JP4026431B2 - Manufacturing method of optical fiber support - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical fiber support member for fixing the tip of the optical fiber, about the method of manufacturing an optical fiber support member used in the optical fiber array supporting a plurality of optical fibers used in turn the optical switch.
[0002]
[Prior art]
An optical fiber array is a kind of support used for an optical switch or the like, in which a plurality of optical fibers are integrated with high dimensional accuracy. Conventionally, for example, as disclosed in Japanese Patent Application Laid-Open No. 2001-174664, a method has been proposed in which a plurality (N) of V-grooves are formed in a block made of ceramics, optical fibers are installed in the grooves, fixed, and aligned. Has been. Further, a plurality of (M) blocks in which the optical fibers are fixed are stacked and used as an array in which N × M optical fibers are arranged in a matrix. This method is characterized in that the V-groove can be ground with high accuracy, and the optical fiber can be loaded with high accuracy only by placing it in the V-groove.
[0003]
[Problems to be solved by the invention]
In the conventional optical fiber array described above, when a plurality of blocks are stacked to form an array, the number of parts increases, and if these are stacked, it becomes difficult to ensure the positioning accuracy of the optical fiber. There was a problem. For example, when aligning the end faces of optical fibers having an outer diameter of 125 μm, the tolerance of these intervals is required to be within several μm. In addition, the shape itself is limited in that it is necessary to secure a certain block thickness for grinding, and it is difficult to densely integrate multiple fibers, which increases the size of the array itself. It is also a problem to ensure.
[0004]
On the other hand, in order to solve these problems, for example, a method of forming a plurality of through holes having an outer diameter of approximately 125 μm in a thickness direction of a substrate by etching on a substrate such as silicon and inserting an optical fiber into the through holes to form an array Has been devised. However, simply by providing a through hole, it is practically difficult to insert an optical fiber into a hole having substantially the same diameter, and problems such as the fiber being in contact with the substrate surface and being broken frequently occur. For this reason, it is conceivable to create a guide by expanding the opening of the hole and make it easier to insert the optical fiber. However, it is difficult to easily obtain such a shape by etching, and silicon is required for machining. Due to the brittleness of the material, an edge is generated in the opening, causing breakage during assembly of the optical fiber and disconnection after assembly. In addition, it is conceivable to attach a member in which a guide hole is formed to the surface of the substrate by bonding or the like, but it is difficult to bond the through hole and the guide hole with high accuracy, and there is no practicality.
[0005]
In view of the above, the present invention is particularly fine with respect to an optical fiber support (an optical fiber array in the case where there are a plurality of through-holes) provided with a through-hole in a silicon substrate so that the optical fiber can be easily inserted into the through-hole. A method for producing a support on which a guide is produced is proposed.
[0006]
[Means for Solving the Problems]
In the present invention, a brittle material structure in which an optical fiber guide hole corresponding to the through hole is directly joined on a substrate provided with a through hole for inserting an optical fiber is directly bonded . In the manufacturing method , the optical fiber guide hole is a substantially frustoconical space whose diameter increases from a joint surface between the substrate and the brittle material structure toward the surface of the brittle material structure. A method for producing a featured optical fiber support is provided.
[0007]
As described above, when the optical fiber guide hole is formed by modifying the substrate itself by etching or machining, a problem occurs particularly when a silicon substrate or the like is used. Therefore, for example, this is solved by forming a structure having a thickness of several tens of μm by directly bonding it to the substrate surface. When inserting the optical fiber into the through hole, first pass through this optical fiber guide hole, and even if the axis of the through hole and the optical fiber is slightly shifted, the position is corrected by the guide and the fiber does not break. Is preferable.
[0008]
In the present invention, the structure of the brittle material is polycrystalline, the crystals constituting the structure have substantially no crystal orientation, and a grain boundary layer made of a glass layer is substantially formed at the interface between the crystals. In addition, the present invention provides a method for manufacturing an optical fiber support, wherein a part of the structure is an anchor portion that bites into the surface of the substrate.
[0009]
This structure is a feature of a structure manufactured by an aerosol deposition method to be described later. The optical fiber guide preferably has a hardness equal to or higher than that of a silicon substrate or an optical fiber, and is therefore preferably formed of a ceramic material or silicon. Having an anchor portion is preferable because it can improve the adhesion to the substrate.
[0010]
In the present specification, the polycrystal and the like are defined as follows.
(Polycrystalline)
In this case, it refers to a structure in which crystallites are joined and integrated. The crystallite is essentially one crystal, and its diameter is usually 5 nm or more. However, the case where the fine particles are taken into the brittle material structure without being crushed rarely occurs, but is substantially polycrystalline.
(Crystal orientation)
This refers to the degree of orientation of crystal axes in a structure that is polycrystalline. Whether or not there is orientation is generally measured data of raw material fine particles considered to be substantially non-orientated or powder X-ray diffraction, etc. JCPDS (ASTM) data, which is standard data by, is determined as an index.
The peak intensity of the three major diffraction peaks in this index, which lists substances that form brittle material crystals in the structure, is 100%, and the peak intensity of the most important peak in the same substance measurement data of the structure is aligned with this. In this case, the state in which the deviation of the peak intensity of the other two peaks is within 30% of the index value is referred to as having substantially no orientation in this case.
(interface)
In this case, it refers to the region that forms the boundary between crystallites.
(Grain boundary layer)
It is a layer with a certain thickness (usually several nm to several μm) located at the grain boundary in the interface or sintered body. It usually has an amorphous structure different from the crystal structure in the crystal grain, and in some cases, segregates impurities. Accompany.
(Anchor part)
Refers to the unevenness formed at the interface between the base material and the brittle material structure, and in particular, the surface accuracy of the original base material is changed during the formation of the brittle material structure, instead of forming the unevenness in the base material in advance. It refers to the unevenness that is done.
[0011]
As a means for producing the optical fiber support having this structure, in the present invention, fine particles of a brittle material are passed through the through hole toward a predetermined region including the through hole on the substrate surface provided with the through hole. The brittle material structure is formed by spraying an aerosol dispersed in a gas, and bonding and depositing the brittle material fine particles or fragments crushed on only the substrate surface. A method for producing an optical fiber support, characterized in that a substantially frustoconical space whose diameter increases from the joint surface with the substrate toward the surface of the brittle material structure is formed corresponding to the through hole. provide.
[0012]
As a new technique for forming a thick film of a brittle material such as ceramics on a substrate, a method called an aerosol deposition method is disclosed in Japanese Patent No. 3265481 and International Patent Application WO 01/27348 A1. In this method, an aerosol in which fine particles of a brittle material are dispersed in a gas is sprayed toward the substrate, and the particles or fragments are joined together by pulverizing and deforming the particles by the collision energy. In this method, a structure having the same strength as that of the fired body can be formed without firing.
By using this method, it is easy to form a brittle material structure having a thickness of several tens of μm on the substrate while ensuring good adhesion by the anchor portion. Here, in the case where a brittle material structure is formed by an aerosol deposition method in a cut portion or a hole perpendicular to the substrate (including a cut portion or a hole whose sectional wall is inclined toward the substrate as it goes deeper) The authors have found that the structure is not formed perpendicular to the substrate surface at the end of the cut portion or hole on the surface, but grows with an inclination inclined toward the structure side. That is, if the aerosol deposition method is used, the optical fiber guide hole having the above-mentioned frustoconical space can be naturally formed by utilizing such a characteristic characteristic of the method. In this case, the angle at which the aerosol is sprayed onto the substrate is most preferably perpendicular to the substrate surface.
[0013]
Further, in the present invention, as a means for producing another optical fiber support, resin or grease is sealed in a through hole of a substrate, and then fine particles of a brittle material are directed toward a predetermined region including the through hole on the surface of the substrate. An aerosol dispersed in a gas is sprayed to produce a brittle material structure in which the brittle material fine particles or fragments broken by this are bonded and deposited only on the substrate surface, and then the resin or grease is dissolved and removed. Thus, in this brittle material structure, a substantially frustoconical space whose diameter increases from the joint surface with the substrate toward the surface of the brittle material structure is formed corresponding to the through hole. An optical fiber support manufacturing method is provided.
[0014]
In the aerosol deposition method, when the angle at which the aerosol is sprayed on the substrate deviates from the vertical direction, a structure may be formed on the inner wall of the hole. Since the inner diameter of the through hole is set to 125 μm which is substantially the same as the outer diameter of the optical fiber, it is impossible to insert the optical fiber when a structure is formed on the inner wall. In order to prevent this, it is preferable to fill the hole with resin or grease in advance and seal it. Of course, a resin that does not form a structure is selected. For example, a certain kind of polyimide, polycarbonate, polyethylene, polypropylene-based material and the like can be mentioned. Grease is preferable because the structure is not formed because the impact of aerosol is relaxed and received. These resins and grease may be dissolved and removed after the structure is formed.
[0015]
In the present invention, the above-described aerosol spraying is performed in a room temperature environment. Here, normal temperature refers to a temperature sufficiently lower than the melting point of the brittle material and the temperature of the heat treatment described above, and is substantially 200 ° C. or lower.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows an aerosol in which fine particles of brittle material are dispersed in a gas. The aerosol is sprayed toward a base material to collide with the fine particles, and used to form a structure constituting an optical fiber guide hole on the base material. The schematic diagram of the structure formation apparatus 10 using the aerosol deposition method is shown as one embodiment of the present invention.
[0017]
In the forming apparatus 10, a gas cylinder 101 such as nitrogen is connected to an aerosol generator 103 containing brittle material fine particles via a gas transport pipe 102, and is installed in a formation chamber 105 via an aerosol transport pipe 104. It is connected to a nozzle 106 having an opening 0.4 mm wide and 5 mm wide. At the tip of the nozzle 106, a substrate holder 108 having a hole, which is installed on the XY stage 107, is attached, and a portion where a plurality of through holes having a diameter of about 125 μm are formed here is related to the hole portion of the substrate holder 108. Thus, a silicon substrate 109 having a thickness of 1 mm is disposed. The surface of the silicon substrate 108 and the nozzle 106 are in a substantially vertical positional relationship. The formation chamber 105 is connected to the vacuum pump 110.
[0018]
A procedure for manufacturing the optical fiber guide hole by the manufacturing apparatus 10 having the above configuration will be described below. The gas cylinder 101 is opened, and gas is introduced into the aerosol generator 103 through the transport pipe 102 to generate an aerosol containing brittle material fine particles. The aerosol is sent to the nozzle 106 through the transport pipe 104 and ejected at a high speed from the opening of the nozzle 106. At this time, the inside of the forming chamber 105 is placed in a reduced pressure environment of several kPa by the operation of the vacuum pump 110. The brittle material fine particles collide with the substrate 109 arranged at the tip of the opening of the nozzle 106, the fine particles are bonded to each other, and a porous structure made of the fine particle material is formed on the substrate. The substrate 108 is swung by the XY stage 107, and a structure is formed in a desired shape and area. In the region of the through hole of the substrate 108, the aerosol passes and no structure is formed. The above operation is performed in a room temperature environment.
[0019]
[Example 1]
An attempt was made to produce a guide hole of an optical fiber array using a production apparatus having a form according to the production apparatus 10 described above. As a substrate, an array substrate was prepared in which a total of 64 through-holes with a diameter of 125 μm were formed in the thickness direction in 8 columns and 8 rows in single crystal silicon 10 mm long × 10 mm wide × 1 mm thick.
[0020]
As the brittle material fine particles, aluminum oxide fine particles having an average fine particle diameter of 0.6 μm and a purity of 99.8% were used. As film formation conditions, an opening of 10 mm x 0.4 mm was used for the nozzle, helium was used as the gas, the flow rate was 7 L / min, and the XY stage was reciprocally swung 5 mm in one direction to try to form the structure. It was. Various conditions were set for the structure formation time of 5 to 20 minutes. As a result, guide holes of an optical fiber array made of an aluminum oxide structure having an area of 10 mm × 5 mm and a film thickness of 20 to 60 μm could be formed on the substrate.
[0021]
FIG. 2 shows a scanning electron microscope (S-800, manufactured by Hitachi, Ltd.) image of the guide hole of the optical fiber array obtained. It can be seen from this photograph that a frustoconical space is formed. When the inclination angles of the plurality of guide holes produced under the above conditions were measured, the angle between the substrate surface (interface between the substrate and the structure) and the inclined surface was in the range of 50 to 66 °.
[0022]
FIG. 3 shows a transmission electron microscope (Hitachi) showing an aluminum oxide structure (alumina film) formed on the surface of a single crystal silicon substrate manufactured in the same process, near the interface between the structure and the substrate. The image image | photographed by cross-sectional observation in Seisakusho H-9000UHR) is shown. It is confirmed that irregularities of about 100 nm that can be seen as anchor portions are formed at the interface.
[Brief description of the drawings]
FIG. 1 is a schematic view of a structure forming apparatus using an aerosol deposition method according to the present invention.
FIG. 2 is a scanning electron microscope image of the guide hole of the optical fiber array according to the present invention.
FIG. 3 is an image taken by observing a cross section with a transmission electron microscope in the vicinity of an interface between a structure and a substrate according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Structure formation apparatus, 101 ... Gas cylinder, 102 ... Gas conveyance pipe, 103 ... Aerosol generator, 104 ... Aerosol conveyance pipe, 105 ... Formation chamber, 106 ... Nozzle, 107 ... XY stage, 108 ... Substrate holder, 109 ... Silicon substrate, 110 ... Vacuum pump

Claims (3)

  An aerosol in which fine particles of a brittle material are dispersed in a gas so as to pass through the through-hole toward a predetermined region including the through-hole on the substrate surface provided with the through-hole, and the brittle material is applied only to the substrate surface. By creating a brittle material structure in which fine particles or fragments that are crushed are joined and deposited, the brittle material structure has a diameter from the joint surface with the substrate toward the surface of the brittle material structure. A method of manufacturing an optical fiber support, wherein a substantially frustoconical space in which the width of the optical fiber extends is formed corresponding to the through hole.   Resin or grease is sealed in the through hole of the substrate, and then an aerosol in which fine particles of the brittle material are dispersed in the gas is sprayed toward a predetermined region including the through hole on the substrate surface, and the brittleness is only applied to the substrate surface. By creating a brittle material structure in which material fine particles or fragments that have been crushed are bonded and deposited, and then dissolving and removing the resin or grease, the brittle material structure is separated from the bonding surface with the substrate. A method for producing an optical fiber support, characterized in that a substantially frustoconical space whose diameter increases toward the surface of the brittle material structure is formed corresponding to the through hole. The method for producing an optical fiber support according to claim 1 , wherein the aerosol is sprayed in a room temperature environment.

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