The present invention relates to an encapsulation technology field of display devices, and more particularly to a mask used for thin-film encapsulation of a flexible OLED panel.
With the development of mobile communication technology, mobile phone functions have been greatly developed. The development of smart phones tends to be big screen, but oversize screens can affect the portable performance of mobile phones. Therefore, foldable smart phones have attracted great attention in the field of the mobile communications.
Now, with the continuous development of OLED display technology, a flexible OLED panel has achieved mass production, and its main focus is on a curved screen. But there are still many problems to be solved urgently in the development process of foldable flexible OLED substrates. The main problem is that a bending zone of the flexible substrate is not durable enough when folded repeatedly. This is due to the different stress of each film in the bending zone, which may cause the separation of the film or the destruction of the encapsulation layer in the process of repeated bending.
Furthermore, the glass encapsulation technology used in a traditional display panel is difficult to meet the flexible requirement. At this stage, the main packaging method used in flexible panel is TFE (Thin Film Encapsulation) technology. At present, the TFE used in mass production is Barix encapsulation technology. The principle is to construct multilayer films with alternating inorganic-organic layer on the substrate surface by a chemical vapor deposition method and an ink jet printing method, so as to complete the encapsulation of the substrate. The function layer for blocking water and oxygen is the inorganic encapsulation layer. The main function of the organic layer is to disperse the internal stress of the inorganic layer when bending the substrate. Moreover, because the inorganic layer is a rigid layer, when bending, the inorganic layer is easily separated from the substrate due to the excessive internal stress of the inorganic layer, or the inorganic layer breaks or falls off due to uneven stress. All of these will result in the failure of the encapsulation.
Hence, it is necessary to design a mask used for thin-film encapsulation of a flexible OLED panel to overcome the shortcomings of the existing technology.
An aspect of the invention is to provide a mask used for thin-film encapsulation of a flexible OLED panel, which can transform an inorganic encapsulation layer on a bending area of the OLED panel from an original integral encapsulation layer to multiple independent modular encapsulation structures, thereby reducing an internal stress of the inorganic encapsulation layer when bending, and further reducing the risk of damage to the inorganic encapsulation layer during repeated bending.
The technical scheme adopted by the present invention is as follows.
A mask used for thin-film encapsulation of a flexible OLED panel comprises a mask frame and a mask housing disposed in the mask frame. Wherein the mask housing defines a shadow region and an opening region. The opening region is corresponding to an active area of the flexible OLED panel. The opening region defines a precision mask region, which is corresponding to a bending area of the flexible OLED panel. The precision mask region defines multiple precision openings separated from each other, and each precision opening is corresponding to one or more pixels in the bending area.
Further, in the different embodiments, each precision opening is corresponding to one pixel including red, green and blue sub-pixels, in the bending area of the OLED panel.
Or each precision opening is corresponding to three pixels representing red, green and blue pixels respectively, in the bending area of the OLED panel. In other embodiments, each precision opening is preferably corresponding to three pixels or an integer multiple of three pixels (e.g. 6, 9, 12 etc), which are corresponding to red, green and blue pixels in actual use.
Further, in the different embodiment, each precision opening is corresponding to a row of pixels perpendicular to a bending direction of the bending area of the OLED panel.
Further, in the different embodiment, each precision opening is corresponding to 2-N pixels arranged to be different pattern in the bending area of the OLED panel, where N is an integer equal to or greater than three.
Wherein in the different embodiments, the number of the precision openings defined by the precision mask region can be 3, 4, 5, 6, 7, 8, 9, 10, and so on, depending on the actual needs, but there is no limit. Correspondingly, the precision openings can be of the same size or of different sizes. The precision openings can be corresponding to the same number of pixels or different number of pixels respectively. It can be decided according to actual needs, and there is no limit.
Further, in the different embodiment, the precision mask region is corresponding to the bending area and extends 100-1000 μm toward both sides thereof.
Further, in the different embodiment, the precision mask region is formed by a method of electroforming, etching or metal wire drawing.
Further, in the different embodiment, the opening region is corresponding to the active area and extends 100-500 um outward.
Further, in the different embodiment, the mask housing defines two or more opening regions, at least one of which defines the precision mask region.
Further, in the different embodiment, a thickness of the mask housing is 0.02-0.2 mm.
Further, in the different embodiment, a surface of the mask housing is covered with protective films, which may be PTFE coatings or Al2O3 inorganic coatings.
Comparing with the prior art, the present invention has the advantages that a design concept of a precise metal mask is introduced into the mask used for thin-film encapsulation of the flexible OLED panel, and the metal mask originally used in packaging process is partially or wholly designed as a precise metal mask region with PPI slightly lower than that of the substrate PPI. After design modification, the mask of the present invention can partially or wholly divide the encapsulation region of the inorganic encapsulation layer. Thus, the inorganic encapsulation layer of the bending area of the flexible OLED panel, which is made by the mask of the present invention, can be transformed from the original integral encapsulation layer to multiple independent modular encapsulation structures, thereby reducing an internal stress of the inorganic encapsulation layer when bending, and further reducing the risk of damage to the inorganic encapsulation layer during repeated bending.
For more clearly understanding above content of the present invention, the following text will briefly introduce the accompanying drawings used in the preferred embodiment of the present invention. It is obvious that the accompanying drawings in the following description are only some embodiments of the present invention. For the technical personnel of the field, other drawings can also be obtained from these drawings without paying creative work.
Reference numerals in
The following text will give a further detailed description of the technical scheme of a mask used for thin-film encapsulation of a flexible OLED panel with reference to the accompanying drawings and embodiments.
Please refer to
The mask housing 10 defines a shadow region 11 and an opening region 12. The opening region 12 is corresponding to an active area (AA) of the flexible OLED panel. The opening region 12 defines a precision mask region 14 being corresponding to a bending area of the flexible OLED panel.
The mask housing 10 is fixed on the mask frame 20 by laser spot welding. A thickness of the mask housing 10 is 0.02-0.2 mm. A surface of the mask housing 10 can be covered with protective films such as Al2O3 or PTFE coatings to prevent the mask from being damaged in a TFE process. The opening region 12 is corresponding to the active area, and extends 100-500 um outward, but is not limited to this. It can be decided according to actual needs. The precision mask region 14 can be formed by a method of electroforming, etching or metal wire drawing. The precision mask region 14 is corresponding to the bending area, and extends 100-1000 μm toward both sides thereof.
Further, the precision mask region defines multiple precision openings separated from each other. Each precision opening is corresponding to one or more pixels in the bending area of the flexible OLED panel. Specifically, please refer to
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Furthermore, in different embodiments, the number of the precision openings 140 defined by the precision mask region 14 can be 3, 4, 5, 6, 7, 8, 9, 10, and so on, depending on the actual needs. But there is no limit. Correspondingly, the precision openings can be of the same size or of different sizes. The precision openings can be corresponding to the same number of pixels or different number of pixels respectively. It can be decided according to actual needs, and there is no limit.
The mask described in the present invention can be used to encapsulate a flexible OLED substrate. Please refer to
Furthermore, please refer to
The mask housing 10 defines a shadow region 11 and multiple opening regions 12. Each opening regions 12 is corresponding to an active area (AA) of the flexible OLED panel, and each opening region 12 defines a precision mask region 14 being corresponding to a bending area of the flexible OLED panel.
The difference between the embodiment shown in
The technical scope of the present invention is not limited to the contents of the above description. A person in the art can make various modifications for the above embodiments without departing from the technical ideas of the present invention, and the modifications shall be included in the scope of protection of the invention.
Number | Date | Country | Kind |
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201811415668.7 | Nov 2018 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2019/070130 | 1/2/2019 | WO | 00 |