JP5067072B2 - Manufacturing method of long ND filter - Google Patents

Description

The present invention relates to an absorptive multilayer ND filter that attenuates transmitted light in the visible range, and in particular, using a roll-to-roll vacuum film forming apparatus, leaving undeposited portions on both sides of a long resin film substrate. The present invention relates to a method for producing a long ND filter that can easily produce a long ND filter provided with a plurality of absorption multilayer films.

  Recently, ND filters that attenuate transmitted light in the visible range have been widely used, and this type of ND (Neutral Density Filter) filter includes a reflective ND filter that reflects and attenuates incident light, Absorptive ND filters that absorb and attenuate incident light are known. In addition, when an ND filter is incorporated in a lens optical system in which reflected light is a problem, an absorption ND filter is generally used. In this absorption ND filter, an absorbing substance is mixed in the substrate itself (colored glass ND filter) or There are a type in which an absorbing material is applied and a type in which the thin film formed on the surface of the substrate has no absorption and has absorption. In the latter case, an absorption-type multilayer ND filter is also known in which the thin film is formed of a multilayer film to prevent reflection on the surface of the thin film, and has an antireflection effect as well as a function of attenuating transmitted light.

By the way, in the above-mentioned absorption type multilayer ND filter used for a small and thin digital camera, it is necessary to make the substrate itself thin because of a small installation space, and a resin film is an optimum substrate. As this type of absorption multilayer ND filter (hereinafter sometimes referred to as ND filter), Patent Document 1 discloses that an absorption multilayer film is composed of an oxide dielectric film layer such as SiO ₂ and Ni. An ND filter composed of a metal absorption film layer is disclosed.

  When this type of ND filter is incorporated into a digital camera or the like, the ND filter is cut to form an ND filter chip, and the ND filter chip is fixed to a metal plate or a resin plate by an adhesive or laser fusion or the like. It was necessary to form a unit. The laser fusion means that the ND filter chip is irradiated with a laser to melt the resin film substrate of the chip and fixed to a metal plate or a resin plate.

  When the ND filter chip is fixed to the metal plate or the resin plate constituting the ND filter unit with an adhesive or the like, the absorption film is present on the resin film substrate of the ND filter chip. And the metal plate and the resin plate cannot be directly bonded, and the absorption multilayer film on the resin film substrate is directly bonded to the metal plate and the resin plate. For this reason, the adhesive strength between the metal plate / resin plate and the ND filter chip depends on the adhesive strength between the metal plate / resin plate and the absorption multilayer film, and this adhesive strength is based on the value required for the ND filter unit. There is concern that it will be lowered.

  The ND filter chip is obtained by cutting the ND filter. And since the absorption type multilayer film of patent document 1 in which the oxide dielectric film was used is hard like glass, when an ND filter is cut and processed, a crack (crack) will arise in an absorption type multilayer film. When this ND filter chip is incorporated in a digital camera or the like, there is a concern that the cracked film peels off and adheres to a driving part such as a shutter or an aperture, causing malfunction.

  Therefore, in the invention described in Patent Document 2, a part of the resin film substrate 1 is covered with a mask 2 as shown in FIG. A method of forming a film by shielding the part from a vapor deposition source or a sputtering source is employed. As a constituent material of the mask 2, a metal plate or a resin sheet having no flexibility is used.

According to the method using the mask, the absorptive multilayer film 3 is formed only on the resin film substrate 1 exposed from the mask 2, and the absorptive multilayer film is not deposited on the portion shielded by the mask 2. When the obtained ND filter is cut to obtain the ND filter chip, the ND filter is cut along the region where the absorption-type multilayer film 3 is not formed (unformed part), so that the periphery of the absorption-type multilayer film is obtained. An ND filter chip that leaves an undeposited portion can be manufactured. Therefore, when the ND filter is cut, it is possible to avoid the above-described cracking of the absorption multilayer film, and the above-mentioned non-film formation portion of the ND filter chip is used as a metal plate or a resin plate of the ND filter unit. Therefore, it is expected that the adhesive strength between the metal plate or resin plate and the ND filter chip can be improved.
JP 2006-178395 A JP 2005-345747 A

  By the way, in the film forming method described in Patent Document 2, it is difficult to use a resin film substrate having a large area in order to ensure the uniformity of the film thickness distribution of the absorption multilayer film. Only batch production using a sheet-shaped resin film substrate was possible, and the production efficiency was poor. In this case, the long resin film base material wound up in a roll shape is sequentially unwound, and the long resin film base material is wound using a roll-to-roll vacuum film forming apparatus while winding the resin film base material. A method of continuously forming a film on top is also conceivable. However, in this method, it is practically difficult to fix a mask made of a metal plate or the like to a moving long resin film substrate. Treatment application was difficult.

The present invention has been made paying attention to such problems, and the problem is that a roll-to-roll vacuum film forming apparatus is used to leave undeposited portions on both sides of a long resin film substrate. Another object of the present invention is to provide a method for easily producing a long ND filter provided with a plurality of absorption multilayer films.

That is, the invention according to claim 1
A long ND comprising a long resin film substrate and a plurality of absorption-type multilayer films that are provided on both surfaces of the resin film substrate with a gap between them and whose shapes and positions coincide with each other on the front and back surfaces On the premise of a method of manufacturing a filter using a roll-to-roll vacuum film forming apparatus,
A lengthy masking film whose thickness dimension is larger than the film thickness of the absorption multilayer film is pasted on both sides of the long resin film substrate, and a shape provided on each of the front and back side long masking films, A sticking step of shielding the long resin film substrate front and back surfaces with the front side and the back side long masking film except for the portions exposed from the plurality of openings whose positions are matched ,
On the front and back surfaces using a roll-to-roll vacuum film forming device , the shape and the surface are exposed from the openings on both sides of the long resin film substrate to which the long side masking film on the front side and the back side is attached. a film forming process position is respectively absorptive multilayer film are matched,
After the above film forming step, the surface-side long masking film affixed to the surface side of the long resin film substrate is peeled to expose the absorption multilayer film formed on the surface side of the long resin film substrate. An exfoliating step,
A half-cut mold is applied from the surface side of the long resin film substrate where the absorption multilayer film is exposed, and the long-cut resin film substrate is cut through the half-cut mold. A half-cut processing step for half-cutting the back-side long masking film without penetrating the half-cut mold,
And the above-mentioned front-side and back-side long masking film is made of a resin film, and the glass transition point of this resin film is 85 ° C. or higher .

The invention according to claim 2
Based on the manufacturing method of the long ND filter according to the invention of claim 1,
In the attaching step, the opening of the long masking film is provided after the masking film is attached to the long resin film substrate,
The invention according to claim 3
Based on the manufacturing method of the long ND filter according to the invention of claim 1,
In the attaching step, the opening of the long masking film is provided before the masking film is attached to the long resin film substrate.

Next, the invention according to claim 4 is:
Based on the manufacturing method of the long ND filter according to any one of claims 1 to 3,
The film formation by the roll-to-roll vacuum film formation apparatus is a sputtering film formation,
The invention according to claim 5
Based on the manufacturing method of the long ND filter according to any one of claims 1 to 4,
The short dimension between the adjacent openings of the long masking film is set wider than the width dimension of the cutting margin when the long ND filter is cut to obtain the ND filter chip. age,
The invention according to claim 6
Based on the manufacturing method of the long ND filter according to any one of claims 1 to 5,
The long masking film has a thickness dimension of 20 μm or more and 110 μm or less .

According to the method for producing a long ND filter according to the present invention,
Site long on both sides of the elongated resin film substrate affixed to elongate masking film, exposed through a plurality of openings where the surface side and each provided with shape and position on the back side elongate masking film meets Since the front and back surfaces of the long resin film substrate are shielded by the long side masking film on the front side and the back side , except for, the interval formed by the non-deposited part using a roll-to-roll vacuum film forming apparatus A plurality of absorptive multilayer films having the same shape and position on the front surface and back surface can be formed continuously.

Moreover , since the long masking film whose thickness dimension is larger than the film thickness of the absorptive multilayer film is pasted on both surfaces of the long resin film substrate, the front side and the back surface on the long resin film substrate Since each absorption-type multilayer film formed in the portion exposed from the side long masking film opening does not protrude outward from the above-mentioned opening, there are scratches on the outer surface of the absorption-type multilayer film during production. It is never formed.
Furthermore, a half-cut mold is allowed to act from the surface side of the long resin film substrate where the absorption type multilayer film is exposed, and the above-mentioned half-cut mold is cut through the long resin film substrate. On the other hand, since the back side long masking film is half cut without penetrating the half cut mold, the ND filter chip is held by the back side long masking film. It is possible to prevent the filter chip from scattering.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, FIG. 1 is explanatory drawing which shows the manufacturing process of the elongate ND filter based on this invention.

That is, in the method for producing a long ND filter according to the present invention, a long masking film is pasted on both sides of a long resin film substrate, and a plurality of openings provided in the long masking film are used. After forming the absorption multilayer film using a roll-to-roll vacuum film forming device on the exposed part, the long masking film is peeled off from the long resin film substrate on which multiple absorption multilayer films are formed. Thus, a long ND filter is manufactured.

Here, the roll-to-roll vacuum film forming apparatus will be described. A first roll and a second roll for winding and unwinding the long resin film substrate are arranged in the film forming chamber. By winding the long resin film substrate wound around one roll around the second roll, the long resin film substrate is conveyed in the film forming chamber. In addition, an absorption multilayer film forming mechanism is provided in the conveyance path between the first roll and the second roll so that the absorption multilayer film is formed on both surfaces of the long resin film substrate. It has become. The film formation mechanism includes sputtering, electron beam evaporation, ion beam sputtering, etc., but sputtering film formation is preferred. This is because sputtering film formation is superior in controllability of film thickness distribution compared to other film formation methods.

  FIG. 3 shows an outline of a roll-to-roll sputtering film forming apparatus as an example of a roll-to-roll vacuum film forming apparatus.

  That is, this roll-to-roll sputtering film forming apparatus is provided in a sputtering chamber, and includes a first roll 4 and a second roll 5 that wind and unwind a long resin film substrate, and a first roll 4. The water-cooled can roll 6 provided in the conveyance path between the first roll 4 and the second roll 5, and between the first roll 4 and the water-cooled can roll 6 and the second roll 5 and the water-cooled can Four guide rolls 61, 62, 63, 64 provided between the roll 6 and the first roll 4 and the second roll 5 are kept in tension balance by a powder clutch. Moreover, the conveyance direction of a long resin film base material is determined by rotation of the water-cooled can roll 6, and in this specification, the long resin film base material is changed from the first roll 4 to the second roll. The rotation direction of the water-cooled can roll 6 wound on the 5 side is defined as the normal rotation direction, and the rotation direction of the water-cooled can roll 6 wound on the second roll 5 from the first roll 4 side is defined as the reverse rotation direction.

In the sputtering chamber, two sputtering cathodes 7 and 8 are disposed along the outer peripheral surface of the water-cooled can roll 6. One of the sputtering cathodes 7 has an oxide dielectric film layer (for example, a SiO ₂ film layer). A target (not shown) for forming a metal absorption film layer (for example, Ni alloy layer) is attached to the other sputtering cathode 8.

And at the time of forward conveyance by which a long resin film base material is wound up from the 1st roll 4 to the 2nd roll 5 side, with respect to the long resin film base material conveyed along the water-cooled can roll 6 outer peripheral surface After winding the long resin film substrate with the second roll 5 while forming an oxide dielectric film layer (for example, SiO ₂ film layer) with one sputtering cathode 7, the rotation direction of the water-cooled can roll 6 is changed. At the time of reverse conveyance of the long resin film substrate, the metal absorbing film layer (for example, Ni alloy) is formed by the other sputtering cathode 8 on the long resin film substrate conveyed along the outer peripheral surface of the water-cooled can roll 6. Layer) is wound up by the first roll 4, and thereafter, these steps are repeated to form an absorption multilayer film in which an oxide dielectric film layer and a metal absorption film layer are alternately laminated. It can be formed on one side of the base material. In addition, film thickness control of an absorption type multilayer film can be performed by controlling the conveyance speed of a elongate resin film base material.

  And since the continuous film formation of the absorption type multilayer film becomes possible by transporting the long resin film substrate through the film forming chamber of the roll-to-roll vacuum film forming apparatus, the batch type vacuum film forming apparatus Productivity higher than when used is possible.

  FIG. 4A is a schematic cross-sectional view showing a state in which a long masking film 10 having a plurality of openings is provided on one side of a long resin film substrate 9. The long masking film 10 is a long mask provided with a plurality of openings, and the exposed portion is formed by exposing the surface of the long resin film substrate 9 through the openings. And it absorbs on the exposed part of the elongate resin film base material 9 and the said elongate masking film 10 with a roll-to-roll vacuum film-forming apparatus as shown to FIG. 4 (A) and FIG. 4 (B). A mold multilayer film 11 is formed. In FIG. 4B, the display of the absorption multilayer film 11 formed on the long masking film 10 is omitted. Further, the shape of the absorption multilayer film 11 formed on the long resin film substrate 9 is appropriately selected and determined by the shape of the opening provided in the long masking film 10.

  Here, when sticking the elongate masking film 10 to the elongate resin film base material 9, care is required so that air bubbles may not enter between them. If air bubbles enter between the long resin film substrate 9 and the long masking film 10, contamination may occur in the roll-to-roll vacuum film forming apparatus, or the exposed portion in the long resin film substrate 9. This is because there is a possibility of causing a position shift of. In addition, in order to stick so that air bubbles may not enter between the long resin film substrate 9 and the long masking film 10, it is desirable to use a laminator that is pressure-bonded with a press roll having a roll-to-roll structure.

  The long masking film is affixed to a long resin film substrate and conveyed through the roll-to-roll vacuum film forming apparatus together with the long resin film substrate. In a roll-to-roll vacuum film forming apparatus, when masking is performed using a mask composed of a metal plate or the like, the mask is detached when the long resin film substrate is transported in a bent part such as a roll. End up. When the mask is detached, it is necessary to overlap the mask every time the respective layers are formed, so that the mask alignment becomes complicated. Furthermore, since it is necessary to stop the rotation of the roll on the winding side when the masks are stacked, the long resin film substrate cannot be wound with a uniform force, and the long resin film substrate cannot be wound. There is also concern that the unevenness of the film is caused and the long resin film substrate or the absorption multilayer film is damaged. Moreover, since the conveyance speed of the long resin film substrate cannot be kept constant due to uneven winding of the long resin film substrate, the film thickness of the absorption multilayer film cannot be kept constant, and the resulting ND filter Variations in the transmissivity of the light will occur. In addition, the said sticking is bonding together so that a long masking film may not peel from a long resin film base material, when carrying out roll conveyance of a long masking film with a long resin film base material. If the long masking film is peeled off from the long resin film substrate during film formation, positioning of the long masking film becomes complicated. It is to do.

  As a means for sticking the long masking film to the long resin film substrate, there is a method using an adhesive, and an adhesive is applied to the surface of the long masking film in contact with the long resin film substrate. The method of sticking is illustrated. In addition, the adhesive strength of the adhesive is such that the long masking film does not peel off when the long resin film substrate is wound around the first or second roller, and an absorption multilayer film is formed. The strength is arbitrary as long as it is an adhesive force capable of intentionally peeling the long masking film from the long resin film substrate later. The type of the adhesive is arbitrary as long as it does not erode the long masking film or the long resin film substrate. The specific adhesive strength of the adhesive is 0.05 N / 20 mm or more as measured by a method in accordance with “180 ° peeling adhesive strength to test plate” described in JIS Z0237 (revised in 2000). 0.90 N / 20 mm or less. If the above value is 0.05 N / mm or more, the long masking film will not be peeled off during the conveyance of the long resin film substrate, and if the above value is 0.90 N / 20 mm or less, it is long. The long masking film can be intentionally peeled from the long resin film substrate. However, it is desirable that no adhesive remains on the long resin film substrate after the long masking film is peeled off. If the adhesive of the long masking film remains on the long resin film substrate, when the long ND filter is cut to obtain a sheet-like ND filter or ND filter chip, the press mold becomes long. It may become impossible to penetrate the scale-shaped resin film substrate. In addition, since the resin film substrate surface is not flattened by the remaining adhesive, there may be a problem when the ND filter chip is bonded or laser-welded to the metal plate or resin plate of the ND filter unit.

  Next, the opening of the long masking film can be formed before or after applying the long masking film to the long resin film substrate. In order to form the opening after pasting, it is possible to make a cut in the attached long masking film with a press die or the like and remove the inside of the cut with vacuum tweezers or the like. Moreover, in order to form the said opening part before sticking, it can form using a press die etc., for example, just before sticking a long masking film and a long resin film base material with the laminator mentioned above. You may carry out so that an opening part may be provided in.

Moreover, it is preferable that the short dimension between the adjacent openings of the long masking film is set wider than the width of the cutting margin when the long ND filter is cut to obtain the ND filter chip. . This is because when the dimension with a short interval between the openings is set wider than the width dimension of the cutting margin, an ND filter chip in which an undeposited part is left in the peripheral part of the absorption multilayer film can be obtained. When the ND filter chip has an undeposited portion, when the ND filter chip is fixed to the metal plate or resin plate of the ND filter unit, the resin film substrate surface of the ND filter chip is directly bonded to the metal plate or resin plate. Can be fused.

  Here, the cutting margin corresponds to an undeposited portion left in the periphery of the absorption multilayer film in the obtained ND filter chip when the ND filter chip is obtained by cutting the long ND filter, When cutting with a press die or the like, the value obtained by adding a width dimension that does not cause bending deformation of the ND filter chip when pressed to the blade width dimension of the mold becomes the cutting margin, and the above cutting is performed with a laser. When performing, the value obtained by adding a width dimension that does not cause thermal deformation of the ND filter chip when the laser is cut to the width dimension of the beam is the cutting margin. The specific numerical value of the cutting margin is usually about several hundred μm although it depends on the accuracy of the processing position alignment.

Next, in order to form the absorption multilayer film on the front and back of the long resin film substrate, the long masking film may be attached to the front and back of the long resin film substrate. If the shape and position of the opening of each long masking film affixed to the front and back of the long resin film base material match the front and back of the long resin film base material, the same absorption multi-layer A long ND filter having films formed on the front and back sides can be obtained.

  FIG. 6 is an explanatory view showing a process of peeling the long masking film 13 having the opening 14 after the absorption multilayer films 15 and 16 are formed on the front and back of the long resin film substrate 12, and FIGS. 8 is an explanatory view showing a process of manufacturing the ND filter chip 100 by cutting the obtained long ND filter 50.

  That is, as shown in FIG. 6, by peeling the long masking film 13 from the long resin film substrate 12 having the absorption multilayer films 15 and 16 formed on the front and back thereof, the long masking film 13 The long ND filter 50 in which the absorption multilayer films 15 and 16 are formed only in the portion corresponding to the opening 14 can be obtained.

  Further, as shown in FIG. 7A, by cutting a long ND filter 50 in which absorption multilayer films 18 and 19 are formed on the front and back of a long resin film substrate 17 with a press die 20. 7B, the resin film substrate 17 and the absorption multilayer film 18 formed on the front and back of the resin film substrate 17 are formed, and an undeposited portion having a width dimension α in the periphery of the absorption multilayer film 18 The ND filter chip 100 having the above can be manufactured.

  Further, as shown in FIG. 8, a long masking film on the back side of a long ND filter 50 composed of a long resin film substrate 21 and absorption multilayer films 23 and 24 formed on the front and back sides. The ND filter chip can also be manufactured by half-cutting with the half-cut mold 25 before removing 22. In addition, as shown in FIG. 8, half-cut processing means that the long resin film substrate 21 of the long ND filter 50 is cut through the half-cut mold 25, but the long resin. The long masking film 22 affixed to the film base 21 means processing that does not allow the half-cut mold 25 to penetrate. Since the ND filter chip is held by the long masking film 22 by the half-cut process without cutting the long masking film 22, the ND filter chip can be prevented from scattering. For the half-cut processing, the surface to which the long masking film 22 or the like that does not want to penetrate the half-cut mold 25 is attached as the back side, and the half-cut mold 25 is used from the front side of the long ND filter 50. Process it.

  In the present invention, since the thickness dimension of the long masking film is set larger than the film thickness of the absorption multilayer film, the long masking film is formed in a portion exposed from the long masking film opening on the long resin film substrate. In addition, each absorption multilayer film does not protrude outward from the opening. Accordingly, since the outer surface of the absorption multilayer film does not come into contact with the first or second roller, the guide roller, or the like during the manufacturing process, no scratches or the like are formed on the absorption multilayer film.

  As for the specific thickness dimension of the said elongate masking film, 20 micrometers or more and 110 micrometers or less are desirable. When the thickness exceeds 110 μm, the half-cut mold penetrates deeply when half-cut, and the half-cut mold is a tapered blade, so the penetrated blade width becomes thick. Deformation of the long masking film occurs. Then, the absorbing multi-layer film is subjected to compressive stress by the intruding blade or the deformed long masking film, and cracking may occur. Furthermore, in the case of a long masking film having a thickness exceeding 110 μm, when half-cut, the long ND filter may bite into the long masking film and the bending absorption multilayer film may be broken. On the other hand, if the thickness of the long masking film is less than 20 μm, there may be a problem in mechanical strength.

  Next, a resin film etc. are mentioned as a material of a elongate masking film. When the long masking film is composed of a resin film, etc., the surface of the long masking film becomes smooth, so the long resin film substrate with the long masking film attached to the first or second roller. When wound up, the long resin film substrate is not damaged.

  And when a long masking film is comprised with a resin film, it is desirable for a glass transition point to become 85 degreeC or more. This is because when the glass transition point is lower than 85 ° C., the long masking film may melt when the absorption multilayer film is formed on the long resin film substrate. When the absorption multilayer film is formed, the temperature on the film forming side (the film forming surface side of the long resin film substrate) increases. For example, in the case of the roll-to-roll sputtering film forming apparatus shown in FIG. 3, since the long resin film substrate is wound around the water-cooled can roll 6, heat is removed, but the long masking film is long. Since heat is removed via the long resin film substrate, heat is less likely to be removed than the long resin film substrate. For this reason, it is desirable that a glass transition point is 85 degreeC or more.

  Next, the material of the long resin film substrate is not particularly limited. Specific examples thereof include a resin film alone selected from polyethylene terephthalate (PET), polyethersulfone (PES), polyarylate (PAR), polycarbonate (PC), polyolefin (PO), norbornene resin material, or the like. Examples thereof include a composite of a resin film alone selected from materials and an acrylic organic film covering one or both sides of this single body. In particular, as for the resin material of norbornene, representative examples include ZEONOR (trade name) manufactured by Nippon Zeon Co., Ltd. and Arton (trade name) manufactured by JSR Corporation.

Here, in the present invention, the long ND filter means an ND filter comprising a long resin film substrate and a plurality of absorption multilayer films provided on both surfaces of the resin film substrate with a space therebetween. Say. Further, the sheet-like ND filter is formed by cutting the long ND filter into an arbitrary length, and is provided on both surfaces of the sheet-like resin film substrate and the resin film substrate with a space therebetween. An ND filter comprising a plurality of absorption multilayer films. Further, the ND filter tip, the elongate ND filter or constructed by cutting a sheet-like ND filter, a single absorption-type multi-layer film provided on both surfaces of the resin film substrate the resin film substrate An ND filter comprising:

  Examples of the present invention will be specifically described below.

  First, a film structure (see Table 1) of an absorptive multilayer ND filter having an average transmittance of 6.3% at a wavelength of 400 to 700 nm was designed. FIG. 5 shows the spectral transmittance of the designed absorption multilayer ND filter. The spectral transmission characteristics of the ND filter were measured using a self-recording spectrophotometer (V570 manufactured by JASCO Corporation).

吸収型多層膜の成膜には図３に示したロール・ツー・ロール・スパッタリング成膜装置を用い、金属吸収膜を成膜するためのターゲットとしてＮｉ合金ターゲット［住友金属鉱山（株）社製］を用い、酸化物誘電体膜であるＳｉＯ_２を成膜するためのターゲットとしてＳｉターゲット［住友金属鉱山（株）社製］を用いた。また、上記Ｎｉ合金ターゲットはＡｒガスを導入するＤＣマグネトロンスパッタリングにより成膜され、一方、ＳｉターゲットはＡｒガスを導入するデュアルマグネトロンスパッタリングにより成膜され、ＳｉからＳｉＯ_２を成膜するためにインピーダンスモニター（ボンアルデンヌ社製 プラズマエミッションモニター）により酸素導入量を制御した。

The roll-to-roll sputtering film forming apparatus shown in FIG. 3 is used to form the absorption multilayer film, and a Ni alloy target [manufactured by Sumitomo Metal Mining Co., Ltd.] is used as a target for forming the metal absorption film. The Si target [manufactured by Sumitomo Metal Mining Co., Ltd.] was used as a target for depositing SiO ₂ which is an oxide dielectric film. The Ni alloy target is formed by DC magnetron sputtering that introduces Ar gas, while the Si target is formed by dual magnetron sputtering that introduces Ar gas, and an impedance monitor is used to form SiO ₂ from Si. The amount of oxygen introduced was controlled by a plasma emission monitor manufactured by Bon Ardennes.

Moreover, a PET film with a double-sided easy-adhesion layer (manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was used as the long resin film substrate. In addition, the long masking film has a 65 μm thick polyethylene laminate film (Nitto Denko Corporation: E-MASK R-200, adhesive strength: 0.5 N / 20 mm, with openings of 10 mm pitch and 5 mm diameter). ), The short dimension of the gap between the opening of the long masking film and the adjacent opening is 5 mm. In addition, about the said elongate masking film, a 50-micrometer-thick polyethylene laminated film (Nitto Denko KK-made: E-MASK RB-300S, adhesive force: 0.35N / 20mm), and a 59-micrometer-thick polyester laminate A film (manufactured by Nitto Denko Corporation: E-MASK RP-300, adhesive strength: 0.25 N / 20 mm) may be used.

  Then, an absorption multilayer film was formed by the following procedure.

  1) The above long masking film was pasted on both sides of a long resin film substrate.

2) The sputtering chamber of the roll-to-roll sputtering film forming apparatus shown in FIG. 3 was evacuated to about 1 × 10 ⁻⁴ Pa.

  3) The conveyance speed of the long resin film substrate was adjusted to 1.50 m / min, and the long resin film substrate was conveyed in the forward direction from the first roll 4 to the second roll 5.

4) 100 sccm of Ar gas was introduced into the sputtering cathode 7 to which the Si target was attached, and SiO ₂ was deposited at a sputtering output of 10 kW. The amount of oxygen introduced was controlled by an impedance monitor.

  5) The conveying speed of the long resin film substrate was adjusted to 0.94 m / min and conveyed in the reverse direction.

  6) Ar gas was introduced at 100 sccm to the sputtering cathode 8 to which the Ni alloy target was attached, and a Ni alloy film layer was formed at a sputtering output of 1 kW.

  7) The transport speed of the long resin film substrate was adjusted to 0.43 m / min and transported in the forward direction.

8) Ar gas was introduced at 100 sccm to the sputtering cathode 7 to which the Si target was attached, and SiO ₂ was deposited at a sputtering output of 10 kW. The amount of oxygen introduced was controlled by an impedance monitor.

  9) The conveying speed of the long resin film substrate was adjusted to 0.94 m / min and conveyed in the reverse direction.

  10) Ar gas was introduced at 100 sccm to the sputtering cathode 8 to which the Ni alloy target was attached, and a Ni alloy film layer was formed at a sputtering output of 1 kW.

  11) The transport speed of the long resin film substrate was adjusted to 0.46 m / min and transported in the forward direction.

12) Ar gas was introduced at 100 sccm into the sputtering cathode 4 to which the Si target was attached, and SiO ₂ was deposited at a sputtering output of 10 kW. The amount of oxygen introduced was controlled by an impedance monitor.

  13) Take out the long resin film base material on which the film formation on one side (front surface) has been completed, reverse the front and back, set it on the first roll 1, and repeat the above steps 2) to 12) to make it long. An absorptive multilayer film was also formed on the back surface of the resin film substrate.

  14) The long resin film substrate having the absorption multilayer film formed on both the front and back surfaces was taken out of the sputtering chamber.

  15) The long masking film is peeled off from the long resin film substrate on which both sides of the absorption multilayer film are formed to obtain a long ND filter, and each of the obtained long ND filters is obtained. An ND filter chip was obtained by punching and pressing with a press die centering on the absorption multilayer film.

  The manufacturing method of the long ND filter according to the present invention is excellent in productivity and also excellent in the bondability of the ND filter chip required for the long ND filter to a metal plate or a resin plate. The present invention has industrial applicability for use in digital cameras and mobile phones with cameras.

Explanatory drawing which shows the manufacturing process of the elongate ND filter which concerns on this invention. Explanatory drawing which shows the manufacturing mounting method of the conventional ND filter which leaves a non-film-forming part and forms a several absorption multilayer film in a resin film base material. BRIEF DESCRIPTION OF THE DRAWINGS Schematic structure explanatory drawing of the roll-to-roll sputtering film-forming apparatus used by this invention. FIG. 4A is a schematic cross-sectional view showing a state in which a long masking film having a plurality of openings provided on one side of a long resin film substrate is attached, and FIG. ) Is a plan view of a long resin film substrate in FIG. The graph which shows the spectral transmittance of the ND filter which concerns on this invention. The schematic sectional drawing which shows the manufacturing process of a elongate ND filter . Figure 7 (A) is a schematic sectional view showing a step of obtaining the ND filter tip by cutting the elongated ND filter, FIG. 7 (B) a plan view of the resulting ND filter tip. The schematic sectional drawing which shows the half cut process of the manufacturing method which concerns on this invention .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin film base material 2 Mask 3 Absorption type multilayer film 4 1st roll 5 2nd roll 6 Water-cooled can roll 7 Sputtering cathode 8 Sputtering cathode 9 Elongated resin film base material 10 Elongated masking film 11 Absorption type multilayer film 12 Long resin film substrate 13 Long masking film 14 Opening 15 Absorbing multilayer film 16 Absorbing multilayer film 17 Long resin film substrate 18 Absorbing multilayer film 19 Absorbing multilayer film 20 Press mold 21 Long Scale-shaped resin film base material 22 Long-length masking film 23 Absorption-type multilayer film 24 Absorption-type multilayer film 25 Half-cut mold 50 Long-length ND filter 61 Guide roll 62 Guide roll 63 Guide roll 64 Guide roll 100 ND filter chip

Claims (6)

A long ND comprising a long resin film substrate and a plurality of absorption-type multilayer films that are provided on both surfaces of the resin film substrate with a gap between them and whose shapes and positions coincide with each other on the front and back surfaces In a method for producing a filter using a roll-to-roll vacuum film forming apparatus,
A lengthy masking film whose thickness dimension is larger than the film thickness of the absorption multilayer film is pasted on both sides of the long resin film substrate, and a shape provided on each of the front and back side long masking films, A sticking step of shielding the long resin film substrate front and back surfaces with the front side and the back side long masking film except for the portions exposed from the plurality of openings whose positions are matched ,
A portion exposed from the surface side and back surface side elongate masking film affixed to the elongated resin film substrate side of the opening, and its shape on the front and back surfaces using a roll-to-roll vacuum deposition apparatus a film forming process position is respectively absorptive multilayer film are matched,
After the above film forming step, the surface-side long masking film affixed to the surface side of the long resin film substrate is peeled to expose the absorption multilayer film formed on the surface side of the long resin film substrate. An exfoliating step,
A half-cut mold is applied from the surface side of the long resin film substrate where the absorption multilayer film is exposed, and the long-cut resin film substrate is cut through the half-cut mold. A half-cut processing step for half-cutting the back-side long masking film without penetrating the half-cut mold,
A long ND filter characterized in that the front side and back side long masking films are made of a resin film, and the glass transition point of the resin film is 85 ° C. or higher. Manufacturing method.   2. The method for producing a long ND filter according to claim 1, wherein, in the attaching step, the opening of the long masking film is provided after the masking film is attached to a long resin film substrate. .   In the said sticking process, the opening part of the said elongate masking film is provided before a masking film is affixed on a elongate resin film base material, The manufacture of the elongate ND filter of Claim 1 characterized by the above-mentioned. Method.   The method for producing a long ND filter according to any one of claims 1 to 3, wherein the film formation by the roll-to-roll vacuum film formation apparatus is a sputtering film formation. The short dimension between the adjacent openings of the long masking film is set wider than the width dimension of the cutting margin when the long ND filter is cut to obtain the ND filter chip. The manufacturing method of the elongate ND filter in any one of Claims 1-4. The method for producing a long ND filter according to any one of claims 1 to 5, wherein a thickness of the long masking film is 20 µm or more and 110 µm or less .

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