Method for manufacturing optical film and optical film

Abstract

To provide a method for manufacturing an optical film, which can inexpensively manufacture an optical film in which a first film portion and a second film portion are separated. The method for manufacturing an optical film (1) having a first film portion (10) and a second film portion (12) having a film structure different from that of the first film portion on a film formation surface (F) of a substrate (2), includes: a step of forming the first film portion (10) on a first film formation portion of the film formation surface (F); a step of forming a cleaning-time removal film (W) on the first film portion (10), the cleaning-time removal film (W) having at least any one of a villiform structure, a pyramid group structure, and a flowerpot structure, and being at least one of aluminum and an aluminum compound; a step of forming the second film portion (12) on a second film formation portion of the film formation surface (F) different from the first film formation portion, and on the first film formation portion on which the first film portion (10) and the cleaning-time removal film (W) are formed; and a step of removing the cleaning-time removal film (W) and the second film portion (12) thereon by cleaning.

Description

Technical Field

[0001] The present invention relates to optical thin films formed on the surface of a substrate, and a method for manufacturing such optical thin films. Background Technology

[0002] A camera module built into portable terminals such as smartphones and electronic devices such as digital cameras has an imaging element for capturing a subject and a lens unit for imaging the image of the subject onto the imaging element.

[0003] Furthermore, small lens units, in particular, sometimes include light-shielding components for forming a ring-shaped light-shielding portion. The light-shielding component allows light to enter (transmit) inside the light-shielding portion, while the light-shielding portion around it blocks part or all of the light, thereby limiting the incident light's range into the lens unit, suppressing stray light within the lens unit, preventing halos, lens spots, ghosting, etc., and contributing to improved image quality.

[0004] Patent Document 1 (Japanese Patent Application Publication No. 2020-140130) discloses a thin metal sheet with a through hole formed in the center as such a light-shielding component. This thin metal sheet is manufactured by forming a resist pattern on a metal substrate and etching it as a mask.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-140130 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The light-shielding component in Patent Document 1 is made of a thin metal sheet, thus requiring the transmission portion to be a through-hole. Forming this through-hole necessitates a resist patterning process and an etching process, increasing manufacturing costs. Furthermore, optical films cannot be directly disposed in the transmission portion of the light-shielding component in Patent Document 1. To accommodate the optical film in the transmission portion, other components with optical films formed on a different substrate than the light-shielding portion are bonded to the through-hole portion of the light-shielding component in Patent Document 1. This increases the complexity of the structure and manufacturing costs.

[0010] Therefore, the main objective of the present invention is to provide a method for manufacturing an optical thin film that can inexpensively manufacture an optical thin film with a first thin film portion and a second thin film portion separated.

[0011] In addition, another major objective of the present invention is to provide an optical film in which a first thin film portion in the transmissive portion and a second thin film portion in the light-shielding portion are formed separately in a simple configuration.

[0012] Methods for solving problems

[0013] The invention of technical solution 1 relates to a method for manufacturing an optical thin film having a first thin film portion and a second thin film portion having a different film structure from the first thin film portion, directly or through an intermediate film on the film-forming surface of a substrate. The method is characterized by comprising the following steps: forming the first thin film portion on the first film-forming portion of the film-forming surface; forming a cleaning-removable film on the first thin film portion, the cleaning-removable film having at least one of a fluffy structure, a pyramidal structure, and a sponge-like structure, and being at least one of aluminum and aluminum compounds; forming the second thin film portion on the second film-forming portion of the film-forming surface that is different from the first film-forming portion, and on the first film-forming portion where the first thin film portion and the cleaning-removable film are formed; and removing the cleaning-removable film and the second thin film portion thereon by cleaning.

[0014] The invention of technical solution 2 is as described above, characterized in that the second thin film portion is annular or frame-shaped.

[0015] The invention of technical solution 3 is as described above, characterized in that the cleaning-removable film is formed by immersing the cleaning-removable base film in hot water, and the cleaning-removable base film is formed by physical vapor deposition using at least one of aluminum and aluminum compounds as materials.

[0016] The invention of technical solution 4 is as described above, characterized in that, during the cleaning process, the membrane and the second thin film portion thereon are cleaned by at least one of flowing water and ultrasonic waves.

[0017] The invention of technical solution 5 is as described above, characterized in that the second thin film portion is a light-shielding film that blocks visible light.

[0018] The invention of technical solution 6 is as described above, characterized in that the first thin film portion is an anti-reflective film that suppresses the reflection of visible light.

[0019] The invention of technical solution 7 is as described above, characterized in that, in the process of forming the first thin film portion, the first thin film portion is formed only on the first film-forming portion using a mask.

[0020] The invention of technical solution 8 is as described above, characterized in that, in the process of forming the first thin film portion, after the first thin film portion is formed on the film-forming surface or the entirety or part of the intermediate film that includes the first film-forming portion, the first thin film portion on the film-forming surface or part of the intermediate film other than the first film-forming portion is removed by laser.

[0021] The invention of technical solution 9 is an optical thin film having a first thin film portion and a second thin film portion having a film structure different from the first thin film portion, characterized in that the second thin film portion surrounds the first thin film portion, and no resist remains in the first thin film portion.

[0022] The invention of technical solution 10 is as described above, characterized in that the second thin film portion is a light-shielding film that blocks visible light.

[0023] The invention of technical solution 11 is as described above, characterized in that the first thin film portion is an anti-reflective film that suppresses the reflection of visible light.

[0024] Invention Effects

[0025] The main advantage of this invention is that it provides a method for manufacturing an optical thin film that can inexpensively manufacture an optical thin film with a first thin film portion and a second thin film portion separated.

[0026] In addition, another major advantage of the present invention is that it provides an optical film in which the first thin film portion in the transmission portion and the second thin film portion in the light-shielding portion are formed separately in a simple configuration. Attached Figure Description

[0027] Figure 1 The following are (A) rear view and (B) side view of a light-shielding AR lens component formed by forming an optical thin film of the first embodiment of the present invention on a substrate.

[0028] Figure 2 The following are (A) rear view and (B) side view of an infrared blocking member formed by forming an optical thin film of the second aspect of the present invention on a substrate.

[0029] Figure 3 (A) Figure 3 (K) is a schematic diagram showing the manufacturing method of Embodiment 1 corresponding to the first aspect of the present invention, mainly from the side of the light-shielding AR lens component.

[0030] Figure 4 (A) Figure 4 (H) is a schematic diagram showing the manufacturing method of Embodiment 1, mainly from the back side of the light-shielding AR lens component.

[0031] Figure 5 This is a microscope photograph illustrating a structural example of membrane removal during cleaning according to the present invention.

[0032] Figure 6 This is a graph of the optical constants of SiO2.

[0033] Figure 7 This is a graph of the optical constants of TiO2.

[0034] Figure 8This is a graph of the optical constants of Nb2O5.

[0035] Figure 9 This is a graph of the optical constants of Nb+Si (the sputtering source input powers of Nb and Si in sputtering are 6kW and 8.5kW, respectively).

[0036] Figure 10 This is a graph showing the reflectance distribution of the first thin film portion (AR film) in Example 1.

[0037] Figure 11 This is a graph showing the reflectance distribution of the second thin film portion (light-shielding film) in Example 1.

[0038] Figure 12 This is a graph showing the transmittance distribution of the second thin film portion (light-shielding film) in Example 1.

[0039] Figure 13 (A) Figure 13 (B) is a schematic diagram related to the manufacture of the annular light-shielding film, which is not a comparative example of the present invention. Figure 13 (C) is a rear view of the light-shielding AR lens component LZ in the comparative example.

[0040] Figure 14 This is a graph showing the transmittance distribution of the first thin film portion (infrared blocking film) in Example 2.

[0041] Figure 15 This is a graph showing the reflectance distribution of the first thin film portion (infrared blocking film) in Example 2.

[0042] Figure 16 (A) Figure 16 (D) is a schematic diagram showing the first half of the manufacturing method of Embodiment 3 corresponding to the third aspect of the present invention, mainly from the side of the light-shielding AR lens component.

[0043] Figure 17 This is a photograph showing a sample manufactured using the same manufacturing method as in Example 3.

[0044] Figure 18 yes Figure 17 Enlarged view of the lower right part of the thick black cross and the upper right part of the thick white hollow cross.

[0045] Figure 19 yes Figure 17 A magnified view of the small black ring in the image.

[0046] Figure 20 yes Figure 19 An enlarged view of the lower inner circumference of the ring.

[0047] Figure 21 yesFigure 17 The curves showing the reflectance distribution of the first thin film portion (AR film) and the second thin film portion (light-shielding film) in the sample. Detailed Implementation

[0048] Examples of embodiments of the present invention will be described below with reference to the accompanying drawings.

[0049] It should be noted that the present invention is not limited to the following examples.

[0050] [Method 1]

[0051] like Figure 1 As shown, the optical thin film 1 of the first embodiment of the present invention is formed on the film-forming surface F of the circular substrate 2.

[0052] The material used for substrate 2 is plastic, preferably a thermosetting resin, such as polyurethane resin, thiopolyurethane resin, cyclosulfide resin, polycarbonate resin, polyester resin, acrylic resin, polyethersulfone resin, poly4-methylpentene-1 resin, diethylene glycol dielyl carbonate resin, or combinations thereof. It should be noted that the material for substrate 2 can also be a material other than plastic, such as glass.

[0053] The substrate 2 with the optical thin film 1 is used as a light-shielding AR lens component L in the lens unit of a camera module. It should be noted that the substrate 2 with the optical thin film 1 can also be used for purposes other than the lens unit.

[0054] The substrate 2 is a substrate on which the optical thin film 1 is formed, and in particular, in the case of a plate, it is a substrate. The substrate 2 is transparent, and the transmittance of the substrate 2 for light with wavelengths in the visible light region (400 nm to 750 nm in this case) is approximately 100%. The substrate 2 has a plate-shaped base 2B and a lens portion 2L that bulges out from the center of the base 2B on the film-forming surface F (back side) side of the base 2B to become a convex lens.

[0055] The base 2B is a circular plate with a diameter of about 8 mm.

[0056] The lens section 2L is circular in shape with a diameter of approximately 4mm. The surface of the lens section 2L undergoes a mirror finish. It should be noted that this mirror finish can be omitted.

[0057] Around the lens portion 2L of the substrate 2, a rough surface 2R, appearing as a ring when viewed from the rear, is formed in a textured manner with fine irregularities (e.g., protrusions or concave bodies with a height of approximately several μm). The rough surface 2R scatters the transmitted light. Due to this scattering, the rough surface 2R appears blurred to the naked eye. Furthermore, a peripheral flat portion 2S, appearing as a ring and flat when viewed from the rear, is formed radially outward from the rough surface 2R. The width of the rough surface 2R is approximately 1 mm.

[0058] It should be noted that the rough surface 2R can be formed using a mold with a shape corresponding to the fine irregularities on its inner surface, or it can be formed by coating particles to adhere them. The rough surface 2R may not be textured, or it may be omitted. Alternatively, the peripheral flat portion 2S may be omitted, and the rough surface 2R may be formed up to the periphery of the film-forming surface F of the substrate 2. The lens portion 2L may not be a bulging convex lens, but a concave lens, and multiple lenses may be provided. The size of the substrate 2, the size of a portion of the substrate 2, and its position relative to the whole may also differ from the above.

[0059] The film-forming surface F with the optical thin film 1 and the lens portion 2L in the substrate 2 are arranged to form the interior of the lens unit. In addition, the surface of the base 2B opposite to the lens portion 2L (opposite to the film-forming surface F) is flat and is arranged to form the exterior of the lens unit.

[0060] It should be noted that the light-shielding AR lens component L can also be configured in other ways within the lens unit. Furthermore, one or more intermediate films can be disposed between the substrate 2 and the optical thin film 1. The optical thin film 1 (film-forming surface F) can also replace the surface on the lens portion 2L side, or be disposed together with the surface on the side opposite to the lens portion 2L on the opposite side. The surface of the base 2B opposite to the film-forming surface F can also be curved.

[0061] The optical thin film 1 has a first thin film portion 10 and a second thin film portion 12.

[0062] The first thin film portion 10 is disposed on the surface of the lens portion 2L (the first film-forming portion). The first thin film portion 10 is an optical multilayer film with anti-reflection (AR) function. No resist or other materials (materials other than those constituting the first thin film portion 10 and the second thin film portion 12) remain in the first thin film portion 10. It should be noted that the first thin film portion 10 is not limited to an AR film.

[0063] The second thin film portion 12, viewed from the rear, is annular and disposed on the surface of the rough portion 2R and the surface of the peripheral flat portion 2S (the second film-forming portion). The second thin film portion 12 is a light-shielding film having at least the function of blocking visible light, i.e., light-blocking function. No resist or the like remains on the second thin film portion 12. It should be noted that the second thin film portion 12 is not limited to a light-shielding film. The light-shielding film can be a single-layer film or a multilayer film having multiple layers. Light blocking includes complete blocking, which makes the transmittance approximately 0% in the entire visible light region; incomplete blocking, which makes the transmittance about 10% or less in the visible light region; and partial blocking, which reduces the transmittance before and after transmission.

[0064] The second film portion 12 has a second film portion 12A on the rough portion 2R and a second film portion 12B on the peripheral flat portion 2S. The second film portion 12A and the second film portion 12B have the same film structure, and their difference depends on whether they are placed on the rough portion 2R or on the peripheral flat portion 2S. It should be noted that the arrangement of the first film portion 10 and the second film portion 12 is not limited to the annular second film portion 12 contacting the outer side of the first film portion 10, which is circular in rear view. For example, on the rough portion 2R, the first film portion 10 and the second film portion 12 may overlap or be separated. In addition, the second film portion 12 may not be disposed on part or all of the peripheral flat portion 2S.

[0065] [Method 2]

[0066] like Figure 2 As illustrated, the optical thin film 51 of the second embodiment of the present invention is formed on the film-forming surface F2 (back side) of a rectangular plate-shaped plastic substrate 52. It should be noted that the second embodiment suitably has the same modifications as the first embodiment. For example, the substrate 52 may be made of glass or the like.

[0067] The substrate 52 with the optical thin film 51 is used as an infrared blocking component R. It should be noted that the substrate 52 with the optical thin film 51 can also be used for purposes other than the infrared blocking component R.

[0068] The substrate 52 has a central portion 52C and a rectangular frame-shaped peripheral portion 52R. The film-forming surface F2 side of the central portion 52C is mirror-finished. In addition, the film-forming surface F2 side of the peripheral portion 52R is roughened in the same way as the roughened portion 2R of the first embodiment.

[0069] The optical thin film 51 has a first thin film portion 60 and a second thin film portion 62.

[0070] The first thin film portion 60, viewed from the rear, is rectangular and is disposed on the back side (first film-forming portion) of the central portion 52C. The first thin film portion 60 is an optical multilayer film with infrared blocking function. In the first thin film portion 60, apart from substances such as water that may adhere to it in the air, no resist or the like remains. It should be noted that the first thin film portion 60 is not limited to an infrared blocking film.

[0071] The second film portion 62, viewed from the rear, is rectangular and is disposed on the back side of the peripheral portion 52R (the second film-forming portion). Except for its shape, the second film portion 62 is formed in the same way as the second film portion 12 of the first embodiment.

[0072] The radially inner boundary of the second film portion 62 contacts the boundary of the first film portion 60. It should be noted that the arrangement of the first film portion 60 and the second film portion 62 is not limited to the frame-shaped second film portion 62 contacting the outer side of the first film portion 60, which is rectangular in rear view.

[0073] [Manufacturing methods, etc.]

[0074] The optical films 1 and 51 of methods 1 and 2 are removed during cleaning, specifically by removing the film W (refer to...). Figure 3 , Figure 4 It is manufactured using [method name missing]. The membrane W removed during cleaning is a manufacturing intermediate that is formed during manufacturing and leaves no residue after manufacturing.

[0075] The film W removed during cleaning is aluminum, an aluminum alloy, or an aluminum compound. The aluminum compound is preferably a compound with aluminum as its main component. The main component can be a component that constitutes more than half of the other components by weight or by volume.

[0076] The film removed during cleaning is, for example, aluminum (Al), aluminum oxide (Al2O3), aluminum nitride (AlN), or aluminum oxynitride (AlON). In AlON, the ratio of oxygen atoms to nitrogen atoms can be any ratio. AlON can be a substance with oxygen atoms in majority relative to nitrogen atoms and thus having properties similar to Al2O3, or a substance with oxygen atoms in minority relative to nitrogen atoms and thus having properties similar to AlN, or a substance containing equal amounts of oxygen and nitrogen atoms.

[0077] During cleaning, the membrane W is removed, for example, having Figure 5 At least one of the fine villous structure, pyramidal structure, and sponge-shaped structure shown in (AlN) (hereinafter, for convenience, referred to as "villous structure, etc."). With such villous structure, etc., a film can be formed on a light-shielding film, etc., and the film W to be removed during cleaning can be removed by peeling or other means by cleaning with at least one of running water and ultrasonic waves.

[0078] The cleaning-removable membrane W, which has a villous structure, is formed from a cleaning-removable base membrane WB that does not have a villous structure but is suitable for direct film formation by physical vapor deposition (PVD), vacuum evaporation, sputtering, etc.). The cleaning-removable membrane W is formed, for example, by subjecting the cleaning-removable base membrane WB to at least one of ultrasonic treatment using ultrasound or hot water immersion treatment in hot water.

[0079] It should be noted that during cleaning, the film W may not be completely and strictly removed, leaving a slight residue after the formation of the optical thin film 1. Even in this case, the residual substance is aluminum, aluminum alloy, or an aluminum compound, and will not substantially affect the optical properties of the optical thin film 1. This invention includes cases where a portion of the film W remains after cleaning.

[0080] The optical thin film 1 of the first method can be manufactured as follows: a first thin film portion 10 is formed on the lens portion 2L, a film W is formed on the first thin film portion 10 during cleaning, a light-shielding film of the second thin film portion 12 is formed on the rough portion 2R, the peripheral flat portion 2S, and the film W formed during cleaning, and the film W formed during cleaning is removed together with the film W formed thereon through subsequent cleaning. The light-shielding film on the rough portion 2R and the peripheral flat portion 2S remains even after cleaning, becoming the second thin film portion 12 which is annular when viewed from the rear.

[0081] The optical thin film 51 of the second method can be manufactured as follows: a first thin film portion 60 is formed on the central portion of the film-forming surface F2; a film W is formed on the first thin film portion 60 during cleaning; a light-shielding film of the second thin film portion 62 is formed on the entire surface of the film-forming surface F2 with the first thin film portion 60 and the film W formed during cleaning; the film W formed during cleaning and the light-shielding film formed thereon are removed together by subsequent cleaning; the light-shielding film on the periphery of the film-forming surface F2 remains even after cleaning, becoming the second thin film portion 62 which is rectangular in shape when viewed from the rear.

[0082] [Examples of changes, etc.]

[0083] The following describes further examples of changes to the above methods or modification examples.

[0084] In the first method, the light-shielding film can also be formed in the central part of the film-forming surface F, and the AR film can be formed in the peripheral part.

[0085] In the second method, a light-shielding film can be formed in the central part of the film-forming surface F2, and an infrared blocking film can be formed in the peripheral part.

[0086] Not limited to the above-described methods and modifications, the manufacturing process of the film using the cleaning method to remove film W can be applied to the formation of multiple portions of various film-forming surfaces with different types of film portions. For example, AR film portions with different layer structures can be formed in the central and peripheral portions of film-forming surfaces F and F2. Additionally, mirror film portions with different layer structures can be formed in the central and peripheral portions of film-forming surfaces F and F2. An AR film portion can be formed in the central portion of film-forming surfaces F and F2, and a mirror film portion in the peripheral portion, or the opposite configuration can be used. An AR film portion can be formed in the central portion of film-forming surfaces F and F2, and an infrared blocking film portion in the peripheral portion, or the opposite configuration can be used. An infrared blocking film portion can be formed in the central portion of film-forming surfaces F and F2, and a mirror film portion in the peripheral portion, or the opposite configuration can be used. The arrangement of each film portion is not limited to the central and peripheral portions. This invention is applicable to optical thin films having three or more types of film portions.

[0087] [Method 3]

[0088] In the optical thin film of the third aspect of the present invention, except for the manufacturing method, it is constructed in the same manner as in the first aspect. Components, parts, etc., constructed in the same manner as in the first aspect may be appropriately marked with the same reference numerals, and descriptions are omitted.

[0089] In the manufacturing of the optical thin film 1 according to the third method, for example, a first thin film portion 10 is formed on the rough surface portion 2R, the peripheral flat portion 2S, and the lens portion 2L (on the film forming surface F). The film W is removed during cleaning of the first thin film portion 10. The first thin film portion 10 on the rough surface portion 2R and the peripheral flat portion 2S is removed by laser irradiation or the like, and the film W is removed during cleaning.

[0090] Furthermore, the subsequent manufacturing method is the same as the first method. That is, the subsequent manufacturing is carried out as follows: a light-shielding film of the second thin film portion 12 is formed on the rough surface portion 2R, the peripheral flat portion 2S, and the cleaning removal film W. The cleaning removal film W and the light-shielding film formed thereon are removed together by subsequent cleaning. The light-shielding film on the rough surface portion 2R and the peripheral flat portion 2S remains even after cleaning, becoming the second thin film portion 12 which is annular when viewed from the rear.

[0091] It should be noted that the third method may appropriately have the same variations as the first and second methods.

[0092] Example

[0093] The preferred embodiments of the present invention and comparative examples not belonging to the present invention will be described next.

[0094] It should be noted that the present invention is not limited to the following embodiments. Furthermore, based on the understanding of the present invention, sometimes the following embodiments are essentially comparative examples, and the following comparative examples are essentially embodiments.

[0095] [Example 1]

[0096] Composition of optical thin films, etc.

[0097] Example 1 corresponds to the first method described above (light-shielding AR lens component L).

[0098] In Example 1, as shown in Table 1 below, the first thin film portion 10 (AR film) of the optical thin film 1 is a multilayer optical film with a total of 5 layers, consisting of alternating layers of low refractive index material formed of low refractive index material and high refractive index material formed of high refractive index material. More specifically, in the first thin film portion 10, the 1st, 3rd, and 5th layers (odd-numbered layers) counting from the substrate 2 side are low refractive index layers (SiO2 layers) made of SiO2, and the 2nd and 4th layers (even-numbered layers) are high refractive index layers (TiO2 layers) made of TiO2. It should be noted that in Table 1, the 6th layer is the base film WB (Al2O3) that is not a component of the first thin film portion 10 and is removed during cleaning.

[0099] Furthermore, as shown in Table 2 below, the second thin film portion 12 (light-shielding film) of the optical thin film 1 is a total of 9 layers of optical multilayer film, forming an alternating film of low refractive index layers and high refractive index layers. More specifically, the 1st, 3rd, 5th, 7th, and 9th layers (odd-numbered layers) of the first thin film portion 10, counting from the substrate 2 side, are SiO2 layers; the 2nd layer (part of the even-numbered layers) is a high refractive index layer (Nb2O5 layer) made of niobium oxide (Nb2O5); and the 4th, 6th, and 8th layers (the other part of the even-numbered layers) are high refractive index layers (Nb+Si layers) made of niobium-silicon alloy (Nb+Si). The Nb+Si layer is a light-absorbing layer that absorbs visible light, and according to its characteristics, it exhibits the same behavior as the high refractive index layer.

[0100] It should be noted that the low-refractive-index material can be a mixture of two or more of calcium fluoride (CaF2), magnesium fluoride (MgF2), or SiO2. Furthermore, the high-refractive-index material can be a mixture of two or more of zirconium oxide (ZrO2), tantalum oxide (Ta2O5), niobium oxide (Nb2O5), hafnium oxide (HfO2), selenium oxide (CeO2), aluminum oxide (Al2O3), yttrium oxide (YO2), or TiO2. In the optical multilayer film of the first thin film section 10, since one type of high-refractive-index material and one type of low-refractive-index material are used, the film design is easy and the film formation cost is low.

[0101] [Table 1]

[0102] Layer Material Film thickness (nm) 1st layer SiO2 202.8 2nd layer TiO2 19.1 3rd layer SiO2 37.0 4th layer TiO2 26.4 5th layer SiO2 97.1 6th layer Al2O3 100.0

[0103] [Table 2]

[0104] Layer Film material Film thickness (nm) 1st layer SiO2 100.0 2nd layer [Nb2O5] 14.5 3rd layer SiO2 35.6 4th layer NbSi 8.0 5th layer SiO2 80.6 6th layer NbSi 200.0 7th layer SiO2 66.1 8th layer NbSi 7.5 9th layer SiO2 84.3

[0105] Manufacturing of optical thin films, etc.

[0106] The method for manufacturing Example 1 will now be described.

[0107] It should be noted that the manufacturing method of the optical thin film 1 of the present invention includes the manufacturing apparatus and is not limited to the following methods.

[0108] In the manufacture of Example 1, the first thin film portion 10, the base film WB removed during cleaning, and the second thin film portion 12 of the optical thin film 1 are all formed by DC sputtering using a DC sputtering film deposition apparatus. In the manufacture of Example 1, Al2O3 is used as the base film WB removed during cleaning.

[0109] Table 3 below shows the process conditions for various sputtering processes.

[0110] in addition, Figures 6 to 9 The optical constants of various materials are shown (refractive index distribution and extinction coefficient in the visible light region and adjacent regions).

[0111] It should be noted that at least one of the first thin film section 10, the base film WB removed during cleaning, and the second thin film section 12 can be deposited by other methods such as vapor deposition. Alternatively, an RF sputtering apparatus can be used instead of a DC sputtering apparatus. Furthermore, the number of layers and the thickness of each layer can be appropriately varied.

[0112]

[0113] like Figure 3 (A) Figure 4 As shown in (B), in Figure 4 A mask M is disposed above the film-forming surface F of a substrate 2, which is placed horizontally in a vacuum-sealed film-forming chamber of a sputtering film-forming apparatus with the film-forming surface F (back side) facing upwards. The mask M has a plate-shaped base MB and a through hole MH formed in the center of the base MB in a shape corresponding to the shape of the first thin film portion 10. The mask M is supported on a film-forming sample holder by a support body.

[0114] It should be noted that in the manufacturing method of the optical thin film 1, the various configurations and numbers of elements are not limited to those described above. For example, the substrate 2 and the mask M can be in a vertical orientation. Multiple substrates 2 can be arranged in a longitudinal and transverse manner, and the mask M can also have multiple through holes corresponding to this arrangement.

[0115] Next, asFigure 3 (B) Figure 4 As shown in (C), the first film section 10 is formed, followed by the removal of the base film WB during cleaning. It should be noted that the first film section 10 and the removal of the base film WB during cleaning can also be manufactured using separate devices.

[0116] That is, firstly, various target materials are set up, the film-forming chamber is evacuated, and then, as shown in Table 3 as "pretreatment," O2 gas from a free radical source is supplied to the film-forming chamber at a flow rate of 500 ccm for 30 seconds to become free radical oxygen by applying a high-frequency voltage, thereby cleaning the substrate 2 and the mask M. More specifically, through such irradiation with free radical oxygen, even if organic matter adheres to the substrate 2 and the mask M, the organic matter will be decomposed and peeled off by the ultraviolet light generated by the free radical oxygen and the plasma. Through such cleaning, the adhesion of the subsequently formed film is improved.

[0117] Next, the first layer (SiO2 layer) of the first thin film portion 10 is sputtered under the above process conditions (Table 3). Here, the Si sputtering source works in conjunction with the introduction of argon gas (Ar gas) to introduce oxygen (O2 gas) as a free radical source into the film formation chamber. The mask M is positioned between the substrate 2 and the sputtering source. Next, the second layer (TiO2 layer) of the first thin film portion 10 is sputtered in the same manner. Here, the Ti sputtering source operates to introduce O2 gas as a free radical source into the film formation chamber. Then, layers 3 through 5 are sputtered sequentially to form the first thin film portion 10. It should be noted that Ar gas can be introduced into the free radical source, either in place of the sputtering source or together with the sputtering source. The Ar gas can also be a rare gas other than Ar. Such changes in the Ar gas can be appropriately performed in other film formation processes.

[0118] Next, the base film WB (Al2O3) removed during cleaning is sputtered onto the first thin film portion 10 under the process conditions described above (Table 3). Here, the Al sputtering source works in conjunction with the introduction of Ar gas, and the radical source works in the presence of oxygen radicals.

[0119] The first thin film portion 10 and the base film WB removed during cleaning are formed on the lens portion 2L of the substrate 2 through the through hole MH of the mask M.

[0120] Next, as Figure 3 (C) Figure 4 As shown in (D), the substrate 2 with the first thin film portion 10 and the base film WB removed during cleaning is temporarily removed from the sputtering film forming apparatus.

[0121] After that, as Figure 3 As shown in (D), the substrate 2, which includes the first thin film portion 10 and the base film WB removed during cleaning, is immersed in hot water HW in a water tank T. Thus, as...Figure 3 (E) Figure 4 As shown in (E), the base film WB removed during cleaning transforms into a cleaning-removed film W with a fluffy structure, etc. That is, the uniformly distributed Al2O3 structure in the cleaning-removed base film WB changes to a fluffy structure, etc., as it dissolves in the hot water HW. In other words, the cleaning-removed base film WB undergoes appropriate partial dissolution in the hot water HW, resulting in the growth of numerous fine fluffs, pyramids, cones, needles, etc., along the film thickness direction, slowly transforming into the cleaning-removed film W. During this transformation from the cleaning-removed base film WB to the cleaning-removed film W, the film strength decreases due to the presence of the fluffy structure, etc., and can therefore be considered as etching. On the other hand, the hot water HW does not cause adverse effects such as deformation or short-term brittleness to the first thin film portion 10. It should be noted that the orientation (orientation) of the substrate 2, etc., during immersion is not limited to... Figure 3 The vertical orientation is shown. In addition, etching can also be performed by simultaneously applying ultrasound while immersing in hot water, in addition to immersion in hot water.

[0122] Regarding the temperature of the hot water HW, from the perspective of obtaining a fluffy structure in the shortest possible time, it is 90°C, preferably 60°C to 100°C, more preferably 80°C to 100°C, and even more preferably 90°C to 100°C. To achieve a temperature of 100°C or higher, special treatments such as pressurizing the water are necessary, or substances other than water must be used, which requires time and effort.

[0123] Furthermore, regarding the immersion time in hot water (HW), from the perspective of obtaining a fluffy structure in the shortest possible time, it is preferably 2 seconds to 10 minutes, more preferably 5 seconds to 5 minutes, and even more preferably 15 seconds to 3 minutes. If the immersion time is too short, a fluffy structure cannot be sufficiently obtained; if the immersion time is too long, the processing time becomes longer and the efficiency decreases accordingly.

[0124] Subsequently, as Figure 3 As shown in (F), the substrate 2 with the first thin film portion 10 and the film W removed during cleaning is taken out of the water tank T and returned to the sputtering film forming apparatus, as follows. Figure 3 of (G), Figure 4 As shown in (F), the light-shielding film of the second thin film portion 12 is formed on the entire surface of the film-forming surface F. It should be noted that the first thin film portion 10 and the light-shielding film can be manufactured using different devices.

[0125] That is, firstly, in a maskless state, the first layer (SiO2 layer) of the second thin film section 12 is sputtered in the same manner as the SiO2 layer of the first thin film section 10. Next, the second layer (Nb2O5 layer) of the second thin film section 12 is sputtered under the above process conditions (Table 3). Here, the Nb sputtering source works in conjunction with the introduction of Ar gas, and O2 gas, as a free radical source, is introduced into the film formation chamber. Next, the third layer (SiO2 layer) of the second thin film section 12 is sputtered in the same manner. Next, the fourth layer (Nb+Si layer) of the second thin film section 12 is sputtered in the same manner. During the sputtering of the Nb+Si layer, the Nb sputtering source and the Si sputtering source work simultaneously, and the free radical source does not work. Next, layers 5 to 7 are sputtered sequentially in the same manner, and the light-shielding film of the second thin film section 12 is formed on the rough portion 2R of the substrate 2, the peripheral flat portion 2S, and the film removed during cleaning W.

[0126] After such a light-blocking film is formed on the entire surface, as... Figure 3 As shown in (H), the substrate 2 with the light-shielding film, the film W to be removed during cleaning, and the first film part 10 is placed back into the water tank T and immersed in hot water HW.

[0127] Thus, as Figure 3 of (I), Figure 4 As shown in (G), the light-shielding film removed from the film W during cleaning becomes a weakened second film portion 12E with cracks and a weakened structure. The change from the second film portion 12 to the weakened second film portion 12E on the film W removed during cleaning can be regarded as etching, and since it is the second etching, it can be regarded as re-etching. In the re-etching, no adverse effects such as weakening are introduced to the second film portion 12 and the first film portion 10 on the substrate 2, and the adhesion of the first film portion 10 and the second film portion 12 to the film-forming surface F remains unchanged.

[0128] In addition, during the etching process, the villous structure of the film W is further refined during cleaning, and the film W is partially dissolved during cleaning.

[0129] It should be noted that the water tank T associated with removing the membrane W during cleaning and the water tank T associated with the second thin film portion 12 can be provided separately. Furthermore, at least one of the temperature of the hot water HW and the immersion time in these water tanks T, T can be different from each other. Moreover, the re-etching can suitably have variations of the first etching. For example, in the re-etching, ultrasonic treatment can be performed instead of hot water immersion treatment, or it can be performed together with hot water immersion treatment. Furthermore, the weakening structure of the weakened second thin film portion 12E is not limited to cracks.

[0130] After removing the substrate 2, which includes the first film portion 10, the second film portion 12, the weakened second film portion 12E, and the film W removed during cleaning, from the water tank T, as follows: Figure 3As shown in (J), clean with running water (refer to arrow A). It should be noted that ultrasonic cleaning can also be used instead of running water, or in conjunction with running water.

[0131] Thus, the weakened second film portion 12E and the film W removed during cleaning are separated from the first film portion 10, as... Figure 3 (K) Figure 4 As shown in (H), the light-shielding AR lens component L, i.e., the substrate 2 with an optical film 1 having a second film portion 12 disposed around the first film portion 10 with a uniform film thickness, is completed. That is, by cleaning and removing the film W and the second film portion 12 thereon during cleaning, the first film portion 10 appears on the surface of the lens portion 2L, and the second film portion 12 changes from being disposed on the entire film-forming surface F to being disposed only on the rough portion 2R surface and the peripheral flat portion 2S surface.

[0132] In this optical thin film 1, the Al2O3 removed during cleaning of the film W has reduced adhesion to the underlying first thin film portion 10 due to its fine, velvety structure, etc. Therefore, it is completely removed without residue by cleaning based on at least one of running water and ultrasonic waves. Furthermore, by utilizing the cracked, weakened second thin film portion 12E and the cleaning-removed film W with its velvety structure, only the portion above the lens portion 2L of the light-shielding film is selectively removed. The adhesion of the first thin film portion 10 to the surface of the lens portion 2L, and the adhesion of the second thin film portion 12 to the rough surface 2R and the peripherally flat surface 2S, are both ensured. Therefore, the first thin film portion 10 and the second thin film portion 12 in these portions will not peel off due to cleaning using at least one of running water and ultrasonic waves, and will not be removed from the substrate 2. It should be noted that, as described above, even if a slight residue of the cleaning-removed film W remains, it will not have a significant impact on the optical thin film 1, etc.

[0133] Furthermore, the cleaning-removable film W can be removed without the use of organic solvents, thus preventing organic solvents from affecting the optical film 1, the substrate 2, and the intermediate film. In particular, most plastic substrates 2 are not resistant to organic solvents and can dissolve and crack due to their action. By removing the cleaning-removable film W without using organic solvents, such dissolution and cracking can be prevented. Therefore, the formation of the optical film 1 using the cleaning-removable film W is particularly effective for plastic substrates 2.

[0134] The water temperature can be any temperature, but from the perspective of ease of handling, room temperature (tap water temperature) is preferred.

[0135] The flow rate of the water can be any amount, as long as it is sufficient to weaken the second membrane section 12E and remove the membrane W during cleaning, thus separating the entire membrane. The same applies to the output of the ultrasound.

[0136] Regarding the cleaning time, which is the time for processing using at least one of flowing water and ultrasound, it can be any time as long as it is the time for the second thin film portion 12E to be weakened and the time for the entire membrane W to be separated during cleaning. From the perspective of ensuring thorough cleaning while shortening the time, it is preferably 30 seconds to 10 minutes, more preferably 1 minute to 5 minutes, and even more preferably 2 minutes to 3 minutes.

[0137] Characteristics of Example 1, etc.

[0138] Figure 10 It is a graph showing the reflectance distribution of the visible light region and the adjacent region of the lens portion 2L surface (central point) on which the first thin film portion 10 (AR film) is formed in Example 1.

[0139] As can be seen from the graph, the lens section 2L of Embodiment 1 achieves low reflection of visible light.

[0140] The surface of the lens portion 2L is mirror-finished and a first thin film portion 10 is applied. Since the substrate 2 is light-transmitting, the lens portion 2L of Embodiment 1 can transmit most of the visible light.

[0141] Figure 11 This is a graph showing the reflectance distribution of the visible light region and adjacent regions of the rough surface 2R of the second thin film portion 12 (light-shielding film) formed in Embodiment 1, which is related to the reflectance of reflected light incident from the air and reflected by the second thin film portion 12 (second A thin film portion 12A) (reflectance on the light-shielding film) and the reflectance of reflected light incident from the substrate 2 side and reflected by the rough surface 2R (interface reflectance).

[0142] The reflectance is determined by the proportion of test light emitted from the reflectance meter that returns to the reflectance meter. Since the test light is scattered by the unevenness of the rough surface 2R, the reflectance on the light-shielding film in Example 1 and the reflectance at the interface are both below 0.5% in the entire visible light region, which is sufficiently reduced.

[0143] Figure 12 This is a graph showing the transmittance distribution of the visible light region and adjacent regions of the rough surface 2R of the second thin film portion 12 (light-shielding film) formed in Example 1.

[0144] In the rough section 2R of Embodiment 1, very low transmittance is achieved in the visible light region and adjacent regions. Utilizing such a rough section 2R with the second thin film portion 12, the light-shielding AR lens component L of Embodiment 1 can sufficiently suppress the generation of stray light within the lens unit.

[0145] The following comparative examples illustrate the uniformity of film thickness in the second thin film portion 12 of Example 1.

[0146] Figure 13 (A) Figure 13 (B) is a schematic diagram related to the manufacture of the annular light-shielding film in the comparative example. Figure 13 (C) is a rear view of the light-shielding AR lens component LZ in the comparative example.

[0147] In the comparative example, after forming the AR film 10Z in the center in the same manner as in Example 1, without removing the base film WB during cleaning, a light-shielding film 12Z is ​​formed around the AR film 10Z using a bridging mask MZ.

[0148] The bridging mask MZ has: a base MZB; a circular through-hole MZH of the same size as the light-shielding AR lens component LZ opened in its center; a central mask MZC, which is a circular plate of the same size as the lens component 2LZ and is concentrically arranged with the through-hole MZH; and a bridging MZR that extends from the outer part of the through-hole MZH of the base MZB to any interior in all directions to support the central mask MZC.

[0149] The light-shielding film 12Z is ​​formed in a ring shape using the through-hole MZH in the bridging mask MZ, excluding the central mask MZC portion. The central mask MZC prevents the formation of the light-shielding film on the AR film 10Z.

[0150] However, during the formation of the light-shielding film 12Z, the plurality of (4) bridging MZRs supporting the central mask MZC hinder the film material from reaching the substrate 2Z. Therefore, the comparative example light-shielding film 12Z has a thinning portion 12ZT corresponding to the bridging MZRs, and its film thickness is correspondingly uneven. In the thinning portion 12ZT, sometimes there is no film material of the light-shielding film 12Z at all (unfilmed portion). Such a thinning portion 12ZT is produced even when the bridging MZRs are minimized as much as possible while supporting the central mask MZC.

[0151] In contrast, the second thin film portion 12 of Example 1 is formed by removing the film W during cleaning to achieve a ring shape and extremely high uniformity of film thickness.

[0152] It should be noted that in the comparative example, two types of masks are required: the AR film 10Z mask and the bridging mask MZ. In contrast, in Example 1, only one first film part 10 and the mask M for removing the base film WB during cleaning are required. Compared with the comparative example, Example 1 is easier to manufacture.

[0153] Examples of modifications to the removal of the base membrane during cleaning, etc.

[0154] Table 4 below shows the manufacturing conditions, etc., of a modified example of the formation of the base membrane WB during cleaning.

[0155] It should be noted that the manufacturing conditions at the top of Table 4 are those of Example 1. Additionally, "EB" in Table 4 stands for electron beam.

[0156]

[0157] That is, as shown in the second manufacturing condition from the top in Table 4, the base film WB can be removed during cleaning by an Al film formed by vapor deposition.

[0158] In addition, as shown in the third manufacturing condition from the top in Table 4, the base film WB can be removed during cleaning by an Al2O3 film formed by vapor deposition.

[0159] Furthermore, as shown in the fourth manufacturing condition from the top in Table 4, the base film WB can be removed during cleaning by sputtering an Al film.

[0160] Furthermore, as shown in the fifth manufacturing condition from the top in Table 4, the base film WB can be removed during cleaning by sputtering an AlN film. It should be noted that AlN films are difficult to form using conventional vapor deposition.

[0161] Furthermore, as shown in the first manufacturing condition from the bottom in Table 4, the base film WB can be removed during cleaning by sputtering an AlON film. It should be noted that AlON film formation is difficult using conventional vapor deposition.

[0162] Alternatively, the base membrane WB removed during cleaning can be a combination of elements including elemental Al.

[0163] Regarding these cleaning-removable base membranes (WB), such as the cleaning-removable base membrane WB in Example 1, they exhibit a fine, fluffy structure after being treated with hot water immersion, and can be used as cleaning-removable membranes (WB).

[0164] [Example 2]

[0165] Composition of optical thin films, etc.

[0166] Example 2 corresponds to the second method described above (infrared blocking component R).

[0167] In Example 2, as shown in Table 5 below, the first thin film portion 60 (infrared blocking film) of the optical thin film 51 is a total of 45 layers of optical multilayer film, which is an alternating film of low refractive index layer (SiO2 layer, odd number of layers) and high refractive index layer (TiO2 layer, even number of layers).

[0168] Furthermore, the second film portion 62 (light-shielding film) of the optical film 51 is constructed in the same manner as the second film portion 12 of Embodiment 1.

[0169] It should be noted that in Example 2, including its manufacturing process, there are suitable modifications to the same example as in Example 1.

[0170] [Table 5]

[0171]

[0172] Manufacturing of optical thin films, etc.

[0173] The manufacturing method of Example 2 will be described next.

[0174] It should be noted that the manufacturing method of the optical thin film 51 of the present invention includes the manufacturing apparatus and is not limited to the following methods.

[0175] In the manufacturing of Example 2, except for the number of layers of the first thin film portion 60 and the shape of the mask M, the first thin film portion 60 of the optical thin film 51, the base film WB removed during cleaning, and the second thin film portion 62 are all formed by DC sputtering in the same manner as in Example 1.

[0176] Alternatively, the first thin film portion 60 of the optical thin film 51 can be formed by vapor deposition. The process conditions in this case are shown in Table 6 below.

[0177] In the case where the first thin film portion 60 is formed by vapor deposition, if the base film WB removed during cleaning is also formed by vapor deposition (refer to the second and third manufacturing conditions in Table 4, etc.), the first thin film portion 60 and the base film WB removed during cleaning can be formed using the same apparatus, which ensures ease of manufacturing.

[0178] [Table 6]

[0179]

[0180] The fabrication based on DC sputtering in Example 2 was carried out in the same manner as in Example 1 (see Example 1). Figure 3 , Figure 4 ).

[0181] The first thin film section 60 and the case where the base film WB is removed during cleaning are formed by vapor deposition. Figure 3 (A) Figure 3 (B) Utilizing a vapor deposition apparatus, Figure 3 (G) utilizes a sputtering device.

[0182] It should be noted that etching ( Figure 3 (D)~ Figure 3 (E)) and re-etching ( Figure 3 (H)~ Figure 3 Various conditions, such as the immersion time of at least one of (I) can be adjusted according to the characteristics of the first film part 60 (infrared blocking film).

[0183] Characteristics of Example 2, etc.

[0184] Figure 14 , Figure 15 This is a graph showing the transmittance and reflectance distribution of the visible light region and the near-infrared region (750nm to 1200nm) and the adjacent region of the central part 52C surface (central point) of the first thin film part 60 (infrared blocking film) formed in Example 2.

[0185] According to the graph, in the central part 52C of Example 2, the blocking of near-infrared light is mainly achieved through reflection.

[0186] The transmittance and other properties of the peripheral portion 52R surface where the second thin film portion 62 (light-shielding film) is formed in Example 2 are the same as the transmittance and other properties of the rough portion 2R surface where the second thin film portion 12 is formed in Example 1 (see reference). Figure 11 , Figure 12 ).

[0187] Therefore, in the peripheral portion 52R of Embodiment 2, extremely low transmittance is achieved in the visible light region and adjacent regions. With such a peripheral portion 52R having the second thin film portion 12, the infrared blocking member R of Embodiment 2 can sufficiently suppress the generation of internal stray light.

[0188] Summary, etc.

[0189] The manufacturing methods of Examples 1 and 2 are methods for manufacturing optical films 1 and 51 having a first thin film portion 10 and 60 and a second thin film portion 12 and 62 with a different film structure on the film-forming surfaces F and F2 of the substrate 2 and 52. The method includes the following steps: forming the first thin film portion 10 and 60 on the first film-forming surface F and F2; forming a cleaning-removable film W on the first thin film portion 10 and 60, the cleaning-removable film W having a fluffy structure or the like, and being at least one of aluminum and aluminum compounds; forming the second thin film portion 12 and 62 on the second film-forming surface F and F2 that is different from the first film-forming surface, and on the first film-forming surface where the first thin film portion 10 and 60 and the cleaning-removable film W are formed; and removing the cleaning-removable film W and the second thin film portion 12 and 62 thereon by cleaning.

[0190] Thus, an optical thin film with separate first and second thin film portions can be manufactured with high quality and low cost without the use of resist, bridging mask MZ, and organic solvents.

[0191] It should be noted that the term "above" in the context of the film-forming surface, the first film-forming portion, and the second film-forming portion includes: a state in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion; and a state that is not in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion, but is separated from them by an intermediate film and is located above them.

[0192] Furthermore, in the manufacturing methods of Examples 1 and 2, the second film portion 12, 62 is annular or frame-shaped. Therefore, annular or frame-shaped film portions, which were previously difficult to manufacture at low cost and with high quality, can be produced with low cost and high quality.

[0193] Furthermore, in the manufacturing methods of Examples 1 and 2, the cleaning-removable film W is formed by immersing the cleaning-removable base film WB (which is formed by physical vapor deposition using at least one of aluminum and aluminum compounds as materials) in hot water. This readily forms the cleaning-removable film W having the velvety structure and the like required for the formation of the second film portion 12, 62, which is separate from the first film portion 10, 60.

[0194] Furthermore, in the manufacturing methods of Examples 1 and 2, the membrane W and the second thin film portion 12, 62 thereon are cleaned by at least one of running water and ultrasonic waves during cleaning. This simplifies the cleaning process.

[0195] Furthermore, in the manufacturing methods of Examples 1 and 2, the second thin film portion 12, 62 is a light-shielding film that blocks visible light. Thus, a ring-shaped or frame-shaped light-shielding film for dealing with stray light in a lens unit can be formed at low cost and with high quality.

[0196] Furthermore, in the manufacturing methods of Examples 1 and 2, the first thin film portion 10, 60 is an AR film that suppresses the reflection of visible light. Thus, the first thin film portion 10, 60 is given the function of suppressing the reflection of visible light.

[0197] Furthermore, the optical thin film 1,51 of Examples 1 and 2 has a first thin film portion 10,60 and a second thin film portion 12,62 with a different film structure. The second thin film portion 12,62 surrounds the first thin film portion 10,60, and no resist remains in the first thin film portion 10,60.

[0198] Thus, in the optical films 1,51 of Examples 1 and 2, an optical film 1,51 is provided in which the first film portion 10,60 and the second film portion 12,62 are simply separated in a high-quality state without the presence of resist residue as in Patent Document 1 above, and without the formation of thinned portions 12ZT as in the comparative example above.

[0199] Furthermore, in the optical films 1, 51 of Examples 1 and 2, the second film portion 12, 62 is a light-shielding film that blocks visible light. As a result, the optical film 1, 51 having a ring-shaped or frame-shaped light-shielding film for dealing with stray light in the lens unit exhibits high quality.

[0200] Furthermore, in the optical films 1, 51 of Examples 1 and 2, the first film portion 10, 60 is an AR film that suppresses the reflection of visible light. Thus, in the first film portion 10, 60 surrounded by the second film portion 12, 62, the reflection of visible light is suppressed.

[0201] Furthermore, in the process of forming the first thin film portion 10, 60 in Examples 1 and 2 ( Figure 3 (A) Figure 3 (B) Figure 4 (A) Figure 4 In (D), the first thin film portion 10, 60 is formed only on the first film-forming portion (the surface of the lens portion 2L) using the mask M. Therefore, the first thin film portion 10, 60 can be easily formed in a desired shape corresponding to the shape of the mask M.

[0202] [Example 3]

[0203] Composition of optical thin films, etc.

[0204] Example 3 corresponds to the third method described above (light-shielding AR lens component L).

[0205] In Example 3, the structure of the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) are the same as those in Example 1.

[0206] Manufacturing of optical thin films, etc.

[0207] The manufacturing method of Example 3 will be described next.

[0208] It should be noted that the manufacturing method of the optical thin film 1 of the present invention includes the manufacturing apparatus and is not limited to the following methods.

[0209] In the manufacturing method of Example 3, except for its first half, it is constructed in the same way as in Example 1. Figure 16 This is a schematic diagram showing the first half of the manufacturing method of Example 3.

[0210] like Figure 16 As shown in (A), the substrate 2, before film formation, is placed horizontally in the vacuum-sealed film formation chamber of the sputtering film formation apparatus with the film formation surface F (back side) facing upwards. In the manufacturing method of Example 3, unlike the manufacturing method of Example 1, a mask M is not used.

[0211] Next, as Figure 16As shown in (B), the first film portion 10 and the subsequent cleaning process remove the base film WB in the same manner as in Example 1, except that the mask M is not used.

[0212] The first thin film section 10 and the base film WB removed during cleaning are formed on the film-forming surface F of the substrate 2.

[0213] Next, as Figure 16 As shown in (C), the substrate 2 with the first thin film portion 10 and the base film WB removed during cleaning is temporarily removed from the sputtering film forming apparatus, and the first thin film portion 10 and the base film WB removed during cleaning on the rough portion 2R and the peripheral flat portion 2S are irradiated with laser LA.

[0214] By irradiating with laser LA, the first thin film portion 10 on the rough surface 2R and the surrounding flat portion 2S, as well as the base film WB removed during cleaning, are removed. The first thin film portion 10 and the base film WB removed during cleaning are only disposed on the lens portion 2L.

[0215] The power of the laser LA is set to remove the first thin film portion 10 and the base film WB removed during cleaning, without causing shape changes or other effects on the rough surface portion 2R and the peripheral flat portion 2S exceeding a predetermined level. The power of the laser LA can be adjusted in various ways. For example, when at least a predetermined amount of residue of the first thin film portion 10 and the base film WB removed during cleaning is allowed, the power of the laser LA can be lower than the power required for complete removal. Furthermore, when a light-shielding film is formed on the rough surface portion 2R and the peripheral flat portion 2S, and when shape changes (such as the occurrence of micro-damage) are allowed to be below a predetermined level in order not to impair the light-shielding function (to improve the light-shielding function as needed), the power of the laser LA can be greater than the minimum power required for removing the first thin film portion 10 and the base film WB removed during cleaning. By making the power of the laser LA greater than the minimum power in this way, the first thin film portion 10 and the base film WB removed during cleaning can be removed more reliably.

[0216] The laser LA can track the rough portion 2R and the peripheral flat portion 2S according to the size of the spot diameter. For example, the laser LA is irradiated while scanning the rough portion 2R and the peripheral flat portion 2S with a scanning width that is the same as or slightly smaller than the spot diameter. Through such laser LA irradiation, the first thin film portion 10 and the portion where the base film WB was removed during cleaning are patterned, resulting in the patterning of the first thin film portion 10 and the residual portion where the base film WB was removed during cleaning. Figure 16 (D)).

[0217] Thus, the patterned first thin film portion 10 and the substrate 2 from which the base film WB is removed during cleaning are consistent with those of Example 1. Figure 3 (C) is formed in the same way, and implemented withFigure 3 The same treatment applies to (D) afterwards.

[0218] Characteristics of Example 3, etc.

[0219] To investigate the characteristics of Example 3 more diversely and simply, a sample with an optical thin film formed on a parallel plate substrate 2 was prepared using the same manufacturing method as in Example 3. The substrate 2 of the sample was made of polycarbonate and had dimensions of 50 mm in length, 50 mm in width, and 1.0 mm in thickness. Furthermore, the manufacturing method of Example 3 was suitably modified from the manufacturing method of Example 1.

[0220] Figure 17 This is a photograph of the sample. The black area represents the second thin film portion 12 (light-shielding film) and the substrate 2 beneath it; the other areas represent the first thin film portion 10 (AR film) and the substrate 2 beneath it. Figure 17 As shown, optical thin films 1 are formed in various shapes such as black circles, black crosses, white hollow crosses, black thick crosses, white hollow thick crosses, black small rings, and black large rings.

[0221] It should be noted that the manufacturing method of the optical thin film 1 of the present invention is not limited to the manufacturing method of this sample. In addition, the manufacturing method of this sample can suitably have the same modifications as the other manufacturing methods described above.

[0222] The manufacturing process of the sample will be further explained.

[0223] Under the conditions described in Table 6 of Example 2, the first thin film portion 10 (AR film) is vapor-deposited on the entire single side of the substrate 2 of the parallel plate (corresponding to...). Figure 16 (A) Figure 16 (B)). The first thin film section 10 (AR film) has a total of 7 layers, which are alternating layers of SiO2 (odd-numbered layers) and TiO2 (even-numbered layers). The film structure of the first thin film section 10 (AR film) is shown in Table 7 below.

[0224] [Table 7]

[0225] Layer Material Film thickness (nm) 1st layer SiO2 153.5 2nd layer TiO2 14.0 3rd layer SiO2 27.0 4th layer TiO2 62.0 5th layer SiO2 10.5 6th layer TiO2 37.0 7th layer SiO2 96.0

[0226] Furthermore, under the conditions in row 4 of Table 4, an Al layer (corresponding to the base film WB to be removed during cleaning) is formed on the entire single side of the substrate 2 with the first thin film portion 10 (AR film) by DC sputtering. Figure 16 (B)

[0227] Then, patterning is performed by laser LA irradiation (corresponding to...) Figure 16 (C)~ Figure 16(D)). Here, regarding the emission of the laser LA, the MD-X1520 manufactured by Keyence Corporation was used, with a laser LA wavelength of 1.06 μm, a frequency of 40 kHz, a spot diameter of 80 μm, and a scanning speed of 2000 mm / s. The laser LA was based on YAG. The scanning was mainly based on the driving of the galvanometer.

[0228] Patterning is performed by scanning the shape corresponding to the second thin film portion 12 (light-shielding film, black portion) using a laser.

[0229] It should be noted that at least one of the types and settings of the laser LA, and the patterned shape, can be changed as described above. Specifically, regarding the power of the laser LA, it is sufficient to remove the first thin film portion 10 (AR film) and the base film WB during cleaning (with a suitable allowable residual amount). When the overlap of the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) is permitted, the power of the laser LA is sufficient to remove the base film WB removed during cleaning. Furthermore, when the overlap of the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) is permitted, and a residue of less than a certain amount of film W is allowed during cleaning, the power of the laser LA is sufficient to remove (partially remove) the base film WB removed during cleaning with a residue of less than a certain amount.

[0230] Subsequently, as Figure 3 (D)~ Figure 3 As shown in (F), the base membrane WB is removed during cleaning by immersion in hot water HW, resulting in a cleaning membrane W with a fluffy structure, etc.

[0231] In addition, such as Figure 3 As shown in (G), a second film portion 12 (light-shielding film) is formed on the entire single side of the substrate 2, which has the first film portion 10 (AR film) and the film W removed during cleaning. The film structure of the second film portion 12 (light-shielding film) here is the same as the film structure shown in Table 2 above in Example 1.

[0232] And, as Figure 3 (H)~ Figure 3 As shown in (J), by immersion in hot water HW and rinsing with running water, as Figure 3 As shown in (K), a sample having a first thin film portion 10 (AR film) and a second thin film portion 12 (light-shielding film) is formed.

[0233] Figure 18 yes Figure 17 Enlarged view of the lower right part of the thick black cross and the upper right part of the thick white hollow cross. Figure 19yes Figure 17 A magnified view of the small black ring in the image. Figure 20 yes Figure 19 A magnified view of the inner circumference of the lower ring in the image (bright-field image from a microscope). Figure 20 The upper part is the first thin film part 10 (AR film). Figure 20 The lower part is the second film part 12 (light-shielding film).

[0234] These figures (photographs) show patterning with a certain level of quality or higher. Furthermore, the quality of the patterning can be further improved by at least one of reducing the laser LA spot diameter and decreasing the scanning speed.

[0235] Figure 21 This is a graph showing the reflectance distribution of the visible light region and adjacent regions in the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) of the sample.

[0236] As shown in the graph, the first thin film portion 10 (AR film), which is transparent in the visible light region, achieves low reflectivity for visible light. Furthermore, the second thin film portion 12 (sun-shielding film), which has a light-absorbing shading function, also possesses anti-reflective properties in the visible light region and adjacent areas.

[0237] Summary, etc.

[0238] The manufacturing method of Example 3 (sample) is a method for manufacturing an optical thin film 1 having a first thin film portion 10 and a second thin film portion 12 having a different film structure on the film-forming surface F of a substrate 2. The method includes the following steps: forming the first thin film portion 10 on the first film-forming portion of the film-forming surface F; forming a cleaning-removable film W on the first thin film portion 10, wherein the cleaning-removable film W has a velvety structure or the like and is at least one of aluminum and aluminum compounds; forming the second thin film portion 12 on the second film-forming portion of the film-forming surface F that is different from the first film-forming portion, and on the first film-forming portion on which the first thin film portion 10 and the cleaning-removable film W are formed; and removing the cleaning-removable film W and the second thin film portion 12 thereon by cleaning.

[0239] Thus, an optical thin film with separate first and second thin film portions can be manufactured with high quality and low cost without the use of resist, bridging mask MZ, and organic solvents.

[0240] It should be noted that the term "above" in the context of the film-forming surface, the first film-forming portion, and the second film-forming portion includes: a state in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion; and a state that is not in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion, but is separated from them by an intermediate film and is located above them.

[0241] Furthermore, in the process of forming the first thin film portion 10 in Example 3 (sample), the first thin film portion 10 is formed on the entire surface of a portion containing the film-forming surface F of the first film-forming portion. Figure 16 (A) Figure 16 After (B)), the first thin film portion 10 on the portion of the film-forming surface F other than the first film-forming portion (the second film-forming portion) is removed by laser LA. Figure 16 (C)~ Figure 16 (D)).

[0242] Therefore, the first thin film portion 10 (the second thin film portion 12) can be patterned in any shape. In addition, when the second thin film portion 12 is a light-shielding film, damage to the second film-forming portion caused by removal using laser LA (e.g., turbidity, surface roughness, surface dissolution, residue of at least one of the first thin film portion 10 and the base film WB removed during cleaning) is permissible, it is easier to set the laser LA for removal, and the optical thin film 1 can be manufactured more efficiently.

[0243] Symbol Explanation

[0244] 1,51··Optical thin film, 2,52··Substrate, 10,60··First thin film section, 12,62··Second thin film section, F,F2··Film forming surface, W··Film removed during cleaning, WB··Base film removed during cleaning.

Claims

1. A method for manufacturing an optical thin film, comprising manufacturing an optical thin film having a first thin film portion and a second thin film portion having a film structure different from the first thin film portion directly or through an intermediate film on the film-forming surface of a substrate, characterized in that the method includes the following steps: The process of forming the first thin film portion on the first film-forming portion of the film-forming surface; The process of forming a cleaning-removable film on the first thin film portion, wherein the cleaning-removable film has at least one of a villous structure, a pyramidal structure, and a sponge-shaped structure, and is at least one of aluminum and aluminum compounds. The process of forming the second film portion on a second film-forming portion different from the first film-forming portion on the film-forming surface, and on the first film-forming portion on which the first film portion is formed and the film is removed during the cleaning process; and The process of removing the membrane and the second thin film portion thereon during the cleaning process.

2. The method for manufacturing an optical thin film as described in claim 1, characterized in that, The second thin film portion is annular or frame-shaped.

3. The method for manufacturing an optical thin film as described in claim 1, characterized in that, The cleaning-removable film is formed by immersing a cleaning-removable base film in hot water, which is formed by physical vapor deposition using at least one of aluminum and aluminum compounds as materials.

4. The method for manufacturing an optical thin film as described in claim 1, characterized in that, During the cleaning process, the membrane and the second thin film portion thereon are cleaned by at least one of running water and ultrasonic waves.

5. The method for manufacturing an optical thin film as described in claim 1, characterized in that, The second thin film portion is a light-shielding film that blocks visible light.

6. The method for manufacturing an optical thin film as described in claim 1, characterized in that, The first thin film portion is an anti-reflective film that suppresses the reflection of visible light.

7. The method for manufacturing an optical thin film as described in any one of claims 1 to 6, characterized in that, In the process of forming the first thin film portion, the first thin film portion is formed only on the first film-forming portion using a mask.

8. The method for manufacturing an optical thin film as described in any one of claims 1 to 6, characterized in that, In the process of forming the first thin film portion, after the first thin film portion is formed on the film-forming surface or the entirety or part of the intermediate film that includes the first film-forming portion, the first thin film portion on the film-forming surface or part of the intermediate film other than the first film-forming portion is removed by laser.

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