US-12619011-B2 - Protection film structure with composite hardening layer

US12619011B2US 12619011 B2US12619011 B2US 12619011B2US-12619011-B2

Abstract

A protection film structure with composite hardening layer includes a transparent substrate and at least two tiling layers. The at least two tiling layers includes a first tiling layer, which is arranged on one face of the transparent substrate and includes a plurality of first tiling islands with a gap therebetween, and a second tiling layer, which is arranged on one face of the first tiling layer away from the transparent substrate and includes a plurality of second tiling islands with a gap therebetween. At least one composite hardening layer is arranged between the adjacent tiling layers, and each composite hardening layer includes a first hardening layer and a second hardening layer made from different materials and the material hardness of the first hardening layer is larger than the material hardness of the second hardening layer.

Inventors

HSIANG-YU LEE
Shang CHIN
Ping-Tsun Lin

Assignees

SUPERC-TOUCH CORPORATION

Dates

Publication Date: 20260505
Application Date: 20240603
Priority Date: 20230704

Claims (14)

1 . A protection film structure comprising: a transparent substrate having a first face and a second face; at least two tiling layers comprising: a first tiling layer arranged on one side of the first face of the transparent substrate and comprising a plurality of first tiling islands, two adjacent ones of the first tiling islands, two adjacent one of the first tiling islands having a gap between; a second tiling layer arrange on one face of the first tiling layer away from the transparent substrate and comprising a plurality of second tiling islands, two adjacent ones of the second tiling islands having a gap therebetween; and at least one composite hardening layer arranged between the adjacent tiling layers, and the composite hardening layers comprising: a first hardening layer, wherein the first hardening layer is silicon nitride (SiNx), and a second hardening layer made from a different material than the first hardening layer, wherein a material hardness of the first hardening layer is larger than a material hardness of the second hardening layer.
2 . The protection film structure in claim 1 , wherein one of the second tiling islands of the second tiling layer is at least partially overlapped with at least one of the first tiling islands of the first tiling layer along a projection direction.
3 . The protection film structure in claim 2 , wherein one of the second tiling islands of the second tiling layer is at least partially overlapped with at least two different first tiling islands of the first tiling layer along a projection direction.
4 . The protection film structure in claim 2 , wherein one of the second tiling islands of the second tiling layer is at least partially overlapped with at least three different first tiling islands of the first tiling layer along a projection direction.
5 . The protection film structure in claim 2 , further comprising a third tiling layer arranged on one side of the second tiling layer away from the first tiling layer, the third tiling layer comprising a plurality of third tiling islands, two adjacent ones of the third tiling islands having a gap therebetween, one of the third tiling islands of the third tiling layer is at least partially overlapped with at least one second tiling island of the second tiling layer along a projection direction.
6 . The protection film structure in claim 2 , wherein areas of the first tiling islands and the second tiling islands are respectively not less than 250 square micrometers.
7 . The protection film structure in claim 2 , wherein areas of the first tiling islands and the second tiling islands are not more than 50 square millimeters respectively.
8 . The protection film structure in claim 1 , wherein one of the composite hardening layers comprises three hardening layers.
9 . The protection film structure in claim 1 , further comprising at least one additional hardening layer arranged between the transparent substrate and the first tiling layer.
10 . The protection film structure in claim 1 , further comprising an outer hardening layer arranged on a side of the tiling layer most away from the transparent substrate and the side being opposite to the transparent substrate, the outer hardening layer has a hardness greater than pencil hardness 6H.
11 . The protection film structure in claim 10 , wherein the outer hardening layer is a silicon nitride hardening layer with thickness less than 1 micrometer.
12 . The protection film structure in claim 1 , wherein the tiling layers are made of organic material and have thickness not less than 0.5 micrometers.
13 . The protection film structure in claim 12 , wherein the organic material is acrylic material or photosensitive polyimide.
14 . The protection film structure in claim 1 , wherein the transparent substrate is a polymer material substrate or an ultra-thin glass substrate with thickness not more than 200 micrometers.

Description

BACKGROUND Technical Field The present invention relates to a protection film structure, especially to a protection film structure with composite hardening layer. Description of Related Art Flexible and foldable display are widely used in various applications such as mobile phones, e-books, electronic posters, electronic labels because of lightweight and the capability to attach to curved objects. Traditional display may use protective glass to protect it from being damaged by external forces. However, traditional protective glass is rigid and lacks of bending ability. The protection of flexible display becomes an important issue because the traditional protective glass cannot be used for flexible display. The traditional technologies for protecting flexible display can be classified into two categories below. The first way is to use transparent plastic materials (such as transparent PI, PET) coated with hard coating on surface thereof to replace the traditional protective glass, where the material of the hard coating is generally glass-like materials such as silicon oxide. However, the first technology has poor effect because the plastic material is soft and easy to collapse when contacting foreign objects, which will cause the breakage of surface hard coating. The second way exploits the bendable characteristics of ultra-thin glass to protect flexible display and the ultra-thin glass is currently used for foldable smart phone. However, the production, processing, post-production and yield of ultra-thin glass are poor to cause increased product costs. Besides, a layer of plastic material is required to attach to the surface of the ultra-thin glass to absorb shock and serve as a protective layer therefor because the ultra-thin glass tends to break by impact. This cumbersome traditional architecture causes that the surface of the flexible display has insufficient hardness and has traces when scratched by foreign objects, thus influence display effect. To overcome the disadvantages of the above-mentioned prior art, this present patent intends to provide a hardening layer with crack-resisting ability on a flexible surface, where global chipping will not happen when it is scratched by foreign objects to ensure surface hardness and screen protection. FIG. 1 shows a schematic diagram of a related art electronic product 100′ with a foldable display screen in folded status. The electronic product 100′ is, for example, a smartphone with a foldable display screen or an e-book apparatus with electronic paper. FIG. 2 shows a partial cross-sectional view of the electronic product 100′ with a foldable display screen. As shown in FIG. 2, the electronic product 100′ has, from top to bottom with reference to normal operation orientation, at least a protective layer 10′, a touch layer 20′ and a flexible (or foldable) display screen 30′. This protective layer 10′ is required to have sufficient hardness to provide scratch resistance, and the transparency of the protective layer 10′ is preferably greater than 70%. As the material hardness or the thickness of the protective layer 10′ becomes larger, the more likely the protective layer 10′ has risk of breaking when the electronic product 100′ is bent or folded. FIGS. 3A and 3B are schematic views for explaining the cracking problem of the protective layer 10′ when the electronic product 100′ is bent or folded. As shown in those figures, the protective layer 10′ in prior art electronic product 100′ generally lacks of sufficient flexibility because the material hardness or the thickness of the protective layer 10′ should be larger enough to resist scratch. This causes the protective layer 10′ to break when the electronic product 100′ is bent or folded. Accordingly, the touch layer 20′ below the protective layer 10′ may also have internal breakage. In a worse scenario, the display screen may also be damaged to cause degraded display of the electronic product 100′ or erroneous operation. On the contrary, the material hardness or the thickness of the protective layer 10′ for related art flexible (or foldable) display screen 30′ may be reduced to enhance the flexibility. However, the hardness will be insufficient to cause fragmentation and scratching problems when foreign objects contact with the protective layer 10′. The object of the present invention is to solve the above problems by providing tiling layers with a gap therebetween and composite hardening layer between two adjacent tiling layers. The provision of the composite hardening layer can provide sufficient hardness for the protection film structure and the gap of the tiling layers can provide extension space for the composite hardening layer when it is pressed. SUMMARY Accordingly, the object of the present invention is to provide a protection film structure with composite hardening layer, the protection film structure includes a transparent substrate having a first face and a second face; at least two tiling layers compris