JP2006058473A - Dielectric multilayered film filter and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dielectric multilayered film filter and its manufacturing method by which production yield is high, production cost is low and further a filter of large area and an optional shape can be formed. <P>SOLUTION: In the dielectric multilayered film filter, in which dielectric films 2 of a low refractive index material and a high refractive index material are laminated in multiple times on a substrate, the ssubstrate is a resin sheet 1 having ≤0.5mm thickness, self-holding nature and flexibility. Preferably the resin sheet is constituted of a polyimide resin or a fluorinated polyimide resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dielectric multilayer filter and a manufacturing method thereof, and more particularly, to a dielectric multilayer filter having a high productivity, a large area and an arbitrary shape, and a manufacturing method thereof.

At present, in an optical communication or optical measurement system, a dielectric multilayer filter is frequently used as an optical component for selecting an optical wavelength. In the conventional dielectric multilayer filter, as shown in FIG. 3, a dielectric multilayer film 21 made of TiO ₂ / SiO ₂ or the like is formed on a glass substrate 20 and a dicing saw is used as indicated by a dotted line B. The dielectric multilayer filter of the required size is manufactured by cutting.

In the manufacturing method of the dielectric multilayer filter shown in FIG. 4, in order to reduce the thickness of the support that supports the dielectric multilayer film, as shown in Patent Document 1, a polyimide material is formed on a temporary substrate 30 such as silicon or glass. The polyimide thin film 31 is formed by spin coating, drying and curing, and the dielectric multilayer film 32 made of TiO ₂ / SiO ₂ is formed on the thin film by ion-assisted vapor deposition. A dielectric multilayer filter is obtained by cutting the dielectric multilayer filter together with the temporary substrate into a required size with a dicing saw as indicated by a dotted line C, and finally separating the temporary substrate and the polyimide thin film. In addition, after separating a temporary substrate and a polyimide thin film, it is also possible to cut | disconnect to a required size with a dicing saw.
Japanese Patent Laid-Open No. 4-211203

In the dielectric multilayer filter manufacturing method shown in FIG. 5, as shown in Patent Document 2, a resin thin film 41 is formed on a temporary substrate 40 such as silicon or glass, and the dielectric multilayer film 42 is formed on the resin thin film 41. And a transparent resin layer 43 is attached via a transparent adhesive layer. After that, as indicated by the dotted line D, at least the transparent resin layer 43 and the dielectric multilayer film 42 are cut with a dicing saw, and the resin thin film 41 and the dielectric multilayer film 42 are separated to form a dielectric multilayer filter. Forming. This makes it possible to use a transparent resin having low heat resistance.
JP 11-52128 A

In the method for manufacturing a dielectric multilayer filter shown in FIG. 6, as shown in Patent Document 3, a dielectric multilayer film 51 is formed on a fluorinated polyimide substrate 50 having a self-supporting thickness, and a glass support material is formed. The substrate 50 is bonded and fixed to 52 so that the substrate 50 is located on the upper side, and the substrate is cut and polished (50 ′) to a required thickness (position of the dotted line E), and then at least the substrate 50 ′ as indicated by the dotted line F. The dielectric multilayer film 51 is cut with a dicing saw, and the support material 52 and the dielectric multilayer film 51 are separated to form a dielectric multilayer film filter.
JP 2003-307616 A

  When forming the dielectric multilayer film, as shown in FIG. 7, the film forming jig 62 holding the substrate 64 on which the dielectric multilayer film is to be formed is rotated in the vacuum container 60 and heated by the heating means 63. The substrate 64 is heated to about 300 ° C. to evaporate the dielectric 60 which is a vapor deposition material.

However, in the conventional dielectric multilayer filter as shown in FIGS. 3 to 6, in order to maintain a certain plane when the dielectric multilayer film is formed, the glass substrate 20, the temporary substrates 30, 40, or self The substrate 50 having a supporting thickness is used. Therefore, the number and shape of the substrates 64 mounted on the film forming jig 62 are limited, and the film forming region (the outer circle and the inner part of FIG. 7B) are limited. Only a part of the area between the circle) can be used.
Moreover, in order to produce a dielectric multilayer filter having a large area, the number of filters produced at a time is limited, and in order to increase productivity, it is necessary to enlarge the vacuum container and the film forming jig itself. This increases the manufacturing cost of the filter.

Also, when using a temporary substrate, if a resin layer is formed by spin coating or dipping, the film thickness tends to be non-uniform near the end of the temporary substrate, and the required resin film thickness cannot be secured. A reduction in yield occurs in that only the portion excluding the vicinity of the end portion can be used as a dielectric multilayer filter.
In addition, since the temporary substrate eventually becomes an unnecessary material, it becomes a factor of increasing the entire manufacturing cost and leads to an increase in industrial waste. Even when a temporary substrate is not used, if the substrate is thick as shown in FIG. 3 or FIG. 6, the cutting and polishing work of the substrate is required, and it takes time for manufacturing such as requiring skilled workers. It becomes.

Furthermore, as shown in FIG. 4 or FIG. 5, those using a resin layer as a support means for the dielectric multilayer film are liable to be cracked or chipped with a slight impact, resulting in a further reduction in yield and complicated handling of the filter. It was producing.
In addition, since the conventional dielectric multilayer filter manufacturing method uses a dicing saw to cut the filter, the dicing saw itself is expensive and the apparatus itself is large. In addition, since only linear cutting is possible, there has been a problem that a filter having an arbitrary shape cannot be formed.

  The problem to be solved by the present invention is a dielectric multilayer filter that solves the above-mentioned problems, has a high production yield, has a low production cost, and can form a filter having a large area or an arbitrary shape. And a method of manufacturing the same.

  In the invention according to claim 1, in the dielectric multilayer filter in which a plurality of dielectric films made of the low refractive index material and the high refractive index material on the support are laminated, the support has a thickness of 0.5 mm or less. It is a resin sheet having self-holding property and flexibility.

  In the invention according to claim 2, in the dielectric multilayer filter according to claim 1, the resin sheet is made of polyimide resin or fluorinated polyimide resin.

  According to a third aspect of the present invention, in the method for manufacturing a dielectric multilayer filter in which a plurality of dielectric films made of a low refractive index material and a high refractive index material on a support are laminated, the support is 0.5 mm. A self-holding and flexible resin sheet having the following thickness is used so that the film forming jig disposed at the film forming position in the film forming apparatus covers the filmable region of the film forming jig. Further, the sheet is arranged or fixed as a single piece or divided into a plurality of pieces, and a dielectric film is formed on the sheet.

  The invention according to claim 4 is characterized in that, in the dielectric multilayer filter manufacturing method according to claim 3, the resin sheet has heat resistance equal to or higher than a film forming temperature of the dielectric multilayer film. To do.

  The invention according to claim 5 is characterized in that, in the method for manufacturing a dielectric multilayer filter according to claim 2, the sheet on which the dielectric multilayer film is formed is cut by a scissors, a cutter or a punching machine. And

  According to the first aspect of the present invention, since a resin sheet having a thickness of 0.5 mm or less and having a self-holding property and flexibility is used for the support for forming the dielectric multilayer film, a conventional temporary substrate is unnecessary. In addition, since the support is thin, the work of cutting and polishing the support is not necessary. In addition, when a dielectric multilayer film is directly formed on a resin sheet, it has the property of sufficiently relaxing the stress during the formation of the dielectric multilayer film. For example, the manufactured filter is naturally curled or flat. Even if it returns to a state, a crack and a chip | tip do not arise.

  According to the invention according to claim 2, since a polyimide resin or a fluorinated polyimide resin is used for the resin sheet, the shape of the resin sheet can be stably maintained even at a temperature of 300 ° C. when ion-assisted deposition is used. In addition, the fluorinated polyimide resin can exhibit high transparency even at a wavelength of 1.55 μm frequently used in optical communication.

  According to the invention of claim 3, a self-holding and flexible resin sheet having a thickness of 0.5 mm or less is used for the support for forming the dielectric multilayer film, and the support is formed at a film forming position in the film forming apparatus. With respect to the film forming jig to be formed, the sheet is arranged or fixed so as to cover the film forming region of the film forming jig alone or divided into a plurality of parts, and a dielectric film is formed on the sheet Therefore, the production amount of the filter can be increased up to the production limit of the film forming jig. In addition, since a single resin sheet can secure an area larger than that of the conventional substrate, a large amount of filters can be manufactured at a time even when a large-area dielectric multilayer filter is manufactured. Furthermore, since there is no use of a temporary substrate or cutting / polishing of the support, the manufacturing process can be simplified and the manufacturing cost can be reduced.

  According to the invention of claim 4, since the resin sheet has heat resistance equal to or higher than the film forming temperature of the dielectric multilayer film, the resin sheet is directly attached to the film forming jig, and the dielectric is formed on the sheet by ion-assisted vapor deposition or the like. A film can be directly formed, and the resin sheet can be used as a support for a dielectric multilayer filter.

  According to the invention of claim 5, since the sheet on which the dielectric multilayer film is formed can be easily cut by a scissors, a cutter or a punching machine, an expensive and large-scale dicing saw as in the past is used. Therefore, the dielectric multilayer filter can be freely processed into a desired shape.

The dielectric multilayer filter and manufacturing method thereof according to the present invention will be described in detail below.
FIG. 1 is a schematic view showing a manufacturing process of the dielectric multilayer filter of the present invention.
A feature of the present invention is that a dielectric film made of a high refractive index material such as Ta ₂ O ₅ / SiO ₂ or a low refractive index material is directly formed on the sheet using the resin sheet 1. A dielectric multilayer film is formed using a substrate having a thickness as described above or a temporary substrate without using a separately provided holder having a fixed plane as a reference surface for vapor deposition.

  The resin sheet used in the present invention needs to have self-holding property and flexibility. The self-holding property means that the resin sheet has a self-shaped holding property to such an extent that a plane required for vapor deposition can be maintained when the resin sheet is placed and fixed on a film forming jig in the film forming apparatus. In addition, since the holding surface of the film forming jig is generally arranged in a substantially spherical shape centering on the vapor deposition source so that the vapor deposition material radiated from the vapor deposition source can be uniformly deposited, Means that the resin sheet is flexible enough to be curved at least in a spherical shape.

  Moreover, the resin sheet previously formed into a sheet shape, such as the resin sheet used in the present invention, can arbitrarily select the thickness of the sheet, and the stress generated when the dielectric film is formed on the entire sheet. It is possible to disperse and relax, and to suppress local cracks and chipping.

  On the other hand, when the resin applied on the temporary substrate by spin coating or dipping is cured by baking as in the prior art, the film thickness is about several μm to several tens μm, and a dielectric film is formed. The stress generated at the time is not relaxed sufficiently, and local cracks and chips are likely to occur.

  As a material for the resin sheet, when manufacturing a light transmission type filter, a polyimide resin having a high light transmission property or a fluorinated polyimide resin having a high transmission property in a 1.55 μm wavelength band commonly used for optical communication is used. It can be suitably used. Further, the resin sheet needs to have a heat resistance equal to or higher than the film formation temperature (300 ° C.) of the dielectric multilayer film. For this reason, it can be said that a polyimide resin or a fluorinated polyimide resin is a preferable material also in this respect.

  As for the thickness of the resin sheet, the present invention eliminates the need for a post-process such as cutting and polishing of the resin layer. On the other hand, in order to impart self-holding property, a certain thickness or more is also required. Although it depends on the material used for the resin sheet, if the thickness is 0.5 mm or less, sufficient permeability and flexibility can be secured, and in order to ensure self-holding using a polyimide resin, About 30-150 micrometers is preferable. However, if the self-holding property can be secured, the thickness can be further reduced.

Next, the manufacturing method of the dielectric multilayer filter of this invention is demonstrated.
As shown in FIG. 1, the manufacturing process is performed by first depositing a dielectric multilayer film 2 on a resin sheet 1 in sequence, and then cutting the dielectric multilayer film 2 at a position indicated by a one-dot chain line A. A multilayer filter can be obtained. As described above, the dielectric multilayer filter manufacturing method of the present invention has a simplified manufacturing process and spin coating for forming a resin film on a temporary substrate as compared with the conventional filter manufacturing method. A dedicated apparatus such as a dicing saw or a special apparatus such as a dicing saw is not required. In addition, in a conventional glass substrate or the like, it is necessary to clean using a dedicated cleaning device before dielectric deposition. However, in the resin sheet of the present invention, it is sufficient to wipe with a weak organic solvent such as 2-propanol. Is available.

  When forming the dielectric multilayer film, the resin sheet 1 is cut into a substantially trapezoidal shape shown in FIG. 2A, and a plurality of these are used to form a film forming jig 10 as shown in FIG. 2B. It arrange | positions so that film-forming possible area | region of this may be covered. In FIG.2 (b), it has comprised so that the film-forming possible area | region may be covered with the resin sheet divided into eight, but it is not restricted to this, It is also possible to cover with one resin sheet or an arbitrary number of resin sheets. Is possible. The resin sheet 1 is easily fixed to the film forming jig by an attaching means 11 such as an adhesive tape or a double-sided tape. Moreover, it is not always necessary to arrange the resin sheets in close contact with each other, and it is possible to provide some space for arrangement as necessary. Furthermore, a U-shaped protrusion can be provided in the space of the film forming jig, and a resin sheet can be inserted and fixed to the protrusion.

  The film forming jig 10 to which the resin sheet 1 is attached can be mounted in the film forming apparatus in the same manner as the conventional film forming jig 62 shown in FIG. Can be formed on the resin sheet.

  As described above, in the present invention, since the resin sheet is arranged so as to cover the film forming region as much as possible, the production amount of the filter by the film forming apparatus can be maximized. In addition, when a plate-like substrate 64 such as a conventional glass substrate or temporary substrate is used, a separate fixing jig is required when the substrate 64 is disposed and fixed on the film forming jig 62. Such parts are unnecessary.

  The resin sheet on which the dielectric multilayer film is formed can be easily cut with a scissors or a cutter, so that it is possible to create a filter of any shape and there is no need to use a dedicated dicing saw as in the prior art. . When manufacturing a certain shape in large quantities, it is also possible to use punching.

A polyimide resin sheet (trade name: Kapton 100H, manufactured by DuPont) having a thickness of 25 μm is cut into a trapezoidal shape (upper side 100 mm, lower side 200 mm, height 140 mm) in FIG. 2A, and eight resin sheets are assembled. In addition, they were stuck and fixed on a film forming jig.
Next, 51 layers of Ta ₂ O ₅ / SiO ₂ dielectric multilayer films were formed on the resin sheet by ion-assisted deposition to a total of 5 μm using a film forming apparatus.
The resin sheet on which the dielectric multilayer film was formed was cut into a size of 20 mm square with a scissors to obtain a dielectric multilayer film filter.

When the filter characteristics of the obtained dielectric multilayer filter were examined, the transmission loss of the filter according to the present invention was -0.2 dB, whereas the dielectric multilayer filter using the glass substrate of FIG. Since the dielectric multilayer film filter using the resin film (fluorinated polyimide resin) formed by spin coating shown in FIG. 4 is about −0.1 to −0.3 dB, it is about −0.1 to −0.3 dB. It was confirmed that the same characteristics as the dielectric multilayer filter can be obtained.
In addition, the dielectric multilayer filter of the above example was in a state of being curved with a radius of curvature of about 2.5 mm when allowed to stand naturally, but the dielectric multilayer film was not cracked or chipped. Even when this filter was forced to be in a flat state, it was confirmed that a stable state was similarly maintained. On the other hand, in the case of a dielectric multilayer filter using a resin film formed by spin coating, cracking occurred locally when the filter was forcibly bent with a radius of curvature of about 2.5 mm. Thus, since the dielectric multilayer filter according to the present invention is resistant to bending and mechanical shock, it is extremely easy to handle compared to the conventional one.

  In addition, the dielectric multilayer filter of the above example was subjected to a pressure cooker test (PCT) to accelerate and evaluate the moisture resistance under high temperature, high humidity, and high pressure. When the test was conducted in an environment of 121 ° C., saturated water vapor 2 atm and 12 hours, no deterioration was observed in the appearance and optical characteristics of the filter. This test environment corresponds to a moisture resistance test of about 3 years in the atmosphere at 25 ° C.

  As described above, according to the present invention, there is provided a dielectric multilayer filter capable of forming a filter having a large area and an arbitrary shape and a method for manufacturing the same, with a high production yield and low production cost. It becomes possible to do.

It is a figure which shows the manufacturing process of the dielectric multilayer filter of this invention. (A) is a shape of a resin sheet, (b) is a figure which shows the state which attached the resin sheet to the film-forming jig. It is a figure which shows the manufacturing process of the dielectric multilayer filter using the conventional glass substrate. It is a figure which shows the manufacturing process of the dielectric multilayer filter using the conventional temporary board | substrate. It is a figure which shows the manufacturing process of the other dielectric multilayer filter using the conventional temporary board | substrate. It is a figure which shows the manufacturing process of the dielectric multilayer filter which cut and polished the conventional resin substrate. (A) is the schematic of a film-forming apparatus, (b) is a figure which shows the arrangement | positioning relationship between the conventional film-forming jig and a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin sheet 2 Dielectric multilayer film 10,62 Jig 11 for film-forming Sticking means 60 Vacuum container 61 Deposition source 63 Heating means 64 Substrate

Claims (5)

In a dielectric multilayer filter in which a plurality of dielectric films made of a low refractive index material and a high refractive index material on a support are laminated,
The dielectric multilayer filter, wherein the support is a self-holding and flexible resin sheet having a thickness of 0.5 mm or less.   2. The dielectric multilayer filter according to claim 1, wherein the resin sheet is made of a polyimide resin or a fluorinated polyimide resin. In a method for manufacturing a dielectric multilayer filter in which a plurality of dielectric films made of a low refractive index material and a high refractive index material on a support are laminated,
As the support, a self-holding and flexible resin sheet having a thickness of 0.5 mm or less is used,
With respect to the film forming jig arranged at the film forming position in the film forming apparatus, the sheet is arranged or fixed so as to cover the film forming region of the film forming jig alone or divided into a plurality of parts,
A method for producing a dielectric multilayer filter, comprising forming a dielectric film on the sheet.   4. The method for manufacturing a dielectric multilayer filter according to claim 3, wherein the resin sheet has a heat resistance equal to or higher than a temperature for forming the dielectric multilayer film. 3. The method for manufacturing a dielectric multilayer filter according to claim 2, wherein the sheet on which the dielectric multilayer film is formed is cut with a scissors, a cutter or a punching machine. .

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