Patent Publication Number: US-2023165121-A1

Title: Organic light emitting diode display panel and display device

Description:
BACKGROUND OF INVENTION 
     Field of Invention 
     The present invention relates to the field of display technology, and more particularly, to an organic light emitting diode (OLED) display panel and a display device. 
     Description of Prior Art 
     In recent years and with improvement of people&#39;s requirements for display quality of display panels, in recent years, there has been an increasing demand for high-screen-ratio products. Narrow frame products, such as notched cell phone have been popular, which greatly improves people&#39;s visual enjoyment. In order to realize a narrow frame display panel, pad-bending technology needs to be developed to bend the terminal area, but it may cause cracks in the terminal area circuit during bending process, so the display panel is not working or displaying abnormal. Currently, by applying ultraviolet (UV) glue to the bending area of the pad, the bending area of the pad may be reinforced to avoid the cracks in the bending area of the pad during bending. However, due to strong fluidity of UV glue, if a large amount of UV glue is coated on the bending area of the pad, the UV glue will overflow into an active area (AA). As a result, there are bubbles when attaching polarizers (POL). Now, the large amount of UV glue overflow is adjusted by the coating machine, but it is not easy to control overflow of the UV glue, and control accuracy is low. 
     Therefore, the display panels have a problem in that the accuracy of controlling the large amount of UV glue overflow is not well. 
     SUMMARY OF INVENTION 
     An organic light emitting diode (OLED) display panel and a display device are provided, so as to solve the technical problem of low ultraviolet (UV) glue overflow control accuracy in the bending area of the display panel in the prior art. 
     An OLED display panel comprises: 
     a transistor array substrate comprising a plurality of transistors arranged in an array, and the transistor array substrate comprises a display area, a bending area, and a driving area, and the plurality of transistors arranged in the array are disposed in the display area; 
     a light emitting functional layer disposed in the display area of the transistor array substrate; 
     a driving component disposed in the driving area of the transistor array substrate; 
     a plurality of traces disposed in the bending area of the transistor array substrate and electrically connected to the plurality of transistors and the driving component; 
     a reinforcement layer formed on a surface of the bending area; and 
     a blocking member formed on a surface of the transistor array substrate and located between the reinforcement layer and the light emitting functional layer. 
     In one embodiment, the blocking member is formed by forming a new added layer on the surface of the transistor array substrate. 
     In one embodiment, a material of the blocking member comprises one of polyimide, an insulating organic compound, and an insulating inorganic compound. 
     In one embodiment, the transistor array substrate further comprises a planarization layer, and the planarization layer is patterned to form the blocking member. 
     In one embodiment, a surface shape of the blocking member is straight or curved. 
     In one embodiment, a cross-sectional shape of the blocking member comprises one of a rectangle and a trapezoid. 
     In one embodiment, the blocking member is arranged in multiple columns. 
     In one embodiment, a material of the reinforcement layer comprises ultraviolet curing glue. 
     In one embodiment, a height of the reinforcement layer is less than a height of the blocking member. 
     A display device comprises:
         an organic light emitting diode (OLED) display panel;   a touch panel disposed on the OLED display panel; and   a polarizer disposed on the touch panel, and the OLED display panel comprises:
           a transistor array substrate comprising a plurality of transistors arranged in an array, and the transistor array substrate comprises a display area, a bending area, and a driving area, and the plurality of transistors arranged in the array are disposed in the display area;   a light emitting functional layer disposed in the display area of the transistor array substrate;   a driving component disposed in the driving area of the transistor array substrate;   a plurality of traces disposed in the bending area of the transistor array substrate and electrically connected to the plurality of transistors and the driving component;   a reinforcement layer formed on a surface of the bending area; and   a blocking member formed on a surface of the transistor array substrate and located between the reinforcement layer and the light emitting functional layer.   
               

     In one embodiment, and the blocking member is formed by forming a new added layer on the surface of the transistor array substrate. 
     In one embodiment, a material of the blocking member comprises one of polyimide, an insulating organic compound, and an insulating inorganic compound. 
     In one embodiment, the transistor array substrate further comprises a planarization layer, and the planarization layer is patterned to form the blocking member. 
     In one embodiment, a surface shape of the blocking member is straight or curved. 
     In one embodiment, a cross-sectional shape of the blocking member comprises one of a rectangle and a trapezoid. 
     In one embodiment, the blocking member is arranged in a multiple columns. 
     In one embodiment, a material of the reinforcement layer comprises ultraviolet curing glue. 
     In one embodiment, a height of the reinforcement layer is less than a height of the blocking member. 
     In one embodiment, the blocking member is connected to the touch panel. 
     In one embodiment, the blocking member is not connected to the touch panel. 
     The present invention has beneficial effects described as follows: an OLED display panel and a display device are provided, and the OLED display panel comprises a blocking member formed on a surface of the transistor array substrate and located between the reinforcement layer and the light emitting functional layer. Moreover, the blocking member is connected to the touch panel, so as to support the touch panel and maintain a stability of the touch panel during bending. One or more blocking members are formed between the reinforcement layer and the light emitting functional layer to prevent the ultraviolet curing glue of the reinforcement layer from overflowing to the display area, thereby effectively controlling the amount of glue overflow, and maintaining the stability of the distribution of ultraviolet curing glue in the bending area. Therefore, the control accuracy of the amount of glue overflow in the bending area is improved. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In order to more clearly illustrate the technical solutions in the embodiments, the drawings described in the description of the embodiments are briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Other drawings can also be obtained from those skilled persons in the art based on drawings without any creative effort. 
         FIG.  1    is a schematic side view of first structure of an organic light emitting diode (OLED) display panel according to one embodiment of the present invention. 
         FIG.  2    is a schematic side view of a part of second structure of the OLED display panel according to one embodiment of the present invention. 
         FIG.  3    is a schematic partial bottom view of the OLED display panel of  FIG.  2   . 
         FIG.  4    is a schematic bottom view of a part of third structure of the OLED display panel according to one embodiment of the present invention. 
         FIG.  5    is a schematic side view of a part of fourth structure of the OLED display panel according to one embodiment of the present invention. 
         FIG.  6    is a schematic side view of a structure of a display device according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Directional terms mentioned in this application, such as “up,” “down,” “forward,” “backward,” “left,” “right,” “inside,” “outside,” “side,” etc., are merely indicated the direction of the drawings. Therefore, the directional terms are used for illustrating and understanding of the application rather than limiting thereof. In the drawings, similar components are marked with the same reference numerals. 
     As for a problem in that the accuracy of controlling the large amount of UV glue overflow is not well, the present invention may solve the problem. 
     Referring to  FIG.  1   , an organic light emitting diode (OLED) display panel  100  comprises a transistor array substrate  10  comprising a plurality of transistors  11  arranged in an array, and the transistor array substrate  10  comprises a display area (AA), a bending area (ZX), and a driving area (QD), and the plurality of transistors  11  arranged in the array are disposed in the display area (AA); 
     a light emitting functional layer  20  disposed in the display area (AA) of the transistor array substrate  10 ; 
     a driving component  80  disposed in the driving area (QD) of the transistor array substrate  10 ; 
     a plurality of traces (CL) disposed in the bending area (ZX) of the transistor array substrate  10  and electrically connected to the plurality of transistors  11  and the driving component  80 ; 
     a reinforcement layer  40  formed on a surface of the bending area (ZX); and 
     a blocking member  50  formed on a surface of the transistor array substrate  10  and located between the reinforcement layer  40  and the light emitting functional layer  20 . 
     Specifically, the OLED display panel  100  further comprises a packaging layer  30  formed on the light emitting functional layer  20 . 
     Furthermore, the transistor array substrate  10  further comprises a flexible substrate  12 . 
     In one embodiment, the reinforcement layer  40  comprises ultraviolet curing glue. 
     In one embodiment, a material of the blocking member  50  comprises one of polyimide (PI), an insulating organic compound such as acrylic, an insulating inorganic compound such as SiN x  or SiO x . The selected materials have an insulation property and are not reacted with the reinforcement layer  40  such as ultraviolet curing glue, and do not affect the normal working of the reinforcement layer  40 . 
     Referring to  FIG.  1   , a cross-sectional shape of the blocking member  50  is rectangle. 
     In one embodiment, the bending area (ZX) comprises a curved region (WQ), and the ultraviolet curing glue of the reinforcement layer  40  covers the curved region (WQ) and exceeds the curved region (WQ), so as to better protect the traces (CL) of the bending area (ZX) from cracking or breaking during bending. 
     In one embodiment, an OLED display panel is provided. By forming a blocking member between the reinforcement layer and the light emitting function layer in the OLED display panel, the ultraviolet curing glue of the reinforcement layer is prevented from overflowing to the display area, thereby effectively controlling the amount of glue overflow, and maintaining the stability of the distribution of ultraviolet curing glue in the bending area. Therefore, the control accuracy of the amount of glue overflow in the bending area is improved. 
     Referring to  FIG.  2   , it is a schematic side view of a part of second structure of the OLED display panel according to one embodiment of the present invention. Details of the driving component  80  and the transistor array substrate  10  are not shown. The OLED display panel  101  comprises a blocking member  50 ′. The difference from the previous embodiments is that the blocking member  50 ′ has a trapezoidal cross-sectional shape. Specifically, the cross-sectional shape of the blocking member may be one of a rectangle, a trapezoid, or other polygons. The cross-sectional shape of this embodiment is a trapezoid. 
     In one embodiment, the blocking member is formed by forming a new added layer on a surface of the transistor array substrate  10  and located between the reinforcement layer  40  and the light emitting functional layer  20 . In another embodiment, the blocking member and some other layers of the OLED display panel may be formed simultaneously. 
     Referring to  FIG.  3   , it is a schematic partial bottom view of the OLED display panel  101 . Details of the driving component  80  and the transistor array substrate  10  are not shown. In one embodiment, a surface of the blocking member  50 ′ is straight or curved. The surface of the blocking member  50  in this embodiment is straight. 
     Referring to  FIG.  4   , in another embodiment, the surface of the blocking member  50 ″ of the OLED display panel  102  has a curved shape. 
     In one embodiment, the blocking member  50 ′ may be arranged in one column or multiple columns. In this embodiment, the blocking member  50 ′ is arranged in one column as shown in  FIG.  2   . 
     In one embodiment, the blocking member may be formed by one of processes such as chemical vapor deposition (CVD) or inkjet printing (IJP). In this embodiment, the blocking member is formed by inkjet printing. 
     Specifically, inkjet printing is a film-forming method in which inks of functional materials are ejected drop-by-drop to corresponding positions as needed under computer control, so as to form a pattern. It has advantages such as simple operation, non-contact, no mask, low equipment cost, and high material utilization. It is considered to be an effective way to realize flexible large-area displays. Therefore, the blocking member is formed by inkjet printing, so that the height and width of the blocking member may be accurately controlled by the process conditions to achieve high accuracy and low cost. 
     Specifically, the ultraviolet curing glue of the reinforcement layer  40  may be formed on the surface of the curved region (WQ) by coating, and a height (h 1 ) of the ultraviolet curing glue coated on the surface of the curved region (WQ) is less than a height (h 2 ) of the blocking member  50 ′, and the height (h 2 ) of the blocking member  50 ′ are determined by the height (h 1 ) of the ultraviolet curing glue to be coated in the curved region as shown in  FIG.  2   . 
     Specifically, the ultraviolet curing glue has fluidity characteristics. When the ultraviolet curing glue is applied, the blocking member  50 ′ is blocking, and the height (h 2 ) of the blocking member  50 ′ is greater than the height (h 1 ) of the ultraviolet curing glue, so that it prevents the ultraviolet curing glue from overflowing into the display area and affecting the subsequent process. 
     Specifically, a distance between the blocking member and the ultraviolet curing glue may be determined by the ultraviolet curing glue to be applied to the curved region. A distance between the blocking member and the display area may be determined by the light emitting functional layer according to actual needs. 
     Referring to  FIG.  2   , the OLED display panel  101  further comprises a packaging layer  30  formed on the light emitting functional layer  20 . The packaging layer  30  is a packaging film and comprises a first inorganic packaging layer, a first organic packaging layer, and a second inorganic packaging layer (not shown) that are stacked. 
     Referring to  FIG.  5   , the OLED display panel  103  comprises a transistor array substrate  10 ′, a light emitting functional layer  20 , and a packaging layer  30 . The transistor array substrate  10 ′ further comprises a flexible substrate  12  and a planarization layer  17 . 
     In one embodiment, a material of the flexible substrate  12  comprises polyimide or other flexible polymers. The flexible substrate in this embodiment is made of polyimide. 
     In one embodiment, the planarization layer  17  is a top layer of the transistor array substrate  10 , and the planarization layer  17  extends from the display area (AA) of the transistor array substrate  10  to the bending area (ZX). 
     Specifically, the material of the planarization layer comprises polyimide or other organic compounds, and the planarization layer in this embodiment is made of polyimide. 
     Specifically, the planarization layer may be deposited on the transistor array substrate by chemical vapor deposition. 
     In one embodiment, the planarization layer  17  is patterned to form a convex blocking member  50 ′″, and the blocking member  50 ′″ is located between the curved region (WQ) and the display area (AA) of the transistor array substrate. Specifically, the blocking member  50 ′ is located between the reinforcement layer  40  and the light emitting functional layer  20 . 
     In one embodiment, a surface shape of the blocking member  50 ′″ is straight or curved. 
     In one embodiment, a cross-sectional shape of the blocking member  50 ′″ is one of a rectangle, a trapezoid, or other polygons. In this embodiment, the cross-sectional shape of the blocking member  50 ′″ is rectangle as shown in  FIG.  5   . 
     In one embodiment, the blocking member  50 ′″ is arranged in a column or multiple columns. In this embodiment, the blocking member  50 ′″ is arranged in a column as shown in  FIG.  5   . 
     In one embodiment, a reinforcement layer  40  is formed on a surface of the curved region (WQ), and the reinforcement layer  40  is used for structural reinforcement of the curved region (WQ). Cracks or breakage of internal wiring in the curved region (WQ) may cause the OLED display panel  103  failure or to display abnormal. The reinforcement layer  40  may avoid cracks or breakage of internal wiring in the curved region (WQ) during the bending. 
     Specifically, the reinforcement layer  40  comprises ultraviolet curing glue, and the ultraviolet curing glue may be formed on the surface of the curved region by coating, and a height (h 1 ′) of the ultraviolet curing glue coated on the surface of the curved region is less than a height (h 2 ′) of the blocking member  50 ′″, and the height (h 2 ′) of the blocking member  50 ′″ are determined by the height (h 1 ′) of the ultraviolet curing glue to be coated in the curved region as shown in  FIG.  5   . 
     Specifically, the ultraviolet curing glue has fluidity characteristics. When the ultraviolet curing glue is applied, the blocking member  50 ′ is blocking, and the height (h 2 ′) of the blocking member  50 ′″ is greater than the height (h 1 ′) of the ultraviolet curing glue, so that it prevents the ultraviolet curing glue from overflowing into the display area and affecting the subsequent process. 
     Specifically, a distance between the blocking member and the ultraviolet curing glue may be determined by the ultraviolet curing glue to be applied to the curved region. A distance between the blocking member and the light emitting functional layer may be determined by the light emitting functional layer according to actual needs. 
     In one embodiment, The packaging layer  30  is a packaging film and comprises a first inorganic packaging layer, a first organic packaging layer, and a second inorganic packaging layer (not shown) that are stacked. 
     Referring to  FIG.  6   , a display device  200  is provided in one embodiment. The display device comprises an organic light emitting diode (OLED) display panel  104 , a touch panel  60  disposed on the OLED display panel  104 , and a polarizer  70  disposed on the touch panel  60 . 
     In one embodiment, the OLED display panel of the display device  200  may be one of the above-mentioned OLED display panels. Herein, the OLED display panel  104  shown in  FIG.  6    comprises: 
     a transistor array substrate  10  comprising comprises a display area and a non-display area; 
     a light emitting functional layer  20  disposed in the display area (AA) of the transistor array substrate  10 ; 
     a reinforcement layer  40  formed on a surface of the curved region (WQ); and 
     a blocking member  50 ′″ formed on a surface of the transistor array substrate  10  and located between the reinforcement layer  40  and the light emitting functional layer  20   
     In one embodiment, the blocking member  50 ″″ may be formed by chemical vapor deposition or inkjet printing. The blocking member  50 ″″ is a new added layer formed on the surface of the transistor array substrate  10 . 
     In one embodiment, a surface shape of the blocking member  50 ″″ is straight or curved. 
     In one embodiment, a cross-sectional shape of the blocking member  50 ″″ is one of a rectangle, a trapezoid, or other polygons. In this embodiment, the cross-sectional shape of the blocking member  50 ″″ is trapezoid as shown in  FIG.  6   . 
     In one embodiment, the blocking member  50 ″″ is arranged in multiple columns. In this embodiment, the blocking member  50 ″″ is arranged in two columns as shown in  FIG.  6   . 
     In one embodiment, the reinforcement layer  40  comprises ultraviolet curing glue, and the ultraviolet curing glue may be formed on the surface of the curved region (WQ) by coating, and a height of the ultraviolet curing glue coated on the surface of the curved region (WQ) is less than a height of the blocking member  50 ″″, and the height of the blocking member  50 ″″ are determined by the height of the ultraviolet curing glue to be coated in the curved region. 
     Specifically, the ultraviolet curing glue has fluidity characteristics. When the ultraviolet curing glue is applied, the blocking member  50 ″″ is blocking, and the height of the blocking member  50 ″″ is greater than the height of the ultraviolet curing glue, so that it prevents the ultraviolet curing glue from overflowing into the display area and affecting the subsequent process. 
     Specifically, a distance between the blocking member and the ultraviolet curing glue may be determined by the ultraviolet curing glue to be applied to the curved region. A distance between the blocking member and the light emitting functional layer may be determined by the light emitting functional layer according to actual needs. 
     In one embodiment, the touch panel  60  is attached to the OLED display panel  104  through the pressure sensitive adhesive  90 , and the top surface of the blocking member  50 ″″ is connected to the touch panel  60  to support the touch panel  60 . 
     In one embodiment, the touch panel  60  further comprises a peripheral flexible printed circuit (FPC)  61 . The flexible printed circuit  61  may be bent together with the curved region (WQ) of the OLED display panel  104 . 
     In one embodiment, the blocking member  50 ″″ is connected to the touch panel  60 , which effectively prevents the substrate of the flexible printed circuit  61  from cracking during the bending, so as to keep the stability of the touch panel  60 . 
     In one embodiment, if it does not need to consider a supporting function of the blocking member on the touch panel, the blocking member only needs to ensure that the ultraviolet curing glue may not effectively overflow to the display area. Therefore, the blocking member may not be connected to the touch panel. 
     In one embodiment, the polarizer  70  may be attached to the touch panel  60  by pressure sensitive adhesive (not shown). 
     In the display device provided in this embodiment, a blocking member is formed between the reinforcement layer and the light emitting functional layer. A height of the blocking member is greater than that of the ultraviolet curing glue of the reinforcement layer, and the blocking member is connected to the touch panel. The blocking member blocks the overflow of glue in the process of coating the ultraviolet curing glue, so as to maintain the uniformity of the amount of glue. Also, the blocking member effectively prevents the ultraviolet curing glue from overflowing into the display area and affecting the subsequent process. At the same time, the blocking member supports the touch panel and maintains its stability during bending. 
     In one embodiment, the blocking member may also be made into an adhesive tape, a tape-reel type, and manually attached between the reinforcement layer and the light emitting functional layer of the OLED display panel. 
     In one embodiment, a method of manufacturing an organic light emitting diode (OLED) display panel comprises following steps: 
     step S 1 : forming a transistor array substrate, and the step S 1  comprises providing a flexible substrate and sequentially forming a buffer layer, an active layer, a gate insulating layer, a gate, an interlayer insulating layer, a source/drain layer and a planarization layer on the flexible substrate; 
     step S 2 : forming a light emitting functional layer, and the step S 2  comprises forming a pixel electrode layer, a pixel definition layer, a light emitting layer, and a cathode layer on the transistor array substrate in order; 
     step S 3 : forming a blocking member, and the step S 2  comprises forming the blocking member between the light emitting functional layer and a bending area on the transistor array substrate by inkjet printing; 
     step S 4 : forming a reinforcement layer, and the step S 4  comprises forming the reinforcement layer on the bending area of the transistor array substrate; and 
     step S 5 : forming a packaging layer, and the step S 5  comprises forming the packaging layer on the light emitting functional layer. 
     Specifically, in the step S 4 , the reinforcement layer comprises ultraviolet curing glue. 
     Specifically, in the step S 3 , the blocking member is formed between the reinforcement layer and the light emitting functional layer. 
     Specifically, in the step S 3 , a material of the blocking member comprises one of polyimide, an insulating organic compound, and an insulating inorganic compound. The selected materials have an insulation property and are not reacted with the reinforcement layer such as ultraviolet curing glue, and do not affect the normal working of the ultraviolet curing glue. 
     Specifically, in step S 3 , a surface shape of the blocking member is straight or curved. 
     Specifically, in step S 3 , a cross-sectional shape of the blocking member comprises one of a rectangle and a trapezoid. 
     Specifically, in step S 3 , the blocking member is arranged in one column or multiple columns. 
     Specifically, in step S 3 , a height of the blocking member is greater than that of the ultraviolet curing glue of the reinforcement layer, and a distance between the blocking member and the ultraviolet curing glue may be determined by the ultraviolet curing glue to be coated in the bending area according to actual needs. A distance between the blocking member and the light emitting functional layer may be determined by the light emitting functional layer according to the actual needs. 
     Accordingly, in the above-mentioned embodiment, an OLED display panel, a method of manufacturing thereof, and a display device are provided. A blocking member is formed between the reinforcement layer and the light emitting functional layer. A height of the blocking member is greater than that of the ultraviolet curing glue of the reinforcement layer, and the blocking member is connected to the touch panel. The blocking member blocks the overflow of glue in the process of coating the ultraviolet curing glue, so as to maintain the uniformity of the amount of glue. Also, the blocking member effectively prevents the ultraviolet curing glue from overflowing into the display area and affecting the subsequent process. At the same time, the blocking member supports the touch panel and maintains its stability during bending. 
     In the above, the present application has been described in the above preferred embodiments, but the preferred embodiments are not intended to limit the scope of the invention, and a person skilled in the art may make various modifications without departing from the spirit and scope of the application. The scope of the present application is determined by claims.