Substrate manufacturing method and the substrate manufactured from it

Abstract

A method for manufacturing a substrate according to one embodiment of the present invention may include the steps of forming an elastomer to which a crosslinking agent has been added, curing the elastomer, placing a mask having a pattern formed thereon on the cured elastomer, and depositing a crosslinking agent on a portion of the elastomer exposed through the pattern.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a substrate and a substrate manufactured thereby, and more specifically, to a substrate having a simple process and excellent physical properties and a method for manufacturing the same. Background Technology

[0002] In the fabrication of displays, research on the production of substrates using flexible materials has recently been underway. This is intended to solve the problem of distortion occurring on the display screen due to material shrinkage when freely shaping the display or applying the display to folding or wearable devices.

[0003] To manufacture such displays, a stretchable substrate capable of controlling the Poisson ratio of the material is required. Stretchable substrates made using elastomers are produced through molding or 3D printing processes. When manufacturing substrates using the molding method, it is difficult to control the material thickness during the process of forming complex shapes and thin substrates required to control the Poisson ratio, and damage to the substrate may occur during the demolding process. When manufacturing substrates using the 3D printing process, material replacement is required, and production time may be prolonged.

[0004] Therefore, there is a need for a substrate manufacturing method capable of stably and rapidly producing a substrate having a complex structure for controlling the Poisson ratio, and for the substrate produced thereby. The problem to be solved

[0005] One embodiment of the present invention provides a method for manufacturing a substrate that reduces process time and production costs and has excellent mechanical properties, and a substrate manufactured thereby.

[0006] The problems that the present invention aims to solve are not limited to those mentioned above, and other problems not mentioned herein will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0007] A method for manufacturing a substrate according to one embodiment of the present invention may include the steps of: forming an elastomer to which a crosslinking agent has been added; curing the elastomer; placing a mask having a pattern formed thereon on the cured elastomer; and depositing a crosslinking agent on a portion of the elastomer exposed through the pattern.

[0008] The step of depositing the crosslinking agent may include: placing the elastomer and the crosslinking agent, on which the mask is placed, in an oven; heating the oven to form crosslinking agent vapor; and depositing the crosslinking agent in a vapor state on the portion exposed through the pattern of the elastomer.

[0009] The above pattern may be an Ogzetic structure shape.

[0010] The above elastomer can be formed from PDMS material.

[0011] A substrate manufactured by a method for manufacturing a substrate according to one embodiment of the present invention comprises a base portion having a first concentration of a crosslinking agent; and a pattern portion having a second concentration of a crosslinking agent; wherein the second concentration may be greater than the first concentration.

[0012] The above pattern part may be characterized by having a negative Poisson ratio. Effects of the invention

[0013] According to one embodiment of the present invention, the shape of the substrate can be determined by changing the pattern mask, making design changes easy, and the process time can be reduced through the crosslinking agent vapor deposition method.

[0014] The various beneficial advantages and effects of the present invention are not limited to those described above and may be more easily understood in the process of explaining specific embodiments of the invention. Brief explanation of the drawing

[0015] FIG. 1 is a drawing illustrating a method for manufacturing a substrate according to one embodiment of the present invention. FIG. 2 is a diagram illustrating the step of depositing a crosslinking agent in a substrate manufacturing method according to one embodiment of the present invention. FIG. 3 is a drawing illustrating a substrate manufactured by a substrate manufacturing method according to one embodiment of the present invention. FIG. 4 is a drawing illustrating a pattern mask according to one embodiment of the present invention. FIG. 5 is a diagram illustrating the deposition of a crosslinking agent according to one embodiment of the present invention. FIG. 6 is a cross-sectional view of a substrate according to one embodiment of the present invention. Specific details for implementing the invention

[0016] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0017] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0018] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0019] Furthermore, throughout the specification, when the term "connected" is used, it does not mean only that two or more components are directly connected, but may also mean that two or more components are indirectly connected through other components, that they are connected not only physically but also electrically, or that they are a single unit although referred to by different names depending on their location or function.

[0020] Furthermore, when described as being formed or placed on the “top or bottom” of each component, “top or bottom” includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as “top or bottom,” it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0021] Hereinafter, an embodiment of a substrate manufacturing method according to the present invention and a substrate manufactured thereby will be described in detail with reference to the accompanying drawings. In describing with reference to the accompanying drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0022] Conventional displays and the substrates used with them lack flexibility, which limits their application fields. However, as displays are integrated into various applications, it has become important to make both the displays and substrates flexible.

[0023] Flexible substrates can be applied to wearable devices or foldable devices. When a flexible substrate is applied to a wearable device, the substrate can be stretched or contracted to fit the wearer's body. In addition, in the case of a foldable device, the display placed at the hinge portion can be folded and at least partially stretched, and can return to its original state when the fold is released.

[0024] In this way, flexible displays and substrates can be fabricated to significantly increase the utility of the display. However, the manufacturing method for flexible substrates is not easy. The material generally has a positive Poisson ratio. The Poisson ratio corresponds to the ratio of transverse strain to longitudinal strain when force is applied to the material.

[0025] When a material with a positive Poisson ratio is stretched along its length, it increases in length by at least some extent, but it may decrease in width. Similarly, when the material is contracted along its length, it may increase in width.

[0026] Due to the material properties having a positive Poisson ratio, image distortion may occur when the flexible substrate is deformed, such as by folding. To prevent this, it is necessary to fabricate a flexible substrate that exhibits behavior with a negative Poisson ratio.

[0027] In the case of a material with a negative Poisson ratio, if the material is stretched in the longitudinal direction, its length also increases in the width direction. Similarly, if the material is contracted in the longitudinal direction, its length in the width direction also decreases. A material with a negative Poisson ratio can be realized by forming the internal structure of the material in a specific way. Alternatively, the material itself may have a positive Poisson ratio, but if the material is formed into a specific shape, it may exhibit behavior with a negative Poisson ratio macroscopically.

[0028] An auxetic structure is a representative structure that possesses a negative Poisson ratio. When an auxetic structure is applied, the material itself has a positive Poisson ratio, but the entire structure exhibits behavior with a negative Poisson ratio.

[0029] When an aggetic structure is formed on a substrate, the substrate may also exhibit characteristics similar to having a negative Poisson ratio. However, the aggetic structure itself is a complex shape, and the process of forming a fine aggetic structure on a substrate may not be easy.

[0030] Conventional substrates have been manufactured using molds, direct ink writing (DIW), or 3D printing. When manufacturing substrates containing auxetic structures using molds or 3D printing, forming a mold corresponding to the fine auxetic structure can be difficult and costly. Additionally, the fine structure may be damaged during the process of demolding the substrate from the mold. When utilizing the 3D printing process, the auxetic structure may be formed from a mixture with a different ratio than the substrate, requiring material replacement and potentially prolonging the processing time.

[0031] The present invention provides a substrate manufacturing method that can easily form a fine aggetic structure on the surface of a substrate and reduce the time required to manufacture the substrate, and a substrate manufactured thereby.

[0032] FIG. 1 is a drawing illustrating a method for manufacturing a substrate according to one embodiment of the present invention, and FIG. 2 is a drawing illustrating a step of depositing a crosslinking agent in a method for manufacturing a substrate according to one embodiment of the present invention.

[0033] Referring to FIG. 1, a method for manufacturing a substrate according to one embodiment of the present invention may include the steps of forming an elastomer with a crosslinking agent added (S1), curing the elastomer (S2), placing a mask with a pattern formed on the cured elastomer (S3), and depositing a crosslinking agent on a portion exposed through the pattern of the elastomer (S4).

[0034] First, an elastomer (12) is formed by adding a crosslinking agent (30). The elastomer can be manufactured by mixing the crosslinking agent (30) and a base at a specific concentration. The elastomer (12) corresponds to the base portion (12) of the substrate (10) to be described later. In this case, the concentration of the crosslinking agent (30) can be formed at a low level. The base may be an organosilicon chemical (PDMS) material. Since organosilicon chemicals possess viscosity and elasticity, they can be utilized in the production of deformable substrates.

[0035] For example, the base and the crosslinking agent (30) can be mixed in a mass ratio of 30 to 1, and Sylgard 184 can be used as the crosslinking agent. A mass ratio of 30 to 1 is an example, and it is also possible to mix the base and the crosslinking agent in a mass ratio of 40 to 1. The concentration of the crosslinking agent can be applied as long as it is at a level that ensures sufficient elasticity.

[0036] The base can be formed from silicon, for example. An elastomer (12) to form the substrate (10) can be formed by mixing silicon and a crosslinking agent.

[0037] Afterward, the elastomer (12) may undergo a curing process. Before the elastomer (12) is cured, a degassing process may be performed. Since certain dissolved gases may be included in the mixing process of the crosslinking agent (30) and the organosilicon chemical, a process to remove such dissolved gases may be necessary.

[0038] The degassing process can be performed in a vacuum. After the degassing process, a process of curing the elastomer (12) can be performed. Since the crosslinking agent (30) is mixed into the elastomer (12), the elastomer (12) can be cured through the curing process.

[0039] Curing can be performed with the elastomer (12) placed in a mold. The elastomer (12) can be cured after being placed in a mold corresponding to the specifications of the substrate (10) being manufactured. The elastomer (12) can be cured by being exposed to a specific temperature for a specific time in an oven (40). For example, the elastomer (12) can be cured by being exposed to a temperature of 70 degrees for 1 hour in an oven (40).

[0040] After the elastomer (12) is cured, a step of placing a pattern mask (20) on the elastomer (12) may be performed. The pattern mask (20) may be formed in the shape of a thin film, but at least a portion may be cut along the shape of the pattern (22). The elastomer (12) is covered by the pattern mask (20), but a portion corresponding to the cut pattern (22) area may be exposed. There are no limitations on the shape of the pattern (22).

[0041] For example, the pattern (22) may correspond to an aggetic shape. In this case, one side of the elastomer (12) may have a portion corresponding to the pattern (22) formed in an aggetic shape exposed.

[0042] Subsequently, a step of depositing a crosslinking agent (30) on the elastomer (12) may be performed. The elastomer (12) with the pattern mask (20) placed thereon and the crosslinking agent (30) are placed in an oven (40), and crosslinking agent (30) vapor is formed so that the crosslinking agent (30) can be deposited on the exposed portion through the pattern (22) of the elastomer (10). The crosslinking agent can be deposited on one side of the elastomer (12) so as to correspond to the shape of the pattern.

[0043] The step (S4) of depositing a crosslinking agent on the exposed portion through the pattern of the elastomer may include the step (S41) of placing the elastomer with the mask and the crosslinking agent in an oven, the step (S42) of heating the oven to form crosslinking agent vapor, and the step (S43) of depositing the crosslinking agent in a vapor state on the exposed portion through the pattern of the elastomer.

[0044] An elastomer (12) with a pattern mask (20) placed thereon and a liquid crosslinking agent (30) can be placed inside a sealed oven (40). Subsequently, the oven (40) is heated to a specific temperature so that the liquid crosslinking agent (30) undergoes a phase change to a vapor state. The vapor crosslinking agent (30) can be deposited on an exposed portion of the elastomer (12) corresponding to the pattern (22). The deposited portion corresponds to a portion of the elastomer (12) where the density of the crosslinking agent (30) is different from that of other portions of the elastomer (12).

[0045] The shape of the pattern on which the crosslinking agent (30) is deposited can be determined through the pattern mask (20). Therefore, different shapes can be easily formed during the fabrication of the substrate (10). The shape of the crosslinking agent (30) to be deposited can be changed by changing the pattern (22) formed on the pattern mask (20).

[0046] In the case of manufacturing methods using molds, a mold corresponding to a new substrate shape must be produced, which has the disadvantage of significantly increasing production costs when design changes occur. However, in the case of the substrate manufacturing method according to the present invention, design changes can be accommodated by producing only a new pattern mask.

[0047] The elastomer (12) can be placed on a Teflon film placed inside the oven (40). The Teflon film does not deform at high temperatures and can prevent the heated elastomer (12) from adhering to the surface of the oven (40).

[0048] Since the crosslinking agent (30) in a vapor state is deposited simultaneously over the entire area of ​​the pattern (22), the process time can be significantly shortened. In the case of the DIW method or 3D printing, there is a problem that the production time is long because the material is injected one by one to correspond to the shape of the pattern, but in the case of the present invention, the crosslinking agent (30) is deposited simultaneously over the entire area of ​​the pattern (22), so the time can be shortened.

[0049] For example, the oven (40) can heat the interior to 120 degrees. Inside the oven (40) heated to 120 degrees, the crosslinking agent (30) is deposited and the elastomer (12) can be further cured.

[0050] A high concentration of crosslinking agent (30) may be utilized for the deposited crosslinking agent (30). If the concentration of the crosslinking agent (30) mixed in the step of forming the elastomer (12) is called the first concentration, and the concentration of the crosslinking agent (30) used in the step of depositing on the elastomer (12) is called the second concentration, the second concentration may be greater than the first concentration.

[0051] FIG. 3 is a drawing showing a substrate manufactured by a substrate manufacturing method according to one embodiment of the present invention, and FIG. 4 is a drawing showing a pattern mask according to one embodiment of the present invention.

[0052] Referring to FIG. 3, a substrate (10) can be seen having a crosslinking agent (30) pattern (22) formed on one side that corresponds to the pattern (22) of the pattern mask (20). The pattern (22) of the pattern mask (20) shown in FIG. 4 corresponds to an ogetic shape.

[0053] In the case of a foldable or wearable device, it is necessary to minimize the deformation that occurs when the substrate (10) is bent. For example, when the device is bent and pulled in a first direction, contraction may occur in a second direction orthogonal to the first direction. This may be the case where the material has a positive Poisson ratio. If the material has a positive Poisson ratio, when the material is stretched in one direction, it may contract in the other direction to compensate for this.

[0054] When a substrate (10) is manufactured using a material having a positive Poisson ratio, the quality of the device may deteriorate, such as when deformation occurs, such as when the substrate (10) bends, or when distortion occurs on the screen of a display, etc.

[0055] Since most materials have a positive Poisson ratio, the material can be formed into an augmented structure to prevent the above phenomenon. Although the material itself has a positive Poisson ratio, the structure itself can behave macroscopically as if it has a negative Poisson ratio.

[0056] The pattern (22) shown in FIG. 4 corresponds to an ogetic structure. When the structure of the shape corresponding to the pattern (22) in FIG. 4 is pulled up and down relative to the drawing, it also expands to the left and right, and when compressed up and down, it can also be compressed to the left and right.

[0057] The ogzetic structure illustrated in FIG. 4 includes an inclined portion forming a predetermined angle, and the inclined portion and the left and right boundaries can be connected. The internal space can be formed to be empty.

[0058] When the auxetic structure is pulled up and down, the angle formed by the inclined portion can increase. That is, the inclined portion can unfold into a shape close to a straight line. In this case, the left and right boundaries may be pushed outward and exhibit behavior of expanding to the left and right.

[0059] When the angular structure is compressed vertically, the inclined portion may be pushed into the inner empty space. That is, the angle formed by the inclined portion may be reduced and folded. Accordingly, the left and right boundaries may also be pulled inward in response and exhibit behavior of contracting to the left and right.

[0060] A substrate (10) manufactured by a substrate manufacturing method according to one embodiment of the present invention comprises a base portion (12) and a pattern portion (14). The base portion (12) is manufactured by mixing a crosslinking agent (30) and a base material and then curing. The pattern portion (14) is formed by depositing a crosslinking agent (30).

[0061] The pattern portion (14) and the base portion (12) can be formed with different concentrations of crosslinking agent (30). The base portion (12) has a first concentration of crosslinking agent (30), and the pattern portion (14) has a second concentration of crosslinking agent (30). In this case, the second concentration may be greater than the first concentration. Since the concentration of crosslinking agent (30) in the pattern portion (14) corresponds to a high concentration, the elasticity of the pattern portion (14) may be greater than that of the base portion (12).

[0062] When the pattern portion (14) is formed in an aggetic shape, the substrate (10) may behave similarly to having a negative Poisson ratio. When the aggetic-shaped pattern portion (14) formed on one surface of the substrate (10) causes contraction or compression of the substrate (10) in a first direction, it may cause contraction or compression of the substrate (10) in a second direction intersecting therefrom, thereby preventing a decrease in the quality of the device.

[0063] In the case of substrates produced by conventional processes, even when using the same material with controlled physical properties, the substrate is manufactured in a form where the pattern portion is bonded to the base portion. In this case, an interface is formed between the bonded structure and the base portion, and there is a problem in that mechanical durability is significantly affected by the adhesion force at the interface.

[0064] In the case of the substrate (10) according to the present invention, the density of the crosslinking agent (30) of the pattern portion (14) is partially increased to exhibit the behavior of a composite material, and since no separate interface is formed, a reduction in mechanical durability that may occur at the interface does not occur. That is, uniform physical properties and durability can be provided throughout the entire substrate (10).

[0065] FIG. 5 is a drawing illustrating the deposition of a crosslinking agent according to one embodiment of the present invention, and FIG. 6 is a cross-sectional view of a substrate according to one embodiment of the present invention.

[0066] Referring to FIG. 5, the base portion (12), which corresponds to an elastomer (12) to which a crosslinking agent (30) has been added, can be placed inside an oven (40) with a pattern mask (20) placed on top. The pattern mask (20) is cut into the shape of a pattern (22), so that an area corresponding to the shape of the pattern (22) of the base portion (12) is exposed. A high concentration of the crosslinking agent (30) is placed together inside the oven (40).

[0067] The oven (30) is heated to a preset temperature for a preset time. The crosslinking agent (30) undergoes a phase change to a vapor state, and the crosslinking agent (30) in the vapor state can be deposited on the base portion (12) exposed through the pattern (22). Through this, deposition of the entire area of ​​the pattern (22) can be achieved simultaneously.

[0068] After the deposition is completed, the pattern mask (20) is removed, and a pattern portion (14) can be formed on one side of the base portion (12) as shown in FIG. 6. The pattern portion (14) is formed in the same shape as the pattern (22) of the pattern mask (20).

[0069] The pattern portion (14) corresponds to a part of the base portion (12), and corresponds to a portion formed with different crosslinking agent (30) densities by depositing a crosslinking agent (30) on at least a part of the base portion (12). The pattern portion (14) is exposed through one side of the base portion (12) but is formed inside the base portion (12). Since the density of the crosslinking agent (30) is set differently through deposition, an interface is not formed between the base portion (12) and the pattern portion (14), and continuous physical properties of the substrate (10) can be realized.

[0070] By forming a pattern portion (14) corresponding to the shape of the pattern (22) through a pattern mask (20), the design for changing the shape of the pattern (22) is easy, and costs can be reduced. In addition, since deposition is performed on the entire area of ​​the pattern (22) at once, the process time can be significantly shortened. Furthermore, there is an advantage that complex shapes of patterns (22), such as an auxetic structure, can be easily formed.

[0071] Although the present invention has been described above with reference to specific embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as set forth in the following claims. Explanation of the symbols

[0072] 10 : Substrate 12 : Base part 14 : Pattern section 20 : Pattern Mask 22 : Pattern 30: Crosslinking agent 40: Oven

Claims

Claim 1 A method for manufacturing a substrate comprising: a step of forming an elastomer to which a crosslinking agent is added; a step of curing the elastomer; a step of placing a mask having a pattern formed thereon on the cured elastomer; and a step of depositing a crosslinking agent on a portion of the elastomer exposed through the pattern; wherein the elastomer comprises a base portion having a first concentration of the crosslinking agent and a pattern portion having a second concentration of the crosslinking agent, and wherein the second concentration is greater than the first concentration. Claim 2 A method for manufacturing a substrate according to claim 1, comprising: a step of depositing the crosslinking agent; a step of placing the elastomer on which the mask is placed and the crosslinking agent in an oven; a step of heating the oven to form crosslinking agent vapor; and a step of depositing the crosslinking agent in a vapor state on a portion exposed through the pattern of the elastomer. Claim 3 In paragraph 2, the above pattern is a method for manufacturing a substrate having an aggetic structure shape. Claim 4 delete Claim 5 A method for manufacturing a substrate according to claim 1, wherein the pattern portion has a negative Poisson ratio.

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