Foldable display module, preparation method thereof and display device

Abstract

Some embodiments of the present application provide a foldable display module, a preparation method thereof and a display device. The foldable display module has two non-bending regions and a bending region. The foldable display module comprises a substrate, a circuit function layer, a display function layer, a circuit board assembly and an electrical connection structure. The substrate has a hole groove structure corresponding to the bending region. The substrate has a support part corresponding to each of the two non-bending regions. The substrate has an elastic bending part corresponding to the bending region. The substrate has an avoiding groove in one of the non-bending regions. The circuit function layer comprises a plurality of pads. The pads are exposed from the avoiding groove of the substrate. The circuit board assembly comprises a plurality of pins. The electrical connection structure comprises a plurality of connection lines. The connection lines are electrically connected to the corresponding pads and pins. The foldable display module can reduce the thickness and achieve a narrow frame.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a foldable display module, its manufacturing method, and a display device. Background Technology

[0002] Organic light-emitting diode (OLED) displays have many advantages, such as self-illumination and high contrast, making them a promising display device with broad application prospects. Due to their characteristics, OLEDs can be made into flexible displays and used as foldable display panels.

[0003] With the rapid development of flexible OLEDs, people are increasingly demanding thinner and lighter designs with narrower bezels. Summary of the Invention

[0004] This application provides a foldable display module, its manufacturing method, and a display device, aiming to achieve product thinning and narrowing of bezels.

[0005] In a first aspect, some embodiments of this application provide a foldable display module having two non-bending areas and a bending area located between the two non-bending areas. The foldable display module includes a substrate, a circuit functional layer, a display functional layer, a circuit board assembly, and an electrical connection structure.

[0006] The substrate is located in two non-bending regions and a bending region. The portion of the substrate corresponding to the bending region has a hole and groove structure. The portion of the substrate corresponding to the two non-bending regions has a support portion. The portion of the substrate corresponding to the bending region has an elastic bending portion. The substrate has a clearance groove in one non-bending region.

[0007] The circuit functional layer is located on one side of the substrate. The circuit functional layer includes multiple signal lines and multiple pads. The signal lines are electrically connected to the corresponding pads, and the pads are exposed from the clearance grooves of the substrate.

[0008] The display functional layer is located on the side of the circuit functional layer that is away from the substrate.

[0009] The circuit board assembly is fixedly mounted on the side of the substrate away from the circuit functional layer, and the circuit board assembly includes multiple pins.

[0010] The electrical connection structure includes multiple connecting lines, which are electrically connected to corresponding pads and pins.

[0011] In some embodiments, the substrate includes ultrathin glass, and the thickness of the two support portions is greater than the thickness of the elastically bent portion.

[0012] Preferably, the thickness of the support portion is 400-800 micrometers, and the thickness of the elastic bending portion is 10-50 micrometers; Preferably, the thickness of the support portion is 450-500 micrometers, and the thickness of the elastic bending portion is 20-30 micrometers.

[0013] In some embodiments, the substrate includes a base sublayer, two reinforcing sublayers, and two adhesive sublayers. The base sublayer is located in two non-bending regions and a bending region. The two reinforcing sublayers are respectively located in a non-bending region and on the side of the base sublayer away from the circuit functional layer. The two reinforcing sublayers are fixed to the base sublayer by the adhesive sublayers. The two reinforcing sublayers and the base sublayer enclose a hole-groove structure. The portion of the base sublayer located in the bending region forms an elastic bending portion. The portion of the base sublayer located in the non-bending region, the adhesive layer, and the reinforcing layer constitute a support portion. Preferably, both reinforcing sublayers and the substrate sublayer are made of ultrathin glass; Preferably, the thickness of the matrix sublayer is 10-50 micrometers; Preferably, both reinforcing sublayers are fixed to the matrix sublayer by adhesive sublayers.

[0014] In some embodiments, the substrate includes ultrathin glass, has multiple slot structures, the slot structures are grooves, and the edge of the bending area is aligned with the edge of at least one groove. Preferably, the groove is a through hole or blind hole formed on the surface of the substrate away from the display functional layer.

[0015] In some embodiments, the substrate has a plurality of first dividing grooves and a plurality of first support bars separated by the first dividing grooves in the groove wall of the clearance groove. The top surface of the first support bar extends obliquely, and the connecting line includes a first segment, which is at least partially located on the top surface of the first support bar.

[0016] In some embodiments, the material of the first support strip includes silver, and the surface roughness of the first support strip is greater than a preset value; Preferably, the surface roughness of the top surface of the first support strip is greater than the surface roughness of the side surface of the substrate away from the circuit functional layer.

[0017] In some embodiments, the circuit board assembly is fixed to the substrate by an adhesive sublayer and is located on one side of the clearance groove. The pins are located at the edge of the circuit board assembly near the clearance groove. An auxiliary connector is provided between the end of the circuit board assembly and the clearance groove on the substrate. The auxiliary connector has an inclined surface that extends at an angle relative to the substrate. The connecting line also includes a second segment. The second segments of a plurality of connecting lines are arranged at intervals on the inclined surface. Preferably, the auxiliary connector has a plurality of second dividing grooves and a plurality of second support strips separated by the second dividing grooves, and the second segment is located on the top surface of the second support strip; Preferably, the material of the auxiliary connector includes epoxy resin; or the material of the auxiliary connector includes photosensitive polyimide PSPI and epoxy resin, or includes photosensitive polyimide PSPI and an acrylic system.

[0018] Secondly, some embodiments of this application provide a method for manufacturing a foldable display module. The foldable display module includes two non-bending areas and a bending area located between the two non-bending areas. The method for manufacturing the foldable display module includes: A display motherboard is provided, comprising a substrate, a circuit functional layer, a display functional layer, and a circuit board assembly. The substrate has a clearance groove formed in a non-bending area, a plurality of first dividing grooves located on the groove wall of the clearance groove, and a plurality of first support strips separated by the first dividing grooves. The top surface of the first support strips extends obliquely. The circuit functional layer includes a plurality of pads, which are exposed from the clearance groove of the substrate. The circuit board assembly is fixedly disposed on the side of the substrate away from the circuit functional layer, and the circuit board assembly includes a plurality of pins. With the substrate of the display motherboard positioned away from the ground relative to the circuit functional layer, multiple connecting lines with connecting pads and corresponding silver feet are formed by printing silver paste on the first support strip. The connecting lines include a first segment, which is at least partially located on the top surface of the first support strip.

[0019] In some embodiments, an auxiliary connector is provided between the end of the circuit board assembly and the clearance groove on the substrate. The auxiliary connector has an inclined surface that extends at an angle relative to the substrate. The connecting line also includes a second segment, and the second segments of a plurality of connecting lines are arranged at intervals on the inclined surface. Preferably, the auxiliary connector has a plurality of second dividing grooves and a plurality of second support strips separated by the second dividing grooves, and the second segments are at least partially located on the top surface of the second support strips; Preferably, the surface roughness of the top surface of the first support bar is greater than a preset value.

[0020] Thirdly, some embodiments of this application provide a display device, which includes the display module described above, or includes a display module prepared according to the method for preparing the display module described above.

[0021] The foldable display module, its manufacturing method, and display device provided in some embodiments of this application, on the one hand, form a groove structure in the portion of the substrate corresponding to the bending area, so that the bending strength of the substrate corresponding to the non-bending area is greater than that of the substrate corresponding to the bending area. Thus, a support portion is formed in the portion of the substrate corresponding to each of the two non-bending areas, and an elastic bending portion is formed in the portion of the substrate corresponding to the bending area by forming a groove structure. In this way, it is not necessary to set up a support layer structure as in related technologies, so the thickness of the foldable display module can be reduced. On the other hand, by forming a relief groove in one non-bending area of ​​the substrate, the pads of the circuit functional layer are exposed from the relief groove of the substrate. The circuit board assembly is fixedly disposed on the side of the substrate away from the circuit functional layer, and the pins of the circuit board assembly are electrically connected to the corresponding pads and pins through connecting lines. It is not necessary to set a large bezel for the bending portion of the related technologies, and the problem of needing to rely on the support of a flexible substrate to form the bending portion in the related technologies is overcome, thereby achieving a narrow bezel. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A cross-sectional view of a display module provided in one embodiment of this application; Figure 2 A cross-sectional view of another display module provided in one embodiment of this application; Figure 3 A cross-sectional structural schematic diagram of another display module provided for one embodiment of this application; Figure 4 A cross-sectional structural schematic diagram of another display module provided for one embodiment of this application; Figure 5 A cross-sectional view of a portion of a display module is provided as one embodiment of this application. Figure 5 The corresponding cutting positions are those corresponding to the first and second dividing grooves; Figure 6 A bottom view of a portion of the structure in another display module provided for one embodiment of this application; Figure 7 This is a bottom view of another display module provided in one embodiment of this application.

[0024] Explanation of reference numerals in the attached figures: Non-bending area FZ, bending area WZ, substrate 20, base sublayer 201, reinforcing sublayer 202, adhesive sublayer 203, hole and groove structure 21, groove 211, clearance groove 22, first support bar 23, first dividing groove 24, support part 25, elastic bending part 26, circuit function layer 30, signal line 31, pad 32, insulating dielectric layer 33, display function layer 40, light-emitting unit 46, encapsulation layer 47, first sub-encapsulation layer 471, second sub-encapsulation layer 472, third sub-encapsulation layer 473, optical function layer 48, circuit board assembly 50, pin 51, chip 52, electrical connection structure 60, connecting line 61, first segment 62, second segment 63, auxiliary connector 70, inclined surface 71, second dividing groove 72, second support bar 73, inorganic protective layer 81, circuit protective layer 85 Detailed Implementation To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0025] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, this does not indicate any order, quantity, or importance, but is merely used to distinguish different components. These terms are used only to distinguish one element from another. For example, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. Words such as “comprising” or “including” mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, without excluding other elements or objects.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] The following is in conjunction with the attached figure. Figures 1-7 The technical solution of this application will be described in detail.

[0028] A related foldable display panel uses a flexible substrate and an additional support layer structure. Its bezel area includes a bent portion extending from the display area. The bent portion bends to the back of the display area to connect to the driving circuit structure. This product has a large thickness because it requires both a flexible substrate and a support layer structure. Because the bent portion is located in the bezel area, it has a large bezel size.

[0029] To address the aforementioned issues, firstly, this application provides a foldable display module in some embodiments, please refer to... Figures 1-7 The foldable display module has two non-bending areas FZ and a bending area WZ located between the two non-bending areas FZ. The foldable display module includes a substrate 20, a circuit functional layer 30, a display functional layer 40, a circuit board assembly 50, and an electrical connection structure 60.

[0030] The substrate 20 is located in two non-bending regions FZ and a bending region WZ. The portion of the substrate 20 corresponding to the bending region WZ has a hole and groove structure 21. The portion of the substrate 20 corresponding to the two non-bending regions FZ has a support portion 25. The portion of the substrate 20 corresponding to the bending region WZ has an elastic bending portion 26. The substrate 20 has a clearance groove 22 in one non-bending region FZ.

[0031] The circuit functional layer 30 is located on one side of the substrate 20. The circuit functional layer 30 includes multiple signal lines 31 and multiple pads 32. The signal lines 31 are electrically connected to the corresponding pads 32. The pads 32 are exposed from the clearance grooves 22 of the substrate 20.

[0032] The display functional layer 40 is located on the side of the circuit functional layer 30 that is away from the substrate 20.

[0033] The circuit board assembly 50 is fixedly disposed on the side of the substrate 20 away from the circuit functional layer 30, and the circuit board assembly 50 includes a plurality of pins 51.

[0034] The electrical connection structure 60 includes a plurality of connection lines 61, which are electrically connected to corresponding pads 32 and pins 51.

[0035] On the one hand, by forming a groove structure 21 in the portion of the substrate 20 corresponding to the bending region WZ, the bending strength of the substrate 20 corresponding to the non-bending region FZ is greater than that of the substrate 20 corresponding to the bending region WZ. Thus, a support portion 25 is formed in each of the two non-bending regions FZ, and an elastic bending portion 26 is formed in the portion of the substrate 20 corresponding to the bending region WZ by opening the groove structure 21. This eliminates the need for a separate support layer structure as in related technologies, thereby reducing the thickness of the foldable display module; on the other hand… In this configuration, a clearance groove 22 is formed in a non-bending region FZ of the substrate 20. The pads 32 of the circuit functional layer 30 are exposed from the clearance groove 22 of the substrate 20. The circuit board assembly 50 is fixedly disposed on the side of the substrate 20 away from the circuit functional layer 30. The pins 51 of the circuit board assembly 50 are electrically connected to the corresponding pads 32 and pins 51 via connecting lines 61. This eliminates the need for a large bezel for the bending portion in related technologies and overcomes the problem of requiring a flexible substrate to support the bending portion in related technologies, thereby achieving a narrow bezel. It should be noted that the number of via structures 21 can be one or more, and they can penetrate or not penetrate the substrate 20 depending on the specific arrangement. The circuit board assembly 50 may also include a chip 52.

[0036] Please refer to Figures 1-5 In some embodiments of the foldable display module provided in this application, the substrate 20 includes ultra-thin glass (UTG), and the thickness of the two support portions 25 is greater than the thickness of the elastic bending portion 26; that is, the thickness of the substrate 20 corresponding to the two non-bending regions FZ is greater than the thickness of the substrate 20 corresponding to the bending region WZ.

[0037] In some embodiments of the foldable display module provided in this application, the thickness of the support portion 25 is 400-800 micrometers, and the thickness of the elastic bending portion 26 is 10-50 micrometers.

[0038] In some embodiments of the foldable display module provided in this application, the thickness of the support portion 25 is 450-500 micrometers, and the thickness of the elastic bending portion 26 is 20-30 micrometers.

[0039] By using ultra-thin glass as the substrate 20, on the one hand, its flatness is good and suitable for fabricating various film layers on it. On the other hand, a portion of the ultra-thin glass with a certain thickness (such as 400~800 micrometers) serves as the support portion 25, which can better meet the rigidity requirements of the support portion 25. Furthermore, after the structure is thinned to a certain extent (10~50 micrometers), it has good elastic bending characteristics, which can well meet the characteristic requirements of the elastic bending portion 26. It can achieve bending and also maintain a certain curvature of the elastic bending portion 26, which is particularly suitable for protecting the array functional layer and display functional layer on it.

[0040] It should be noted that the thickness of the elastic bending portion 26 is 20~30 micrometers, which can maintain good bending characteristics while providing good protection for the various functional film layers on the substrate 20.

[0041] Please refer to Figure 3 In some embodiments of the foldable display module provided in this application, the substrate 20 includes a base sublayer 201, two reinforcing sublayers 202 and two adhesive sublayers 203. The base sublayer 201 is located in two non-bending regions FZ and bending regions WZ. The two reinforcing sublayers 202 are respectively located in a non-bending region FZ and on the side of the base sublayer 201 away from the circuit functional layer 30. The two reinforcing sublayers 202 are fixed to the base sublayer 201 by the adhesive sublayers 203. The two reinforcing sublayers 202 and the base sublayer 201 enclose a hole-groove structure 21. The portion of the base sublayer 201 located in the bending region WZ forms an elastic bending portion 26. The portion of the base sublayer 201, adhesive layer 203 and reinforcing layer 202 located in the non-bending region FZ constitutes a support portion 25.

[0042] Since the substrate 20 includes a base sublayer 201, two reinforcing sublayers 202 and two adhesive sublayers 203, the two reinforcing sublayers 202 are fixed to the base sublayer 201 by the adhesive sublayers 203, and the two reinforcing sublayers 202 and the base sublayer 201 enclose a hole and groove structure 21, the part of the base sublayer 201 located in the bending region WZ forms an elastic bending portion 26, and the part of the base sublayer 201, adhesive layer 203 and reinforcing layer 202 located in the non-bending region FZ constitutes a support portion 25, the manufacturing process of the substrate 20 is simple and can effectively reduce the product manufacturing cost.

[0043] In some embodiments of the foldable display module provided in this application, the materials of the two reinforcing sub-layers 202 and the substrate sub-layer 201 are both ultra-thin glass, and the thickness of the substrate sub-layer 201 is 10~50 micrometers (preferably 20~30 micrometers).

[0044] By using ultra-thin glass for both the two reinforcing sub-layers 202 and the substrate sub-layer 201, and with the substrate sub-layer 201 having a thickness of 10-50 micrometers (preferably 20-30 micrometers), a portion of the ultra-thin glass with a thickness (e.g., 10-50 micrometers) matching the thickness of the elastic bending portion 26 can be directly formed as the elastic bending portion 26. This further simplifies the manufacturing process and reduces product manufacturing costs. Please refer to [reference needed]. Figure 1 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In the foldable display module provided in some embodiments of this application, the substrate 20 includes ultra-thin glass (UTG), there are multiple slot structures 21, the slot structure 21 is a groove 211, and the edge of the bending area WZ is aligned with the edge of at least one groove 211. In some embodiments of the foldable display module provided in this application, the groove 211 is a through hole or blind hole opened on the surface of the substrate 20 away from the display functional layer 40.

[0045] The substrate 20 includes ultra-thin glass and has multiple slot structures 21. The slot structure 21 is a groove 211, and the edge of the bending region WZ is aligned with the edge of at least one groove 211. This not only forms an elastic bending portion 26, but also the groove wall between adjacent grooves 211 can play a supporting role.

[0046] The groove 211 is preferably a blind via, and the bottom wall of the blind via can provide some protection for the relevant functional film layers formed on the substrate 20. The extension dimension of the groove 211 is equal to the width of the substrate 20 (reference). Figure 7 ).

[0047] Please refer to Figures 1-7 In some embodiments of the foldable display module provided in this application, the substrate 20 has a plurality of first dividing grooves 24 and a plurality of first support bars 23 separated by the first dividing grooves 24 in the groove wall of the relief groove 22. The top surface of the first support bar 23 extends obliquely, and the connecting line 61 includes a first segment 62, which is at least partially located on the top surface of the first support bar 23.

[0048] The first support bar 23 can support the connecting line 61, and the first dividing groove 24 between adjacent first support bars 23 can prevent the printing liquid from overflowing in the area between adjacent "first support bars 23" when the connecting line 61 is formed by printing or other methods, thus preventing the adjacent connecting line 61 from short-circuiting. The top surface of the first support bar 23 extends at an angle, and the first segment 62 of the connecting line 61 is located on the top surface of the first support bar 23, which can effectively avoid the problem of poor connection or even breakage of the connecting line 61 due to the large segment difference.

[0049] It should be noted that the inclined extension of the top surface of the first support strip 23 refers to the overall direction of this part. Specifically, it can extend at the same inclination angle, or the inclination angle can vary, or it can extend in a stepped shape. The width of the first dividing groove 24 (corresponding to the spacing between adjacent first support strips 23) can be 1~10 micrometers.

[0050] In some embodiments of the foldable display module provided in this application, the material of the first support strip 23 includes silver, and the surface roughness of the first support strip 23 is greater than a preset value.

[0051] The material of the first support strip 23 includes silver. The roughness of the top surface of the first support strip 23 is greater than a preset value, which ensures that the silver paste can reliably adhere to the first support strip 23 during and after the formation of the connecting line 61. This avoids problems such as short circuits between different connecting lines 61 and disconnection of the connecting line 61 from the first support strip 23 due to poor affinity and weak bonding between the silver paste and the ultra-thin glass material of the first support strip 23 during and after the formation of the connecting line 61.

[0052] In some embodiments of the foldable display module provided in this application, the top surface roughness of the first support strip 23 is greater than the roughness of the side surface of the substrate 20 away from the circuit functional layer 30.

[0053] By ensuring that the top surface roughness of the first support strip 23 is greater than the roughness of the side surface of the substrate 20 away from the circuit functional layer 30, the roughening treatment area can be reduced, the processing process can be simplified, and the product cost can be reduced, while avoiding problems such as poor affinity and weak bonding between the silver paste forming the connecting line 61 and the first support strip 23 made of ultra-thin glass material, and avoiding problems such as short circuits between different connecting lines 61 and disconnection of connecting lines 61 from the first support strip 23.

[0054] Please refer to Figures 1-5 In some embodiments of the foldable display module provided in this application, the circuit board assembly 50 is fixed to the substrate 20 by an adhesive sublayer 203 (which can be made of NCF material, Non-Conductive Film) and is located on one side of the relief groove 22. The pin 51 is located at the edge of the circuit board assembly 50 near the relief groove 22. An auxiliary connector 70 is provided between the end of the circuit board assembly 50 and the relief groove 22 on the substrate 20. The auxiliary connector 70 has an inclined surface 71 that extends at an angle relative to the substrate 20. The connecting line 61 also includes a second segment 63. The second segments 63 of the plurality of connecting lines 61 are arranged at intervals on the inclined surface 71.

[0055] The circuit board assembly 50 is fixed to the substrate 20 via the adhesive sublayer 203 and is located on one side of the clearance groove 22. The pin 51 is located at the edge of the circuit board assembly 50 near the clearance groove 22. An auxiliary connector 70 is provided between the end of the circuit board assembly 50 and the clearance groove 22 on the substrate 20. The auxiliary connector 70 has an inclined surface 71 that extends at an angle relative to the substrate 20. The connecting line 61 also includes a second segment 63. The second segments 63 of multiple connecting lines 61 are arranged at intervals on the inclined surface 71, which can effectively avoid the problem of poor connection or even breakage of the connecting line 61 due to the large segment difference.

[0056] It should be noted that the auxiliary connector 70 is made of insulating material and can be formed using adhesives including epoxy resin.

[0057] In some embodiments of the foldable display module provided in this application, the auxiliary connector 70 has a plurality of second dividing grooves 72 and a plurality of second support bars 73 separated by the second dividing grooves 72, and the second segment 63 is located on the top surface of the second support bar 73. By forming a plurality of second dividing grooves 72 and a plurality of second support bars 73 separated by the second dividing grooves 72 on the auxiliary connector 70, and the second segment 63 being located on the top surface of the second support bar 73, the second dividing grooves 72 between adjacent second support bars 73 can prevent printing liquid from overflowing in the area corresponding to adjacent "second support bars 73" and causing short circuits in adjacent connection lines 61 when forming connection lines 61 by printing or other means.

[0058] Please refer to Figures 1-7 In some embodiments of the foldable display module provided in this application, the material of the auxiliary connector 70 includes epoxy resin; or the material of the auxiliary connector 70 includes photosensitive polyimide PSPI and epoxy resin, or includes photosensitive polyimide PSPI and an acrylic system. (Good adhesion to silver paste and silver wires) The auxiliary connector 70 is made of (1) epoxy resin; or (2) photosensitive polyimide PSPI and epoxy resin; or (3) photosensitive polyimide PSPI and acrylic system. The selection of these three components in the auxiliary connector 70 ensures that the formed auxiliary connector 70 maintains a strong bonding force during and after the formation of the silver wire using silver paste, thereby avoiding problems such as short circuits between adjacent connecting lines 61 and open circuits caused by the detachment of connecting lines 61 from the second support strip 73.

[0059] It should be noted that acrylic acid systems generally refer to polymer material systems formed by polymerizing acrylic acid and its derivatives as core raw materials.

[0060] An inorganic protective layer 81 with a protective function can be provided on the side of the substrate 20 facing the circuit functional layer 30. The material of the inorganic protective layer 81 can be silicon oxide (SiOx) or amorphous silicon (a-Si), and the thickness of the inorganic protective layer 81 can be 3000-6000 Å (angstroms) to block moisture intrusion and improve performance reliability.

[0061] The circuit functional layer 30 may include multiple insulating dielectric layers 33 located on the side of the pad 32 facing the display functional layer 40. One insulating dielectric layer 33 closest to the substrate 20 may be made of SiOx with a thickness of 3000-6000 Å. Other insulating dielectric layers 33 may also include composite film layers for blocking ion and moisture intrusion. Specifically, the composite film layer may include a silicon nitride sublayer (SiNx) with a thickness of 400-500 nm, a silicon oxide sublayer (SiOx) with a thickness of 2300-2700 nm, and a silicon nitride sublayer (SiNx) with a thickness of 460-550 nm.

[0062] The light-emitting functional layer may include multiple light-emitting units 46, an encapsulation layer 47, and an optical functional layer 48, etc. The encapsulation layer 47 may further include a first sub-encapsulation layer 471 fabricated by chemical vapor deposition, a second sub-encapsulation layer 472 formed by inkjet printing and comprising organic materials, and a third sub-encapsulation layer 473 fabricated by chemical vapor deposition. The thickness of the second sub-encapsulation layer 472 is 1~20 micrometers.

[0063] A circuit protection layer 85 can be covered on the connecting wire 61. The circuit protection layer 85 can be formed of a waterproof adhesive material and can provide reliable protection for the connecting wire 61 and other parts.

[0064] Secondly, some embodiments of this application provide a method for manufacturing a foldable display module; please refer to [reference needed]. Figures 1-7 The fabrication method of the foldable display module includes two non-bending regions FZ and a bending region WZ located between the two non-bending regions FZ. A display motherboard is provided, which includes a substrate 20, a circuit functional layer 30, a display functional layer 40, and a circuit board assembly 50. The substrate 20 has a clearance groove 22 formed in a non-bending area FZ, a plurality of first dividing grooves 24 located on the groove wall of the clearance groove 22, and a plurality of first support bars 23 separated by the first dividing grooves 24. The top surface of the first support bars 23 extends obliquely. The circuit functional layer 30 includes a plurality of pads 32, which are exposed from the clearance groove 22 of the substrate 20. The circuit board assembly 50 is fixedly disposed on the side of the substrate 20 away from the circuit functional layer 30, and the circuit board assembly 50 includes a plurality of pins 51. With the substrate 20 of the display motherboard positioned away from the ground relative to the circuit functional layer 30, a plurality of connecting pads 32 and corresponding silver pins are formed by printing silver paste on the first support strip 23. The connecting line 61 includes a first segment 62, which is at least partially located on the top surface of the first support strip 23.

[0065] A relief groove 22 is formed in a non-bending area FZ of the substrate 20, a plurality of first dividing grooves 24 located on the groove wall of the relief groove 22, and a plurality of first support bars 23 separated by the first dividing grooves 24. The top surface of the first support bars 23 extends obliquely. When the substrate 20 in which the display motherboard is set is far away from the ground relative to the circuit functional layer 30, a plurality of connecting pads 32 and corresponding silver pin connecting lines 61 are formed by printing silver paste on the first support bars 23. When at least part of the connecting lines 61 is located on the top surface of the first support bars 23, it can not only solve the problem that the first segment 62 of the connecting line 61 is located on the top surface of the first support bar 23, which can effectively avoid the problem of poor connection or even breakage of the connecting line 61 due to the large segment difference, but also prevent the paste used to form the connecting lines 61 from overflowing into the area corresponding to the adjacent "first support bars 23" under the action of gravity when forming the connecting lines 61, thus preventing the adjacent connecting lines 61 from short-circuiting.

[0066] It should be noted that when printing silver paste to form the connecting lines 61, EHD (Electrohydrodynamic) printing method can be used. In the fabrication method of the foldable display module provided in some embodiments of this application, an auxiliary connector 70 is provided between the end of the circuit board assembly 50 and the clearance groove 22 on the substrate 20. The auxiliary connector 70 has an inclined surface 71 that extends at an angle relative to the substrate 20. The connecting lines 61 also include second segments 63, and the second segments 63 of a plurality of connecting lines 61 are arranged at intervals on the inclined surface 71.

[0067] The circuit board assembly 50 is fixed to the substrate 20 via the adhesive sublayer 203 and is located on one side of the clearance groove 22. The pin 51 is located at the edge of the circuit board assembly 50 near the clearance groove 22. An auxiliary connector 70 is provided between the end of the circuit board assembly 50 and the clearance groove 22 on the substrate 20. The auxiliary connector 70 has an inclined surface 71 that extends at an angle relative to the substrate 20. The connecting line 61 also includes a second segment 63. The second segments 63 of multiple connecting lines 61 are arranged at intervals on the inclined surface 71, which can effectively avoid the problem of poor connection or even breakage of the connecting line 61 due to the large segment difference.

[0068] In some embodiments of the foldable display module provided in this application, the auxiliary connector 70 has a plurality of second dividing grooves 72 and a plurality of second support bars 73 separated by the second dividing grooves 72, and the second segment 63 is at least partially located on the top surface of the second support bar 73.

[0069] The auxiliary connector 70 has a plurality of second dividing grooves 72 and a plurality of second support bars 73 separated by the second dividing grooves 72. The second segment 63 is located on the top surface of the second support bar 73. The second dividing grooves 72 between adjacent second support bars 73 can prevent printing liquid from overflowing in the area between adjacent "second support bars 73" and causing adjacent connection lines 61 to short circuit when forming connection lines 61 by printing or other means.

[0070] It should be noted that the auxiliary connector 70 should be an insulating structure to prevent short circuits from forming in the second segment 63 of adjacent connecting lines 61. In the foldable display module provided in some embodiments of this application, the top surface roughness of the first support strip 23 is greater than a preset value. Since the material of the first support strip 23 includes silver, and the top surface roughness of the first support strip 23 is greater than the preset value, it ensures that the silver paste can reliably adhere to the first support strip 23 during and after the formation of the connecting lines 61. This avoids problems such as short circuits between different connecting lines 61 or disconnection of the connecting lines 61 from the first support strip 23 due to poor affinity and weak bonding between the silver paste and the ultra-thin glass material of the first support strip 23 during and after the formation of the connecting lines 61.

[0071] It should be noted that the grooves 211, which serve as both the clearance groove 22 and the hole groove structure 21, can be formed simultaneously to simplify the manufacturing process and reduce manufacturing costs. When forming the clearance groove 22 and the grooves 211 of the hole groove structure 21, etching can be performed using an etching solution or a laser.

[0072] The preset roughness value of the top surface of the first support strip 23 can be determined through multiple experiments during the sample manufacturing process. Furthermore, the roughness of the top surface of the second support strip 73 should be greater than another corresponding preset value.

[0073] Thirdly, some embodiments of this application provide a display device, which includes the display module described above, or includes a display module prepared according to the method for preparing the display module described above.

[0074] It should be noted that the different technical features in the aforementioned different embodiments can all be used as features in the same embodiment scheme if there is no conflict.

[0075] When using the terms “including,” “having,” and “comprising” as described herein, another component may be added unless explicitly qualifying terms such as “only,” “consisting of,” etc. are used. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A foldable display module, comprising two non-bending areas and a bending area located between the two non-bending areas, characterized in that, include: A substrate is located in two non-bending regions and a bending region. The substrate has a hole and groove structure formed in the portion corresponding to the bending region. A support portion is formed in the portion corresponding to each of the two non-bending regions. An elastic bending portion is formed in the portion corresponding to the bending region. A clearance groove is formed in one of the non-bending regions. A circuit functional layer is located on one side of the substrate. The circuit functional layer includes multiple signal lines and multiple pads. The signal lines are electrically connected to the corresponding pads. The pads are exposed from the clearance groove of the substrate. The display functional layer is located on the side of the circuit functional layer opposite to the substrate. A circuit board assembly is fixedly disposed on the side of the substrate opposite to the circuit functional layer, and the circuit board assembly includes a plurality of pins; and An electrical connection structure includes multiple connecting lines that are electrically connected to corresponding pads and pins.

2. The foldable display module according to claim 1, characterized in that, The substrate includes ultra-thin glass, and the thickness of the two support portions is greater than the thickness of the elastic bending portion; Preferably, the thickness of the support portion is 400-800 micrometers, and the thickness of the elastic bending portion is 10-50 micrometers; Preferably, the thickness of the support portion is 450-500 micrometers, and the thickness of the elastic bending portion is 20-30 micrometers.

3. The foldable display module according to claim 2, characterized in that, The substrate includes a base sublayer, two reinforcing sublayers, and two adhesive sublayers. The base sublayer is located in the two non-bending regions and the bending region. The two reinforcing sublayers are respectively located in one of the non-bending regions and on the side of the base sublayer away from the circuit functional layer. The two reinforcing sublayers are fixed to the base sublayer by the adhesive sublayers. The two reinforcing sublayers and the base sublayer enclose the hole-groove structure. The portion of the base sublayer located in the bending region forms an elastic bending portion. The portion of the base sublayer, adhesive layer, and reinforcing layer located in the non-bending region constitutes a support portion. Preferably, the materials of the two reinforcing sublayers and the substrate sublayer are both ultrathin glass; Preferably, the thickness of the matrix sublayer is 10-50 micrometers; Preferably, both reinforcing sublayers are fixed to the matrix sublayer by adhesive sublayers.

4. The foldable display module according to claim 1, characterized in that, The substrate includes ultrathin glass, and there are multiple hole and groove structures, each of which is a groove, and the edge of the bending area is aligned with the edge of at least one of the grooves. Preferably, the groove is a through hole or blind hole formed on the surface of the substrate away from the display functional layer.

5. The foldable display module according to claim 2, 3 or 4, characterized in that, The substrate has a plurality of first dividing grooves and a plurality of first support bars separated by the first dividing grooves on the wall of the clearance groove. The top surface of the first support bar extends obliquely. The connecting line includes a first segment, and the first segment is at least partially located on the top surface of the first support bar.

6. The foldable display module according to claim 5, characterized in that, The material of the first support strip includes silver, and the surface roughness of the first support strip is greater than a preset value; Preferably, the surface roughness of the top surface of the first support strip is greater than the surface roughness of the side surface of the substrate away from the circuit functional layer.

7. The foldable display module according to claim 5, characterized in that, The circuit board assembly is fixed to the substrate by an adhesive sublayer and is located on one side of the clearance groove. The pin is located at the edge of the circuit board assembly near the clearance groove. An auxiliary connector is provided between the end of the circuit board assembly and the clearance groove on the substrate. The auxiliary connector has an inclined surface that extends at an angle relative to the substrate. The connecting line also includes a second segment. The second segments of a plurality of connecting lines are arranged at intervals on the inclined surface. Preferably, the auxiliary connector has a plurality of second dividing grooves and a plurality of second support strips separated by the second dividing grooves, and the second segment is located on the top surface of the second support strip; Preferably, the auxiliary connector is made of epoxy resin; or the auxiliary connector is made of photosensitive polyimide PSPI and epoxy resin, or of photosensitive polyimide PSPI and acrylic system.

8. A method for manufacturing a foldable display module, the foldable display module comprising two non-bending regions and a bending region located between the two non-bending regions, characterized in that, include: A display motherboard is provided, the display motherboard including a substrate, a circuit functional layer, a display functional layer and a circuit board assembly. The substrate has a relief groove formed in a non-bending area, a plurality of first dividing grooves located on the groove wall of the relief groove and a plurality of first support strips separated by the first dividing grooves. The top surface of the first support strips extends obliquely. The circuit functional layer includes a plurality of pads, the pads protruding from the relief groove of the substrate. The circuit board assembly is fixedly disposed on the side of the substrate away from the circuit functional layer, and the circuit board assembly includes a plurality of pins. With the display motherboard configured such that the substrate is far from the ground relative to the circuit functional layer, a plurality of connecting lines connecting the pads and the corresponding silver feet are formed by printing silver paste on the first support strip. The connecting lines include a first segment, which is at least partially located on the top surface of the first support strip.

9. The method for manufacturing a foldable display module according to claim 9, characterized in that, An auxiliary connector is provided between the end of the circuit board assembly and the clearance groove on the substrate. The auxiliary connector has an inclined surface that extends at an angle relative to the substrate. The connecting line also includes a second segment, and the second segments of a plurality of connecting lines are arranged at intervals on the inclined surface. Preferably, the auxiliary connector has a plurality of second dividing grooves and a plurality of second support strips separated by the second dividing grooves, and the second segment is at least partially located on the top surface of the second support strip; Preferably, the roughness of the top surface of the first support strip is greater than a preset value.

10. A display device, characterized in that, It includes the display module according to any one of claims 1-7, or the display module prepared by the method of preparing the display module according to claim 8 or 9.

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