JP2003202447A - Optical fiber array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber array which has superior adhesion between a substrate and an adhesive layer, is free of peeling between the substrate and adhesive layer and a position shift of an optical fiber, and can accurately transmit a light signal. <P>SOLUTION: The optical fiber array, constituted by forming a plurality of grooves on part of the top surface of the substrate, storing optical fibers in the grooves, and fitting a lid part which covers the optical fibers onto the substrate across the adhesive layer, is characterized by that at least part of the top surface of the substrate is roughened to 5 to 1000 nm mean roughness. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical fiber array.

[0002]

2. Description of the Related Art In recent years, attention has been focused on optical fibers mainly in the communication field. Particularly in the IT (information technology) field, communication technology using optical fibers is required to maintain a high-speed Internet network. Optical fiber has the features of low loss, high bandwidth, small diameter / light weight, no induction, resource saving, etc. In the communication system using the optical fiber having this feature, the communication using the conventional metallic cable is used. Compared with the system, the number of repeaters can be greatly reduced, construction and maintenance are facilitated, and the communication system can be made economical and highly reliable.

Further, in the optical fiber, not only the light of one wavelength but also the light of many different wavelengths can be simultaneously multiplexed and transmitted by one optical fiber, so that it has a large capacity for various purposes. This has a great advantage that a transmission line can be realized and a video service can be supported.

In optical communication using an optical fiber, an optical fiber ribbon in which a plurality of optical fibers are arranged in parallel and a coating resin layer is formed around the optical fibers is used. Then, this optical fiber ribbon is used for a light receiving element, a light emitting element, various terminal devices (personal computer, mobile, game, etc.)
In order to connect with the optical fiber ribbon, the coating resin layer at the end of the optical fiber ribbon is usually removed to expose the ends of the plurality of optical fibers, and the exposed optical fibers are mounted in the groove of the substrate having the V groove. There is used an optical fiber array in which a plurality of optical fibers are arranged at a predetermined interval by placing, fixing, and further attaching a lid portion covering the exposed optical fibers to a substrate via an adhesive layer.

Therefore, conventionally, as an optical fiber array, for example, the optical fibers are housed in alignment with each of a plurality of V grooves formed on a substrate, and the optical fibers are covered with an adhesive layer on the substrate. Thus, the one with the lid attached is disclosed.

[0006]

In such an optical fiber array, when the optical fiber array is connected to an optical element or when an external force is applied to the optical fiber array due to heat or humidity. The position of the optical fiber may be displaced or the optical fiber may be damaged in some cases, resulting in a poor connection between the optical fiber array and the optical element such as the light receiving element or the light emitting element. It could be the cause. Further, when reliability evaluation such as a heat cycle test is performed using such an optical fiber array, peeling may occur between the substrate and the adhesive layer. It is considered that such positional deviation of the optical fiber and peeling of the adhesive layer occur due to insufficient affinity (adhesion) with the substrate.

[0007]

Therefore, the present inventors have
As a result of diligent research on means for solving the above-mentioned various problems, it was found that the adhesion between the substrate and the adhesive layer should be improved. Specifically, a surface facing the upper surface of the substrate is predetermined. It was found that a roughened surface having a surface roughness of 1 is sufficient, and the optical fiber array of the present invention was completed.

That is, the optical fiber array of the present invention is
An optical fiber array in which a plurality of grooves are formed in a part of the upper surface of the substrate, the optical fibers are housed in the grooves, and a lid portion covering the optical fibers is attached on the substrate via an adhesive layer. A roughened surface is formed on at least a part of the upper surface of the substrate, and the roughened surface has an average roughness of 5 to 1000 nm.

In the optical fiber array of the present invention, the material of the substrate is preferably silicon or glass. In the above optical fiber array,
A roughened surface is formed on the surface of the groove, and the average roughness of the roughened surface is preferably 5 to 100 nm. In the optical fiber array, the average roughness is
It is preferably measured by a surface roughness meter using interference fringes.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The optical fiber array of the present invention will be described below. In the optical fiber array of the present invention, a plurality of grooves are formed in a part of the upper surface of the substrate, the optical fibers are housed in the grooves, and a lid portion covering the optical fibers is mounted on the substrate via an adhesive layer. A roughened surface is formed on at least a part of the upper surface of the substrate, and the roughened surface has an average roughness of 5 to 1000 nm.

In the optical fiber array of the present invention, a roughened surface is formed on at least a part of the upper surface of the substrate, and the average roughness of the roughened surface is within the above range. Is excellent in adhesiveness, peeling does not occur between the substrate and the adhesive layer, and positional deviation of the optical fiber does not occur due to external force caused by heat or humidity. The array can accurately transmit an optical signal.

The optical fiber array of the present invention will be described below with reference to the drawings. 1A is a partial perspective view schematically showing an example of the optical fiber array of the present invention, and FIG. 1B is a sectional view taken along the line AA of FIG.
(C) is a perspective view showing a lid part constituting the optical fiber array of (a), and (d) is a partial perspective view showing a substrate accommodating the optical fibers forming the optical fiber array of (a). It is a figure.

As shown in FIG. 1, an optical fiber array 10 is provided.
In No. 0, the optical fiber 115 is housed and fixed to each of the plurality of V grooves 157 formed in parallel on a part of the upper surface of the substrate 151 via the adhesive layer 159. A lid portion 160 is formed on a substrate 151 accommodating the optical fiber ribbon 110 via an adhesive layer 159, and a portion of the optical fiber 115 (a groove 157 of the optical fiber is formed on the lid portion 160. A part 161 which is not stored in the above is collectively formed. In the above optical fiber array, the groove formed on the upper surface of the substrate is not limited to the V groove, and for example, a groove having a rectangular cross section in a direction perpendicular to the axis of the optical fiber may be used. Good.

In the optical fiber array of the present invention, at least a part of the upper surface of the substrate has an average roughness of 5 to 1000.
A roughened surface of nm is formed. A substrate having a roughened surface having such an average roughness has excellent adhesiveness with an adhesive layer formed on the substrate. This is because the contact area between the substrate and the adhesive layer is larger than that in the case where the upper surface of the substrate is smooth, and even if external stress occurs, the stress can be absorbed by the roughened surface. Because. Here, the external stress means a force applied from the outside due to heat, humidity and the like. If the average roughness is less than 5 nm, the adhesiveness between the substrate and the adhesive layer may not be sufficiently obtained, and further, the stress generated may cause a positional deviation of the optical fiber, resulting in an external light guide. Abnormality may occur in optical signal transmission between the waveguide and the optical component. On the other hand, even if the average roughness exceeds 1000 nm, the adhesiveness to the adhesive layer is not improved so much, and the adhesive layer is formed, for example, by pouring an uncured adhesive between the substrate and the lid, Further, it is carried out by performing a curing treatment, but when the average roughness is more than 1000 nm, filling of the uncured adhesive may be hindered, and in this case, a portion or a void where the adhesive layer is not formed is formed. Occurrence of cracks may occur in the adhesive layer, or peeling may occur between the substrate and the adhesive layer, starting from this portion. The average roughness of the roughened surface is the average roughness Ra based on JIS B 0601.
Is desirable.

In the above optical fiber array, the average roughness of the roughened surface formed on the upper surface of the substrate is excellent in adhesion with the adhesive layer in consideration of the material of the substrate and the like. Therefore, it is desirable to appropriately determine. Specifically, for example, when the material of the substrate is silicon, the lower limit of the average roughness is preferably 5 nm, and more preferably 10 nm. On the other hand, the upper limit of the average roughness is preferably 500 nm, and more preferably 100 nm. When a roughened surface is formed on a substrate whose material is silicon and the average roughness Ra is less than 5 nm, it may not be possible to sufficiently relax the external stress when it is generated. .
On the other hand, when the thickness exceeds 500 nm, when the uncured adhesive is filled during manufacturing, the filling of the adhesive may be hindered, and further, the substrate is likely to be damaged (chip, crack, etc.). . In particular, when the average roughness of the roughened surface formed on the substrate made of silicon does not exceed 100 nm, the uncured adhesive follows the shape of the roughened surface when filling the uncured adhesive. Does not decrease, and a portion not filled with the adhesive and voids are not generated. for that reason,
The connectivity between the optical fibers forming the optical fiber array of the present invention and external parts and the reliability of the optical fibers are excellent. Therefore, when the material of the substrate is silicon, the average roughness of the roughened surface formed on the substrate is 5 to 100.
More preferably, it is nm.

When the material of the substrate is glass, the lower limit of the average roughness is preferably 5 nm, more preferably 10 nm. on the other hand,
The upper limit of the average roughness is preferably 500 nm, more preferably 100 nm. When a roughened surface is formed on a substrate whose material is glass, if the average roughness Ra is less than 5 nm, it may not be possible to sufficiently relax the external stress when it is generated. .
On the other hand, when the thickness exceeds 500 nm, when the uncured adhesive is filled during manufacturing, the filling of the adhesive may be hindered, and further, the substrate is likely to be damaged (chip, crack, etc.). . In particular, when the average roughness of the roughened surface formed on the glass substrate does not exceed 100 nm,
When filling the uncured adhesive, the followability of the uncured adhesive with respect to the shape of the roughened surface does not decrease, and a portion not filled with the adhesive and voids do not occur. Therefore, the connectivity between the optical fibers forming the optical fiber array of the present invention and external parts and the reliability of the optical fibers are excellent. Therefore, when the material of the substrate is glass, the average roughness of the roughened surface formed on the substrate is more preferably 5 to 100 nm.

In the optical fiber array of the present invention, the roughened surface is formed on at least the surface of the groove on the upper surface of the substrate, and the average roughness of the roughened surface is 5 to 100 nm.
Is more desirable. Thus, the roughened surface is formed on the surface of the groove, and the average roughness of the roughened surface is 5 to 10
When the thickness is 0 nm, when the uncured adhesive is poured into the gap between the groove and the optical fiber at the time of manufacturing the optical fiber array, the fluidity of the uncured adhesive is secured and the uncured adhesive is secured. This is because the adhesiveness between the optical fiber and the groove after the adhesive is cured is secured via the adhesive layer.

The surface roughness of the roughened surface has, in addition to having the above-described average roughness, JIS B 0601.
The average spacing Sm of irregularities based on
And the upper limit is preferably 100 μm. This is because when the roughened surface formed on the substrate has the average spacing Sm of the irregularities in the above range, the adhesiveness between the substrate and the adhesive layer becomes more excellent. A more desirable lower limit of the average spacing Sm of the irregularities is 1 μm, and a more desirable upper limit thereof is 50 μm.

Further, in the roughened surface formed on the upper surface of the substrate, it is desirable that the wall surface of the unevenness forming the roughened surface has a depression. In this way, when the uneven wall surface has a depression, the contact area between the substrate and the adhesive layer is larger, so the adhesive strength between the two is further improved, and peeling between the substrate and the adhesive layer occurs more. It gets harder. The size of the depressions on the wall surface of the irregularities is not particularly limited as long as the opening diameter of the depressions is smaller than the average interval Sm of the irregularities. Specifically, for example, when the roughened surface having the depression is viewed in a plane with a microscope, the depression is observed as an image of the particulate matter, and in this case, the average particle diameter of the particulate matter, The lower limit is 100 nm and the upper limit is 1000 nm
Is desirable. A more desirable lower limit of the average particle diameter is 200 nm, and a more desirable upper limit thereof is 5
00 nm. The average particle size of the particulate matter (hereinafter, simply referred to as the average particle size of the particulate matter) observed when the roughened surface having the depressions is viewed in a plane with a microscope is also the surface roughness of the roughened surface. It is one of the indexes that show the quality. The particle size of the particulate matter refers to the length of the longest part of the particulate matter.

When the wall surface of the unevenness forming the roughened surface has a depression, the surface roughness of the roughened surface is JIS B 06.
The average interval S of local peaks based on 01, the lower limit of which is 10
It is desirable that 0 nm and the upper limit thereof be 1000 nm. This is because the roughened surface having the average spacing S of the local peaks in this range has more excellent adhesion to the adhesive layer. The lower limit of the average spacing S between the local peaks is more preferably 200 nm, and the upper limit of the average spacing S between the local peaks is more preferably 500 nm.

In the above optical fiber array,
It is preferable that a roughened surface is also formed on a portion of the lid portion mounted on the substrate via an adhesive layer, the portion facing the substrate, and the surface roughness of the roughened surface is JIS B 06.
In the average roughness Ra based on 01, the lower limit is preferably 5 nm, more preferably 10 nm.
The upper limit of the average roughness Ra is preferably 1000 nm, more preferably 500 nm, and particularly preferably 100 nm. This is because the adhesion between the lid portion and the adhesive layer becomes more excellent.

Further, when a roughened surface is formed on the lid portion, the surface roughness of the roughened surface is JIS B 060.
The average spacing Sm of the irregularities based on 1 and the lower limit is 0.1μ.
m is preferable, and 1 μm is more preferable. On the other hand, the upper limit of the average spacing Sm of the irregularities is 1
The thickness is preferably 00 μm, more preferably 50 μm. This is because if the average spacing Sm of the irregularities is in this range, the adhesion between the lid and the adhesive layer will be more excellent.

Further, in the lid portion having the roughened surface formed, it is desirable that the wall surface of the unevenness forming the roughened surface has a dent, and in this case, the roughened surface is viewed in plan view by a microscope. In doing so, the depressions were observed as an image of the particulate matter, and the lower limit of the average particle size of the particulate matter was 100 nm.
Therefore, the upper limit is preferably 1000 nm. Also,
A more desirable lower limit of the average particle diameter is 200 nm,
A more desirable upper limit is 500 nm. Further, in the roughened surface having a recess on the wall surface of the unevenness formed on the lid portion, the surface roughness of the roughened surface is an average interval S of local peaks according to JIS B 0601, the lower limit of which is 100 nm, and the upper limit thereof is 100 nm. Is preferably 1000 nm. This is because the roughened surface having the average spacing S of the local peaks in this range has more excellent adhesion to the adhesive layer. The lower limit of the average spacing S between the local peaks is more preferably 200 nm, and the upper limit of the average spacing S between the local peaks is more preferably 500 nm.

Here, the average roughness Ra based on JIS B 0601, the average spacing Sm of the unevenness, and the average spacing S of the local peaks will be briefly described with reference to the drawings. FIG. 2 is a reference diagram for explaining the average roughness Ra based on JIS B 0601, the average spacing Sm of the irregularities, and the average spacing S of the local peaks. Figure 2
In, 501 is a roughness curve of a roughened surface, and 502 is an average line. The roughness curve of the roughened surface shown in FIG.
This is an example for explaining the parameters of the surface roughness described above, and does not show the actual roughness curve of the roughened surface formed on the lid portion constituting the optical fiber array of the present invention.

The average roughness Ra is obtained by extracting a reference length from the roughness curve in the direction of the average line, taking the X axis in the direction of the average line of the extracted portion, and the Y axis in the direction of longitudinal magnification.
When the roughness curve is represented by y = f (x), it means a value obtained by the following formula (1).

[0026]

[Formula 1]

(Where l is the reference length). In addition,
In the present specification, the average roughness Ra is nanometer (n
It is represented by m).

The average spacing Sm of the irregularities is the roughness curve 50.
Sampling the standard length from 1 in the direction of the average line 502
In this sampling part, one mountain and its neighbor
The sum of the lengths of the average line 502 corresponding to one matching valley (below
Bottom, uneven distance: Sm in the figure ₁, Sm_TwoIndicates)
Was calculated, and the distance of these many irregularities was expressed by the arithmetic mean value.
Of. In addition, in this specification, the average interval of the unevenness is
Sm is expressed in micrometers (μm). Also,
The above-mentioned mountain means that when the roughness curve is cut at the average line
Roughness curve and average line between two adjacent points at these intersections
The actual part composed of (for example, the part indicated by 503 in the figure)
Min), and the above valley is the roughness curve cut by the average line.
Sometimes, the roughness curve between two adjacent points at those intersections
A space portion composed of a line and an average line (for example, 5 in the figure)
(Part indicated by 04).

The average spacing S of the local peaks is the roughness curve 5
The length of the average line corresponding to the distance between the adjacent local peaks in this extracted portion is extracted from 01 in the direction of the average line 502 (hereinafter, referred to as the interval between the local peaks: S ₁ and S _{2 in the} figure). Is shown), and the interval between the large number of local peaks is represented by an arithmetic mean value. In addition, in this specification, the average interval S of the local peaks is nanometer (n
It is represented by m). Further, the local mountain peak is the highest elevation point in the local mountain (for example, the point indicated by 505a in the figure), and the local mountain is the actual portion between two adjacent minimum points of the roughness curve. (For example, a portion indicated by 505 in the drawing).

The average roughness Ra representing the surface roughness of the roughened surface formed on the substrate, the average spacing Sm of the irregularities, and the average spacing S of the local peaks are the surface roughness using interference fringes. It is desirable that it is measured by a gauge.
This is because the surface roughness meter using the interference fringes is a combination of an interferometer and an optical microscope, and can measure the surface shape of a substrate or the like with high accuracy and high sensitivity.
Further, the surface roughness meter using the above interference fringes can measure the surface state of the sample (substrate or the like) in a non-contact manner, so that the surface of the substrate is not damaged.

Generally, in the interferometer using the above interference fringes,
The light emitted from the light source is split into two by the beam splitter, one of which is reflected by the reference mirror and returns to the beam splitter, and the other of which is reflected by the surface of the sample and returns to the beam splitter. The two lights of the above become one light again by the beam splitter, and this one light is taken into a detector such as a CCD camera.
At this time, the light reflected by the reference mirror and the light reflected by the surface of the sample interfere with each other when they become one light again by the beam splitter. Therefore, the surface state of the sample is determined by the image of the interference light. Can be measured.

In addition, in the optical fiber array 100 of the present invention, a coating resin layer holding portion 158 for holding the optical fibers together with the coating resin layer 114 around the optical fiber is collectively provided on the upper surface of the substrate 151 in addition to the groove 157. Has been formed. The upper surface of the coating resin layer holding portion 158 is lower than the groove forming surface in which the groove 157 is formed. Further, an adhesive layer 159 ′ is formed around the coating resin layer 114 placed on the coating resin layer holding portion 158. The coating resin layer holding portion 158 may be formed as needed,
Only the V groove may be formed on the substrate. In the figure, 110 is an optical fiber ribbon, 111 is a core, and 112 is a core.
Is the clad.

When forming the coating resin layer holding portion together with the groove on the upper surface of the substrate, the boundary between the groove forming surface and the coating resin layer holding portion may be a vertical wall surface. It is desirable that the wall surface has an inclination so that it goes down toward the coating resin layer holding portion as shown. This is because when the optical fiber is stored, the load applied to the optical fiber can be reduced. In the present specification, the wall surface of the boundary between the groove forming surface and the coating resin layer holding portion is also included in the coating resin layer holding portion. Further, in such an optical fiber array in which the boundary between the groove forming surface and the covering resin layer holding portion is a wall surface having an inclination, the optical fiber exposed in the groove is fixed, and the exposed optical fiber in the covering resin layer holding portion is fixed. And the coating resin layer are fixed.

FIG. 3 is a partial perspective view schematically showing another example of the optical fiber array of the present invention. As shown in FIG. 3, in the optical fiber array 102 of the present invention, instead of the coating resin layer holding portion, the optical fiber array 102 of the present invention is provided with a concave portion 1158 that can accommodate the optical fiber together with the surrounding coating resin layer.
May be formed. Further, the height of the side wall surface of the recess may be the same as the height of the upper surface of the groove forming region of the substrate as shown in FIG. 3, or may be lower than this. Further, in the optical fiber array 102, the lid 116 having a plate-like shape is formed on the substrate 151 via the adhesive layer 159.
0 is attached. In addition, in the configuration of the optical fiber array 102 shown in FIG. 3, the concave portion is formed instead of the covering resin layer holding portion, and the shape of the lid portion is a plate-like body, except that the optical fiber array of FIG. Is almost the same as.

In the optical fiber array of the present invention, the shape of the lid attached to the substrate via the adhesive layer is such that a concave portion for accommodating a part of the optical fibers as shown in FIG. 1 is formed. However, the shape of the lid is not limited to such a shape, and may be, for example, a plate-like body as shown in FIG. It may have a shape in which a groove for separately storing the fibers is formed. In addition, in the lid portion having a shape in which a concave portion for collectively storing a part of the optical fiber is formed,
Since there is a gap between the optical fibers housed in the recesses, the relative displacement of the optical fibers is unlikely to occur, and furthermore, an uncured adhesive or the like is easily filled in the gap.

Further, when a recess is formed in the lid for accommodating a part of the optical fibers, the shape of the recess may be a combination of only planes intersecting at right angles, or a curved surface. The formed shape, the shape which combined the flat surface and the curved surface, etc. are mentioned.

The lid may have a cross-section in a direction perpendicular to the axis of the optical fiber such that both side lower portions of the rectangle are cut off. In this case, Examples of the cut-out shape include a shape surrounded by a triangle, a quadrangle, a polygon, and two straight lines orthogonal to an arc (elliptic arc).

Further, the size of the lid is not particularly limited as long as it can cover the optical fiber housed in the groove, and as shown in FIGS. It may be sized to cover only the top surface or may be sized to cover the entire top surface of the substrate. Further, a lid having a shape covering only the grooved area of the substrate and a lid having a shape covering only the coating resin layer holding portion may be separately attached. In this case, the lid covering the grooved area is attached. There may or may not be a gap between the portion and the lid portion that covers the coating resin layer holding portion.

The optical fiber array 1 shown in FIGS.
In Nos. 00 and 102, four optical fibers are accommodated, but the number of optical fibers accommodated in the groove of the optical fiber array of the present invention is not limited to four, and three optical fibers are accommodated.
The number may be less than or equal to 5 or may be greater than or equal to 5.

Next, the constituent members of the optical fiber array of the present invention will be described. Examples of the material of the substrate include inorganic materials such as silicon, silicon carbide, alumina, aluminum nitride, mullite, ceramics, gallium arsenide, zirconia; quartz glass, high silicate glass, soda lime glass, borosilicate glass, lead glass. , Glass such as fluoride glass; metal materials such as copper, iron, nickel; thermosetting resins, thermoplastic resins, photosensitive resins, organic materials such as composites thereof, and reinforcement of glass fibers etc. to these organic materials Examples include those impregnated with a material. The material of the lid may be the same as the material of the substrate, for example. The material of the lid and the material of the substrate may be the same or different.

The materials of the substrate and the lid are:
Silicon and high silicate glass are desirable in that they do not expand or contract (deform) due to heat or humidity and are excellent in mechanical strength. As a combination thereof, one of the substrate and the lid is made of silicon and the other is made of high silicate. Is it acid glass,
Alternatively, it is desirable that both the substrate and the lid are made of high silicate glass. Further, each of the substrate and the lid may have a two-layer structure in which silicon and high silicate glass are bonded together.

In particular, silicon is used as the material of the substrate,
It is desirable to use high silicate glass as the material of the lid. When the material of the substrate is silicon, the V groove can be formed in the substrate by anisotropic etching, so that the formed groove has excellent positional accuracy, and the material of the lid is made of high silicate glass. In some cases, since the lid portion has excellent transparency to ultraviolet rays and the like, when the optical fiber array of the present invention is manufactured by using the ultraviolet curable adhesive as the material of the adhesive layer, ultraviolet rays are radiated through the lid portion. By doing so, the adhesive layer can be preferably formed. When the material of the lid is high silicate glass, the target mark (target mark for aligning with the lid etc.) formed on the substrate is used as a target for aligning with external parts. It can also be used as a mark.

The method for forming the roughened surface having the surface roughness within the above range on the substrate is not particularly limited, and may be, for example, a solution containing an acid, an alkali, an oxidizing agent or the like, or a liquid such as a solvent. Examples of the method include immersing the lid portion in, or applying the liquid by spraying. The specific method to be selected may be appropriately determined in consideration of the material of the lid portion, the surface roughness to be formed, and the like. Therefore, a method of forming a roughened surface on each of the substrate made of high silicate glass and the substrate made of silicon will be described below.

Examples of the method for forming the roughened surface on the upper surface of the substrate made of the high silicate glass include etching treatment using a roughening solution containing fluoride, and the roughening solution containing fluoride. specific examples of, for example, HF solution, HF-NH ₄ F mixture, NaF aqueous solution, BaF ₂ aqueous solution, KF aqueous solution, CaF ₂ aqueous solution, XeF ₂ aqueous solution, and the like. Among these, a solution containing HF is desirable. This is because the roughened surface having the above-mentioned surface roughness can be formed in a short time.

The following conditions are desirable as specific conditions for forming a roughened surface having the above-mentioned surface roughness by using an HF aqueous solution on a substrate made of the above-mentioned high silicate glass. That is, the concentration of the HF aqueous solution is HF:
H ₂ O = 1: 10 to 1:30 is desirable, and HF: H ₂ O
= 1: 20 is more desirable. The lower limit of the etching treatment temperature is preferably 30 ° C.
It is more preferable that the temperature is ° C. On the other hand, the upper limit of the etching temperature is preferably 80 ° C, and 50 ° C.
It is more desirable that it is a degree. Further, the etching treatment time is preferably 10 to 120 minutes, more preferably about 30 minutes.

Further, usually, even if an etching treatment is applied to a high silicate glass plate having a smooth surface state, the etching is difficult to proceed. This is because the etching using the above-mentioned roughening solution progresses (erodes) from the irregularities and scratches on the surface of the high silicate glass as the starting points, so the etching progresses on the high silicate glass plate with a smooth surface. This is because there are few starting points for doing. Therefore, when a roughened surface is formed on the substrate made of the high silicate glass by an etching treatment using the roughening solution, pretreatment such as polishing treatment is performed in advance so that the high silicate glass surface is ground glass. It is desirable to keep.
Specifically, single-sided grain polishing (# 500, # 700, # 1
000, # 1500), alumina-based abrasive grains, diamond abrasive grains or the like. Further, commercially available ground glass may be used.

As a method for forming a roughened surface on a substrate made of silicon, for example, etching treatment using a solution containing an alkali such as KOH or NaOH can be mentioned. Among these, etching treatment using a solution containing KOH is desirable. This is because the etching rate is high and the roughened surface can be formed in a short time. Also, N
When etching is performed using a solution containing aOH, the treated surface may be discolored or foreign matter may be generated on the treated surface in some cases.

The following conditions are desirable as specific conditions for forming a roughened surface having the above-mentioned surface roughness using a solution containing KOH on a substrate made of silicon. That is, the concentration of the KOH solution is preferably 10 to 40% by weight, more preferably about 20% by weight. When the concentration of the solution containing KOH is less than 10% by weight or more than 40% by weight, the etching rate may be slow. The etching temperature is preferably 30 to 90 ° C, more preferably 40 to 60 ° C. Further, the etching time is preferably 4 to 10 minutes, more preferably 5 to 7 minutes.

When a roughened surface is formed on a substrate made of high silicate glass or a substrate made of silicon under the above-mentioned conditions, the surface roughness of the roughened surface is the average of the above range. In addition to satisfying the roughness Ra, usually, the average spacing Sm of the irregularities in the above range and the average spacing S of the local peaks are
Will also be satisfied.

For a substrate made of silicon, KOH
When a roughened surface is formed under the above etching conditions using a solution containing, the average roughness Ra formed by the crystal surface will be different. Specifically, for example, K
When a roughened surface is formed under a desirable treatment condition using a solution containing OH, a roughened surface having an average roughness Ra of 50 to 500 nm is formed on the (100) surface,
A roughened surface having an average roughness Ra of 5 to 100 nm is formed on the (111) surface. Furthermore, when the roughened surface is formed under the more desirable processing conditions described above, (100)
A roughened surface having an average roughness Ra of 200 to 300 nm is formed on the surface, and a roughened surface having an average roughness Ra of 10 to 80 nm is formed on the (111) surface.

The optical fiber array 1 shown in FIGS.
In Nos. 00 and 102, the optical fiber ribbon 110 in which the optical fiber is exposed by removing the coating resin layer at one end is stored in the substrate 151 in which the plurality of V grooves 157 are formed. The optical fiber ribbon is not particularly limited, and a conventionally known one can be used. For example, the primary coating resin layer 113 is provided around the optical fiber 115 including the core 111 and the clad 112 as shown in FIG.
It is possible to use the optical fiber ribbon 110 in which the optical fibers 115 coated with the primary coating resin layer 113 are arranged in parallel and are collectively coated with the secondary coating resin layer 114.

Optical Fiber 1 Constituting Optical Fiber Ribbon
As 15, there are, for example, a silica-based optical fiber whose main component is silica glass (SiO ₂ ), a multi-component optical fiber whose main component is soda lime, glass, borosilicate glass, and a plastic such as silicone resin or acrylic resin. Examples include plastic optical fibers containing as a main component. Of these, quartz optical fiber is desirable. By forming a roughened surface on the surface, the adhesiveness with the adhesive layer is particularly improved, which is suitable for the optical fiber array of the present invention.

The primary coating resin layer 113 plays a role as a protective layer for preventing the optical fiber from being damaged. The material is not particularly limited,
For example, a thermosetting resin such as an epoxy resin, a silicone resin, a urethane resin, a phenol resin, a polyimide resin, a polyolefin resin, or a fluororesin, or methacrylic acid or acrylic acid is used, and the thermosetting group of the thermosetting resin described above is used. Examples thereof include (meth) acrylated photosensitive resins. The number of the primary coating resin layers is not limited to one and may be two or more.

The secondary coating resin layer 114 plays a role of protecting the optical fiber formed around the primary coating resin layer and maintaining the shape of the optical fiber ribbon in which the optical fibers are arranged in parallel. There is. The material is not particularly limited, and examples thereof include the same thermosetting resin and photosensitive resin as the material of the primary coating resin layer. The number of the secondary coating resin layers is not limited to one, and
It may be more than one layer.

In the optical fiber arrays 100 and 102, the coating resin layer may be removed and a roughened surface (not shown) may be formed on the surface of the optical fiber housed in the V groove 157. This is because the adhesion between the optical fiber and the adhesive layer is improved. The lower limit of the average roughness Ra of the roughened surface is preferably 1 nm, and the upper limit thereof is 100 n.
It is desirable that it is m. When the average roughness Ra is less than 1 nm, the adhesiveness between the optical fiber and the adhesive layer is hardly improved, while when the average roughness Ra exceeds 100 nm, the unevenness of the surface of the optical fiber becomes large, so that The shape of the cross section deviates from the circular shape, the positional deviation of the optical fiber is likely to occur, and the optical signal transmission may be adversely affected. The lower limit of the average roughness Ra of the roughened surface is 10 n.
m is more preferable, and its upper limit is more preferably 50 nm.

The method for forming the roughened surface is not particularly limited, but it is desirable to use a roughening solution containing fluoride. This is because the roughened surface having the average roughness Ra in the above range can be formed in a short time.

As the roughening liquid containing the above-mentioned fluoride, for example, the same one as that used for forming the roughened surface on the substrate made of the above-mentioned high silicate glass can be mentioned. Among them, a solution containing HF is desirable. Without adversely affecting the optical fiber (deformation of the optical fiber, etc.),
This is because it is possible to form a roughened surface having a desired average roughness Ra in a short time, and it is particularly suitable for forming a roughened surface on the surface of a silica optical fiber or a multi-component optical fiber. .

In each of the optical fiber arrays 100 and 102, the optical fiber ribbon from which the coating resin layer at one end is removed is housed in the substrate, but a plurality of optical fibers are housed in the groove of the substrate. It may be a single-core optical fiber or a laminated optical fiber ribbon in which a plurality of optical fiber ribbons are stacked. When a laminated optical fiber ribbon is used, a plurality of optical fibers can be arranged in high density in parallel in the groove of the substrate.

FIG. 4 (a) is a partial perspective view schematically showing an example of the optical fiber array of the present invention using the laminated optical fiber ribbon, and FIG. 4 (b) shows the optical fiber array of FIG. It is a partial perspective view which shows only the board | substrate and laminated | multilayer optical fiber ribbon, (c) is the sectional view on the AA line of (a). As shown in FIG. 4, in the optical fiber array 200, the exposed optical fibers 235 and 245 at one end of the laminated optical fiber ribbon 210 are housed in the V groove 257 on the substrate 251 via the adhesive layer 259, and the laminated optical fiber A part of the ribbon 210 is covered with the coating resin layer, and the coating resin layer holding portion 258 is provided.
Held in. An adhesive layer 259 ′ is formed around the coating resin layer held by the coating resin layer holding portion 258.

In the laminated optical fiber ribbon 210, two optical fiber ribbons 230 and 240 each having an exposed optical fiber at one end are stacked, and the optical fiber 245 exposed at the lower optical fiber ribbon 240 and the upper optical fiber 245 at the upper stage. The exposed optical fibers 235 of the optical fiber ribbon 230 are alternately arranged.

In the laminated optical fiber ribbon 210,
The exposed optical fibers 235, 245 are arranged so that the exposed optical fibers 235, 245 are arranged at the same height.
Each is bent in part. In the laminated optical fiber ribbon 210, the upper optical fiber ribbon 2
Although the exposed optical fibers 235 of 30 and the exposed optical fibers 245 of the lower optical fiber ribbon 240 are partly bent, both optical fibers can be arranged at the same height. If so, only the exposed optical fiber of the upper optical fiber ribbon may be bent, or only the exposed optical fiber of the lower optical fiber ribbon may be bent.

In the laminated optical fiber ribbon 210, it is desirable that the upper optical fiber ribbon 230 and the lower optical fiber ribbon 240 are fixed to each other with an adhesive or the like. This is because the positional deviation of the optical fibers arranged in parallel at high density is less likely to occur. Also,
Also in this optical fiber array 200, when the coating resin layer holding portion is formed together with the groove on the upper surface of the substrate, the boundary between the groove forming surface and the coating resin layer holding portion is lowered toward the coating resin layer holding portion. A wall surface having an inclination is desirable, and instead of the coating resin layer holding portion, a recess for accommodating the optical fiber together with the coating resin layer may be formed.

In the optical fiber array of the present invention, the optical fiber is housed in the groove, and the lid portion covering the optical fiber is attached on the substrate through the adhesive layer. Further, when the cover resin layer holding portion is formed on the substrate, the optical fiber is fixed to the cover resin layer holding portion together with the cover resin layer via the adhesive layer.

Examples of the material of the adhesive layer include organic adhesives such as a cured product of a resin composition containing at least one of a thermoplastic resin, a thermosetting resin, and a photosensitive resin. Among these, a cured product of a resin composition containing a thermosetting resin or a photosensitive resin is desirable. Examples of the thermosetting resin include epoxy resin, phenol resin, silicone resin, polyimide resin, and fluororesin.

Examples of the epoxy resin include bisphenol type epoxy resin and novolac type epoxy resin. The use of the above bisphenol type epoxy resin is desirable in that the viscosity can be adjusted by selecting an A type or F type resin without using a diluting solvent, and it is preferable to adjust the viscosity to a lower value. The bisphenol F type epoxy resin is more preferable in that it can be obtained. Further, it is preferable to use the above novolac type epoxy resin because the resin has high strength, excellent heat resistance and chemical resistance, and is less likely to be thermally decomposed. Further, as the novolac type epoxy resin, a phenol novolac type epoxy resin and a cresol novolac type epoxy resin are desirable.

The bisphenol type epoxy resin and the novolac type epoxy resin are preferably mixed and used. In this case, the mixing ratio of the bisphenol type epoxy resin and the novolac type epoxy resin is preferably 1: 1 to 1: 100. This is because mixing within this range can suppress an increase in viscosity.

Further, as the above-mentioned photosensitive resin, for example,
Examples thereof include resins obtained by imparting photosensitivity to the thermosetting resin. Specifically, for example, the one in which the thermosetting group of the thermosetting resin is (meth) acrylated by using (meth) acrylic acid or the like can be mentioned. Among these, the (meth) acrylate of the epoxy resin is preferable, and the epoxy resin having two or more epoxy groups in one molecule is more preferable.
Examples of the photosensitive resin also include acrylic resin and the like. These photosensitive resins may be used alone or in combination of two or more.

As the material of the adhesive layer, for example, a cured product of an epoxy-based or acrylate-based UV-curable resin composition can be used. As will be described later, when an optical fiber array is manufactured, if an uncured adhesive (resin composition) is poured into the gap between the optical fiber and the groove or the gap between the optical fiber and the lid, the gap is caused by the surface tension. In this case, the uncured adhesive is filled in, but in the ultraviolet curable resin composition, the gap between the optical fiber and the groove can be more surely filled, and therefore, the ultraviolet curable resin composition. Positional deviation does not occur in the optical fiber fixed through the cured product. Further, the cured product of this epoxy or acrylate-based ultraviolet curable resin composition can also be used as an adhesive layer for fixing the coating resin layer to the coating resin layer holding portion. Moreover, it is desirable that a part of the cured product of the ultraviolet curable resin composition is fluorinated. By fluorinating, it is difficult for water to be generated in the adhesive layer and the moisture resistance is improved. Also,
Insulation, heat resistance, chemical resistance, etc. are also improved.

Specific examples of the epoxy-based UV-curable resin composition include, for example, Optodyne UV-1000, Optodyne UV-1100, manufactured by Daikin Industries, Ltd.
Optodyne UV-2100, Optodyne UV-31
00, Optodyne UV-3200, Optodyne UV
-4000 etc. are mentioned.

Specific examples of the acrylate-based UV-curable resin composition include, for example, Optodyne UV-2.
000, Optodyne UV-3000 and the like.
Specific examples of the acrylate-based UV curable resin composition include, for example, 40 to 50% by weight of acrylate oligomer, 1 to 10% by weight of vinyl ester resin, and 45.
-55 wt% acrylate-based monomer, and 1-
Those containing 10% by weight of a polymerization initiator are also included.

Further, it is desirable that a part of the acrylate oligomer or the acrylate-based monomer is fluorinated. Thus, when a part of the components contained in the ultraviolet curable resin composition is fluorinated,
Since the ultraviolet curable resin composition has excellent translucency, the entire resin composition will be cured in a short time upon irradiation with ultraviolet rays.

When the adhesive layer is a cured product of the ultraviolet curable resin composition, both the exposed optical fiber, the lid, and the adhesive layer for fixing the coating resin layer are used as the adhesive layer. A cured product of an epoxy-based or acrylate-based UV-curable resin composition may be used,
Using a cured product of an epoxy-based ultraviolet curable resin composition as an adhesive layer for fixing the exposed optical fiber and the lid,
A cured product of an acrylate-based UV-curable resin composition may be used as the adhesive layer for fixing the coating resin layer.

By using a cured product of a relatively hard epoxy-based UV-curable resin composition as the adhesive layer for fixing the exposed optical fiber and the lid, positional deviation of the optical fiber is less likely to occur, and the coating resin By using a cured product of a relatively soft acrylate-based UV-curable resin composition as an adhesive layer for fixing the layers, the coating resin layer portion should be deformed to some extent according to the shape of the portion to which the optical fiber array is attached. Will be possible.
In addition, in the case of attaching a lid part having a shape covering the entire surface of the substrate, the adhesive layer is preferably made of a cured product of one type of ultraviolet curable resin composition.

When the cured product of the ultraviolet curable resin composition is used as the adhesive layer, the viscosity of the ultraviolet curable resin composition at 25 ° C. is not particularly limited, but it is 2
It is desirable that it is from 00 to 2000 mPa · s. If the viscosity is less than 200 mPa · s, the viscosity is too low, so that the UV curable resin composition poured into the gap between the groove and the optical fiber may flow out before curing.
If it exceeds 00 mPa · s, the gap between the groove and the optical fiber may not be reliably filled.

Further, 25 of the above ultraviolet curable resin composition
As for the viscosity at 0 ° C., the viscosity of the ultraviolet curable resin composition used for fixing the exposed optical fiber and the lid is 2
It is also desirable that the UV curable resin composition used for fixing the optical fiber together with the coating resin layer has a viscosity of 5,000 to 30,000 mPa · s. By using a resin composition having a viscosity in the above range as the ultraviolet curable resin composition for fixing the optical fiber, the resin composition is reliably filled in the gap between the optical fiber and the groove, When a resin composition having a viscosity in the above range is used as the ultraviolet curable resin composition for fixing the fiber together with the resin composition, it is easy to apply the resin composition around the coating resin layer. The viscosity of the ultraviolet curable resin composition may be adjusted by adjusting the blending amount of the solvent and various additives.

As the adhesive layer for fixing the optical fiber together with the coating resin layer, instead of the cured product of the acrylate-based UV-curable resin composition, or the acrylate-based UV-curable resin composition. A silicone adhesive may be used in combination with the cured product. As the silicone-based adhesive, for example, manufactured by Shin-Etsu Chemical Co.,
KJC-7806, Dow Corning 734, etc. are mentioned.

If necessary, the above-mentioned organic adhesive contains additives such as a curing agent, resin particles, inorganic particles, particles such as metal particles, a brightener, a reaction stabilizer and a photopolymerization agent. Good. By including these additives, it is possible to improve the fluidity and adjust the degree of curing. The curing agent is not particularly limited, and commonly used curing agents can be used, and specific examples thereof include an imidazole curing agent and an amine curing agent.

Examples of the resin particles include thermosetting resins, thermoplastic resins and the like. Specifically, for example, amino resins (melamine resin, urea resin,
(Guanamine resin), epoxy resin, phenol resin, phenoxy resin, polyimide resin, polyphenylene resin,
Examples include polyolefin resins, fluororesins, bismaleimide-triazine resins, and the like. These may be used alone or in combination of two or more. Also,
As the resin particles, particles made of rubber such as acrylonitrile-butadiene rubber and polychloroprene rubber can also be used.

Examples of the inorganic particles include aluminum compounds such as alumina and aluminum hydroxide, calcium compounds such as calcium carbonate and calcium hydroxide, potassium compounds such as potassium carbonate, magnesium compounds such as magnesia, dolomite, and basic magnesium carbonate. Examples thereof include silicon compounds such as silica and zeolite, titanium compounds such as titania, and the like. These may be used alone or in combination of two or more, and as the above-mentioned inorganic particles, phosphorus or a phosphorus compound may be used.

Examples of the metal particles include gold, silver,
Examples include copper, tin, zinc, stainless steel, aluminum, nickel, iron and lead. These may be used alone or in combination of two or more. By including these particles, adjustment of the thermal expansion coefficient and improvement of flame retardancy can be achieved.

The organic adhesive may contain a solvent or may not contain a solvent at all. When a solvent is included, the solvent may be, for example, N
Examples thereof include MP (normal methylpyrrolidone), DMDG (diethylene glycol dimethyl ether), glycerin, cyclohexanol, cyclohexanone, methylcellosolve, methylcellosolve acetate, methanol, ethanol, butanol and propanol.

The material of the adhesive layer is not limited to the organic adhesive as described above, but may be solder or the like. As a specific example of the solder, for example, S
n-Pb, Sn-Sb, Sn-Ag, etc. are mentioned. When solder is used as the material of the adhesive layer, the substrate upper surface, the surface of the lid portion facing the substrate, or a part or all of the surface of the exposed optical fiber that contacts the adhesive layer,
It is necessary to form a metal layer in advance. The method of forming the metal layer will be described later.

Next, a method for manufacturing the optical fiber array of the present invention will be described in the order of steps. (1) Using the above-mentioned substrate made of silicon or the like as a starting material, a plurality of grooves are formed in a part of the upper surface of the substrate. Specifically, for example, the groove can be formed on the upper surface of the substrate by going through the following steps (i) to (vii). Figure 5 (a)
(G) is sectional drawing which shows an example of the method of forming a groove | channel in a board | substrate.

(I) First, the mask layer 15 is formed on the substrate 151.
2 (152a, 152b) are formed (see FIG. 5A). The number of mask layers is not limited to two layers as shown in FIG. 5, and may be one layer or three or more layers.

As a method of forming the mask layer 152,
For example, a method of forming a thin film by sputtering, CVD, plating or the like, a method of forming an oxide film by thermal oxidation or the like, a method combining these, or the like can be used. Among these, for example, when forming a mask layer on a substrate made of silicon, first an oxide film (SiO ₂ film) is formed by thermal oxidation, and then a thin film is formed on this oxide film by CVD. A method of forming is desirable. By forming such a mask layer, it is possible to form a mask having an arbitrary shape by subjecting an arbitrary portion to etching treatment in a later step.

(Ii) Next, a resist resin layer 154 is formed on the mask layer 152 (see FIG. 5B). Specifically, a method in which a resist resin composition whose viscosity has been adjusted in advance is applied by a spin coater, a curtain coater, a roll coater, printing, or the like, or a resist resin film which has been formed into a film shape in advance is attached. A method of attaching can be used.

The resin composition for resist and the resin film for resist are composed of, for example, a resin component and a curing agent, particles, a rubber component, an additive, a reaction stabilizer, a solvent and the like which are blended as necessary. There are things. Examples of the resin component include a thermosetting resin, a thermoplastic resin, a photosensitive resin, a resin in which a part of the thermosetting resin is replaced with a photosensitive group, a composite resin of these, and the like.

Specifically, for example, thermosetting resins such as epoxy resin, phenol resin, polyimide resin, bismaleimide resin, polyphenylene resin, polyolefin resin, and fluororesin; thermosetting groups of these thermosetting resins (for example, , (Epoxy group in epoxy resin) is reacted with methacrylic acid or acrylic acid to form an acrylic group (photosensitive group).
Resins provided with: thermoplastics such as phenoxy resin, polyether sulfone (PES), polysulfone (PSF), polyphenylene sulfone (PPS), polyphenylene sulfide (PPES), polyphenyl ether (PPE), and polyetherimide (PI) Resin: Acrylic resin, photosensitive resin such as ultraviolet curable resin, and the like. Among these, epoxy resin, phenol resin, polyimide resin, acrylic resin, and ultraviolet curable resin are preferable. This is because when the mask layer under the resist resin layer is treated with an etching solution in a later step, the resistance to the etching solution is excellent. Examples of the curing agent include imidazole curing agents, amine curing agents, acid anhydride curing agents, and the like.

The thickness of the resist resin layer is 10
˜50 μm is desirable. The resist resin layer may be in a cured state or a semi-cured state. Specifically, for example, in the case where the resist resin layer in the portion corresponding to the groove to be formed on the substrate is removed by exposure and development in a later step, it is preferably in a semi-cured state. When the resist resin layer corresponding to the groove is removed, it may be in a cured state or a semi-cured state. In the case of forming a resist resin layer in a completely cured state or a semi-cured state, it is desirable to perform the curing treatment by heating at 70 to 200 ° C, for example. Moreover, you may perform step hardening which changes a heating temperature step by step.

(Iii) Next, a part of the resist resin layer 154, that is, a part corresponding to a groove formed in the substrate 151 is removed to obtain an etching resist 155 (FIG. 5).
(See (c)). The resist resin layer 154 can be removed by, for example, exposure and development treatment. Specifically, for example, a mask is placed on the semi-cured resin layer for resist, an exposure process is performed, and then a development process using a chemical solution such as an alkaline solution or an organic solvent is performed. The developing treatment can be performed by immersing the substrate having the resin layer for resist in the chemical solution or spraying the chemical solution. As the mask, it is possible to use a mask in which a groove pattern is drawn in a portion corresponding to the removed portion of the resist resin layer.

The removal of the resist resin layer 154 is
Alternatively, laser processing may be used. Examples of the laser used for the laser processing include carbon dioxide gas laser, excimer laser, UV laser, and YAG laser.
These lasers may be selectively used in consideration of the shape of the removed portion of the resist resin layer, the composition of the resist resin layer, and the like. By adjusting the shape of the etching resist formed in this step, it is possible to adjust the shape of the groove formed through the subsequent steps.

(Iv) Next, the mask layer 152 exposed in the portion where the etching resist 155 is not formed is removed, and the substrate 151 is removed.
A mask 156 is formed by exposing the portion where the groove is formed (see FIG. 5D). The mask layer 152 is removed by, for example, RIE (reactive ion etching), plasma treatment using oxygen plasma or nitrogen plasma, corona treatment,
It can be performed by dry etching treatment such as reverse sputtering. Specifically, for example, it can be performed by irradiating the mask layer with oxygen plasma under vacuum or reduced pressure. By performing such a dry etching process, it is possible to selectively remove only the mask layer in the resist non-forming portion without causing damage or deformation of the etching resist.

The mask layer 152 can be removed by, for example,
It is also performed by immersing the substrate on which the mask layer 152 is formed in an etching solution or an acid solution, immersing the substrate in the solution and performing ultrasonic treatment, or spraying the etching solution or the acid solution on the mask layer. be able to. The removal method to be specifically selected may be appropriately determined in consideration of the material and thickness of the mask layer. For example, when the mask layer is made of an oxide film, plasma treatment or etching solution is used. When the mask layer is made of a metal layer, reverse sputtering or a treatment with an etching solution may be selected.

(V) Next, the etching resist 155 is peeled and removed (see FIG. 5E). The removal of the etching resist 155 should be carried out using an alkaline solution such as NaOH, KOH, an acid solution such as sulfuric acid, acetic acid, carbonic acid, alcohols such as methanol and ethanol, amines, ketones, organic solvents such as acetone, and the like. You can This allows
Only the mask 156 having the opening corresponding to the portion where the groove is formed is formed on the substrate 151.

(Vi) Next, the groove 157 is formed in the substrate 151 (see FIG. 5F). The groove 157 is, for example, the substrate 1
It can be formed by spraying an etching solution on 51 through the mask 156 or by immersing the substrate 151 on which the mask 156 is formed in the etching solution. Examples of the etching solution include NaOH and K
An alkali such as OH, an acid such as nitric acid, phosphoric acid, sulfuric acid, a fluorine-based compound such as hydrogen fluoride or bromine fluoride, a halide, a hydrogen peroxide solution, an alcohol such as methanol or ethanol, or the like can be used. When the groove is formed by using these etching solutions, the cross-sectional shape of the groove is V-shaped, inverted trapezoidal shape, rectangular shape, or a combination thereof.

The concentration of the etching solution is preferably 10 to 50% by weight. If the concentration is less than 10% by weight, the etching process may take a long time, while if it exceeds 50% by weight, the etching rate hardly changes.
The temperature of the etching solution is preferably 20 to 90 ° C., and the etching rate is preferably 0.5 to 5.0 μm / min. If the temperature of the etching solution is lower than 20 ° C., the etching may not be sufficiently performed, and even if the temperature of the etching solution exceeds 90 ° C., the etching amount is hardly changed, and the safety during the work is lowered.

Here, when the groove is formed in the substrate whose material is silicon or gallium arsenide, it is desirable to perform etching treatment using an alkaline solution such as KOH. When a substrate made of silicon or gallium arsenide is subjected to etching treatment, a groove having a desired shape is formed by selecting an appropriate etching surface, type of etching solution, and shape of the etching resist non-forming portion. be able to.

That is, when a silicon substrate is etched using an etching solution containing KOH, the (100) plane of the silicon substrate is preferentially etched as compared with the (111) plane and the (110) plane, and each crystal is crystallized. Since the etching rate ratio of the surface is almost constant, a groove having a desired shape can be formed. Specifically, when the (100) surface of the silicon substrate is subjected to etching treatment, it is possible to form a groove having a V-shaped or inverted trapezoidal cross section.
When the (110) plane is subjected to etching treatment, a groove having a rectangular cross section can be formed.

When etching the gallium arsenide substrate with an etching solution containing KOH, (11
1) The slowest etching rate of Ga surface is (111) A
By utilizing the fact that the s-plane has the highest etching rate, it is possible to form a groove having a desired shape.

When the etching treatment is carried out in this step, a surfactant or the like may be added to the etching liquid. When the foaming occurs violently during the etching process, irregularities may be formed on the etching surface due to the foaming, but by adding a surfactant, the foaming during the etching process can be suppressed. Also,
The etching process may be performed while applying ultrasonic waves. This is because foaming can also be suppressed by applying ultrasonic waves.

When the substrate is dipped in the etching solution to perform the etching process, the etching process may be performed while the substrate is swung or the etching solution is stirred.

(Vii) Next, if necessary, the substrate 151
The upper mask 156 is removed (see FIG. 5G). By removing the mask layer 156, the entire upper surface of the substrate including the surface of the groove is made of the same composition, and when a roughened surface is formed on the upper surface of the substrate in a later step, the substrate It is possible to form a roughened surface on the entire upper surface under the same conditions.

As a method of removing the mask 156, the same method as the method used in the step (iv) can be used. That is, the process used to remove the mask layer 152 exposed in the etching resist 155 non-forming portion in the above step (iv) may be performed in this step as well.

It is not necessary to remove the mask 156. In that case, in a strict sense, the portion for accommodating the optical fiber in the subsequent step is strictly a portion where the mask-unformed portion and the groove provided on the substrate are combined. However, in the present specification, unless otherwise specified, the portion in which the mask non-forming portion and the groove provided in the substrate are combined is also referred to as a groove. Therefore, the wall surface of the mask may form a part of the surface of the groove. Through the steps (i) to (vii) described above, a groove having a desired shape can be formed in the substrate.

Further, in the step (1), the method of forming the groove in the substrate is not limited to the method of performing the etching treatment as described above, and the material of the substrate, the shape of the groove to be formed, etc. are taken into consideration. The optimum forming method may be selected. In particular,
For example, when forming a groove on a substrate made of high silicate glass, the groove can be formed by performing a cutting process using an apparatus equipped with a diamond blade. Even when a groove is formed on a substrate made of silicon, the groove may be formed by performing a cutting process. Generally, when the groove is formed by anisotropic etching, the groove is formed by a cutting process. Since the relative positional accuracy of adjacent grooves is superior to that in the case, it is desirable to form the grooves by anisotropic etching when forming the grooves on the substrate made of silicon.

In the step (1), it is desirable to form the groove in the substrate and to form the coating resin layer holding portion for holding the optical fiber or the optical fiber ribbon together with the coating resin layer. The method for forming the coated resin layer holding portion is not particularly limited, and examples thereof include a method using a device equipped with a diamond blade. Further, the formation of the coating resin layer holding portion may be performed once or may be performed twice or more.

When the coating resin layer holding portion is formed, the upper surface of the coating resin layer holding portion may have irregularities. In this case, a polishing process may be performed to flatten the unevenness, but if the unevenness is such that the optical fiber ribbon is greatly inclined when holding the optical fiber ribbon or the like, the polishing process is particularly performed. It is desirable to leave it as it is. This is because when the coating resin layer holding portion holds the coating resin layer via the adhesive layer, the adhesion effect improves the adhesion between the coating resin layer holding portion and the adhesive layer. Further, when forming the coated resin layer holding portion here, even if a plurality of holding surfaces having different heights are formed in the coated resin layer holding portion so as to follow the shape of the optical fiber ribbon or the like to be held. Good.

When forming the above-mentioned coating resin layer holding portion together with the groove on the upper surface of the substrate, the boundary between the groove forming surface and the coating resin layer holding portion is the coating resin layer holding portion as shown in FIG. It is desirable that the wall surface has a slope that descends. This is because the load on the optical fiber can be reduced. Further, instead of the coating resin layer holding portion,
You may form the recessed part which can accommodate the optical fiber with the coating resin layer of the circumference | surroundings. The concave portion can also be formed by using a device equipped with a diamond blade.

(2) Next, a roughened surface (not shown) is formed on all or part of the upper surface of the substrate on which the groove is formed (including the surface of the groove). The roughened surface may be formed only on a part of the upper surface of the substrate (for example, the surface of the groove or a portion of the upper surface of the substrate where the groove is not formed), but is formed on the entire upper surface of the substrate. Is desirable. This is because the adhesion with the adhesive layer is further improved. The roughened surface may be formed by the above-mentioned method using a solution containing an acid, an alkali, an oxidizing agent or the like, or a liquid such as a solvent.

When the groove is formed in the plate-like body made of silicon or the like through the step (1), the mask may or may not be removed as described above. Therefore, the plate-shaped body may be exposed or the mask may be exposed on the upper surface (including the surface of the groove) of the substrate.

Specifically, a mask made of a SiO ₂ film and a Si ₃ N ₄ film is formed on the surface of a plate-shaped body made of silicon, and then the exposed surface of the substrate manufactured through the above-mentioned steps is formed. The material is silicon, SiO ₂ , or Si ₃ N
_In the optical fiber array of the present invention, a roughened surface is formed on a part or all of the exposed surface made of these materials. Since we have already explained how to form a roughened surface on the exposed surface made of silicon,
Here, a method for forming a roughened surface on a SiO ₂ film or a Si ₃ N ₄ film will be briefly described, that is, Si
When the roughened surface is formed on the O ₂ film or the Si ₃ N ₄ film, for example, the method of removing the mask described in the step (iv) of (1) above may be performed under mild conditions.

When solder is used as the material of the adhesive layer formed in the subsequent step, in the step (2),
A metal layer is formed on a part or all of a portion of the upper surface of the substrate which will be in contact with solder through a post process. The material of the metal layer is not particularly limited as long as it has excellent adhesiveness to solder, and examples thereof include copper, nickel, and noble metals.

Examples of the method for forming the above metal layer include plating and sputtering. When the metal layer is formed, at least a part of the surface of the metal layer is a roughened surface. As a method of making the surface of the metal layer a roughened surface, a method of forming the metal layer so as to follow the roughened surface formed on the upper surface of the substrate by using the above-mentioned solution of acid or alkali may be used. After forming a metal layer having a smooth surface, the surface of the metal layer is subjected to blackening (oxidation) -reduction treatment, etching treatment using an etching solution containing a cupric complex and an organic acid salt, and the like. A roughened surface may be formed on the surface. Furthermore, a metal layer having a roughened surface may be formed by Cu-Ni-P acicular alloy plating or the like.

After the above step (1), the metal layer is formed on the surface of the substrate whose surface is smooth without performing the above method of forming a roughened surface using a solution of acid or alkali. Then, after that, a roughened surface may be formed on the surface of the metal layer by the above-described method such as etching treatment or blackening-reduction treatment.

(3) Here, apart from the production of the substrate, an optical fiber ribbon in which a part of the coating resin layer is removed and the optical fiber is exposed is produced. Here, the coating resin layer to be removed may be the coating resin layer at one end of the optical fiber ribbon or may be a portion of the coating resin layer other than both ends of the optical fiber ribbon. It is desirable that it is a part of the coating resin layer other than both end portions of. In such an optical fiber ribbon from which a part of the coating resin layer other than both ends is removed, both ends of the exposed optical fiber are fixed, so that variation in the axial direction of the optical fiber is less likely to occur, and in a post-process. This is because it is suitable for being stored in the substrate.

The above-mentioned coating resin layer is removed, for example, by a mechanical removal method using a coating resin layer peeling device such as a stripper, or by chemically dissolving the coating resin layer by using an organic solvent. The method etc. can be used. Alternatively, a method of removing by irradiation with laser light may be used.

After removing the coating resin layer, it is desirable to form a roughened surface on the surface of the optical fiber by the method described above. When the roughened surface is formed on the surface of the optical fiber, the degree of inflow of the uncured adhesive due to the surface tension is substantially uniform when the uncured adhesive is poured from the end surface of the substrate in the subsequent process. As a result, the uncured adhesive can be reliably poured into the gap between the groove and the optical fiber.

(4) Next, the optical fiber ribbon produced in the above step (3) with a part of the optical fiber exposed (including the case where a metal layer is formed on the surface) is formed in the groove of the substrate. Store. Here, when storing the optical fiber ribbon from which the coating resin layer at one end is removed, the optical fiber ribbon may be stored so that the end face of each optical fiber and the side face of the substrate are aligned, or each optical fiber is placed on the substrate. You may store so that it may protrude from the side surface of a certain length. When the optical fiber ribbon from which the coating resin layer at one end thereof is removed is stored, it is desirable to store the exposed optical fiber while holding it with an aligner or the like. This is because the optical fiber can be reliably stored at the predetermined position.

When the optical fiber ribbon from which a part of the coating resin layer other than both ends thereof is removed is housed, the optical fiber ribbon which has not been housed in the substrate after housing the optical fiber ribbon is housed. Will be cut off at one end. In addition, when cutting and removing one end of the optical fiber ribbon, it may be cut and removed so that the end face of each optical fiber and the side surface of the substrate are aligned, or each optical fiber has a certain length from the side surface of the substrate. You may cut and remove so that it may protrude. The cutting and removal of the optical fiber ribbon can be performed by cutting using a cutter or the like. Alternatively, mechanical polishing may be performed.

When the coating resin layer holding portion is formed in the step (1), the optical fiber is housed in the groove and the optical fiber ribbon is placed on the coating resin layer holding portion in this step. Place the coating resin layer together. Also, on the substrate,
When the concave portion for accommodating the optical fiber ribbon together with the coating resin layer is formed, the optical fiber ribbon together with the coating resin layer is accommodated in the concave portion.

(5) Next, if necessary, an uncured organic adhesive is filled in the portion of the groove where the optical fiber is not housed, and then a curing treatment is applied, or the optical fiber is not housed in the groove. The optical fiber is fixed in the groove by applying a method of filling the portion with molten solder. Specifically, for example, uncured adhesive is poured from the end face of the substrate (end of the groove),
After that, it is hardened, or the end face of the substrate (the end of the groove)
The optical fiber is fixed by pouring the melted solder from above. Further, when the coating resin layer holding portion is formed on a part of the substrate and the optical fiber ribbon is placed on the coating resin layer holding portion together with the coating resin layer, or when the concave portion is formed on a part of the substrate, the optical fiber ribbon is formed. When the coating resin layer is to be housed in the recess, an uncured adhesive or the like is applied around the coating resin layer, and the coating resin layer is fixed by curing the uncured adhesive. May be. Here, when the shape of the coating resin layer holding portion is a shape including an inclined wall surface, in this coating resin layer holding portion, a part of the exposed optical fiber and the coating resin layer are fixed via an adhesive layer. It is desirable to do. In addition, before storing the optical fiber, an uncured adhesive may be poured into the groove or the like in advance, and after storing the optical fiber, the adhesive may be cured to fix the optical fiber.

The uncured adhesive is cured by, for example, 8
It can be performed by heating at 0 to 250 ° C.
Further, the ultraviolet curable resin composition or the adhesive containing the photosensitive resin may be cured by irradiating with ultraviolet rays or infrared rays.

(6) Next, a lid is attached on the substrate via an adhesive layer so as to cover the optical fiber housed in the groove of the substrate. In the case where the lid part attached in this step has a shape in which a concave part for accommodating a part of the optical fiber is formed, or the shape of the cross section in the direction perpendicular to the axis of the optical fiber is rectangular. When both side lower parts have a cut-out shape, the above-described shape is cut in advance.

When attaching the lid, the uncured adhesive is applied in advance to the portion of the upper surface of the substrate facing the lid, and the lid is placed on the uncured adhesive. Place it and then harden it to attach the lid,
The molten solder may be applied to a portion of the upper surface of the substrate facing the lid, and the lid may be mounted by placing the lid on the molten solder. Place the lid on the (fiber), then pour uncured adhesive, molten solder, etc. into the gap between the lid and the substrate or optical fiber, and further subject it to curing treatment, etc. Therefore, it is desirable to attach the lid. When the lid is placed on an uncured adhesive or the like, air easily enters between the adhesive layer and the lid, and the adhesive layer and the lid may be separated from this air. Because.

Further, in the above step (5), only the optical fiber is stored without forming an adhesive layer in the optical fiber non-storage portion of the groove, and the substrate (optical fiber) is processed in this step.
After placing the lid on top, when pouring uncured adhesive or molten solder into the gap between the lid and the substrate or optical fiber,
At the same time, an uncured adhesive or the like may be poured into the optical fiber non-accommodating portion of the groove.

Further, in this step, it is desirable to previously form a roughened surface having a surface roughness in the above range on the portion of the lid portion facing the substrate. The surface roughness of the roughened surface formed on the lid portion is the average roughness R as described above.
It is desirable to have a, the average spacing Sm of irregularities and the average spacing S of local peaks. The roughened surface may be formed by the method described above.

In the step (4), when the optical fiber ribbon from which a part of the coating resin layer other than both ends thereof is removed is housed, the optical fiber ribbon is attached after the lid is attached in this step. The part which was not stored in the substrate is cut and removed.

After storing the optical fiber ribbon whose one end is exposed, or after storing a part of the exposed optical fiber other than both ends and cutting and removing one end of the optical fiber ribbon, It is desirable to polish the end surface of the optical fiber. Here, when performing the polishing treatment, it is desirable to perform the polishing treatment so that the end faces of the optical fiber, the substrate and the lid are inclined. This is because it is possible to suppress the generation of return light when transmitting an optical signal. In this case, while polishing the end face of the optical fiber,
The side surface of the substrate or the lid may be polished.

Through the above steps, the optical fiber array of the present invention can be manufactured. Although the method of manufacturing the optical fiber array using the optical fiber ribbon has been described here, the optical fiber array of the present invention can be manufactured by using a single-core optical fiber or a laminated optical fiber ribbon. be able to.

Specifically, when an optical fiber array is manufactured using a single-core optical fiber, for example, a plurality of optical fibers from which the coating resin layer at one end is peeled off are arranged in parallel using an aligner. Then, in the step (5), the substrate is stored in the substrate while being held by the aligner, and then the optical fiber is fixed and the lid is formed using the same method as described above. Thus, the optical fiber array can be manufactured.

When an optical fiber array is manufactured using the laminated optical fiber ribbon, for example, a laminated optical fiber ribbon 300 in which a part of the coating resin layer is removed is prepared as shown in FIG. After that, the optical fiber array can be manufactured by housing and fixing this laminated optical fiber ribbon on the substrate. FIG. 6 is a partial perspective view schematically showing an embodiment of the laminated optical fiber ribbon.

As shown in FIG. 6, the laminated optical fiber ribbon 300 has a part of the optical fibers 345a other than both ends thereof.
Between the exposed optical fibers 345a of the exposed second optical fiber ribbon (lower optical fiber ribbon) 340,
The first optical fiber ribbon 330 and the second optical fiber 330 are arranged so that the exposed optical fiber 335a of the first optical fiber ribbon (upper optical fiber ribbon) 330 with the optical fiber 335a at one end thereof exposed. Ribbon 340
And are stacked.

In the laminated optical fiber ribbon 300,
The exposed optical fibers 335a, 345a are arranged so that the exposed optical fibers 335a, 345a are arranged at the same height.
Each of 5a is bent at a part thereof. Thus, optical fiber 335a and optical fiber 345a
By arranging the same at the same height, it becomes a shape suitable for being housed in the groove of the substrate.

In the laminated optical fiber ribbon 300,
The exposed optical fiber 3 of the first optical fiber ribbon 330
35a and a part of each of the exposed optical fibers 345a of the second optical fiber ribbon 340 are bent, but if both optical fibers can be arranged at the same height, Only the exposed optical fiber of the optical fiber ribbon may be bent, or only the exposed optical fiber of the second optical fiber ribbon may be bent.

In the laminated optical fiber ribbon 300, it is desirable that the first optical fiber ribbon 330 and the second optical fiber ribbon 340 be fixed to each other with an adhesive. The laminated optical fiber ribbon 3 shown in FIG.
In No. 00, eight optical fibers are arranged at the same height, but the number of optical fibers in the laminated optical fiber ribbon is not limited to eight, and may be seven or less, or nine. It may be more than. Further, the number of optical fibers in each of the first and second optical fiber ribbons is the same as in the optical fiber ribbon shown in FIG. 6, the first optical fiber ribbon is one more, or It is desirable that the number of the second optical fiber ribbons is one.
This is because in such a case, the optical fibers can be arranged at the highest density.

In the production of the laminated optical fiber ribbon, for example, first, the coating resin layer at one end of the optical fiber ribbon is
As described above, a method of using the coating resin layer peeling device, a method of dissolving with an organic solvent, a method of irradiating with a laser beam and the like to produce a first optical fiber ribbon by removing it, apart from this, A second optical fiber ribbon is produced by removing a part of the coating resin layer other than both end portions of the optical fiber ribbon by using the same method for removing the coating resin layer as described above. After bending the part, the first and second optical fiber ribbons may be stacked with an adhesive so that the two optical fibers are alternately arranged at equal intervals.

As a method for accommodating and fixing such a laminated optical fiber ribbon on a substrate, the same methods as those used in the above steps (5) and (6) can be used. Even when an optical fiber array is manufactured using the laminated optical fiber ribbon, after the laminated optical fiber ribbon is housed and fixed in the substrate, the second optical fiber ribbon is cut off and the end face of the optical fiber is removed. And the like.

[0138]

The present invention will be described in more detail below.

(Example 1) A. Fabrication of an optical fiber ribbon from which a part of the coating resin layer has been removed.
Optical fiber ribbons (Sumitomo Electric Industrial Co., Ltd.) in which eight fibers of 50 μm are arranged in parallel, and a coating resin layer (primary coating layer 113 and secondary coating layer 114) made of an acrylate-based ultraviolet curable resin is coated around the optical fibers. Made),
A coating resin layer (primary coating layer and secondary coating layer) at a portion 5 to 50 mm from one end of this optical fiber ribbon
Was peeled off with a coating resin layer peeling device (see FIG. 7A).

B. Manufacture of lid part A plate-like body made of high silicate glass is cut using a device equipped with a diamond blade to form a recess 161 for accommodating an exposed optical fiber. (See FIG. 8A). The recess has a rectangular cross section.

Next, a roughened surface was formed on the surface of the lid 160 facing the substrate by the following method. That is, first, the surface of the lid portion 160 facing the substrate is subjected to single-sided grain polishing (# 1000), and then the lid portion is subjected to HF:
A roughened surface was formed by immersing in an HF aqueous solution of H ₂ O = 1: 20 and a temperature of 45 ° C. for 30 minutes.

The surface roughness of the roughened surface formed in this step is
Average roughness Ra based on JIS B 0601 is 95 nm
Met. The average spacing Sm of the irregularities according to JIS B 0601 on the roughened surface was 20 μm, and the average spacing S of the local peaks was 300 nm. The average roughness of the roughened surface according to JIS B 0601 is a surface roughness meter using interference fringes (manufactured by Veeco Instruments, W
It was measured using a YKO NT-2000 system).

C. Fabrication of optical fiber array (1) Thickness 0.5-2.0 with polishing treatment on its surface
A silicon substrate 151 having a size of mm was used as a starting material, and a mask layer 152 was formed on the silicon substrate 151 by the following method (see FIG. 5A). That is, first, the surface of the silicon substrate 151 by thermal oxidation furnace to form a SiO ₂ film 152a having a thickness of 0.04 .mu.m, then using a vacuum CVD method on this SiO ₂ film, a thickness of 0. 1 μm Si ₃ N ₄
The SiO ₂ film 152a is formed by forming the film 152b.
And a Si ₃ N ₄ film 152b as a mask layer 15 composed of two layers.
Formed 2.

(2) Next, a resin composition for resist is applied onto the mask layer 152 by using a spin coater to give a thickness of 2
A resist resin layer 154 having a thickness of 5 μm was formed (see FIG. 5).
(See (b)).

(3) Next, the resist resin layer 154 is formed.
Place a mask with a groove pattern drawn on it, 800m
It is exposed to J / cm ² and then developed with an alkaline solution to form an etching resist 15 on the mask layer.
5 was formed (see FIG. 5 (c)).

(4) Next, the mask layer exposed in the portion where the etching resist 155 is not formed is removed by the following method,
A mask 156 was formed by exposing a part of the substrate 151 (see FIG. 5D). That is, first, exposed Si ₃
The N ₄ film is exposed by RIE treatment at 50 W for 2.5 hours to expose the SiO ₂ film, and the SiO ₂ film is wet-etched with a 3 wt% HF solution for 3 minutes. It was removed by application to expose the silicon substrate.

(5) Next, the etching resist was peeled and removed using a 10 wt% NaOH aqueous solution (FIG. 5).
(See (e)). As a result, on the silicon substrate 151, only the mask 156 having the opening corresponding to the portion where the groove is formed is formed.

(6) Next, the silicon substrate 151 on which the mask 156 is formed is subjected to a KOH concentration of 25% by weight and a liquid temperature of 7%.
8 ° C. etching solution (KOH: 100 g, H ₂ O: 30
0 g) to form eight V-grooves having a depth of 120 μm (see FIG. 5 (f)).

(7) Next, the mask 156 composed of the Si ₃ N ₄ film and the SiO ₂ film was removed by the following method (see FIG. 5G). That is, the Si ₃ N ₄ film is removed by performing the same process as the RIE process used in the above step (4), and then the SiO ₂ film is subjected to the wet etching process used in the above step (4). The mask 156 was removed by performing the same process and removing it. Through this process, the upper surface of the substrate (including the surface of the groove)
All will be composed of silicon.

Thereafter, a coating resin layer holding portion 158 (see FIG. 7A) for holding the optical fiber ribbon together with the coating resin layer on a part of the substrate 151 is cut using a device equipped with a diamond blade. It was formed by applying. Although only four grooves are formed on the substrate shown in FIG. 7, this figure is a schematic diagram, and in fact, as described above, eight grooves were formed on the substrate.

(8) Next, a roughened surface was formed under the following conditions on the entire upper surface (including the surface of the groove) of the substrate on which the groove and the coating resin layer holding portion were formed. That is, a roughened surface was formed on the entire upper surface of the substrate by immersing the substrate in a KOH solution having a concentration of 20% by weight and a temperature of 50 ° C. for 6 minutes. As for the surface roughness of the roughened surface formed on the upper surface of the substrate in this step, the average roughness Ra based on JIS B 0601 is 20 nm on the surface {(111) surface} of the groove, and the groove-unformed portion on the upper surface of the substrate. And the upper surface of the coating resin layer holding portion {(100) surface}
Was 95 nm. Moreover, the average roughness Ra is a surface roughness meter (WYKO NT-2000 s using an interference fringe).
system).

(9) Next, the exposed portion of the optical fiber 115 of the optical fiber ribbon 110A produced in the above A is
It was housed in the V-shaped groove 157 (see FIGS. 7A and 7B), and the lid 160 manufactured in the above B was placed on the substrate 151 (see FIG. 8A). Furthermore, the gap between the groove 157 and the optical fiber 115, and the lid 160 and the substrate 151.
An uncured adhesive (UV-3000, manufactured by Daikin Industries, Ltd.) was poured into the gap with the (optical fiber 115). The uncured adhesive (UV-3000) was also applied around the coating resin layer placed on the coating resin layer holding portion 158.

Next, an ultraviolet ray of 10 J / cm ² is irradiated from the upper portion of the substrate 151 provided with the lid portion 160 with a high pressure mercury lamp, and then the adhesive is heated at 60 ° C. for 1 hour. It was completely cured and the lid 160 was fixed. Further, here, by irradiating the coating resin layer holding portion with ultraviolet rays as well, a part of the exposed optical fiber and the coating resin layer are exposed to the coating resin layer holding portion via an adhesive (not shown). Fixed

(10) Next, the optical fiber ribbon 110A
Resin layer 114a not housed in the substrate at one end of the
And the optical fiber covered with this coating resin layer are cut and removed by a diamond cutter, and further, a polishing process is performed so that the end face of the optical fiber and the end faces of the substrate and the lid are aligned, and the optical fiber array 102 is formed. Manufactured (Figure 8)
(See (b)).

(Embodiment 2) In the process B of Embodiment 1, except that the concave portion is not formed and the lid portion of the plate-like body having the roughened surface formed on the portion facing the substrate is manufactured, An optical fiber was manufactured in the same manner as in Example 1. The surface roughness of the roughened surface of the lid portion manufactured in this example is (average roughness R
a, the average spacing Sm of the unevenness, and the average spacing S) of the local peaks are the same as the surface roughness of the roughened surface formed on the lid in Example 1.

(Example 3) An optical fiber array was manufactured in the same manner as in Example 1 except that the step (8) was not performed. In the substrate of the optical fiber array manufactured in this example, the roughened surface is formed only in the portion of the surface of the groove where the silicon is exposed, and the roughened surface is not formed in the portion where the groove is not formed. Remained smooth.

Example 4 An optical fiber array was manufactured in the same manner as in Example 1 except that only the Si ₃ N ₄ film was removed in the step (8) of Example 1. In the substrate of the optical fiber array manufactured in this example, the roughened surface is formed only in the portion of the surface of the groove where the silicon is exposed, and the roughened surface is not formed in the portion where the groove is not formed. Remained smooth.

Example 5 In the step C of Example 1, a substrate made of high silicate glass was used in place of the substrate made of silicon, and a groove was formed in this substrate by the following method. Except that a roughened surface is formed on the upper surface of
An optical fiber array was manufactured in the same manner as in Example 1. That is, a high silicate glass substrate having a thickness of 0.5 to 2.0 mm was used as a starting material, and eight V-grooves were formed on this substrate by using a device equipped with a diamond blade. Further, a roughened surface was formed on the entire upper surface of the substrate including the surface of the groove under the same conditions as the conditions for forming the roughened surface on the lid portion in the step B of Example 1. JIS B 0601 of the roughened surface formed on the upper surface of the substrate
The average roughness Ra based on is 400 nm, and the average spacing S of the irregularities is
m was 20 μm, and the average spacing S between local peaks was 300 nm. In addition, the upper surface of the substrate is observed with an electron microscope (S
As a result of observation with EM), particulate matter was observed on the uneven wall surface of the roughened surface, and the average particle diameter of this particulate matter was 300 nm.
Met.

(Embodiment 6) Similar to Embodiment 5, except that a lid made of silicon and having the following roughened surface formed on the portion facing the substrate is used as the lid. To produce an optical fiber array. In this optical fiber array, the material of the lid is silicon and the material of the substrate is high silicate glass. Therefore, when curing the uncured adhesive, ultraviolet rays were irradiated from the bottom of the substrate. Also,
The roughened surface was formed by immersing a plate-like body (cover) made of silicon in a KOH solution having a concentration of 20% by weight and a temperature of 50 ° C. for 6 minutes. As a result, a roughened surface having an average roughness Ra of 20 nm according to JIS B 0601 was formed on the portion of the lid portion facing the substrate {(111) plane}.

(Embodiment 7) In the step B (preparation of the lid portion) of the embodiment 1, a concave portion 1 for accommodating exposed optical fibers having different depths is formed in a substrate made of high silicate glass.
71 and a lid 170 having a recess 172 for accommodating the optical fiber ribbon together with the coating resin layer are produced (see FIG. 9).
(See (a)), in the step (8) of C in Example 1,
An optical fiber array 101 was manufactured in the same manner as in Example 1 except that the lid 170 was attached to the substrate (FIG. 9).
(See (b)).

Regarding the optical fiber arrays obtained in Examples 1 to 7, a cycle of holding at 130 ° C. for 3 minutes and at −65 ° C. for 3 minutes was defined as one cycle, and this cycle was set to 10 cycles.
A heat cycle test was repeated for 100 cycles, and then the optical fiber array was cut in a direction perpendicular to the axial direction of the optical fiber, and the cross section was observed. As a result, in the optical fiber arrays of Examples 1 to 7, no peeling was observed between the substrate and the adhesive layer, and no crack was generated in the adhesive layer.
Furthermore, no peeling was observed between the lid and the adhesive layer.

When the optical fiber arrays of Examples 1 to 7 were connected to a light receiving device having eight light receiving elements and the coupling loss was measured, the coupling loss was 1.0 dB or less. It became clear that there was almost no positional deviation, and the quality required for the product was fully satisfied.

Further, an optical fiber array was manufactured in the same manner as in Example 1 except that the average roughness Ra of the substrate was changed to an arbitrary size, and the amount of positional deviation of the optical fiber and the coupling loss were calculated from the data. Was simulated. The results are shown in Tables 1 and 2. In addition, the amount of positional deviation of the optical fiber is calculated as follows:
The amount of positional deviation is measured in the −Y direction, and the amount of deviation is shown. The coupling loss is measured by connecting the optical fiber array to the light receiving element after the heat cycle test.

[0164]

[Table 1]

[0165]

[Table 2]

As is clear from the results shown in Tables 1 and 2, in the optical fiber array in which the roughened surface is formed on the substrate made of silicon, the average roughness Ra of the roughened surface is less than 5 nm or 1000 nm. When the average roughness Ra is in the range of 5 to 1000 nm, all the positional deviations of the optical fiber are 1 mm or less, while the positional deviation of the optical fiber exceeds 1 mm. Further, it can be seen that the positional deviation amount of the optical fiber is particularly small in the range where the average roughness Ra is 5 to 100 nm. Also, in an optical fiber array in which a roughened surface is formed on a substrate made of silicon,
If the average roughness Ra of the roughened surface is less than 5 nm or 100
When it exceeds 0 nm, some have a coupling loss of more than 1.0 dB, while the average roughness Ra is 5 to 1
In the range of 000 nm, all coupling losses are 1.0 dB or less. Further, it can be seen that the coupling loss is particularly small in the range where the average roughness Ra is 5 to 100 nm.

Further, an optical fiber array was manufactured in the same manner as in Example 5 except that the average roughness Ra of the substrate was changed to an arbitrary size, and the amount of positional deviation of the optical fiber and the coupling loss were calculated from the data. Was simulated. The results are shown in Tables 3 and 4.

[0168]

[Table 3]

[0169]

[Table 4]

As is clear from the results shown in Tables 3 and 4, in the optical fiber array in which the roughened surface is formed on the substrate made of high silicate glass, the average roughness Ra of the roughened surface is 5 nm.
If the average roughness Ra is in the range of 5 to 1000 nm, the positional deviation of the optical fiber may be greater than 1 mm. Are all 1 mm or less. Further, it can be seen that the positional deviation amount of the optical fiber is particularly small in the range where the average roughness Ra is 5 to 100 nm. Further, in an optical fiber array in which a roughened surface is formed on a substrate made of high silicate glass, when the average roughness Ra of the roughened surface is less than 5 nm or exceeds 1000 nm,
While some have a coupling loss of more than 1.0 dB, when the average roughness Ra is in the range of 5 to 1000 nm,
Coupling losses are all below 1.0 dB. Further, it can be seen that the coupling loss is particularly small in the range where the average roughness Ra is 5 to 100 nm.

In the optical fiber array of the present invention, the smaller the positional deviation amount of the optical fibers, the more preferable it is. However, if the positional deviation amount is within 1.0 mm, it is within the allowable range, and there is no problem as a product. Further, in the optical fiber of the present invention, the smaller the coupling loss is, the more preferable it is. The above coupling loss is 1.0
If it exceeds dB, a problem easily occurs in the transmission of the optical signal.
The optical fiber array of the present invention, if the positional deviation amount and the coupling loss are within the above ranges, the separation of the substrate and the adhesive layer and the positional deviation of the optical fiber are less likely to occur, and even if various stresses occur, The stress can be further relaxed.

[0172]

As described above, since the optical fiber array of the present invention has the above-mentioned structure, the substrate and the adhesive layer have excellent adhesiveness, and peeling may occur between the substrate and the adhesive layer. In addition, the optical fiber array of the present invention can accurately transmit an optical signal without causing displacement of the optical fiber.

[Brief description of drawings]

FIG. 1A is a partial perspective view schematically showing an example of an optical fiber array of the present invention, and FIG. 1B is a part A of FIG.
-A line sectional drawing, (c) is a perspective view which shows the lid part which comprises the optical fiber array of (a), (d) is.
It is a perspective view which shows the board | substrate which accommodated the optical fiber which comprises the optical fiber array of (a).

FIG. 2 is a reference diagram for explaining an average spacing Sm of irregularities based on JIS B 0601, an average spacing S of local peaks, and an average roughness Ra.

FIG. 3 is a partial perspective view schematically showing another example of the optical fiber array of the present invention.

FIG. 4A is a partial perspective view schematically showing an example of an optical fiber array of the present invention using a laminated optical fiber ribbon, and FIG. 4B constitutes the optical fiber array of FIG. It is a partial perspective view which shows only a board | substrate and a laminated optical fiber ribbon, (c) is the sectional view on the AA line of (a).

5A to 5G are cross-sectional views showing an example of a method for forming a groove in a substrate.

FIG. 6 is a partial perspective view schematically showing an embodiment of a laminated optical fiber ribbon.

7A and 7B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

8A and 8B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

9A and 9B are perspective views schematically showing a part of the manufacturing process of the optical fiber array of the present invention.

[Explanation of symbols]

110 optical fiber ribbon 115, 235, 245 optical fiber 151,251 substrate 157,257 groove 160, 170 lid 100,200 Fiber Optic Array 210 laminated optical fiber ribbon

Claims (5)

[Claims] 1. A plurality of grooves are formed in a part of the upper surface of the substrate,
An optical fiber array in which an optical fiber is housed in the groove, and a lid portion covering the optical fiber is attached on the substrate via an adhesive layer, and at least a part of the upper surface of the substrate is roughened. A surface is formed, and the roughened surface has an average roughness of 5 to 1000 nm. 2. The optical fiber array according to claim 1, wherein the material of the substrate is silicon. 3. The material of the substrate is glass.
The optical fiber array described in. 4. The optical fiber array according to claim 1, wherein a roughened surface is formed on the surface of the groove, and the average roughness of the roughened surface is 5 to 100 nm. 5. The optical fiber array according to claim 1, wherein the average roughness is measured by a surface roughness meter using interference fringes.