JP-7856004-B2 - A laminate of an inorganic substrate/polymer film layer with a protective film, a stack of the laminate, a method for storing the laminate, and a method for transporting the laminate.

JP7856004B2JP 7856004 B2JP7856004 B2JP 7856004B2JP-7856004-B2

Inventors

▲徳▼田桂也
前田郷司
奧山哲雄
渡辺直樹

Assignees

東洋紡株式会社

Dates

Publication Date: 20260511
Application Date: 20220222
Priority Date: 20210304

Claims (9)

The material comprises an inorganic substrate, a polymer film layer, and a first protective film in this order, wherein the surface roughness Ra of the inorganic substrate on the side opposite to the polymer film layer is 0.02 μm to 1.2 μm. The polymer film layer is a polyimide film, The first laminate is characterized in that the laminate of the inorganic substrate/polymer film layer is formed into a continuous sheet by the first protective film .
The first laminate according to claim 1, characterized in that the coefficient of dynamic friction between the surface of the first protective film opposite to the polymer film layer and the surface of the inorganic substrate opposite to the polymer film layer is in the range of 0.02 to 0.25.
The second protective film, an inorganic substrate, a polymer film layer, and a first protective film are included in this order, and the surface roughness Ra of the side of the second protective film opposite to the inorganic substrate is 0.02 μm to 1.2 μm. The polymer film layer is a polyimide film, The first protective film forms the laminate of the inorganic substrate/polymer film layer into a continuous sheet, and the second protective film is separated for each laminate of the inorganic substrate/polymer film layer, or The second protective film forms the laminate of the inorganic substrate/polymer film layer into a continuous sheet, and the first protective film is separated for each laminate of the inorganic substrate/polymer film layer. A second laminate characterized by the above.
The second laminate according to claim 3, characterized in that the coefficient of dynamic friction between the surface of the first protective film opposite to the polymer film layer and the surface of the second protective film opposite to the inorganic substrate is in the range of 0.02 to 0.25.
The second laminate according to claim 3 or 4, characterized in that the coefficient of dynamic friction between the surfaces of the second protective film opposite to the inorganic substrate is in the range of 0.02 to 0.25.
The laminate according to any one of claims 1 to 5, characterized in that the diameter of the circumscribed circle of the inorganic substrate is 310 mm or more.
A laminated stack characterized by stacking four or more laminates according to any one of claims 1 to 6, all oriented in the same direction in the layering direction.
A method for storing a laminate, characterized by storing it in the form of a laminate stack described in claim 7.
A method for transporting a laminate, characterized by transporting it in the form of a laminate stack described in claim 7.

Description

This invention relates to the form, storage method, and transportation method of a laminate consisting of an inorganic substrate and a polymer film layer. The use of polymer films such as polyimide is being considered as substrate materials for manufacturing flexible electronic devices. Since such polymer films are manufactured in long rolls, a roll-to-roll manufacturing line is generally considered ideal for the production of flexible devices. On the other hand, many conventional electronic devices, such as display devices, sensor arrays, touchscreens, and printed circuit boards, use rigid substrates such as glass substrates, semiconductor wafers, or glass fiber reinforced epoxy substrates, and manufacturing equipment is also configured on the premise that such rigid substrates are used. Against this backdrop, a method for manufacturing flexible electronic devices using existing manufacturing equipment is known, which involves using a rigid inorganic substrate such as a glass substrate as a temporary support, handling the temporary support with a polymer film temporarily attached, processing the electronic device on the polymer film, and then peeling the polymer film with the electronic device formed on it from the temporary support. (Patent Document 1) Furthermore, a method for manufacturing flexible electronic devices using existing manufacturing equipment is known, which involves using a rigid substrate such as a glass substrate as a temporary support, applying a polymer solution or polymer precursor solution to the temporary support, drying it to form a precursor film, and then causing a chemical reaction to convert the precursor into a polymer film, thereby obtaining a laminate of the temporary support and the polymer film. After similarly forming an electronic device on the polymer film, the laminate is peeled off to manufacture a flexible electronic device. (Patent Document 2) Incidentally, in the process of forming a desired functional element on a laminate formed by bonding a polymer film and an inorganic support, the laminate is often exposed to high temperatures. For example, the formation of functional elements such as polysilicon and oxide semiconductors requires processes in the temperature range of approximately 200°C to 600°C. Furthermore, in the fabrication of hydrogenated amorphous silicon thin films, temperatures of approximately 200°C to 300°C may be applied to the film, and heating to approximately 450°C to 600°C may be necessary to heat and dehydrogenate amorphous silicon to produce low-temperature polysilicon. Therefore, the polymer film constituting the laminate needs to have heat resistance, but in reality, there are only a limited number of polymer films that can withstand such high temperatures, and polyimide is often chosen. In other words, both methods involve a laminate in which a rigid temporary support and a polymer film layer, which is ultimately peeled off and becomes the substrate for a flexible electronic device, are superimposed. Since such a laminate can be handled as a rigid plate material, it can be handled in the same way as a glass substrate using equipment for manufacturing liquid crystal displays, plasma displays, or organic EL displays that use conventional glass substrates. Patent No. 5152104Patent No. 5699606 Figure 1(a) shows an example of a process for a first laminate, in which a polymer solution or polymer precursor solution 11 is coated onto an inorganic substrate 12 to create an inorganic substrate 12/polymer film layer 15 laminate, and then processed into a continuous sheet shape by attaching a first protective film 14 to the surface of the polymer film layer 15. Figure 1(b) shows an example of a process for a second laminate, in which a polymer solution or polymer precursor solution 11 is coated onto an inorganic substrate 12 to create an inorganic substrate 12/polymer film layer 15 laminate, and then processed into a continuous sheet shape by attaching a first protective film 14 and a second protective film 16 to the surface of the polymer film layer 15.Figure 2 is a schematic diagram showing the cross-sectional structure of a stack of four first laminates (first protective film 23/polymer film layer 22/inorganic substrate 21) stacked on top of each other. The laminates form a continuous sheet and are folded one by one.Figure 3 is a schematic diagram showing the cross-sectional structure of a stack of four second laminates (first protective film 33 / polymer film layer 31 / inorganic substrate 32 / second protective film 34) stacked on top of each other. The protective film-containing laminates are in the form of continuous sheets and are folded for each laminate.Figure 4 is a schematic diagram showing the cross-sectional structure of a stack formed by stacking four second laminates (first protective film 43 / polymer film layer 42 / inorganic substrate 41 / second protective film 44).Figure 5 is a schematic diagram illustrating the silane coupling ag