Manufacturing method of display device and display device

Abstract

The invention discloses a manufacturing method of a display device and the display device. Lines used for driving light-emitting chips are formed on the front face and the back face of a substrate; attaching a protective film on the side surface of the first side edge of the substrate, wherein the protective film comprises a plurality of hollow patterns with strip-shaped structures; depositing a conductive material on the protective film; stripping the protective film to form a plurality of side lines on the side surface of the substrate; the two ends of the side wires are connected with the signal lines on the front face and the back face of the substrate body respectively, so that electrical conduction of the front face lines and the back face lines is achieved, and the side wires are manufactured through the stripping process so that influences on driving elements can be avoided. The binding area is arranged on the back face of the substrate, a frame on the front face of the display device can not be occupied, therefore, the frame area of the display device is reduced, the screen-to-body ratio is increased, and when the display device is applied to a spliced screen, splicing seams can be reduced, and the display effect can be optimized.

Description

Technical Field

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

[0002] Light Emitting Diode (LED) display technology refers to the display technology that uses light emitting diodes as display devices. Micro LED (Micro Light Emitting Diode, Micro LED) inherits the high efficiency, high brightness, high reliability and fast response time of traditional light emitting diodes, and has the characteristics of self-luminescence without backlight, and has the advantages of energy saving, simple structure, small size and thinness. Micro LED direct display technology has been vigorously developed.

[0003] Active-driven Micro LED displays have the advantages of low power consumption and good display effects. Because low-temperature polysilicon (LTPS) has a high mobility, it is used to make thin-film transistors (TFT) to drive Micro LED chips for image display.

[0004] In order to reduce the border of the display device, the back binding form is required. To achieve this goal, the side wiring technology is required to electrically connect the front and back wiring of the substrate. However, traditional exposure and development processes are difficult to perform on the side, so laser etching processes are often used to make side wiring, but laser etching will have adverse effects on TFT devices. Summary of the invention

[0005] According to a first aspect of an embodiment of the present invention, there is provided a method for manufacturing a display device, comprising:

[0006] Circuits for driving the light-emitting chip are formed on the front and back sides of the substrate; the circuit on the front side of the substrate includes a plurality of transistors, a plurality of first signal lines connected to each of the transistors, and a plurality of connecting pins, at least part of the first signal lines extend to the first side of the substrate near the edge of the front side, each of the connecting pins is located at the first side and is connected to each of the first signal lines extending to the first side in a one-to-one correspondence, and the first side is any side of the substrate; the circuit on the back side of the substrate includes a plurality of second signal lines, each of the second signal lines extends to the first side near the edge of the back side; each of the second signal lines extending to the first side is arranged in a one-to-one correspondence with each of the connecting pins;

[0007] A protective film is attached to the side of the first side of the base substrate; the protective film includes a hollow pattern, the hollow pattern includes a plurality of strip structures, each of the strip structures corresponds to each of the connecting pins extending to the first side, one end of the strip structure exposes a portion of the corresponding connecting pin, and the other end of the strip structure exposes a portion of the corresponding second signal line;

[0008] depositing a conductive material on the protective film;

[0009] The protective film is peeled off to form a plurality of side wirings; two ends of the side wirings are respectively connected to the corresponding connecting pins and the second signal lines.

[0010] In some embodiments of the present invention, the step of attaching a protective film to the side surface of the first side edge of the base substrate comprises:

[0011] Providing a protective film;

[0012] Etching the protective film into the hollow pattern;

[0013] Attaching the protective film having the hollow pattern to the side surface of the first side edge of the base substrate;

[0014] Alternatively, the step of attaching a protective film to the side surface of the first side edge of the base substrate comprises:

[0015] Attaching a complete protective film to the side surface of the first side edge of the base substrate;

[0016] The protective film is etched to form the hollow pattern.

[0017] In some embodiments of the present invention, the hollow pattern of the protective film is formed by a laser etching process.

[0018] In some embodiments of the present invention, forming circuits for driving the light-emitting chip on the front and back sides of the substrate includes:

[0019] Forming a plurality of transistors, a plurality of first signal lines connected to the transistors, and a plurality of connecting pins on the front side of the base substrate;

[0020] forming a photoresist layer on the back side of the base substrate;

[0021] exposing and developing the photoresist layer to form a hollow pattern that is the same as the pattern of the plurality of second signal lines;

[0022] depositing a conductive material on the photoresist layer;

[0023] The photoresist layer is removed to form the plurality of second signal lines.

[0024] In some embodiments of the present invention, after forming a plurality of transistors, a plurality of first signal lines connected to each of the transistors, and a plurality of connecting pins on the front surface of the base substrate, and before forming a photoresist layer on the back surface of the base substrate, the method further includes:

[0025] A plurality of light emitting chips are transferred to the front side of the base substrate and electrically connected to the circuits on the front side of the base substrate.

[0026] In some embodiments of the present invention, after transferring the plurality of light-emitting chips to the front surface of the base substrate and before forming a photoresist layer on the back surface of the base substrate, the method further includes:

[0027] forming a first protective layer on the front surface of the base substrate, wherein the first protective layer covers each of the transistors and each of the first signal lines, and the first protective layer exposes a partial area of ​​each of the connecting pins;

[0028] After removing the photoresist layer to form the plurality of second signal lines, the method further includes:

[0029] A second protection layer is formed on the back side of the base substrate, the second protection layer covers each of the second signal lines, and the second protection layer exposes ends of each of the second signal lines near the edge of the first side.

[0030] In some embodiments of the present invention, before attaching a protective film to the side surface of the first side edge of the base substrate, the method further includes:

[0031] The side edge of the substrate at the first side edge is rounded.

[0032] In some embodiments of the present invention, after forming the side routing, the method further includes:

[0033] The first protective layer and the second protective layer are removed.

[0034] According to a second aspect of an embodiment of the present invention, there is provided a display device, comprising: at least two display screens, each of the display screens being arranged in an array, and adjacent display screens being spliced ​​together;

[0035] Wherein, any of the display screens in the display device is manufactured using any of the above-mentioned manufacturing methods.

[0036] In some embodiments of the present invention, a side of the display screen facing away from the display surface includes a binding area, and the binding area is used to bind a flexible circuit board or a driver chip.

[0037] The manufacturing method and display device provided by the embodiment of the present invention form circuits for driving light-emitting chips on the front and back of the substrate; attach a protective film on the side of the first side of the substrate, the protective film including a plurality of hollow patterns of strip structures; deposit a conductive material on the protective film; peel off the protective film, so that a plurality of side routing lines can be formed on the side of the substrate; the two ends of the side routing lines are respectively connected to the signal lines on the front and back of the substrate, so as to achieve electrical conduction between the front and back circuits, and the side routing lines are manufactured by the peeling process to avoid affecting the driving elements. The binding area is set on the back of the substrate, so that the frame on the front of the display device does not occupy the frame, thereby reducing the frame area of ​​the display device and improving the screen-to-body ratio. When applied to a spliced ​​screen, the splicing seam can also be reduced to optimize the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] 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.

[0039] Figure 1 It is a schematic diagram of the planar structure of a display screen in the related art;

[0040] Figure 2 To adopt Figure 1 One of the planar structural diagrams of the display screen assembly splicing screen shown;

[0041] Figure 3 To adopt Figure 1 The second schematic diagram of the planar structure of the display screen assembly splicing screen shown;

[0042] Figure 4 A schematic diagram of the planar structure of a spliced ​​screen provided in an embodiment of the present invention;

[0043] Figure 5 One of the flow charts of the method for manufacturing a display device provided by an embodiment of the present invention;

[0044] Figure 6 A schematic diagram of a circuit diagram of the front side of a substrate provided by an embodiment of the present invention;

[0045] Figure 7 A schematic diagram of the circuit on the back side of a substrate provided by an embodiment of the present invention;

[0046] Figure 8 A schematic diagram of a cross-sectional structure of a substrate provided by an embodiment of the present invention after forming front circuits and back circuits;

[0047] Fig. 9 A schematic diagram of the cross-sectional structure of a substrate after a protective film is attached to the side surface of the substrate provided by an embodiment of the present invention;

[0048] Fig.10 A schematic diagram of the planar structure of a protective film provided by an embodiment of the present invention;

[0049] Fig.11 A second flowchart of a method for manufacturing a display device provided by an embodiment of the present invention;

[0050] Fig.12 A schematic diagram of a cross-sectional structure after forming a circuit on the front side of a substrate provided by an embodiment of the present invention;

[0051] Fig.13 A schematic diagram of the cross-sectional structure after the light-emitting chip is transferred according to an embodiment of the present invention;

[0052] Fig.14 A schematic diagram of a cross-sectional structure after forming a first protective layer provided by an embodiment of the present invention;

[0053] Fig.15 A schematic diagram of a cross-sectional structure after forming a circuit on the back side of a substrate provided by an embodiment of the present invention;

[0054] Fig.16 A schematic diagram of a cross-sectional structure after forming a second protective layer provided by an embodiment of the present invention;

[0055] Fig.17 A schematic diagram of a cross-sectional structure after rounding the side edges of a substrate provided by an embodiment of the present invention;

[0056] Fig.18 A schematic diagram of a cross-sectional structure after forming a protective film according to an embodiment of the present invention;

[0057] Fig.19 This is a schematic diagram of the cross-sectional structure after the protective film is peeled off according to an embodiment of the present invention. DETAILED DESCRIPTION

[0058] 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.

[0059] LED display technology refers to display technology that uses light-emitting diodes as display devices. Micro LED refers to miniaturized light-emitting diode chips. Generally, the size of Micro LED is in the micron level, for example, the size of Micro LED is less than 100μm. When the size of Micro LED chips is reduced to the pixel level, Micro LED can be directly used as the light-emitting unit for image display.

[0060] Each Micro LED in a Micro LED display device can be individually addressed and driven as a sub-pixel. Because Micro LED has the characteristics of low power consumption, long life, high stability, and self-luminescence without a backlight source, it has the advantages of energy saving and high integration, and can be applied to almost all mainstream display fields. It is considered to be the ideal form of future display technology.

[0061] The typical structure of a Micro LED display device generally includes a driving substrate and a light-emitting chip. The current Micro LED display device requires the light-emitting chip and the driving substrate to be manufactured separately using different processes. After the light-emitting chip and the driving substrate are manufactured, tens of millions or even hundreds of millions of light-emitting chips need to be transferred to the driving substrate through mass transfer technology.

[0062] Among them, the light-emitting chip is a Micro LED chip, which is different from LED. Specifically, it refers to a miniaturized light-emitting diode chip. Generally, the size of a Micro LED chip is in the micrometer range. When a Micro LED display device is used for full-color display, a pixel unit includes three sub-pixels that emit red light, green light, and blue light respectively. The three sub-pixels can each use a Micro LED chip that emits light of different colors.

[0063] Active-driven Micro LED display devices have the advantages of low power consumption and good display effects. Because LTPS has a high mobility, it is used to make TFT driver substrates to drive Micro LED chips for image display. However, the mobility uniformity of LTPS is poor, and large-size display devices cannot be produced. In order to produce large-size Micro LED display devices, small-size display screens can be spliced. In addition, since the bottleneck of mass transfer is difficult to break through, if a large-size TFT driver substrate is used, the manufacturing yield is low and the cost is high. The splicing method of small-size Micro-LED display screens can reduce production costs on the one hand, and maintenance costs on the other.

[0064] Figure 1 Schematic diagram of the planar structure of a display screen in the related art. A single actively driven Micro LED display device is referred to as a display screen hereinafter.

[0065] In related technologies, such as Figure 1 As shown, the display screen Y generally includes a display area AA and a non-display area VA; wherein, a plurality of light-emitting chips are arranged in the display area AA for image display, and a plurality of signal lines are arranged in both the display area AA and the non-display area VA. The signal lines in the display area AA are used to connect the driving elements and the light-emitting chips, and the signal lines are used to transmit the driving signals. The light-emitting chips emit light under the drive of the driving signals, thereby displaying images. These driving signals are generally provided by the driving chips, so the signal lines in the display area AA will extend to the non-display area VA, and finally bind the external circuits or driving chips in the non-display area VA after reasonable wiring. The wiring area in the non-display area VA for binding the external circuits or driving chips is generally referred to as a binding area. The display screen includes at least one binding area. Due to the existence of the binding area, the border of the display screen cannot be reduced, thereby reducing the space of the display area, and a larger screen-to-body ratio cannot be achieved.

[0066] Figure 2 and Figure 3 To adopt Figure 1 The diagram shows the planar structure of the display screen assembled splicing screen.

[0067] like Figure 2 and Figure 3 As shown, when using Figure 1 When the display screen shown is used as a unit display screen to assemble a spliced ​​screen, the non-display area VA of the display screen will produce obvious splicing seams G between some adjacent display screens. Figure 2 The display screens Y in the spliced ​​screen shown are arranged in the same manner, so a splicing seam G is generated between the display screens Y adjacent to each other in the horizontal direction. Figure 3In the spliced ​​screen shown, the non-display areas VA of the display screens Y are arranged adjacent to each other, so a relatively large splicing seam G is generated between the horizontally adjacent display screens Y. The splicing seam in the spliced ​​screen will destroy the continuity of the displayed image, and the larger the width of the splicing seam G, the more obvious the grid effect of the image display.

[0068] In order to reduce the non-display area VA of the display screen and enable seamless splicing of the display screen, the binding area of ​​the display screen needs to be transferred to the back of the display screen. Figure 4 A schematic diagram of the planar structure of a spliced ​​screen provided in an embodiment of the present invention.

[0069] In the embodiment of the present invention, Figure 4 As shown, by transferring the binding area to the back of display screen Y, the original non-display area can be converted into display area AA, increasing the area of ​​display area AA, thereby increasing the screen-to-body ratio of a single display screen. Then, after the display screens are spliced, the splicing seams between the display screens can be effectively reduced, thereby optimizing the display effect of the picture.

[0070] In order to achieve back bonding, the side wiring technology is needed to electrically connect the front and back lines of the display. However, traditional exposure and development processes are difficult to perform on the side, so laser etching is often used to make side wiring, but laser etching will have adverse effects on TFT devices.

[0071] In view of this, an embodiment of the present invention provides a method for manufacturing a display device. The manufacturing method is applicable to manufacturing a single display screen, and can also be used to manufacture each display screen in a spliced ​​screen. Figure 5 One of the flow charts of the method for manufacturing a display device provided by an embodiment of the present invention; Figure 6 A schematic diagram of a circuit diagram of the front side of a substrate provided by an embodiment of the present invention; Figure 7 A schematic diagram of the circuitry on the back side of a substrate provided in an embodiment of the present invention.

[0072] like Figure 5 As shown, the manufacturing method of the display device provided by the embodiment of the present invention includes:

[0073] S10, forming circuits for driving the light-emitting chip on the front and back sides of the base substrate;

[0074] S20, attaching a protective film to the side of the first side edge of the base substrate;

[0075] S30, depositing a conductive material on the protective film;

[0076] S40, peeling off the protective film to form a plurality of side routing lines.

[0077] Among them, the base substrate is often located at the bottom of the display device and has a supporting and bearing function. The base substrate can be a glass substrate or a flexible substrate, which is not limited here. In the embodiment of the present invention, the order of making the circuit on the base substrate is to first make the circuit on the front side of the base substrate, then make the circuit on the back side of the base substrate, and finally make the circuit on the side of the base substrate, and the circuit on the side makes the circuit on the front side electrically connected with the circuit on the back side.

[0078] In an embodiment of the present invention, the display device is an actively driven Micro LED display screen. After providing a substrate, the circuit on the front side thereof can be manufactured using a thin film process in the relevant technology. For example, GIP and EIP technologies can be used to form the routing on the front side of the substrate, which will not be elaborated here.

[0079] like Figure 6 As shown, the circuit on the front side of the substrate includes a plurality of transistors t, a plurality of first signal lines l1 connected to each transistor, and a plurality of connecting pins ( Figure 5 These first signal lines l1 may include:

[0080] A plurality of scanning signal lines g extend along a first direction z1 and are arranged along a second direction z2.

[0081] A plurality of data signal lines d extend along the second direction z2 and are arranged along the first direction z1.

[0082] The first direction z1 intersects with the second direction z2. The first direction z1 may be a direction of a pixel unit row, and the second direction z2 may be a direction of a pixel unit column. In some embodiments, the first direction z1 and the second direction z2 are perpendicular to each other.

[0083] Each scanning signal line g and each data signal line d divides a plurality of pixel units p. A scanning signal line g connects a row of pixel units p, and a data signal line d connects a column of pixel units p. In the embodiment of the present invention, the pixel unit p refers to a unit light-emitting area for displaying an image. In a specific application, a light-emitting chip needs to be connected to the position where the pixel unit p is located in order to emit light. In some embodiments, the light-emitting chip can specifically be a Micro LED chip.

[0084] A plurality of transistors t correspond to each pixel unit p one by one, and the transistor t is used to load the data signal transmitted by the corresponding data signal line d to the corresponding pixel unit p under the control of the scanning signal transmitted by the corresponding scanning signal line g. The transistor t is an active driving element in the display screen Y. By setting a transistor t in each pixel unit p, each pixel unit p in the main display screen Y can be scanned line by line. In the embodiment of the present invention, the transistor t can be a TFT.

[0085] The driving signals of the first signal lines are provided by the driving chip, and the driving chip is directly or indirectly bound to the binding area. In the embodiment of the present invention, the binding area is a line located on the back side of the substrate. In order to connect the first signal line on the front side of the substrate to the binding area, such as Figure 6 As shown, at least part of the first signal line l1 extends to the first side edge of the substrate near the edge of the front side, and a plurality of connecting pins are also arranged on the front surface of the substrate, each connecting pin is located at the first side edge and is connected to each first signal line l1 extending to the first side edge in a one-to-one correspondence. The first side edge can be any side edge of the substrate. Figure 6 The middle is the lower side.

[0086] After the circuit on the front side of the substrate is fabricated, the circuit on the back side of the substrate is fabricated. Figure 7 As shown, the circuit on the back side of the substrate may include a plurality of second signal lines l2, each of which extends to the first side ( Figure 7 The lower side of the substrate is near the edge of the back side; each second signal line extending to the first side is arranged in a one-to-one correspondence with each connecting pin on the front side of the substrate. Figure 7 As shown, each second signal line l2 will be reasonably wired on the back side of the substrate and finally collected in the binding area B. A plurality of binding pins e3 are provided in the binding area B. The binding pins e3 are connected to the second signal lines l2 one by one, and the binding pins e3 can be manufactured simultaneously with each second signal line l2.

[0087] Then, on the first side ( Figure 6 and Figure 7 After the wiring is formed on the side of the lower side (in the middle), the connection pins on the front side of the substrate can be connected one by one with the second signal lines on the back side, and finally the lines are collected in the binding area on the back side to achieve electrical conduction between the front line and the back line.

[0088] Figure 8 A schematic diagram of the cross-sectional structure of a substrate after forming front and back circuits on the substrate provided in an embodiment of the present invention.

[0089] The circuit on the front side of the substrate is manufactured by thin film technology, so the transistor, the first signal line and the connecting pin are formed in different film layers. Figure 8 As shown, the above-mentioned multi-film layer specifically includes:

[0090] The gate metal layer 12 is located on the base substrate 11 and includes the pattern of the scanning signal line g (not shown) and the gate G of the transistor. The gate metal layer 12 can be a single-layer or multi-layer metal stacked structure, which is not limited here.

[0091] The gate insulating layer 13 is located on the side of the gate metal layer 12 facing away from the base substrate 11. The gate insulating layer 13 is used to insulate the gate metal layer 12, so that other metal layers can be formed on the gate insulating layer 13. The gate insulating layer 13 can be an inorganic layer of silicon oxide, silicon nitride or metal oxide, and can include a single layer or multiple layers.

[0092] The active layer a is located on the side of the gate insulating layer 13 away from the gate metal layer 12. The active layer a includes a source region and a drain region formed by doping N-type impurity ions or P-type impurity ions. The region between the source region and the drain region is an undoped channel region.

[0093] The source-drain metal layer 14 is located on the side of the active layer a and the gate insulating layer 13 away from the gate metal layer 12. The source-drain metal layer 14 includes a data signal line d (not shown) and the source S and drain D of the transistor. The source-drain metal layer 14 can be a single-layer or multi-layer metal stacked structure, which is not limited here.

[0094] The flat layer 15 is located on the side of the source-drain metal layer 14 away from the gate insulating layer 13. The flat layer 15 is used to insulate and protect the source-drain metal layer 14, and at the same time, flatten the surface of the film layer, which is conducive to forming the connecting pin e2 on the surface of the flat layer 15. The flat layer 15 can be made of inorganic materials or organic materials, which is not limited here. The surface of the flat layer 15 has a via hole that exposes the drain D of the transistor and the first signal line l1.

[0095] A plurality of connection pads e1 and a plurality of connection pins e2 are located on the surface of the flat layer 15. Each connection pad e1 is used for soldering the light emitting chip. Each connection pin e2 is connected to a first side edge ( Figure 8 The first signal lines l1 on the right side of the planar layer 15 correspond one to one, and the connecting pins e2 are electrically connected to the corresponding first signal lines l1 through the via holes of the planar layer 15.

[0096] In the process of making the side wiring located on the first side, Fig. 9 A schematic diagram of the cross-sectional structure of a substrate after a protective film is attached to the side surface of the substrate provided by an embodiment of the present invention, Fig.10 A schematic diagram of the planar structure of a protective film provided in an embodiment of the present invention.

[0097] Specifically, if Fig. 9 As shown, a protective film b is first attached to the first side of the substrate. The material of the protective film b can be a flexible material such as polyimide (PI). Fig.10As shown, the protective film b includes a hollow pattern, and the hollow pattern includes a plurality of strip structures u. When the protective film b is attached to the first side of the base substrate 11, each strip structure u corresponds to each connecting pin e2 extending to the first side, and one end of the strip structure u exposes a portion of the corresponding connecting pin e2, and the other end of the strip structure u exposes a portion of the corresponding second signal line l2. The hollow pattern on the protective film b can be formed by a laser etching process.

[0098] The strip structure u is a hollow structure on the protective film b. Therefore, after the conductive material is deposited on the protective film b, the conductive material will be directly deposited on the base substrate 11 at the hollow portion. After the protective film is peeled off, a plurality of side routings can be formed on the side of the base substrate 11, and the two ends of the side routings are respectively connected to the corresponding connecting pins e2 and the second signal line l2, thereby realizing electrical conduction between the first signal line l1 and the second signal line l2.

[0099] Since traditional exposure and development processes are difficult to perform on the side of the substrate, laser etching is often used to form side routing. However, laser etching can have an adverse effect on TFT devices and result in a low manufacturing yield. In an embodiment of the present invention, a protective film is laser-etched to form a hollow pattern. The protective film with the hollow pattern is attached to the side of the substrate and then a conductive material is deposited to form the side routing on the side of the substrate. This can reduce the effect of laser etching on the TFT device and improve the manufacturing yield.

[0100] In a specific implementation, the order of attaching the protective film b and forming the hollow pattern on the protective film b may be different.

[0101] In some embodiments, a complete protective film may be provided first; a hollow pattern may be etched on the protective film; and finally the protective film with the hollow pattern may be attached to the side of the first side edge of the substrate. Etching the hollow pattern first and then attaching the protective film may avoid the laser etching step on the substrate, thereby completely avoiding the influence of the laser etching on the transistor (TFT) on the substrate.

[0102] In some embodiments, a complete protective film may be first attached to the side of the first side edge of the base substrate; and then the protective film may be etched to form a hollow pattern. Attaching the protective film first and then etching the hollow pattern can ensure that the hollow pattern of the formed strip structure is more accurately aligned with the connection pins on the front side of the base substrate and the second signal line on the back side, and alignment is not required when attaching the protective film.

[0103] In specific implementation, the order of attaching the protective film and laser etching the protective film can be adjusted according to the process accuracy and application scenario. The embodiment of the present invention does not limit the processing order of the protective film.

[0104] Before the above step S20, the side edge of the substrate substrate at the first side edge may be rounded. The first side edge of the substrate substrate is subjected to glass edge grinding and chamfering processes, so that the connection between the front side, the back side and the side of the substrate substrate is rounded, so that the transition of the first side edge is smoother, which is conducive to the deposition of the conductive material.

[0105] In an embodiment of the present invention, the circuit on the back side of the base substrate can be manufactured by a lift-off process. Compared with the related art in which the circuit on the back side of the base substrate is manufactured by a laser etching process, the lift-off process can avoid the adverse effects of laser etching on the TFT.

[0106] Fig.11 The present invention provides a second flowchart of a method for manufacturing a display device according to an embodiment of the present invention.

[0107] like Fig.11 As shown, forming a circuit on the back side of the substrate may include:

[0108] S101, forming a photoresist layer on the back side of the substrate;

[0109] S102, exposing and developing the photoresist layer to form a hollow pattern that is the same as a pattern of the plurality of second signal lines;

[0110] S103, depositing a conductive material on the photoresist layer;

[0111] S104 , removing the photoresist layer to form a plurality of second signal lines.

[0112] Specifically, a photoresist layer can be spin-coated on the back of the substrate, and after exposure and development, a hollow pattern identical to the pattern of the plurality of second signal lines can be obtained, and then a conductive material can be deposited on the photoresist layer, and finally the photoresist layer can be peeled off by a lift-off process to obtain the pattern of the second signal lines on the back of the substrate. Because transistors and other driving elements have been formed in the circuits on the front of the substrate before the circuits on the back of the substrate are made, if the laser etching process is continued to be used to form the circuits on the back of the substrate, it will have an adverse effect on the transistors. The embodiment of the present invention uses the lift-off process to make the circuits on the back of the substrate to avoid the above-mentioned effects.

[0113] In the specific implementation, the conductive material deposited on the surface of the protective film b and the photoresist layer can be a metal material. A uniform metal layer can be formed on the surface of the protective film b and the photoresist layer through physical vapor deposition technology. After the protective film or the photoresist layer is peeled off, a trace can be formed at the corresponding position of the substrate.

[0114] In some embodiments, after forming a plurality of transistors and a plurality of first signal lines connected to the transistors on the front side of the substrate, and before forming a photoresist layer on the back side of the substrate, the method further includes:

[0115] The plurality of light emitting chips are transferred to the front side of the base substrate and electrically connected to the circuits on the front side of the base substrate.

[0116] In some embodiments, after transferring the plurality of light-emitting chips to the front surface of the base substrate and before forming the photoresist layer on the back surface of the base substrate, the method further includes:

[0117] A first protective layer is formed on the front surface of the base substrate.

[0118] After removing the photoresist layer to form a plurality of second signal lines, the method further includes:

[0119] A second protective layer is formed on the back side of the base substrate.

[0120] For the specific process sequence, please refer to Figures 12 to 19 ,in, Fig.12 A schematic diagram of a cross-sectional structure after forming a circuit on the front side of a substrate provided by an embodiment of the present invention; Fig.13 A schematic diagram of the cross-sectional structure after the light-emitting chip is transferred according to an embodiment of the present invention; Fig.14 A schematic diagram of a cross-sectional structure after forming a first protective layer provided by an embodiment of the present invention; Fig.15 A schematic diagram of a cross-sectional structure after forming a circuit on the back side of a substrate provided by an embodiment of the present invention; Fig.16 A schematic diagram of a cross-sectional structure after forming a second protective layer provided by an embodiment of the present invention; Fig.17 A schematic diagram of a cross-sectional structure after rounding the side edges of a substrate provided by an embodiment of the present invention; Fig.18 A schematic diagram of a cross-sectional structure after forming a protective film according to an embodiment of the present invention; Fig.19 This is a schematic diagram of the cross-sectional structure after the protective film is peeled off according to an embodiment of the present invention.

[0121] like Fig.12 As shown, after the circuit on the front side of the base substrate is manufactured by using a conventional thin film process, the surface of the base substrate includes a plurality of connection pads e1 for welding the light emitting chip and a plurality of connection pins e2 for connecting the first signal line l1.

[0122] like Fig.13 As shown, multiple light-emitting chips are transferred to the circuit on the front side of the substrate and electrically connected to the corresponding connection pads e1. In a specific implementation, the light-emitting chip can be a Micro LED chip, and the Micro LED chip can be transferred to the circuit on the front side of the substrate by using a mass transfer process, an elastic stamp transfer or a laser mass transfer technology.

[0123] like Fig.14 As shown, after the light-emitting chip is transferred, a first protective layer b1 is formed on the front side of the base substrate, the first protective layer b1 covers each transistor t and each first signal line l1, and the first protective layer b1 exposes a part of each connecting pin e2. Before making the circuit on the back side of the base substrate, a first protective layer b1 is formed on the front side to protect the light-emitting chip and the circuit on the front side. In a specific implementation, the first protective layer b1 can be made of a material with high temperature resistance such as photoresist or PI, which is not limited here.

[0124] like Fig.15 As shown, the pattern of the second signal line l2 is formed on the back side of the base substrate by using the above lift-off process.

[0125] like Fig.16 As shown, after forming the circuit on the back side of the base substrate, a second protective layer b2 is formed on the back side of the base substrate, the second protective layer b2 covers each second signal line l2, and the second protective layer b2 exposes the end of each second signal line l2 near the edge of the side. In a specific implementation, the second protective layer b2 can be made of a material with high temperature resistance such as photoresist or PI, which is not limited here.

[0126] like Fig.17 As shown, before making the side routing, the edge of the substrate is rounded first, which can be more conducive to the attachment of the protection film and the deposition of conductive materials on the side.

[0127] like Fig.18 As shown, a protective film b for forming side wiring is attached to the side of the base substrate, and a hollow pattern corresponding to the pattern of the side wiring is formed on the protective film b.

[0128] like Fig.19 As shown in FIG. 1 , a conductive material is deposited on the protective film b, and then the protective film is peeled off, and a side trace l3 can be formed on the side of the substrate to make the first signal line l1 and the corresponding second signal line l2 electrically conductive. Finally, after removing the first protective layer and the second protective layer, the following can be obtained: Fig.19 The display device shown.

[0129] The embodiment of the present invention further provides a display device, such as Figure 4 As shown, the display device includes: at least two display screens Y, each display screen Y is arranged in an array, and adjacent display screens Y are spliced ​​together; wherein any display screen Y in the display device is manufactured using the above-mentioned manufacturing method.

[0130] The front of the display screen made by the manufacturing method provided by the embodiment of the present invention can be used entirely for image display, and has a large screen-to-body ratio. The display screen can be used alone or spliced ​​together as a large-size spliced ​​screen. The lift-off process is used to make the back and side wiring of the substrate, which can avoid the adverse effects of laser etching on driving elements such as transistors. A binding area is formed on the side of the display screen away from the display surface, and the binding area is used to bind a flexible circuit board or a driver chip. The driver chip provides a driving signal to each signal line, thereby driving the light-emitting chip to display an image.

[0131] 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.

[0132] 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 method for manufacturing a display device, characterized in that: include: Forming circuits for driving the light-emitting chip on the front and back sides of the base substrate; The circuit on the front side of the substrate includes a plurality of transistors, a plurality of first signal lines connected to the transistors, and a plurality of connecting pins, at least part of the first signal lines extend to the first side of the substrate near the edge of the front side, each connecting pin is located at the first side and is connected to each first signal line extending to the first side in a one-to-one correspondence, and the first side is any side of the substrate; The circuit on the back side of the base substrate comprises a plurality of second signal lines, each of which extends to the vicinity of the edge of the first side on the back side; each of the second signal lines extending to the first side is arranged in one-to-one correspondence with each of the connecting pins; A protective film is attached to the side of the first side of the base substrate; the protective film includes a hollow pattern, the hollow pattern includes a plurality of strip structures, each of the strip structures corresponds to each of the connecting pins extending to the first side, one end of the strip structure exposes a portion of the corresponding connecting pin, and the other end of the strip structure exposes a portion of the corresponding second signal line; depositing a conductive material on the protective film; The protective film is peeled off to form a plurality of side wirings; two ends of the side wirings are respectively connected to the corresponding connecting pins and the second signal lines.

2. The method according to claim 1, characterized in that: The step of attaching a protective film to the side surface of the first side edge of the base substrate comprises: Providing a protective film; Etching the protective film into the hollow pattern; Attaching the protective film having the hollow pattern to the side surface of the first side edge of the base substrate; Alternatively, the step of attaching a protective film to the side surface of the first side edge of the base substrate comprises: Attaching a complete protective film to the side surface of the first side edge of the base substrate; The protective film is etched to form the hollow pattern.

3. The method according to claim 2, characterized in that: The hollow pattern of the protective film is formed by laser etching process.

4. The method according to any one of claims 1 to 3, characterized in that: The circuits for driving the light-emitting chip are formed on the front and back sides of the substrate, including: Forming a plurality of transistors, a plurality of first signal lines connected to the transistors, and a plurality of connecting pins on the front side of the base substrate; forming a photoresist layer on the back side of the base substrate; exposing and developing the photoresist layer to form a hollow pattern that is the same as the pattern of the plurality of second signal lines; depositing a conductive material on the photoresist layer; The photoresist layer is removed to form the plurality of second signal lines.

5. The method according to claim 4, characterized in that: After forming a plurality of transistors, a plurality of first signal lines connected to each of the transistors, and a plurality of connecting pins on the front surface of the base substrate, and before forming a photoresist layer on the back surface of the base substrate, the method further includes: A plurality of light emitting chips are transferred to the front side of the base substrate and electrically connected to the circuits on the front side of the base substrate.

6. The method according to claim 5, characterized in that: After transferring the plurality of light-emitting chips to the front surface of the base substrate and before forming a photoresist layer on the back surface of the base substrate, the method further includes: forming a first protective layer on the front surface of the base substrate, wherein the first protective layer covers each of the transistors and each of the first signal lines, and the first protective layer exposes a partial area of ​​each of the connecting pins; After removing the photoresist layer to form the plurality of second signal lines, the method further includes: A second protection layer is formed on the back side of the base substrate, the second protection layer covers each of the second signal lines, and the second protection layer exposes ends of each of the second signal lines near the edge of the first side.

7. The method according to claim 6, characterized in that: Before attaching a protective film to the side surface of the first side edge of the base substrate, the method further includes: The side edge of the substrate at the first side edge is rounded.

8. The method according to claim 6, characterized in that: After forming the side routing, it also includes: The first protective layer and the second protective layer are removed.

9. A display device, characterized in that: include: At least two display screens, each of which is arranged in an array, and adjacent display screens are spliced ​​together; Wherein, any of the display screens in the display device is manufactured using the manufacturing method according to any one of claims 1 to 8.

10. The display device according to claim 9, characterized in that The side of the display screen facing away from the display surface comprises a binding area, and the binding area is used to bind a flexible circuit board or a driving chip.

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