Patent Application
20130115426
The present invention relates generally to a flexible electronic device, and more particularly, to a method for manufacturing a flexible electronic device.
There are two methods mainly applied in manufacturing flexible displays: roll to roll and attaching a flexible substrate to a glass substrate. For the latter method, separating the flexible substrate from the glass substrate so as to complete the flexible display manufacturing process has been proven to be challenged. One of conventional release methods is to insert a sacrificial layer between the flexible substrate and the glass substrate in which the material of the sacrificial layer are oxides that absorb energy of laser at certain wavelengths. By laser scanning the rear side of the glass substrate, the oxide layer absorbs the laser energy penetrated through the glass substrate, so that the flexible substrate and the glass substrate are separated. However, the use of laser increases the cost and induces damages to electronic components.
Another method is to dispose an organic release layer between the flexible substrate and the glass substrate. However, during the process the organic release layer may form small islands, which may causes holes to be formed in the flexible substrate and non-uniform thickness of the flexible substrate.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.
In one aspect of the present invention, a method for manufacturing a flexible electronic device includes providing a substrate, forming a first layer on the substrate to define a first area and a second area surrounding the first area in the substrate such that the substrate is exposed at least partially in the first area and the first layer is in the second area, forming a second layer on the first area and the first layer over the second area such that an adhesion force between the second layer and the substrate in the first area is weaker than that between the second layer and the first layer in the second area, forming an electronic device layer on the second layer over the first area, where the electronic device layer defines a boundary thereon, and the boundary is projectively within the first area, and separating the electronic device layer and the partial second layer from the substrate by cutting through the second layer along a contour that is equal to or larger than the boundary of the electronic device layer but within the first area.
In another aspect of the present invention, a method for manufacturing a flexible electronic device comprises providing a substrate having a first surface and an opposite, second surface, coating a first polyamic acid on the first surface of the substrate to form a first polyimide (PI) layer so as to define a first area on which the first PI layer is formed and a second area surrounding the first area in the substrate, coating a second polyamic acid which synthesized with organic silane on the first PI layer in the first area of the substrate and on the second area of the substrate to form a second PI layer thereon, such that an adhesion force between the first PI layer and the substrate in the first area is weaker than that between the second PI layer and the substrate in the second area, forming an electronic device layer on the second PI layer over the first area, where the electronic device layer defines a boundary thereon, and the boundary is projectively within the first area, and separating the electronic device layer, the partial second PI layer and the partial first PI layer from the substrate by cutting through the second PI layer and the first PI layer along a contour that is equal to or larger than the boundary of the electronic device layer but within the first area.
In yet another aspect, the present invention relates to a flexible electronic device layer manufactured according to the methods disclosed above.
These and other aspects of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure.
The accompanying drawings illustrate one or more embodiments of the invention and, together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment, and wherein:
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout.
It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed as a second element, component, region, layer or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including” or “has” and/or “having” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top”, may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower”, can therefore, encompasses both an orientation of “lower” and “upper,” depending of the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
As used herein, “around”, “about” or “approximately” shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term “around”, “about” or “approximately” can be inferred if not expressly stated.
As used herein, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.
The term “layer”, as used herein, refers to a thin sheet or thin film.
The description will be made as to the embodiments of the present invention in conjunction with the accompanying drawings in
Referring now to
An adhesion promoting layer 120 is then formed on the first surface 112 of the substrate 110 with an adhesion promoting material, as shown in
In one embodiment, forming the adhesion promoting layer 120 includes the steps of coating the first surface 112 of the substrate 110 with the adhesion promoting material of organic silane, and baking the organic silane coated substrate 110 at a first temperature for a first period of time to form the adhesion promoting layer 120 on the substrate 110, as shown in
In another embodiment, forming the adhesion promoting layer 120 includes vapor coating the first surface 112 of the substrate 110 with the adhesion promoting material to form the adhesion promoting layer 120, as shown in
Further, a patterning process is performed on the adhesion promoting layer 120 to define a first area 111 and a second area 113 that surrounds the first area 111 in the substrate 110. In one embodiment, the patterning process includes transferring a mask 126 having a pattern corresponding to the first area 111 and the second area 113 over the adhesion promoting layer 120, and treating them with UV light 128 in an environment of air or oxygen, for example, an oven, such that the adhesion promoting layer 120 on the first area 111 is illuminated with the UV light and the adhesion promoting layer 120 on the second area 113 is masked from the UV light, as shown in
Next, a plastic layer 130 is formed on the first area 111 and the adhesion promoting layer 120 over the second area 113, as shown in
Additionally, an electronic device layer 140 is formed on the plastic layer 130 over the first area 111 in which the electronic device layer 140 defines a boundary 142 thereon, as shown in
Then, the electronic device layer 140 and the partial plastic layer 130 are separated from the substrate 110 by cutting through the plastic layer 130 along a contour that is equal to or larger than its boundary 142, but within the first area 111, as shown in
The method starts with forming an anti-peeling layer 220 on the flat top surface 212 of the substrate 210 with an anti-peeling material comprising a metal oxide, as shown in
Next step is to pattern the anti-peeling layer 220 to define a first area 211 and a second area 213 surrounding the first area 211 in the substrate 210. The step of patterning the anti-peeling layer 220, in one embodiment, includes defining a photo resistor 226 having a pattern corresponding to the first area 211 and the second area 213 over the anti-peeling layer 220; etching anti-peeling layer with etchant or plasma 228 on the first area 211, and removing the photo resistor 226 on the second area 213, as shown in
In one embodiment, the anti-peeling layer 220 in the first area 211 is patterned to expose completely the top surface 212 of the substrate 210, as shown in
In another embodiment, the anti-peeling layer 220 in the first area 211 is patterned to expose partially the top surface 212 of the substrate 210, as shown in
Further, a plastic layer 230 is formed on the first area 211 and the anti-peeling layer 220 over the second area 213 with PI, as shown in
On the plastic layer 230, an electronic device layer 240 is formed over the first area 211 in which the electronic device layer 240 defines a boundary 242 thereon, as shown in
Then, the electronic device layer 240 and the plastic layer 230 are separated from the substrate 210 by cutting through the plastic layer 230 along a contour that is equal to or larger than its boundary 242, but within the first area 211, as shown in
Referring now to
Next step is to coat a first PAA on the flat top surface 312 of the substrate 310 to form a first PI layer 320 so as to define a first area 311 on which the first PI layer 320 is formed and a second area 313 surrounding the first area 311 in the substrate 310, as shown in
Then, a second PAA containing organic silane is coated on the first PI layer 320 in the first area 311 of the substrate 310 and on the second area 313 of the substrate 310 to form a second PI layer 330 thereon, as shown in
On the second PI layer 330, an electronic device layer 340 is formed over the first area 311 in which the electronic device layer 340 defines a boundary 342 thereon, as shown in
The electronic device layer 340, the first PI layer 320 and the second PI layer 330 are then separated from the substrate 310 by cutting through the first and second PI layers 320 and 330 along a contour that is equal to or larger than its boundary 342, but within the first area 311, as shown in
In one aspect of the present invention, a method for manufacturing a flexible electronic device includes providing a substrate having a first surface and an opposite, second surface, forming a first layer on the first surface of the substrate to define a first area and a second area surrounding the first area in the substrate such that the first surface of the substrate is exposed at least partially in the first area and the first layer is in the second area, forming a second layer on the first area and the first layer over the second area such that an adhesion force between the second layer and the substrate in the first area is weaker than that between the second layer and the first layer in the second area, forming an electronic device layer on the second layer over the first area, where the electronic device layer defines a boundary thereon, and the boundary is projectively within the first area, and separating the electronic device layer and the second layer from the substrate by cutting through the second layer along a contour that is equal to or larger than the boundary of the electronic device layer, but within the first area.
In one embodiment, the step of forming the first layer comprises the step of forming an adhesion promoting layer of an adhesion promoting material on the first surface of the substrate, where the adhesion promoting material includes organic silane.
In one embodiment, the step of forming the adhesion promoting layer comprises the steps of coating the first surface of the substrate with the adhesion promoting material, and baking the adhesion promoting material coated substrate at a first temperature for a first period of time to form the adhesion promoting layer, where the first temperature is in a range of about 50-250° C., and the first period of time is in a range of about 5-10 min. In another embodiment, the step of forming the first layer comprises the step of vapor coating the first surface of the substrate with the adhesion promoting material to form the adhesion promoting layer.
In one embodiment, the step of forming the first layer further comprises the steps of forming a mask having a pattern corresponding to the first area and the second area over the adhesion promoting layer, treating the mask with UV light in an environment of air or oxygen such that the adhesion promoting layer on the first area is illuminated with the UV light and the adhesion promoting layer on the second area is masked from the UV light, and removing a portion of the adhesion promoting layer on the first area. In one embodiment, the treating step is performed in an oven at a second temperature for a second period of time, where the second temperature is in a range of about 25-300° C., and the second period of time is in a range of about 1-10 min.
In another embodiment, the step of forming the first layer comprises the step of forming an anti-peeling layer of an anti-peeling material comprising a metal oxide on the first surface of the substrate, where the anti-peeling material comprises indium tin oxide (ITO). In one embodiment, the step of forming the anti-peeling layer comprises the step of sputtering or vapor coating the anti-peeling material on the first surface of the substrate.
In one embodiment, the step of forming the first layer further comprises the steps of defining a photo resistor having a pattern corresponding to the first area and the second area over the anti-peeling layer, etching the anti-peeling layer with etchant or plasma on the first area so as to at least partially expose the substrate in the first area, and removing the photo resistor. In one embodiment, the first area is patterned such that the unexposed portion of the first area is about 0.1-30.0% of the first area, and the area of the second area is larger than the area of unexposed portion of the first area, where the unexposed portion of the first area is patterned to have a slit pattern, an island pattern, or a mesh pattern.
In one embodiment, the step of forming the second layer comprises the steps of coating the first area and the first layer over the second area with polyamic acid to form a coated polyamic acid layer thereon, and curing the coated polyamic acid layer to form the second layer of polyimide.
The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.
The embodiments were chosen and described in order to explain the principles of the invention and their practical application so as to activate others skilled in the art to utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein.
