side E of the light-emitting substrate need to be arranged away from the reflective layer window area K around the light-emitting chip 21. Therefore, a certain distance L1 needs to be reserved between the signal lines 30 between the column of light-emitting elements closest to the side E and the side E, and the edge of the reflective layer window area K corresponding to the column of light-emitting elements closest to the side E.

[0055] Figure 2 A schematic cross-sectional view of a light-emitting substrate provided in an embodiment of the present invention.

[0056] like Figure 2 As shown, the light-emitting substrate includes a substrate 1, a light-emitting element 2 and a driving circuit layer 3. The substrate 1 includes a first surface 11 and a second surface 12 arranged opposite to each other and a plurality of vias H. The light-emitting element 2 is located on the first surface 11 of the substrate 1, and the driving circuit layer 3 is located on the second surface 12 of the substrate 1. The driving circuit layer 3 is electrically connected to the light-emitting element 2 through each via H.

[0057] In an embodiment of the present invention, the light-emitting substrate and the driving circuit layer are located on two different surfaces of the substrate and are connected through vias in the substrate, so that the arrangement of the components on the surface of the side where the light-emitting components are located will not affect the performance of the driving circuit layer, and the arrangement and routing of the components on the two surfaces can be adaptively designed according to requirements.

[0058] like Figure 2As shown, the light-emitting substrate may further include a buffer layer 4, an insulating layer 5 and a reflective layer 6. The buffer layer 4 is located between the second surface 12 of the substrate 1 and the driving circuit layer 3; the insulating layer 5 is located on the side of the driving circuit layer 3 away from the substrate 1, and the insulating layer 5 covers the driving circuit layer 3, which can block the external air and water vapor to avoid adverse effects on the conductive properties of the driving circuit layer 3. The buffer layer 4 and the insulating layer 5 are both formed of insulating materials; the reflective layer 6 is located on the first surface 11 of the substrate 1, and can be formed by coating the substrate 1 with an insulating reflective material such as white oil, etc. The reflective layer 6 includes a plurality of openings for exposing each light-emitting element 2, that is, forming a window of the reflective layer 6. The reflective layer 6 is used to reflect the incident light to the side away from the substrate 1, thereby improving the utilization rate of the light emitted by the light-emitting element 2. In the embodiment of the present invention, the window area and the driving circuit layer are respectively located on the two side surfaces of the substrate, so there will be no problem of air entering from the window area to corrode the driving circuit.

[0059] The embodiment of the present invention is described by using a light-emitting substrate manufactured using chip-on-board (COB) technology. Figure 2 As shown, the light emitting element 2 includes a light emitting chip 21 and a packaging structure 22 .

[0060] The light emitting chip 21 may be an inorganic light emitting element, and its size is preferably 1 mm 2 Below, more preferably 10000 μm 2 Below, more preferably 3000 μm 2 Below, more preferably 700 μm 2 Below, even below 200μm 2 Below, for example, the light emitting chip 21 may be a Mini LED chip, a Micro LED chip, etc., and its specific type and size are not limited here.

[0061] The packaging structure 22 can be formed of a transparent packaging material such as resin, etc. The packaging structure 22 completely covers the light emitting chip 21, which can prevent external air and water vapor from entering the light emitting chip 21 and affecting the performance of the light emitting chip 21. The packaging structure 22 and the driving circuit layer 3 are arranged on different surfaces, so the light emitting substrate provided by the embodiment of the present invention will not have the problem of wiring peeling caused by aging of the material of the packaging structure 22.

[0062] Figure 3 A schematic diagram of the partial structure of a light-emitting substrate provided in an embodiment of the present invention. Figure 3 The structure of the A-A' section can be referred to Figure 2 .

[0063] like Figure 2 and Figure 3As shown, the driving circuit layer 3 includes a plurality of signal lines 30, at least part of the signal lines 30 extend along the first direction X, and the light-emitting elements 2 are arranged in an array along the first direction X and the second direction Y. Since the driving circuit layer 3 and the light-emitting elements 2 are respectively located on the surfaces of both sides of the substrate 1, the orthographic projection of at least one signal line 30 located in the edge area of ​​the substrate 1 on the substrate 1 and the orthographic projection of the light-emitting element 2 adjacent to the signal line 30 on the substrate 1 may have an overlapping area.

[0064] Specifically, the orthographic projection of at least one signal line 30 located in the edge area of ​​the substrate 1 on the substrate 1 has an overlapping area with the orthographic projection of the packaging structure 22 of the light-emitting element 2 adjacent to the signal line 30 on the substrate 1; or, the orthographic projection of at least one signal line 30 located in the edge area of ​​the substrate 1 on the substrate 1 has an overlapping area with the orthographic projections of the packaging structure 22 of the light-emitting element 2 adjacent to the signal line 30 and the light-emitting chip 21 on the substrate 1.

[0065] In the embodiment of the present invention, each signal line 30 can be as close as possible to each light emitting element 2 connected thereto, so that the distance L2 between the side E of the substrate 1 and the row of light emitting elements 2 closest to the side E is smaller than Figure 1 The structure can be made smaller, and the light-emitting substrate provided in the embodiment of the present invention is conducive to reducing the side frame size of the product.

[0066] Furthermore, since the driving circuit layer 3 and each light-emitting element 2 are arranged on different surfaces, each signal line 30 in the driving circuit layer 3 can be appropriately widened, thereby reducing the impedance of the driving circuit and improving the driving ability of the driving circuit. Each signal line 30 is connected to the corresponding light-emitting unit 2 through a via H in the substrate 1. The aperture of the via H can be set to be larger than the line width of the signal line 30 connected to the via H, so that the conductive material filled in the via can have a lower resistance and meet the electrical performance requirements of the circuit. For ease of processing, the aperture of each via H can be the same. In the embodiment of the present invention, the aperture of each via H can be greater than or equal to 0.135 mm. The size of each via H can be adjusted as needed and is not limited here.

[0067] like Figure 3 As shown, the light-emitting substrate may also include a plurality of control chips 7 distributed in an array along a first direction X and a second direction Y on the first surface of the substrate 1, each control chip 7 is connected to the driving circuit layer 3 through a via H in the substrate 1, at least one light-emitting element 2 constitutes a light-emitting unit, and the light-emitting unit includes a first end and a second end. One control chip 7 can be correspondingly connected to and control at least one light-emitting unit.

[0068] The plurality of signal lines 30 include a plurality of fixed potential signal lines 31 , a plurality of address signal lines 32 , a plurality of power supply signal lines 33 , a plurality of common potential signal lines 34 and a plurality of connection lines 35 .

[0069] Among them, a plurality of fixed potential signal lines 31, a plurality of addressing signal lines 32, a plurality of power signal lines 33 and a plurality of common potential signal lines 34 extend along the first direction X and are arranged at intervals along the second direction Y to form a plurality of signal line groups, the first direction X and the second direction Y intersect, each signal line group includes a fixed potential signal line 31, an addressing signal line 32, a power signal line 33 and a common potential signal line 34, and each control chip 7 arranged in a row along the first direction X corresponds to a signal line group. The connecting line 35 can be used to connect the control chip 7 and each light-emitting unit controlled by the control chip 7. When the light-emitting unit includes a plurality of light-emitting elements 2, each light-emitting element 2 in the same light-emitting unit is connected in series through the connecting line 35.

[0070] The control chip 7 is connected to the connecting line 35 through the via H, the first end of each light-emitting unit is connected to the corresponding connecting line 35 through the via H, the second end of each light-emitting unit is connected to the fixed potential signal line 31 in the corresponding signal line group through the via H, and each control chip 7 is respectively connected to the addressing signal line 32, the power signal line 33 and the common potential signal line 34 in the corresponding signal line group through the via H.

[0071] Through the above-mentioned connection method, the signal can be transmitted to the control chip through the signal line to adjust the light-emitting state of each light-emitting unit. The specific driving method is as follows: the addressing signal line 32 includes a plurality of sub-segments arranged at intervals from each other, and each sub-segment can be connected to two adjacent control chips 7. Before starting work, the addressing signal line 32 transmits a starting address to the first control chip 7 as its address, and then the plurality of control chips 7 sequentially connected through the sub-segments obtain the corresponding addresses in turn. When each control chip 7 is working, it can read the corresponding driving control signal according to its corresponding address; the power signal line 33 can transmit a power signal to power the control chip 7, and can also transmit a plurality of address preceding signals. The control chip 7 can select the driving control signal that matches the address prefix according to the address assigned by the addressing signal line 32 for processing. The driving control signal includes the initial signal of the control chip 7 to control each light-emitting unit. The initial signal is processed by the modulation and demodulation module of the control chip 7 into the duty cycle signal and current amplitude required by each light-emitting unit; the fixed potential signal line 31 provides a fixed potential signal for the light-emitting unit, and the common potential signal line 34 transmits a constant potential signal. According to the signal processed by the above-mentioned control chip 7, the on-off time of each light-emitting unit and the current flowing through the light-emitting unit can be controlled, thereby controlling the brightness of the light-emitting unit.

[0072] Reference Figure 3, the orthographic projection of the fixed potential signal line 31 on the substrate near the side E of the substrate 1 and the orthographic projection of a column of light-emitting elements 2 adjacent to the fixed potential signal line 31 on the substrate 1 may have an overlapping area; at the side of the substrate 1 opposite to the side E in the second direction Y, the orthographic projection of the addressing signal line 22, the power signal line 33 and the common potential signal line 34 on the substrate 1 and the orthographic projection of a column of light-emitting elements 2 adjacent to the power signal line 33 on the substrate 1 may all have overlapping areas, thereby reducing the side frame size of the light-emitting substrate.

[0073] According to the inventive concept of the present invention, the light-emitting element and the signal line are arranged on different planes, and the area covered by the signal line does not need to avoid the position where the light-emitting element is located. Therefore, the signal line near the side of the substrate can be arranged as inward as possible, thereby reducing the side width of the light-emitting substrate. The type and number of signal lines will not affect the effect of narrowing the side frame of the product. The embodiment of the present invention gives the above wiring method as an example. In specific implementation, the arrangement of the signal lines in the light-emitting substrate can be adjusted according to usage requirements, which is not limited here.

[0074] In some embodiments, the connecting line 35 can be arranged on the first surface 11 of the substrate 1, and other signal lines can be arranged on the second surface 12 of the substrate 1, so that the signal line located near the side of the substrate can be further arranged closer to the position where the light-emitting element 2 is located, and can even be arranged on the side of the light-emitting element 2 away from the side of the substrate, so that the distance between the light-emitting element 2 and the side of the substrate 1 can be further reduced to achieve an extremely narrow frame design.

[0075] In order to facilitate the control of the signals transmitted by each signal line, the signal line needs to be first wound to the edge of the light-emitting substrate. Therefore, a binding area can also be set in the light-emitting substrate. The binding area is located at a side of the second surface 12 of the substrate 1 in the first direction X. The binding area is bound to the chip on flex (or, chip on film, referred to as COF), and then the control element is connected through the chip on film. The binding area includes a plurality of binding pins. Each fixed signal line 31, addressing signal line 32, power signal line 33 and common potential signal line 34 is respectively connected to at least one binding pin, so that the control element can transmit the corresponding signal to each signal line.

[0076] In the related art, in order to control the cost of COF, it is necessary to control the area of ​​the binding area as small as possible. Therefore, the signal lines far from the binding area have to be routed horizontally in the edge area to extend to the binding area. Then, it is necessary to reserve an area with a certain width near the bottom frame of the substrate for placing the horizontal signal lines, that is, the fan-out area. In the embodiment of the present invention, since the light-emitting element 2 and the driving circuit layer 3 are located on different surfaces of the substrate, the orthographic projection of part of the horizontal routing on the substrate can overlap with the orthographic projection of a row of light-emitting elements adjacent to the horizontal routing on the substrate, thereby reducing the area of ​​the fan-out area to a certain extent and narrowing the size of the bottom frame of the product.

[0077] Based on the same inventive concept, an embodiment of the present invention further provides a backlight module, which includes a back plate and at least one light-emitting substrate located on the back plate, and the light-emitting substrate can be any of the above-mentioned light-emitting substrates.

[0078] Multiple light-emitting substrates can be set on the back plate of the backlight module to meet the design requirements of large-size display products. Multiple light-emitting substrates need to be spliced ​​to form a whole. The size of the seam between adjacent light-emitting substrates will affect the display effect of the product. The most ideal splicing effect requires that the size of the seam between two light-emitting substrates is consistent with the spacing between adjacent light-emitting elements in the light-emitting substrates. If the side frame of the light-emitting substrate is large, it is difficult to achieve an ideal splicing effect when the spacing between light-emitting elements is small.

[0079] In the embodiment of the present invention, the orthographic projection of the signal line 30 adjacent to the splicing point of each light-emitting substrate in the backlight module on the substrate 1 overlaps with the orthographic projection of the light-emitting element 2 adjacent to the signal line 30 on the substrate 1, thereby saving the space required to reserve on the side of the substrate for setting the signal line. The frame of the light-emitting substrate is narrow, so even when the spacing between the light-emitting elements in the light-emitting substrate is small, the distance between the light-emitting elements on both sides of the splicing seam of adjacent light-emitting substrates can be equal to the distance between the adjacent light-emitting elements in the light-emitting substrate. When the spacing between the light-emitting elements in the light-emitting substrate is large, the side width of the substrate can be appropriately increased so that the distance between the light-emitting elements on both sides of the splicing seam of adjacent light-emitting substrates is equal to the distance between the adjacent light-emitting elements in the light-emitting substrate. The light-emitting substrate with a narrow frame provided in the embodiment of the present invention is conducive to achieving an ideal splicing effect and improving the display quality of the product.

[0080] Based on the same inventive concept, an embodiment of the present invention further provides a method for manufacturing a light-emitting substrate.

[0081] Figure 4 This is one of the flow charts of the method for manufacturing a light-emitting substrate provided in an embodiment of the present invention.

[0082] like Figure 4 As shown, the method for manufacturing the light-emitting substrate includes the following steps:

[0083] S1, forming a plurality of via holes at set positions of the substrate;

[0084] S2, depositing a conductive material in each via hole;

[0085] S3, forming a driving circuit layer on the second surface;

[0086] S4. Welding a plurality of light emitting elements on the first surface.

[0087] Specifically, in step S1, the substrate can be a glass substrate, which has the characteristics of good thermal conductivity, high flatness and low expansion and contraction coefficient, and is suitable for COB packaging of light-emitting chips. In addition, the glass substrate has low cost and is easy to obtain, and is suitable for large-size products. Before drilling, the position coordinates of each via hole in the substrate are determined by design drawings. Each via hole corresponds to the position of each light-emitting element and control chip, and then each via hole can be formed by laser drilling technology or etching liquid etching.

[0088] Figure 5 Schematic diagram of the process of depositing conductive material in a via hole of a substrate.

[0089] like Figure 5 As shown in (a), the substrate 1 includes a first surface 11 and a second surface 12 arranged opposite to each other. After completing step S1, the substrate 1 is formed as shown in FIG. Figure 5 In the structure shown in (b), the substrate 1 includes a plurality of via holes H. In the embodiment of the present invention, the aperture of each via hole H is 0.135 mm.

[0090] In step S2, conductive materials are deposited on the first surface 11 and the second surface 12 of the punched substrate 1, respectively, so that the conductive materials completely fill the via holes H in the substrate 1. Figure 5 (c) shows a structure in which the first surface 11 and the second surface 12 of the substrate 1 are both covered with conductive materials. Then, chemical-mechanical polishing (CMP) can be used to remove the excess conductive materials on both sides of the substrate to avoid interference with the light-emitting element and the driving circuit layer. After removing the excess conductive materials, step S2 is completed to form a structure as shown in FIG. Figure 5 (d) The structure shown.

[0091] Figure 6 This is a second flow chart of a method for manufacturing a light-emitting substrate provided in an embodiment of the present invention.

[0092] like Figure 6 As shown, before step S3, the following steps may also be included:

[0093] S203, forming a buffer material layer on the second surface, and patterning the buffer material layer to expose the conductive material in each via hole. Figure 2 After completing step S203 , a buffer layer 4 may be formed, and a pattern of the buffer layer 4 exposes the conductive material in each via H in the substrate 1 .

[0094] Step S3 includes forming a conductive material layer on the buffer layer, and patterning the conductive material layer to form a plurality of signal lines. Specifically, the plurality of signal lines can be formed by coating the buffer layer with copper, and then exposing, developing and etching the copper layer.

[0095] like Figure 6 As shown, after step S3, the following steps may also be included:

[0096] S304, forming an insulating material layer on the plurality of signal lines, and patterning the insulating material layer to expose a portion of the signal lines to form a binding area. Figure 2 After completing step S304, an insulating layer 5 can be formed, and the pattern of the insulating layer 5 exposes the binding area B.

[0097] In step S4, the position of each light emitting element 2 corresponds to a portion of the vias H, and the driving circuit layer 3 is electrically connected to each light emitting element 2 through the conductive material in each via H. After completing step S4, the control chip 7 may be soldered on the first surface 11 at the position corresponding to the portion of the vias H, and white oil may be coated on the first surface 11 of the substrate 1 to form a reflective layer 6, wherein the reflective layer 6 has an opening exposing the light emitting element 2 and the control chip 7. In some embodiments, Figure 2 As shown, the cross-sectional size of the opening is larger than the cross-sectional size of the packaging structure 22, and a white glue pattern 8 can be set between the opening and the packaging structure 22 as needed to fill the gap between the two, thereby further reducing the probability of water and oxygen entering the interior of the substrate; it can be understood that in some embodiments, the cross-sectional size of the opening can also be smaller than the cross-sectional size of the packaging structure 22, and then the orthographic projection of the packaging structure 22 on the substrate 1 overlaps with the orthographic projection of the reflective layer 6 on the substrate 1. Since the driving circuit layer is located on the second surface 12 of the substrate 1, compared with the related art, the probability of water and oxygen entering the interior of the substrate and causing corrosion of the driving circuit layer will also be reduced.

[0098] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0099] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A light-emitting substrate, characterized in that: include: A substrate, the substrate comprising a first surface and a second surface arranged opposite to each other; the substrate further comprising a plurality of vias; A plurality of light emitting elements are located on the first surface; The driving circuit layer is located on the second surface, and the driving circuit layer is electrically connected to each of the light-emitting elements through each of the via holes.

2. The light-emitting substrate according to claim 1, wherein: The driving circuit layer includes a plurality of signal lines, and an orthographic projection of at least one of the signal lines located in an edge region of the substrate on the substrate overlaps with an orthographic projection of the light emitting element adjacent to the signal line on the substrate.

3. The light-emitting substrate according to claim 2, characterized in that: The light-emitting element comprises a light-emitting chip and a packaging structure, wherein the packaging structure completely covers the light-emitting chip; An orthographic projection of at least one of the signal lines located in the edge region of the substrate on the substrate overlaps with an orthographic projection of a packaging structure of the light-emitting element adjacent to the signal line on the substrate; Alternatively, the orthographic projection of at least one of the signal lines located in the edge region of the substrate on the substrate overlaps with the orthographic projection of the packaging structure of the light-emitting element and the light-emitting chip adjacent to the signal line on the substrate.

4. The light-emitting substrate according to claim 2, wherein: The aperture of the via hole is larger than the line width of the signal line connected to the via hole.

5. The light-emitting substrate according to claim 4, characterized in that: The diameter of each via hole is greater than or equal to 0.135 mm.

6. The light-emitting substrate according to any one of claims 1 to 5, characterized in that: It also includes a plurality of control chips distributed in an array on the first surface of the substrate, each of the control chips being connected to the driving circuit layer through the via hole; At least one of the light-emitting elements constitutes a light-emitting unit, and the light-emitting unit includes a first end and a second end; one of the control chips correspondingly controls at least one of the light-emitting units; The plurality of signal lines include: a plurality of connection lines, a plurality of fixed potential signal lines, a plurality of common potential signal lines, a plurality of power signal lines and a plurality of addressing signal lines; The connecting wire is used to connect the control chip and each of the light-emitting units controlled by the control chip, and to connect each of the light-emitting elements in the light-emitting unit; The plurality of fixed potential signal lines, the plurality of common potential signal lines, the plurality of power signal lines and the plurality of addressing signal lines extend along a first direction and are arranged at intervals along a second direction to form a plurality of signal line groups, each of the signal line groups comprising one fixed potential signal line, one common potential signal line, one power signal line and one addressing signal line; each of the control chips arranged in a row along the first direction corresponds to one signal line group; the first direction intersects with the second direction; The control chip is connected to the connecting line through the via, the first end of each of the light-emitting units is connected to the corresponding connecting line through the via, and the second end of each of the light-emitting units is connected to the fixed potential signal line in the corresponding signal line group through the via; each of the control chips is respectively connected to the addressing signal line, the power signal line and the common potential signal line in the corresponding signal line group through the via.

7. The light-emitting substrate according to claim 6, wherein: An orthographic projection of the fixed potential signal line near one side of the substrate on the substrate and an orthographic projection of a column of light emitting elements adjacent to the fixed potential signal line on the substrate have an overlapping area; And / or, the orthographic projections of the power signal line and the common potential signal line near one side of the substrate on the substrate overlap with the orthographic projections of a column of light-emitting elements adjacent to the power signal line on the substrate.

8. The light-emitting substrate according to any one of claims 1 to 5, characterized in that: Also includes: a buffer layer, located between the second surface of the substrate and the driving circuit layer; an insulating layer, located on a side of the driving circuit layer facing away from the substrate; The reflective layer is located on the first surface of the substrate, and the reflective layer includes a plurality of openings for exposing each of the light-emitting elements.

9. The light-emitting substrate according to claim 3, characterized in that: The light-emitting chip is a Mini LED chip.

10. The light emitting substrate according to claim 6, wherein: The driving circuit layer further includes: a binding area, the binding area is located at a side of the second surface in the first direction, the binding area includes a plurality of binding pins, and each of the signal lines is connected to at least one of the binding pins.

11. A backlight module, characterized in that: The light emitting device comprises a back plate and at least one light emitting substrate as claimed in any one of claims 1 to 10 located on the back plate.

12. The backlight module according to claim 11, wherein: The backlight module comprises a plurality of mutually spliced ​​light-emitting substrates, and the orthographic projections of adjacent signal lines at the splicing locations of the light-emitting substrates on the substrate overlap with the orthographic projections of the light-emitting elements adjacent to the signal lines on the substrate.

13. The backlight module according to claim 12, wherein: The distance between the light emitting elements on both sides of the adjacent joint seams of the light emitting substrates is equal to the distance between the adjacent light emitting elements in the light emitting substrates.

14. A method for manufacturing a light-emitting substrate, characterized in that: include: A plurality of via holes are formed at set positions of a substrate; the substrate comprises a first surface and a second surface which are arranged opposite to each other; depositing a conductive material in each of the via holes; forming a driving circuit layer on the second surface; welding a plurality of light emitting elements on the first surface; The position of each of the light-emitting elements corresponds to a portion of the via holes; and the driving circuit layer is electrically connected to each of the light-emitting elements through the conductive material in each of the via holes.

15. The manufacturing method according to claim 14, characterized in that: Before forming the driving circuit layer on the second surface, the manufacturing method further includes: forming a buffer material layer on the second surface, and patterning the buffer material layer to expose the conductive material in each of the via holes; The step of forming a driving circuit layer on the second surface comprises: forming a conductive material layer on the buffer layer, and patterning the conductive material layer to form a plurality of signal lines; After forming a driving circuit layer on the second surface, the manufacturing method further includes: An insulating material layer is formed on the plurality of signal lines, and the insulating material layer is patterned to expose a portion of the signal lines to form a binding region.

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