Structure, structure module, and method for manufacturing a structure

Abstract

The present application provides a structure capable of easily imparting a hydrophobic function while maintaining the optical properties of a sensor device, and easily replacing the sensor device. A structure 100 mounted to the outer surface of a sensor device 400 having a curved surface shape on the outer surface includes a substrate 101, and a fine concavo-convex structure layer provided on both surfaces of the substrate 101, the fine concavo-convex structure layer having a first fine concavo-convex structure layer 102 on the side of the sensor device 400, and a second fine concavo-convex structure layer 103 on the side opposite to the side of the sensor device 400, the second fine concavo-convex structure layer 103 having hydrophobicity, the structure 100 having a three-dimensional shape following the curved surface shape of the outer surface.

Description

Technical Field

[0001] This invention relates to a structure, a structure module, and a method for manufacturing the structure. Background Technology

[0002] Sensor devices used outdoors include in-vehicle camera modules for rear-view monitors or external sensing applications, as well as camera modules for surveillance cameras. The external lenses of the sensors used in such devices typically have a three-dimensional shape to achieve light-gathering functionality. To avoid deterioration in visibility or image quality (color unevenness, ghosting, etc.) due to reflection of external light, anti-reflective treatment is usually applied to the light-incident surface of the lens substrate. As an anti-reflective treatment, methods are known to reduce reflectivity by providing multiple layers of anti-reflective films or forming a fine, uneven structure on the light-incident surface.

[0003] The aforementioned lenses are exposed to external environments containing dust or water droplets when used outdoors, thus requiring high durability. To protect the lenses from the effects of dust or water droplets in the external environment, a method of applying a hydrophobic coating to the outermost surface of the lens is known.

[0004] For example, Patent Document 1 discloses a method for further applying a hydrophobic coating to the surface of a lens to which an anti-reflective coating has been applied. However, when the hydrophobic coating is applied to a microscopically flat surface, there is a problem such as a contact angle as small as about 100 degrees and insufficient hydrophobicity. By coating a nanoporous membrane, a superhydrophobic state can be achieved, but if exposed to UV (Ultra-Violet) light or a scratch resistance test, the hydrophobic coating will be removed, resulting in impaired hydrophobicity.

[0005] Patent Document 2 discloses a technique for reducing reflection by directly forming a concave-convex structure below the wavelength of light detected by a sensor device on the lens surface. This reduces the reflectivity of the curved lens surface. Furthermore, Patent Document 2 also discloses achieving hydrophobicity by adding a hydrophobic material to the lens forming material. This suppresses water droplet or dust adhesion. However, in this method, once the hydrophobicity is lost due to the external environment, it is difficult to restore the lens's performance.

[0006] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2003-161804 Patent Document 2: Japanese Patent No. 5777682 Summary of the Invention

[0007] Technical issues The prior art does not adequately consider providing a structure that can easily impart hydrophobic properties while maintaining the optical characteristics of the sensor device, and is easily replaceable by being mounted to the sensor device as a separate component.

[0008] The purpose of this invention is to provide a structure that can easily be given hydrophobic properties while maintaining the optical characteristics of a sensor device and is easily replaceable relative to the sensor device, a structure module formed by mounting the structure to the sensor device, and a method for manufacturing the structure.

[0009] Technical solution That is, the main structure of the present invention is as follows.

[0010] (1) A structure mounted to the outer surface of a sensor device having a curved shape, the structure comprising: a substrate; and a micro-protrusion structure layer disposed on both sides of the substrate, the micro-protrusion structure layer having: a first micro-protrusion structure layer located on the sensor device side; and a second micro-protrusion structure layer located on the side opposite to the sensor device side, the second micro-protrusion structure layer being hydrophobic, the structure having a three-dimensional shape following the curved shape of the outer surface.

[0011] (2) According to the structure described in (1) above, wherein the first micro-unraveling structure layer has a pitch below the wavelength of the light detected by the sensor device.

[0012] (3) The structure according to (1) or (2) above, wherein the structure is configured to be detachable from the outer surface.

[0013] (4) The structure according to any one of (1) to (3) above, wherein the substrate is thermoplastic.

[0014] (5) The structure according to any one of (1) to (4) above has a total light transmittance of 98% or more.

[0015] (6) The structure according to any one of (1) to (5) above, wherein the water droplet contact angle of the second micro-uneven structure layer is 130 degrees or more.

[0016] (7) A structural module comprising: the sensor device; and a structure as described in any one of (1) to (6) above, which is mounted on the outer surface of the sensor device.

[0017] (8) The structural module according to (7) above, wherein the radius of curvature of the outer surface is more than 5 mm and less than 500 mm.

[0018] (9) The structural module according to (7) or (8) above, wherein the sensor device includes a vehicle-mounted camera module.

[0019] The structural module according to any one of (7) to (9) above, wherein the sensor device includes a camera module for a surveillance camera.

[0020] A method for manufacturing a structure, as described in any one of (1) to (6) above, comprising: a first pressing step, wherein a substrate and a first retaining film having a micro-uneven structure on their surface are used to clamp the first UV-curable resin and press it together in such a way that the micro-uneven structure of the first retaining film contacts the first UV-curable resin; a first curing step, wherein the clamped first UV-curable resin is cured by irradiating it with UV light, thereby forming a first micro-uneven structure layer on one side of the substrate; a first peeling step, wherein the first retaining film is peeled off from the first micro-uneven structure layer; and a second pressing step, wherein the substrate and a first retaining film having a micro-uneven structure on their surface are used to clamp the first UV-curable resin and press it together; a first pressing step, wherein the substrate and a first retaining film having a micro-uneven structure on their surface are used to clamp the first UV-curable resin and press it together in such a way that the micro-uneven structure of the first retaining film contacts the first UV-curable resin; a first curing step, wherein the first UV-curable resin is cured by irradiating it with UV light, thereby forming a first micro-uneven structure layer on one side of the substrate; a first peeling step, wherein the first retaining film is peeled off from the first micro-uneven structure layer; and a second pressing step, wherein the substrate and a first retaining film having a micro-uneven structure on their surface are used to clamp the first UV-curable resin and press it together in a way that the micro-uneven structure of the first retaining film contacts the first UV-curable resin; a first pressing step, wherein the first UV-curable resin is cured by irradiating it with UV light, thereby forming a first micro-uneven structure layer on one side of the substrate; a first peeling step, wherein the first retaining film is peeled off from the first micro-uneven structure layer; and a second pressing step, wherein the first UV-curable resin is cured by irradiating it with UV light, thereby forming a first micro-uneven structure layer on one side of the substrate; A second retaining film having a micro-uneven structure is used to clamp and press the second UV-curable resin in such a way that the micro-uneven structure of the second retaining film and the other side of the substrate are in contact with the second UV-curable resin; a second curing step is performed to cure the clamped second UV-curable resin by irradiating it with UV light, thereby forming a second micro-uneven structure layer on the other side of the substrate; a second peeling step is performed to peel the second retaining film from the second micro-uneven structure layer; and a molding step is performed to mold the substrate having micro-uneven structures formed on both sides into a three-dimensional shape that follows the curved shape of the outer surface of the sensor device to be mounted by applying vacuum heating treatment.

[0021] Technical effect According to the present invention, a structure that can easily be given hydrophobic properties while maintaining the optical characteristics of a sensor device and is easily replaceable relative to the sensor device, a structure module formed by mounting the structure to the sensor device, and a method for manufacturing the structure are provided. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view illustrating a structure according to one embodiment of the present invention.

[0023] Figure 2A This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0024] Figure 2B This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0025] Figure 2C This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0026] Figure 2D This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0027] Figure 2E This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0028] Figure 2F This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0029] Figure 2G This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0030] Figure 2H This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0031] Figure 2I This is a schematic diagram illustrating a step in a method for manufacturing a structure according to an embodiment of the present invention.

[0032] Figure 3 This is a schematic cross-sectional view showing the vicinity of the lens of a structural module obtained by mounting a structure according to one embodiment of the present invention onto a sensor device.

[0033] Symbol Explanation 100: Structure 101: Substrate 102: First micro-textured structure layer 103: Second micro-textured structure layer 1021: Base of the first micro-uneven structure layer 1031: Base of the second micro-uneven structure layer 151: First UV-curable resin 152: Second UV-curable resin 160: Roller laminator 201: First retaining membrane 202: Second retaining membrane 250: First intermediate structure 260: Second intermediate structure 300: Lens for forming 400: Sensor Equipment 401: Lens 500: Structure Module Detailed Implementation

[0034] Hereinafter, a structure of one embodiment of the present invention (hereinafter, sometimes referred to as "the structure of this embodiment") will be described.

[0035] (Structure) like Figure 1 As shown, the structure 100 of this embodiment has a substrate 101 and micro-uneven structure layers disposed on both sides of the substrate 101. The micro-uneven structure layers have a first micro-uneven structure layer 102 and a second micro-uneven structure layer 103. The first micro-uneven structure layer 102 is located on the sensor device 400 side, which will be described later. The second micro-uneven structure layer 103 is located on the side opposite to the sensor device 400 side. The second micro-uneven structure layer 103 is hydrophobic. In this specification, "hydrophobic" means, for example, a water droplet contact angle of 130 degrees or more. The structure 100 is further characterized by having a three-dimensional shape that follows the curved shape of the outer surface of the sensor device 400.

[0036] In this specification, the water droplet contact angle is determined based on JISR 3257 "Test method for wettability of substrate glass surfaces" using the θ / 2 method. Specifically, the angle between the boundary line between the water droplet and the object to which the water is being dropped is measured using an optical reading device, and the straight line connecting one of the points of tangency between the water droplet and the object to which the water is being dropped to the vertex of the water droplet. The obtained value is then multiplied by 2.

[0037] In this specification, "a three-dimensional shape that follows the curved shape of the outer surface" includes, for example, a three-dimensional shape that is the same as or corresponds to the curved shape of the outer surface of the sensor device 400. For example, "a three-dimensional shape that follows the curved shape of the outer surface" includes a three-dimensional shape having a radius of curvature that is the same as or approximately the same as the radius of curvature of the outer surface of the sensor device 400. "Approximate to the radius of curvature of the outer surface of the sensor device 400" means, for example, relative to the radius of curvature of the outer surface, preferably containing an error of 10% or less, more preferably containing an error of 5% or less, and even more preferably containing an error of 1% or less.

[0038] In this specification, the wavelength of the light detected by the sensor device 400 is in the visible light band (approximately 360nm~830nm), and the total light transmittance refers to the transmittance of light in this band.

[0039] In this specification, "transparent" means that light with a wavelength in the visible light band (approximately 360nm to 830nm) has high transmittance, for example, that the transmittance of such light is 70% or more.

[0040] <Substrate> Typically, the substrate 101 used in this embodiment is preferably thermoplastic. There are no particular limitations on the structure of the substrate 101 used in this embodiment; it can be appropriately selected depending on the purpose, and examples include polycarbonate films. The substrate 101 is preferably transparent, and its thickness is preferably 30 μm or more and 200 μm or less. Furthermore, the surface of the substrate 101 may be coated.

[0041] <First Micro-Fine Textured Layer> In this embodiment, the first micro-textured uneven structure layer 102 is formed with a micro-textured uneven pattern (protrusions in the thickness direction of the micro-textured uneven structure and recesses in the thickness direction of the micro-textured uneven structure). This improves anti-reflective properties. The protrusions and recesses can be arranged periodically (e.g., in an alternating grid pattern or a rectangular grid pattern) or randomly. Furthermore, the shapes of the protrusions and recesses are not particularly limited and can be projectile-shaped, conical, columnar, or needle-shaped, etc. It should be noted that the shape of the recess refers to the shape formed by the inner wall of the recess.

[0042] The average period (pitch) of the uneven pattern of the first micro-uneven structure layer 102 is preferably below the wavelength of the light detected by the sensor device 400, more preferably below the visible light wavelength (e.g., below 830 nm), further preferably below 350 nm, and most preferably below 280 nm. The average period (pitch) of the uneven pattern of the first micro-uneven structure layer 102 is more preferably 100 nm or more, and further preferably 150 nm or more. By adopting a so-called moth-eye structure in which the pitch of the uneven pattern of the first micro-uneven structure layer 102 is set below the visible light wavelength, it is possible to further improve the anti-reflection performance.

[0043] The average period of the embossed pattern is the arithmetic mean of the distances between adjacent convex parts and the distances between adjacent concave parts. It should be noted that the embossed pattern can be observed using, for example, a scanning electron microscope (SEM) or a cross-sectional transmission electron microscope (TEM). One method for calculating the average period is to collect multiple combinations of adjacent convex parts and combinations of adjacent concave parts, measure the distances between the convex parts and the distances between the concave parts constituting each combination, and then average the measured values.

[0044] The depth of the recesses (height of the protrusions) in the pattern of the first micro-texture uneven structure layer 102 is not particularly limited, but is preferably 150 nm or more, more preferably 190 nm or more, and preferably 300 nm or less, more preferably 230 nm or less. On the other hand, the portion of the first micro-texture uneven structure layer 102 where no uneven pattern is formed, i.e., the base 1021 (refer to...) Figure 2D The thickness of the portion of the first micro-texture layer 102 that is not part of the micro-texture structure is preferably 250 nm or less. If the thickness of the portion of the first micro-texture layer 102 that is not part of the micro-texture structure is 250 nm or less, the vibrations (ripples) in the reflection spectrum caused by multiple reflections between the substrate 101 and the first micro-texture layer 102 become smaller, further suppressing color unevenness or reflection deterioration. From the same viewpoint, the thickness of the portion of the first micro-texture layer 102 that is not part of the micro-texture structure is more preferably 200 nm or less, more preferably 100 nm or less, and particularly preferably 50 nm or less. On the other hand, from a practical viewpoint, the thickness of the portion of the first micro-texture layer 102 that is not part of the micro-texture structure can be set to 0.01 nm or more. It should be noted that the thickness of the portion of the first micro-texture layer 102 that is not part of the micro-texture structure refers to the distance in the stacking direction or film thickness direction between the surface where the micro-texture structure is not formed and the apex of the deepest recess of the formed micro-texture structure.

[0045] In this embodiment, the first micro-textured structure layer 102 is preferably made of, for example, a UV-curable resin. There are no particular limitations on the UV-curable resin; examples include UV-curable acrylic resins and UV-curable epoxy resins.

[0046] <Second Micro-Fine Textured Layer> The second micro-textured uneven structure layer 103 used in this embodiment is hydrophobic. That is, the water droplet contact angle of the second micro-textured uneven structure layer 103 is, for example, 130 degrees or more, preferably 140 degrees or more, more preferably 145 degrees or more, and even more preferably 150 degrees or more.

[0047] Similar to the first micro-textured structure layer 102 described above, the second micro-textured structure layer 103 has a fine pattern of protrusions and depressions (protrusions in the thickness direction of the micro-textured structure and depressions in the thickness direction of the micro-textured structure). This improves anti-reflective properties. The protrusions and depressions can be arranged periodically (e.g., in an alternating grid pattern or a rectangular grid pattern) or randomly. Furthermore, the shape of the protrusions and depressions is not particularly limited and can be projectile-shaped, conical, columnar, or needle-shaped, etc.

[0048] The average period (pitch) of the uneven pattern in the second micro-uneven structure layer 103 is preferably below the visible light wavelength (e.g., below 830 nm), more preferably below 350 nm, and even more preferably below 280 nm. The average period (pitch) of the uneven pattern in the second micro-uneven structure layer 103 is more preferably above 100 nm, and even more preferably above 150 nm. By employing a so-called moth-eye structure where the pitch of the uneven pattern in the second micro-uneven structure layer 103 is below the visible light wavelength, it is possible to further improve anti-reflective properties.

[0049] Furthermore, the depth of the recesses (height of the protrusions) in the pattern of the second micro-texture layer 103 is not particularly limited, but is preferably 150 nm or more, more preferably 190 nm or more, and preferably 400 nm or less, more preferably 300 nm or less, and even more preferably 230 nm or less. On the other hand, the portion of the second micro-texture layer 103 where no pattern is formed, i.e., the base 1031 ( Figure 2H The thickness of the portion of the second micro-texture layer 103 that is not part of the micro-texture structure is preferably 250 nm or less. If the thickness of the portion of the second micro-texture layer 103 that is not part of the micro-texture structure is 250 nm or less, the vibration (ripples) of the reflection spectrum caused by multiple reflections between the substrate 101 and the second micro-texture layer 103 becomes smaller, and color unevenness or reflection deterioration can be further suppressed. From the same point of view, the thickness of the portion of the second micro-texture layer 103 that is not part of the micro-texture structure is more preferably 200 nm or less, more preferably 100 nm or less, and particularly preferably 50 nm or less. On the other hand, from a practical point of view, the thickness of the portion of the second micro-texture layer 103 that is not part of the micro-texture structure can be set to 0.01 nm or more. It should be noted that the thickness of the portion of the second micro-texture layer 103 that is not part of the micro-texture structure refers to the distance in the stacking direction or film thickness direction between the surface where the micro-texture structure is not formed and the apex of the deepest recess of the formed micro-texture structure.

[0050] The arrangement of the concave and convex portions of the micro-convex structure parts of the first micro-convex structure layer 102 and the second micro-convex structure layer 103, the average period of the concave and convex patterns, and the depth of the concave portions can be the same or different from each other.

[0051] In this embodiment, the second micro-textured structure layer 103 is preferably made of, for example, a UV-curable resin. There are no particular limitations on the UV-curable resin; examples include UV-curable acrylic resins and UV-curable epoxy resins.

[0052] In this embodiment, when the refractive indices of the substrate 101, the first micro-uneven structure layer 102, and the second micro-uneven structure layer 103 are set to n0, n1, and n2, respectively, the absolute value of the difference between the refractive indices of n0 and n1 is preferably within 0.2, and the absolute value of the difference between the refractive indices of n0 and n2 is preferably within 0.2. By satisfying this condition, the vibration (ripples) of the reflection spectrum caused by multiple reflections between layers is reduced, color unevenness or reflection deterioration can be suppressed, and a structure with high transmittance can be obtained.

[0053] The total light transmittance of the structure 100 is preferably 98% or more, more preferably 99% or more, and even more preferably 99.5% or more. Furthermore, the structure 100 has a three-dimensional shape that follows the curved shape of the outer surface of the sensor device 400.

[0054] (Manufacturing method of the structure) The manufacturing method of the structure of the present invention is characterized by including a first pressing step, a first curing step, a first peeling step, a second pressing step, a second curing step, a second peeling step, and a molding step. According to this method, a structure with micro-uneven structural layers disposed on both sides of a substrate, possessing hydrophobicity, and capable of being attached and detached from a sensor device 400 to be mounted can be manufactured.

[0055] The following is for reference Figures 2A-2H A method for manufacturing a structure according to one embodiment of the present invention (hereinafter, sometimes referred to as "the manufacturing method of this embodiment") will be described.

[0056] <First Crimping Process> The first pressing step is a process in which the first UV-curable resin 151 is clamped and pressed together using a substrate 101 and a first retaining film 201 having a micro-uneven structure on its surface, such that the micro-uneven structure of the first retaining film 201 contacts the first UV-curable resin 151. Specifically, in the first pressing step of the manufacturing method of this embodiment, as follows... Figure 2A As shown, firstly, the first UV-curable resin 151 is clamped using a substrate 101 and a first retaining film 201 having a fine uneven structure on its surface, such that the fine uneven structure of the first retaining film 201 contacts the first UV-curable resin 151. This yields the first retainer. There are no particular limitations on the first UV-curable resin 151; examples include UV-curable acrylic resins and UV-curable epoxy resins. Furthermore, various additives such as curing initiators may be added to the first UV-curable resin 151 as needed.

[0057] The viscosity of the first UV-curable resin 151 is preferably 1000 cps or less. If the viscosity of the first UV-curable resin 151 is 1000 cps or less, the film thickness becomes thinner, which can suppress curling caused by shrinkage during curing, and the thermoplastic deformation becomes better.

[0058] Here, for example, a first retaining film 201 having a micro-uneven structure on its surface can be manufactured by forming a micro-uneven layer having a predetermined uneven pattern on a substrate.

[0059] There are no particular limitations on the materials used to form the substrate, but transparent and durable materials are preferred, such as PET (polyethylene terephthalate), TAC (triacetyl cellulose), or PC (polycarbonate). Furthermore, the formation of a micro-uneven layer on the substrate can be achieved, for example, by performing the following method: a step of coating an uncured UV-curable resin onto one side of the substrate; a step of transferring the uneven pattern to the UV-curable resin by bringing a roller with a corresponding uneven pattern into close contact with the coated UV-curable resin; a step of curing the coated UV-curable resin by irradiating it with UV light; and a step of peeling the cured UV-curable resin off the roller. It should be noted that there are no particular limitations on the UV-curable resin; examples include UV-curable acrylic resins and UV-curable epoxy resins. Additionally, various additives such as curing initiators can be added to the UV-curable resin as needed.

[0060] To improve peelability, the first retaining film 201 can also be coated with a film made of inorganic material on the surface of the micro-uneven structure.

[0061] Next, as Figure 2A As shown, the first clamping body is pressed along the clamping direction using a roller laminator 160 and other pressing devices. Here, in the first pressing process, the thickness of the final obtained first micro-textured structure layer 102 can be adjusted by adjusting the pressure during pressing.

[0062] <First Curing Process> The first curing step is a process in which the first UV-curable resin 151 held in a clamp is cured by irradiation with UV light, thereby forming a first micro-textured uneven structure layer 102 on one side of the substrate 101. Specifically, in the first curing step of the manufacturing method of this embodiment, as follows... Figure 2B As shown, the first UV-curable resin 151, which is held in the first pressing process, is irradiated with UV light to cure it. By curing the first UV-curable resin 151, the desired result is obtained. Figure 2CThe first intermediate structure 250 shown has a first micro-uneven structure layer 102 formed on one side of the substrate 101. It should be noted that the first curing process can also be performed at the same time as the first pressing process. The micro-uneven structure of the surface of the first micro-uneven structure layer 102 thus obtained can engage with the micro-uneven structure of the first retaining film 201 without gaps.

[0063] <First Stripping Process> The first peeling step is the process of peeling the first retaining film 201 from the first micro-textured structure layer 102. The first peeling step can be performed after the first curing step. Specifically, in the first peeling step of the manufacturing method of this embodiment, the first retaining film 201 is removed from the first micro-textured structure layer 102. Figure 2C The first retaining film 201 on the first intermediate structure 250 shown peels off and becomes Figure 2D The state shown.

[0064] <Second Crimping Process> The second pressing step involves clamping and pressing the second UV-curable resin 152 using the substrate 101 and the second retaining film 202, which has a micro-uneven structure on its surface, such that the other side of the substrate 101 and the micro-uneven structure of the second retaining film 202 are in contact with the second UV-curable resin 152. The second pressing step can be performed after the first peeling step. Specifically, in the second pressing step of the manufacturing method of this embodiment, as... Figure 2E As shown, the second UV-curable resin 152 is held in contact with the second UV-curable resin 152 by using the other side of the substrate 101, i.e., the side of the substrate 101 opposite to the first micro-texture layer 102, and the second holding film 202 having a micro-texture structure on its surface. This results in a second retainer. The second UV-curable resin 152 is not particularly limited and can include, for example, UV-curable acrylic resins and UV-curable epoxy resins. It is preferable to add hydrophobic additives to the second UV-curable resin 152. This allows the subsequently formed second micro-texture layer 103 to be hydrophobic. Furthermore, various additives such as curing initiators can be added to the second UV-curable resin 152 as needed.

[0065] Examples of additives exhibiting hydrophobicity include fluoropolymers and silicone resins. Furthermore, the amount of this additive added to the second UV-curable resin 152 is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 2% by mass or less, relative to the second UV-curable resin 152.

[0066] The viscosity of the second UV-curable resin 152 is preferably 1000 cps or less. If the viscosity of the second UV-curable resin 152 is 1000 cps or less, the film thickness becomes thinner, which can suppress curling caused by shrinkage during curing, and the thermoplastic deformation becomes better.

[0067] Here, the second retaining film 202 can be manufactured by the same method as the first retaining film 201, for example by forming a micro-unraveling layer with a predetermined uneven pattern on the substrate.

[0068] To improve peelability, the second retaining membrane 202 can also be coated with a membrane made of inorganic material on the surface of the micro-uneven structure.

[0069] Next, as Figure 2E As shown, the second clamping body is pressed along the clamping direction using a roller laminator 160 and other pressing devices. Here, in the second pressing process, the thickness of the final obtained second micro-textured structure layer 103 can be adjusted by adjusting the pressure during pressing.

[0070] <Second Curing Process> The second curing step is a process in which the second UV-curable resin 152, which is held in place, is cured by irradiating it with UV light, thereby forming a second micro-textured uneven structure layer 103 on the other side of the substrate 101. The operation of the second curing step is essentially the same as the first curing step. Specifically, in the second curing step of the manufacturing method of this embodiment, as... Figure 2F As shown, the second UV-curable resin 152, which is held in the second pressing process, is irradiated with UV light to cure it. By curing the second UV-curable resin 152, the desired result is obtained. Figure 2G The second intermediate structure 260, on the other side of the substrate 101 (the side of the first intermediate structure 250), has a second micro-uneven structure layer 103. It should be noted that the second curing process can also be performed at the same time as the second pressing process. The micro-uneven structure of the surface of the second micro-uneven structure layer 103 thus obtained can engage seamlessly with the micro-uneven structure of the second retaining film 202.

[0071] <Second stripping process> The second peeling step is the process of peeling the second retaining film 202 from the second micro-textured structure layer 103. The second peeling step can be performed after the second curing step. The operation of the second peeling step is substantially the same as the first peeling step. Specifically, in the second peeling step of the manufacturing method of this embodiment, the second retaining film 202 present on the second intermediate structure 260 is peeled off to become... Figure 2H The state shown.

[0072] <Molding Process> The forming process involves applying vacuum heating to the substrate 101, on which micro-unfolded structures are formed on both sides, thereby shaping it into a three-dimensional shape with a curved surface that follows the outer surface of the sensor device 400 to which it is mounted. In the forming process of the manufacturing method of this embodiment, firstly, a lens having a curvature close to that of the outer surface is prepared. Next, as... Figure 2I As shown, a second intermediate structure 260, after the second peeling process, is disposed on the prepared lens, and a vacuum heat treatment is applied. The method of vacuum heat treatment is not particularly limited; for example, a method using a heating dryer within a vacuum chamber can be cited. Thus, a structure 100 with a three-dimensional shape having a curved surface shape following the outer surface is obtained. By employing a structure 100 with such a three-dimensional shape, the structure 100 can be mounted to the sensor device 400 without impairing the function of the sensor device 400 described later or the optical properties of the structure, and thus in a spatially stable manner.

[0073] (Structure module) like Figure 3 As shown, the structure module 500 of this embodiment includes a sensor device 400 and a structure 100 mounted on the outer surface of the sensor device 400. The sensor device 400 has a lens 401 located on the outermost side of the sensor device 400. The outer surface of the sensor device 400, i.e., the outer surface of the lens 401, has a curved shape. The radius of curvature of this outer surface is preferably 3 mm or more and 1000 mm or less, more preferably 5 mm or more and 500 mm or less. The structure 100 is preferably configured to be detachable from the outer surface. As a method for mounting the structure 100 to the outer surface, methods such as using screws or physical clamps, or adhesives, can be listed.

[0074] <Uses of Structure Modules> In the structure module 500 of this embodiment, the sensor device 400 may include a vehicle-mounted camera module or a camera module for a surveillance camera. That is, the structure module 500 may, for example, be a vehicle-mounted camera module or a camera module for a surveillance camera on which the structure 100 is mounted.

[0075] Example The present invention will now be described in more detail using examples and comparative examples, but the present invention is not limited to the following examples.

[0076] (Example 1) To produce Figure 3The structure 100 shown has a substrate 101, on which a first micro-uneven structure layer 102 and a second micro-uneven structure layer 103 are formed respectively on both sides, and has a three-dimensional shape that follows the curved shape of the outer surface of the sensor device 400. A structure module 500, formed by mounting the structure 100 to a lens 401 of the sensor device 400, is taken as the model object. The substrate 101 of the structure 100 uses a polycarbonate film with a thickness of 150 μm. The first micro-uneven structure layer 102 is formed using UV acrylic resin, and the micro-uneven structure is set as a moth-eye structure with a pitch of 200 nm and a depth of the recess (height of the protrusion) of 200 nm. The second micro-uneven structure layer 103 is formed using a resin mixture in which approximately 2% by mass of fluorinated resin is added to the UV acrylic resin. The micro-uneven structure of the second micro-uneven structure layer 103 is also set as a moth-eye structure with a pitch of 200 nm and a depth of the recess (height of the protrusion) of 200 nm. The thickness of the base 1021 (the portion where the micro-unstructured texture is not formed) of the first micro-unstructured layer 102 is set to 3000 nm. The thickness of the base 1031 of the second micro-unstructured layer 103 is set to 3000 nm. Furthermore, the refractive index n0 of the substrate 101 is set to 1.6. The refractive index n1 of the first micro-unstructured layer 102 is set to 1.52. The refractive index n2 of the second micro-unstructured layer 103 is set to 1.52.

[0077] According to the manufacturing method of the present invention, a second intermediate structure 260 is fabricated by forming a first micro-uneven structure layer 102 and a second micro-uneven structure layer 103 on both sides of a substrate 101. Subsequently, according to the manufacturing method of the present invention, a molding lens 300 having a curvature close to the outer surface of a sensor device 400 on which the final structure 100 is mounted is prepared. The second intermediate structure 260 is positioned on the molding lens 300 with the first micro-uneven structure layer 102 as the lens side, and a vacuum heat treatment is applied to mold it into a three-dimensional shape following the curved shape of the molding lens 300, thus obtaining the structure 100. Here, the vacuum heat treatment is applied using a heating dryer in a vacuum chamber. The total light transmittance from the second micro-uneven structure layer 103 side of the structure 100 obtained by molding is 99%. Further, the obtained structure 100 is mounted to the outer edge of the lens non-effective area on the outer surface of a camera module using adhesive tape to form a structure module 500. The curvature of the outer surface of the camera module used at this time is approximately 15mm.

[0078] Next, water droplet contact angle tests were conducted on the outer surface of structure 100 (the surface of the second micro-uneven structure layer 103), water droplet adhesion tests were conducted with the sample (structure module 500) tilted at 45 degrees, and water droplet adhesion tests were conducted with the sample set almost horizontally. For the water droplet adhesion test, pure water was dropped onto the second micro-uneven structure layer 103 of the sample using a dropper. It was confirmed whether the water droplet flowed after contacting the sample, and the results were evaluated based on the following evaluation criteria. In addition, after these tests, the installed structure 100 was detached from the camera module to confirm whether it could be reinstalled, and the replaceability was evaluated based on the following evaluation criteria. The results are shown in Table 1.

[0079] The evaluation criteria for the water droplet adhesion test in Table 1 are as follows.

[0080] A: The water droplets were deflected and did not adhere to the sample.

[0081] B: The water droplets were bounced off at the beginning of the experiment, but began to adhere after about 60 seconds.

[0082] C: Water droplets adhere to the surface.

[0083] The evaluation criteria for replaceability in Table 1 are as follows.

[0084] A: Yes, it can be replaced and its functions restored.

[0085] C: Unable to replace or restore functionality.

[0086] (Example 2) The micro-uneven structure of the second micro-uneven structure layer 103 was modeled using the same structural module 500 as in Example 1, except that it was designed as a moth-eye structure with a depth of the concave portion (height of the convex portion) of 400 nm and a UV acrylic resin with approximately 2% fluoropolymer added. The fabricated structure 100 had a total light transmittance of 99% from the side of the second micro-uneven structure layer 103. Water droplet contact angle, water droplet adhesion, and replaceability tests were performed in the same manner as in Example 1. The results are shown in Table 1.

[0087] (Comparative Example 1) A model of a structural module in which a multilayer film composed of dielectric is directly formed on a lens with a curved surface is used as the subject. Here, the surface of the multilayer film is smooth, and the total thickness of the multilayer film is approximately 0.2 μm. Water droplet contact angle and water droplet adhesion tests were performed in the same manner as in Example 1. For the evaluation of replaceability, since the multilayer film was directly formed, it was evaluated whether it could be reformed after removal using a cutting tool (e.g., a leutor). The results are shown in Table 1.

[0088] (Comparative Example 2) A model of a structural module on which a fluorine coating is directly applied to a lens with a curved surface is used as the subject. Here, the thickness of the fluorine coating film is estimated to be 20 nm. Water droplet contact angle and water droplet adhesion tests were performed in the same manner as in Example 1, and replacement tests were performed in the same manner as in Comparative Example 1. The results are shown in Table 1.

[0089] (Comparative Example 3) A model of a structural module in which a lens with a curved surface directly forms a moth-eye structure was used as the subject. A silane coupling treatment was applied to the lens, and a fine concave-convex structure was formed on the lens surface using UV acrylic resin. The fine concave-convex structure exists only on the surface of the structural module, and the surface of the UV acrylic resin in contact with the lens is smooth. Here, the pitch of the moth-eye structure is 200 nm, and the depth of the concave portion (height of the convex portion) is 200 nm. Water droplet contact angle and water droplet adhesion tests were performed in the same manner as in Example 1, and replacement tests were performed in the same manner as in Comparative Example 1. The results are shown in Table 1.

[0090] (Comparative Example 4) Except that the UV acrylic resin used to form the moth-eye structure was a fluorinated UV acrylic resin, the same structural module model as Comparative Example 3 was used. Water droplet contact angle and water droplet adhesion tests were performed in the same manner as in Example 1, and replacement tests were performed in the same manner as in Comparative Example 1. The results are shown in Table 1.

[0091] [Table 1]

[0092] As shown in Table 1, the water droplet contact angle of the structural module 500 in Examples 1 and 2 is 130 degrees or more, it is replaceable, and its total light transmittance is 98% or more. Furthermore, in the water droplet adhesion test when the sample (structural module 500) is tilted at 45 degrees, it is shown that no water droplets adhered in Examples 1 and 2. In the water droplet adhesion test when the sample is horizontal, it is shown that in Example 1, the water droplet began to adhere after about 60 seconds, while in Example 2, no water droplet adhered. Therefore, Example 2 is a structural module 100 with high transmittance and hydrophobicity, which can be detached from the sensor device 400. On the other hand, although Example 1 is not as hydrophobic as Example 2, it is a structural module 100 with high transmittance and can be detached from the sensor device 400. The difference in hydrophobicity between Examples 1 and 2 is considered to be due to the difference in the water droplet contact angle.

[0093] It can be seen that Comparative Examples 1 to 3 have problems in both water droplet adhesion and replaceability. On the other hand, Comparative Example 4 has the same hydrophobicity as Example 2, but it lacks replaceability because the lens has a micro-textured structure layer directly formed. It should be noted that, for Comparative Examples 1 to 4, since the lens is integrally constructed as a structural module, it is theoretically impossible to measure the total light transmittance, therefore no value is recorded.

[0094] Industrial availability According to the present invention, it is possible to provide a three-dimensional structure 100 that can be easily endowed with hydrophobic properties and has a curved surface shape that follows the lens 401 of the sensor device 400, and a method thereof for manufacturing the same. Thus, it is possible to provide a spatially stable structure module 500 that does not lose the functionality and optical properties of the sensor device 400 on which the structure 100 is mounted.

[0095] Furthermore, since the structure 100 formed by the present invention can be detached from the lens 401 of the sensor device 400, even if the hydrophobic function of the structure 100 is damaged, the hydrophobic function can be easily restored by replacing the structure 100. Since the sensor device 400 is used in an outdoor environment, it is impractical to completely avoid performance degradation or surface scratches of the structure 100 due to UV light. Therefore, even if the durability of the structure 100 on the surface of the lens 401 is lost, the hydrophobic function of the structure module 500, including the sensor device 400 and the structure 100, can be easily restored by replacing the structure 100.

Claims

1. A structure, characterized in that, The outer surface of the sensor device is mounted on a surface that has a curved shape. The structure has: substrate; as well as A micro-uneven structure layer is disposed on both sides of the substrate. The micro-uneven structure layer has: A first micro-textured structure layer, located on the sensor device side; and The second micro-uneven structure layer is located on the side opposite to the sensor device side. The second micro-textured structure layer is hydrophobic. The structure has a three-dimensional shape that follows the curved shape of the outer surface.

2. The structure according to claim 1, characterized in that, The first micro-unraveling structure layer has a pitch below the wavelength of the light detected by the sensor device.

3. The structure according to claim 1, characterized in that, The structure is configured to be detachable from the outer surface.

4. The structure according to claim 1, characterized in that, The substrate is thermoplastic.

5. The structure according to claim 1, characterized in that, The structure has a total light transmittance of over 98%.

6. The structure according to claim 1, characterized in that, The water droplet contact angle of the second micro-uneven structure layer is above 130 degrees.

7. A structural module, characterized in that, have: The sensor device; and The structure according to any one of claims 1 to 6 is mounted on the outer surface of the sensor device.

8. The structural module according to claim 7, characterized in that, The radius of curvature of the outer surface is greater than 5 mm and less than 500 mm.

9. The structural module according to claim 7, characterized in that, The sensor device includes a vehicle-mounted camera module.

10. The structural module according to claim 7, characterized in that, The sensor device includes a camera module for a surveillance camera.

11. A method for manufacturing a structure, characterized in that, The method for manufacturing the structure according to any one of claims 1 to 6 The method for manufacturing the structure includes: In the first pressing process, the first UV-curable resin is clamped and pressed using a substrate and a first retaining film having a micro-uneven structure on its surface, with the micro-uneven structure of the first retaining film in contact with the first UV-curable resin. In the first curing process, the first UV-curable resin held in the substrate is cured by irradiating it with UV light, forming a first micro-uneven structure layer on one side of the substrate. The first peeling process involves peeling the first retaining film from the first micro-uneven structure layer. In the second pressing process, the second UV-curable resin is clamped and pressed using the substrate and the second retaining film having a micro-uneven structure on its surface, with the other side of the substrate and the micro-uneven structure of the second retaining film in contact with the second UV-curable resin. In the second curing process, the second UV-curable resin held in the substrate is cured by irradiating it with UV light, forming a second micro-uneven structure layer on the other side of the substrate. The second peeling process involves peeling the second retaining film from the second micro-textured structure layer; and The molding process involves applying vacuum heating to the substrate, which has micro-uneven structures formed on both sides, to shape it into a three-dimensional shape that follows the curved surface of the sensor device to which it is mounted.

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