Patent Application
20180011562
This application is based upon and claims priority to Chinese Patent Application No. 201610520029.1, filed on Jul. 5, 2016, the entire contents thereof are incorporated herein by reference.
The present disclosure generally relates to the field of display device, and more particularly, to a touch display panel that may prevent creases and peelings of touch sensing devices due to bending of the display panel, and a method for manufacturing the same.
Currently, most commercial available display panels are integrated with a touch function and a display function. Accordingly, display panels with both the touch function and the display function are referred to as touch display panels.
In the related art, a touch display panel generally includes successively, in an upward direction, a display structure 10 for the display function and a touch sensing structure 11 for the touch sensing function. The touch sensing structure 11 is attached to the display structure 10 by an adhesion layer 12 (OCA) between the display structure 10 and the touch sensing structure 11.
Currently, touch display panels are developing to be thin and bendable, and are replacing typical panel display devices and becoming mainstream of the display field. In the above assembling means by attaching touch sensing structure 11 to the display structure 10, the adhesion layer 12 (OCA) is required between the display structure 10 and the touch sensing structure 11, thereby increasing the thickness of the touch display panel and being against the slimming demand of the touch display panel. In addition, peelings or creases may occur in the adhesion layer (OCA) after multiple bends, and thus may cause problems such as short lifespan and bad display effect of the touch display panel. Accordingly, the above assembling means is not suitable for free-bendable touch display panels.
It should be noted that, information disclosed in the above background portion is provided only for better understanding of the background of the present disclosure, and thus it may contain information that does not form the prior art known by those ordinary skilled in the art.
According to one aspect of the present disclosure, there is provided a touch display panel including a flexible substrate, a light emitting device, an encapsulating film and a touch sensing device. The light emitting device is provided on the flexible substrate. The encapsulating film covers the light emitting device and encapsulates the light emitting device in a sealed space formed between the flexible substrate and the encapsulating film. The touch sensing device is provided on a portion of an outer surface of the encapsulating film, and is configured to sense an external touch operation. Herein, the touch sensing device is formed directly on the portion of the outer surface of the encapsulating film, such that the touch sensing device is fixed on the portion of the outer surface of the encapsulating film.
According to another aspect of the present disclosure, there is provided a method for manufacturing a touch display panel, the method including:
providing a flexible substrate;
forming a light emitting device on the flexible substrate;
covering the light emitting device with an encapsulating film and encapsulating the light emitting device in a sealed space formed between the flexible substrate and the encapsulating film; and
forming a touch sensing device on a portion of an outer surface of the encapsulating film,
wherein the touch sensing device is formed directly on the portion of the outer surface of the encapsulating film, such that the touch sensing device is fixed on the portion of the outer surface of the encapsulating film.
Other objectives and advantages will be further understood from the technical features set forth in the present disclosure. Hereinafter, detailed descriptions are provided to describe embodiments of the present disclosure with reference to the drawings, such that the above and other objectives, features, and advantages may be more apparent and easily understandable.
This section provides a summary of various implementations or examples of the technology described in the disclosure, and is not a comprehensive disclosure of the full scope or all features of the disclosed technology.
The above and other objectives, features and advantages will become more apparent by describing example embodiments of the present disclosure in detail with reference to the drawings.
The exemplary implementations will now be described more fully with reference to the accompanying drawings. However, the exemplary implementations may be implemented in various forms and should not be understood as being limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the conception of exemplary implementations to those skilled in the art. The accompanying drawings are only schematic illustration of the present disclosure, and may be not drawn to scale. In the drawings, the same reference numerals denote the same or similar structures, thus their detailed description will be omitted.
In addition, the features, structures or characteristics described herein can be combined in one or more embodiments in any appropriate way. In the description hereinafter, many specific details are provided for fully understanding of the embodiments of the present disclosure. However, it will be appreciated by those skilled in the art that the technical solution of the present disclosure can be practiced without one or more of the specific details, or with other methods, components, devices or steps, etc. In addition, known structures, methods, devices, implementations, materials or operations will not be illustrated or described in detail, to avoid obscuration of the aspects of the present disclosure.
The above and other technical content, characteristics and effects may be presented clearly in the following detailed description of the embodiments with reference to the drawings. Directional terms, such as upper, lower, left, right, outer, inner, front, rear, or the like, are merely directions with reference to the drawings. Accordingly, the directional terms are illustrative rather than limiting the present disclosure.
The flexible substrate 20 may be formed of a flexible plastic material. However, the present disclosure is not limited thereto, and the flexible substrate 20 may be formed of a metal substrate that is made of stainless steel and a plurality of flexible materials. The flexible substrate is formed of plastic material with excellent thermal resistance and durability, such as at least one of polyethylene ether phthalate, polyvinyl naphthalene, polycarbonate, polyarylester, polyetherimide, polyethersulfone and polyimide.
The light emitting device 22 is provided on the flexible substrate 20. The light emitting device 22 may be an organic light emitting device (OLED).
The encapsulating film 24 (e.g., tetrafluoroethylene, TFE) is formed on the flexible substrate 20 and covers the light emitting device 22. The encapsulating film 24 encapsulates the light emitting device 22 within a sealed space 28 formed between the flexible substrate 20 and the encapsulating film 24. In the present embodiment, the sealed space 28 is a sealed space enclosed by an upper surface 201 of the flexible substrate 20 and an inner surface 241 of the encapsulating film 24. The light emitting device 22 is sealed in the sealed space 28 to prevent the light emitting device 22 from being exposed to the air, which in turn prevents the light emitting device 22 from being damaged by moisture or oxygen in the air. The encapsulating film 24 may be a thin film isolating layer (Barix) developed by Vitex Systems LLC, which has a permeability to moisture and oxygen corresponding to that of a piece of glass. The Barix is formed by laminating polymer films and ceramic films in vacuum atmosphere, and has a total thickness of 3 μm, which is approximately one twentieth of the diameter of human hair. The isolation layer may be provided over the OLED directly, and may isolate and protect the OLED from moisture and oxygen without using other mechanical encapsulating elements. An organic polymer film may be excellent in film forming property, uniformity and surface smoothness but poor in moisture and oxygen isolation property, while an inorganic thin film such as the ceramic film may be excellent in moisture and oxygen isolation property but poor in film forming property and surface smoothness. Accordingly, a complementary moisture and oxygen isolation unit may be formed by alternatively laminating both of them, and the resulted thin film isolation layer may have a total thickness of only 3 μm, thereby satisfying the ultra-slim and ultra-light requirements of the device.
The organic polymer film may be a single layer or laminated layer formed by at least one of polyethylene terephthalate (PET), polyimide, polycarbonate, epoxy resin, polyethylene and polyacrylate. The organic layer may be formed of polyacrylate, and in particular may include a polymer of monomer compositions including a diacrylate-based monomer and a triacrylate-based monomer. A monoacrylate-based monomer may be further included in the monomer compositions. Further, known photoinitiators such as a 2,4,6-trimethylbenzoyl diphenyl phosphoine (TPO) may be further included in the monomer compositions. However, the present disclosure is not limited thereto.
The inorganic thin film may be a single layer or laminated layer including a metal oxide or a metal nitride. In particular, the inorganic layer may include at least one of SiNx, Al2O3, SiO2 and TiO2.
The touch sensing device 26 is formed on an outer surface 242 of the encapsulating film 24 to sense an external touch operation. The touch sensing device 26 may be directly formed on the outer surface 242 of the encapsulating film 24, such that the touch sensing device 26 may be directly fixed on the outer surface 242 of the encapsulating film 24. The touch sensing device 26 may be patterned on the outer surface 242 of the encapsulating film 24 by printing manufacturing process. In order to improve an adhesive power between the touch sensing device 26 and the encapsulating film 24, surface treatments may be performed on the outer surface 242 of the encapsulating film 24 prior to the printing manufacturing process. The surface treatments may include a chemical scheme, a plasma scheme and a layer growth scheme.
The Chemical Scheme
Chemical Vapor Deposition (CVD) refers to a process of introducing gaseous reactors or vapor of liquid reactors containing thin-film-forming elements and other gases required during the reaction into a reaction chamber and forming a thin film on a substrate by chemical reactions at the surface of the substrate. In a super large scale integration circuit, many thin films are formed by CVD. An adherence of the surface treated film may increase by about 30% after the CVD process, thereby preventing scratches due to bending, stretching or the like of the substrate.
The Plasma Scheme
A plasma cleaner, also known as a plasma cleaning machine, a plasma surface modification device, a plasma surface treating device, a plasma etching device, or the like, may be used for the plasma scheme. The plasma cleaner is widely applicable in plasma cleaning, plasma etching, plasma plating, plasma coating, plasma ashing, surface modifying, or the like.
The Layer Growth Scheme
A sputter deposition, generally a magnetically controlled sputter deposition, belongs to a high speed low temperature sputter deposition method.
During the sputter deposition, an inert gas argon (Ar) is provided at a vacuum degree of about 1×10−3 Torr (i.e., 1.3×10−3 Pa), and a high voltage direct current is applied between a plastic substrate material (an anode electrode) and a metal target material (a cathode electrode). The inert gas is excited by electrons generated by glow discharge between the anode electrode and the cathode electrode to generate a plasma. The plasma bombards out atoms from the metal target material, and the atoms are deposited on the plastic substrate material.
In step S60, a flexible substrate is provided.
In step S62, a light emitting device is formed on the flexible substrate.
In step S64, an encapsulating film is formed on the light emitting device to encapsulate the light emitting device in a sealed space formed between the flexible substrate and the encapsulating film.
In step S66, a touch sensing device is formed on an outer surface of the encapsulating film. In the present embodiment, the touch sensing device is formed directly on the outer surface of the encapsulating film, and the touch sensing device is fixed on the outer surface of the encapsulating film.
As illustrated in
A touch sensing layer is formed on the outer surface of the encapsulating film. Before forming the touch sensing layer on the outer surface of the encapsulating film, the outer surface of the encapsulating film may be surface treated by a chemical scheme, a plasma scheme, or a layer growth scheme, to improve an adhesive power between the touch sensing layer and the encapsulating film. The touch sensing layer may be formed directly on the outer surface of the encapsulating film by printing manufacturing process, so as to form patterned first sensing pads and second sensing pads on the outer surface of the encapsulating film. The touch sensing layer may be formed of transparent metal oxides such as ITO, indium zinc oxide (IZO), aluminium zinc oxide (AZO), gallium zinc oxide (GZO) or the like, or may be formed of conductive materials such as silver nanowire. However, the present disclosure is not limited thereto.
An insulation layer is formed on the touch sensing layer. The insulation layer is formed on the touch sensing layer by printing manufacturing process. The insulation layer covers the first sensing pads and the second sensing pads of the touch sensing layer. The insulation layer may be formed of resin material, silicon oxide, silicon nitride, or the like.
A bridge connecting line is formed on the insulation layer. Corresponding connection holes may be formed in the insulation layer at positions corresponding to two adjacent second sensing pads, by for example etching process, such that the bridge connecting line formed on the insulation layer may connect the adjacent second sensing pads. The bridge connecting line may be formed on the insulation layer at the position corresponding to the two adjacent second sensing pads to be connected by printing manufacturing process. The bridge connecting line may be formed of a conductive material such as ITO, Mo, Al, Cu or the like.
A protection layer is formed on the touch sensing layer and the bridge connecting line. The protection layer may be formed by printing manufacturing process. The protection layer may cover the touch sensing layer and the bridge connecting line to protect the touch sensing layer and the bridge connecting line. The protection layer may be formed of the same material as that of the above insulation layer, e.g., may be formed of resin material, silicon oxide, silicon nitride, or the like.
A lead is formed on the touch sensing layer. The lead may be formed by printing manufacturing process. The lead is connected to the first sensing pads and the second sensing pads of the touch sensing layer, respectively. By connecting the other end of the lead to a signal output terminal of the flexible circuit board, the sensed signal of the touch sensing device may be transmitted to successive signal processing IC for corresponding touch sensing operation. The lead may be formed of transparent metal oxide (e.g., ITO, IZO, AZO, GZO or the like), conductive high polymer material (e.g., PEDOT:PSS), nanotechnology material (e.g., sliver nanowire), carbon nanotube, or the like.
After the above steps, the touch sensing device may be formed directly on the outer surface of the encapsulating film.
The present disclosure, as being compared with bonding the touch sensing device and the display unit using the adhesion layer (OCD) in the prior art, excludes the use of the adhesion layer (OCD), such that the total thickness of the touch display panel becomes thinner. In addition, a subsequent aligning step during the connection process of the touch sensing device and the display unit is unnecessary, thereby simplifying the manufacture process. Further, problems such as creases and peelings of the touch sensing device formed on the encapsulating film due to bending of the panel may be prevented, and thus the present disclosure may be suitable for bendable touch display panels.
In another embodiment, the step S66 may further includes the steps as follows. A touch sensing layer is formed on the outer surface of the encapsulating film. Before forming the touch sensing layer on the outer surface of the encapsulating film, the outer surface of the encapsulating film may be surface treated by a chemical scheme, a plasma scheme, or a layer growth scheme, to improve an adhesive power between the touch sensing layer and the encapsulating film. The touch sensing layer may be formed directly on the outer surface of the encapsulating film by printing manufacturing process, so as to form patterned first sensing pads and second sensing pads on the outer surface of the encapsulating film. The touch sensing layer may be formed of transparent metal oxides such as ITO, IZO, AZO, GZO or the like, or may be formed of conductive materials such as silver nanowire. In the present embodiment, patterned connection are formed between the first sensing pads and between the second sensing pads formed on the outer surface of the encapsulating film. Compared with the above embodiments, the present embodiment may exclude the steps of forming bridge connecting lines for connections of the corresponding sensing pads.
A protection layer is formed on the touch sensing layer. The protection layer may be formed by printing manufacturing process. The protection layer may cover the touch sensing layer to protect the touch sensing layer. The protection layer may be formed of resin material, silicon oxide, silicon nitride, or the like.
A lead is formed on the touch sensing layer. The lead may be formed by printing manufacturing process. The lead is connected to the first sensing pads and the second sensing pads of the touch sensing layer, respectively. By connecting the other end of the lead to a signal output terminal of the flexible circuit board, the sensed signal of the touch sensing device may be transmitted to successive signal processing IC for corresponding touch sensing operation. The lead may be formed of transparent metal oxide (e.g., ITO, IZO, AZO, GZO or the like), conductive high polymer material (e.g., PEDOT:PSS), nanotechnology material (e.g., sliver nanowire), carbon nanotube, or the like.
After the above steps, the touch sensing device may be formed directly on the outer surface of the encapsulating film.
Compared with the above embodiment, by forming the touch sensing device directly on the outer surface of the encapsulating film using the above steps, a step for forming bridge connecting lines may be excluded from the forming process of the touch sensing device, thereby simplifying a process for forming the touch sensing device on the encapsulating film.
Hereinabove, exemplary embodiments of the present disclosure have been illustrated and described in detail. It should be appreciated that the present disclosure is not limited to the detailed structures, arrangements or implementations described herein. Rather, the present disclosure intends to cover various modifications and equivalent arrangements included in the spirit and scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201610520029.1 | Jul 2016 | CN | national |
